Abstracts—1—Keynote Lecture 1
July 29, 9 : 30 AM-10 : 30 AM Grand hall
Reconstructing visual and subjective experience from the brain
Yukiyasu Kamitani
Kyoto University and ATR Computational Neuroscience Laboratories
The internal visual world is thought to be encoded in hierarchical representations of the brain. However, previous attempts to visualize perceptual contents
based on machine-learning analysis of fMRI patterns have been limited to reconstructions with low level image bases or to matchings to exemplars. While
categorical decoding of imagery contents has been demonstrated, the reconstruction of internally generated images has been challenging. I introduce ourrecent study showing that visual cortical activity can be decoded (translated) into the hierarchical features of a pre-trained deep neural network (DNN) for the same input image, providing a way to makeuse of the information from hierarchical visual features. Next I present a novel image reconstruction
method, in which the pixel values of an image are optimized to make its DNN features similar to those
decoded from human brain activity at multiple layers. Our method was able to reliably produce reconstructions that resembled the viewed natural images. While our model was solely trained with natural
images, it successfully generalized to artificial shapes, indicating that our model was not simply matching to exemplars. The same analysis applied to mental imagery demonstrated rudimentary reconstructions of the subjective content. Our method can effectively combine hierarchical neural representations
to reconstruct perceptual and subjective images, providing a new window into the internal contents ofthe brain.
Yukiyasu Kamitani, Ph.D.. Professor at Kyoto University and Department Head and ATR Fellow at
ATR Computational Neuroscience Laboratories. He received B.A. in Cognitive Science from Universityof Tokyo, and Ph.D. in Computation and Neural Systems from California Institute of Technology. He
continued his research in cognitive and computational neuroscience at Harvard Medical School andPrinceton University. In 2004 he joined ATR Computational Neuroscience Laboratories, and since2015 he is Professor at Kyoto University. He is a pioneer in the field of “brain decoding”, which combines neuroimaging and machine learning to translate brain signals to mental contents. He was named
Research Leader in Neural Imaging on the 2005 “Scientific American 50”, and received many awards
including Tsukahara Memorial Award (2013), JSPS Prize (2014), and Osaka Science Prize (2015). In
2018, he was selected as an ATR Fellow. He is recently engaged in activity in contemporary art with
Pierre Huyghe (“UUmwelt” at Serpentine Galleries, London, 2018) and other artists.

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Keynote Lecture 2
July 30, 11 : 15 AM-12 : 15 PM Grand hall
Pluripotent stem cell derived photoreceptor transplantation
Masayo Takahashi
Center for Biosystems Dynamics Research, RIKEN
Photoreceptor transplantation is a possible treatment to restore visual function
to photoreceptor only degenerated retinas such as retinitis pigmentosa. We
have been reported that the sensory retinal sheet transplantation, which supplies photoreceptors and secondary retinal neurons, can reintroduce visualfunction in mice with end-stage retinal degeneration. For the photoreceptor
transplantation, previously many groups used photoreceptor suspension. However, it was revealed in 2017 that in those suspension transplantation GFP positive cells were host cells
that have material transfer from grafted cells. In fact, transplanted retinal sheets survive for a longer
period than suspended cells. Furthermore, only retinal sheets could become mature in the subretinal
space and obtain tissue structure with outer segments of photoreceptors after transplantation. To confirm the functional recovery by the grafted sheets, we developed new disease mice models and functional tests analysis. With those, synaptic contact between graft photoreceptors and host bipolar cells was
confirmed by immunohistochemistry, electrical physiology, and behavior tests. MEA recording showedthat grafted cells could elicit light responses in the host ganglion cells.
Now we are investigating how to increase the number of synapses and efficacy of transplantation. However, immunohistochemical characterization of synapse in the degenerated retina or of grafted retina isoften challenging, as traits are not as clear as in the wild type retina. Therefore, using postnatal wild type
mouse retina as a training data, we developed a new method to objectively count synapses. Using thismethod, we evaluated the synapses of iPSC-retina after transplantation to rd1 mice. The number ofsynapses increased on 30 days after transplantation, while we could not found any synapse formation inin vtro retinal organoids. The synapse numbers were more in the light/dark cycle environment thancompletely dark one.
I will talk about the future strategy of outer retinal transplantation.
Masayo Takahashi M.D., Ph.D. Project leader at Laboratory for Retinal Regeneration, RIKEN Center
for Biosystems Dynamics Research. She received her Ph.D. from Kyoto University. After serving as an
assistant professor in the Kyoto University Hospital, she moved to the Salk Institute, U.S., where she
discovered the potential of stem cells as a tool for retinal therapy. She has joined RIKEN since 2006.

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Keynote Lecture 3
July 31, 5 : 15 PM-18 : 15 PM Grand hall
A motor theory of sleep-wake control
Yang Dan
University of California, Berkeley
Sleep is a fundamental biological process observed throughout the animal
kingdom, and its disruption has devastating health consequences. Using a combination of optogenetics, electrophysiology, imaging, and gene expression profiling, we identify key neurons in the sleep control circuits and map their synaptic connections. Sleep appears to be controlled by a highly distributed
network spanning the forebrain, midbrain, and hindbrain, where REM andnon-REM sleep neurons are part of the central somatic and autonomic motor circuits. The intimate association between the sleep and autonomic/somatic motor control circuits suggests that a primary function of sleep is to suppress movement and promote processes incompatible with motor activity.
Yang Dan, Ph.D. She studied physics as an undergraduate student at Peking University and received
her Ph.D. training in Biological Sciences at Columbia University. She did her postdoctoral research at
Rockefeller University and Harvard Medical School. She is currently Paul Licht Distinguished Professor in the Department of Molecular and Cell Biology and an investigator of the Howard Hughes Medical Institute at the University of California, Berkeley.

—4—Keynote Lecture 4
August 01, 11 : 15 AM-12 : 15 PM Grand hall
ISETBIO: Software for the foundations of vision science
Brian Wandell
Stanford University
Over four centuries scientists have developed theories and made measurementsthat characterize how the visual system converts light into neural signals. Thisknowledge is contained in a diverse set of textbooks and research papers thatcan be hard for young students—or old professors—to integrate. We are developing an open-source Matlab toolbox, ISETBIO, that combines the historicalknowledge into a set of accessible computations. Our hope is that many people
can check the computations and then use them as a basis for further theorizing about visual system
function. Our team has implemented software (Matlab, Docker) to provide scientists and engineers with(a) quantitative computer graphics methods to create a wide range of complex 3D scene spectral radiances, (b) optics simulations that transform these 3D radiances into retinal irradiance using physiological models of the eye, (c) quantitative specifications of the lens transmission, macular pigment andphotopigments, (d) fixational eye movement models, (e) photoreceptor spatial sampling from fovea toperiphery, (f) cone excitation calculations, and (g) cone photocurrent models. This talk will explain how
the current computations, which characterize the initial stages of visual encoding, can be helpful to research scientists and engineers seeking to understand the information available in the nervous systemand how this information impacts perceptual judgments, such as Vernier acuity, contrast sensitivity, andcolor and motion sensitivity. We hope some of you will check our work and extend it. I will discuss
ways these tools might be helpful in developing theories of visual performance and perception.
Collaborative work with David Brainard, Nicolas Cottaris, Trisha Lian, Zhenyi Liu, Joyce Farrell, Haomiao Jiang, Fred Rieke, and James Golden.
Professor Brian A. Wandell, Ph.D. He is the first Isaac and Madeline Stein Family Professor. He joined
the Stanford Psychology faculty in 1979 and is a member, by courtesy, of Electrical Engineering andOphthalmology. He is Director of the Center for Cognitive and Neurobiological Imaging, and Deputy
Director of the Wu Tsai Neuroscience Institute. He graduated from the University of Michigan in 1973
with a B.S. in mathematics and psychology. In 1977, he earned a Ph.D. in social science from the University of California at Irvine. After a year as a postdoctoral fellow at the University of Pennsylvania,
he joined the faculty of Stanford University in 1979. Professor Wandell was promoted to associate
professor with tenure in 1984 and became a full professor in 1988.

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Monday, July 29
Symposium 1-1 2 : 30 PM-4 : 30 PM Grandhall
Physiological, psychological, and computational foundations of scene understanding
Organizers:
Yukako Yamane1, Ko Sakai2(1Osaka University, Okinawa Institute of Science and Technology, 2University of Tsukuba)
Vision science has revealed the nature of human vision and the visual functions in cognition in various
ways, although ‘how humans understand an entire scene?’ is still a challenging problem. How does thevisual system segregate images into meaningful parts and then assemble those parts into informative
representations of the outside world? How do those representations support our immediate, intuitive
knowledge about where we are, what things are present, and how those things relate to each other andto the overall scene? About what just happened in the scene, and what might happen next and how weshould react for? Recent rapid advancement of machine learning algorithms enabled the identification,
description, and even generation of a scene, however, they are still incapable of providing clues forunderstanding a scene as we humans do. We invite world-leading scientists to discuss the physiological,
psychological, and computational foundations of scene understanding.
S1-1-1
Objects, Scenes, and Gravity in Ventral Pathway Visual Cortex
Alexandriya Emonds, Siavash Vaziri, Charles E. Connor(Krieger Mind/Brain Institute, Johns Hopkins University)
It has long been thought that the ventral pathway is dedicated exclusively to visual object processing,while scene understanding is primarily a dorsal pathway function. However, we reported recently thatmany neurons in macaque monkey ventral pathway, including a majority in the TEd channel, are far more
responsive to large-scale scene structure. These neurons are particularly tuned for tilt and slant of planar
surfaces and edges, in ways that suggest they represent the direction of gravity. In new experiments, wehave begun to examine how object information and scene information are integrated in the ventral pathway. Early results show that individual neurons can be congruently selective for ground tilt, object tilt,
and object balance (distribution of mass with respect to points of ground contact). This is consistent withthe theory that visual cortex serves as an intuitive physics engine for understanding the natural world, inparticular the energetic potentials and constraints imposed on objects by the ubiquitous force of gravity.
S1-1-2
Human Scene-selective Areas Represent the Orientation of and Distance to Large Surfaces
Mark Lescroart(University of Nevada, Reno)
A network of areas in the human brain—including the Parahippocampal Place Area (PPA), the Occipital
Place Area (OPA), and the Retrosplenial Complex (RSC)—respond to images of visual scenes.
Long-standing theories suggest that these areas represent the 3D structure of the local visual environment. However, most experiments that study representation of scene structure have relied on operational or categorical definitions of scene structure—for example, comparing responses to open vs closed
scenes. It is not clear, based on such studies, how these areas might respond to scenes that do not fall
into one of the investigated categories. Furthermore, it has been hypothesized that sceneselective areas
represent 2D cues for 3D structure rather than 3D structure per se. To evaluate the degree to which eachof these hypotheses explain variance in scene-selective areas, we develop an encoding model of 3D
scene structure and test it against a model of low-level 2D features. Our 3D structural model uses continuous parameters based on 3D data (surface normals and depth maps) rather than human-assigned
categorical labels such as “open” or “closed”. We fit the models to fMRI data recorded while subjects—6—viewed visual scenes. Variance partitioning on the fit models reveals that scene-selective areas represent
the distance to and orientation of large surfaces, at least partly independent of low-level features. Individual voxels appear to be tuned for combinations of the orientation of and distance to large surfaces.
Principal components analysis of the model weights reveals that the most important dimensions of 3D
structure are distance and openness. Finally, reconstructions of the stimuli based on our model demonstrate that the model captures unprecedented detail about the 3D structure of local visual environment
from BOLD responses in scene-selective areas.
S1-1-3
Perceptual Organization and Attention to Objects
Ernst Niebur(Solomon Snyder Department of Neuroscience and Zanvyl Krieger Mind/Brain Institute, Johns Hopkins
University)
One of the most important strategies of dealing with the extremely high complexity presented by thevisual signal from a cluttered scene is to organize the input into perceptual objects. The task of scene
understanding is then transformed from interpreting ~106 rapidly changing input signals in terms of amuch smaller number of spatio-temporal patterns that mostly correspond to structures in the real world,
and are constrained by physical laws. This task is, however, highly non-trivial and requires to groupthose elements of the raw input that correspond to the same object, and segregate them from those corresponding to other objects and the background. We propose that primates solve this perceptual organization task using small populations of dedicated neurons that represent different objects. We note that
this segregation process does not require the formation of fully-defined recognizable objects: computational models show that this can be accomplished on perceptual pre-cursors of objects with very simple
properties that we call proto-objects. Key features of the models are “grouping” neurons integrating
local features into coherent proto-objects and excitatory feedback to the same local feature neurons
which caused the associated proto-object’s grouping neuron’s activation. Organization of the scene into
proto-objects thus transforms the seemingly impossible task of scene understanding into manageable
sub-tasks. For instance, object recognition can then proceed in a sequential fashion, by operating on one
proto-object at a time. A more general mid-level task is attention to objects and the model explains how
attention can be directed (top-down) to objects even though the central structures that control top-down
attention do not have a representation of the detailed features of these objects.
S1-1-4
How Interactions Between Shading and Color Inform Object and Scene Understanding
Steven W. Zucker(Department of Computer Science, Yale University)
What is the shape of an apple, and what color is it? These are instances of classical questions about
object perception: (i) how is it possible that we can infer the three-dimensional shape of an object (e.g.,
an apple) from its shading, and (ii) how is it possible that we can separate the intensity changes due tomaterial effects (the apple's pigmentation) from intensity changes due to shading. Clearly mistakes insolving (ii) would impact (i). Importantly, these two problems arise in scene perception as well. Objects
are described by surfaces and their parts; scenes are described by surface arrangements and their interactions. For example, when walking along a path through the woods, where is the ground surface andwhy do shadows not effect its perceived shape? Again, mistakes would impact performance if shadows
were interpreted as holes.
We introduce a computational approach to these questions grounded in basic neurophysiology andcomputational theory. Regarding problem (i), we outline a novel approach to shape-from-shading inferences that is based on visual flows, a mathematical abstraction of how information is represented invisual cortex. Regarding (ii), we introduce a model of color representation (hue flows) also based on
visual cortex, that is analogous to the shading flows. Then, given both flows, we can determine when
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hue co-varies generically with shading, thereby addressing problem (ii) and implying a material effect.
We demonstrate psychophysically how hue flows can be designed to alter shape percepts, and we
demonstrate computationally how hue flows pass through cast shadows. Taken together, key aspects of
our abilities to wander through scenes and to describe and manipulate objects are both supported by thefoundational interactions of shading and hue flows.

—8—Symposium 1-2 2 : 30 PM-4 : 30 PM Colloquium
Unpacking cognitive and neural mechanisms underpinning the recognition and representations of
unfamiliar and familiar faces and facial expressions: behavioral, eye movement and ERP studies
Organizer:
Kazuyo Nakabayashi(University of Hull)This symposium addresses some of the key debates in studies of face recognition and expressions.
Here, we provide novel evidence demonstrating perceptual, cognitive and neural mechanisms underlying the representations and recognition of familiar and unfamiliar faces, and facial expressions across a
range of paradigms. One study concerns the role of facial features in detecting facial expressions
through manipulation of spatial frequencies. Two studies report perceptual matching of unfamiliar faces, with one study concerning effects of culture (Japanese vs. British) on eye movements, inversion
effects and Thatcherization. The other study sheds light on the relative contribution of featual and holistic processing to same- and different-identity matching. The two remaining studies investigate cognitive and neural representations of familiar faces, with one study manipulating appearance of famous
faces and their popularity in order to elucidate the representations of familiar faces in the cognitive
system. The other study measures event-related brain potentials (N250) to reveal how semantic andvisual information may interact, giving a rise to the recognition of familiar faces. The symposium will
provide a comprehensive view towards how faces and expressions are processed and stored in memory.
S1-2-1Three dimensional configuration and spatial frequency properties of facial expression
Sakura Torii(Kobe Shoin Women’s University)
The features of happy, angry, sad and surprised faces were studied. In the happy face, it was found that
distinct characteristic changes occurred around the cheeks by the three dimensional analysis, and thatthe deviation range of gray level was wider than that measured in other faces by gray level analysis. By
face recognition experiment using frequency-filtered face images, it was found that only happy face waseasily recognized than other faces even under low-pass condition. These results suggested that emphasizing the contrast in a wide region of the facial surface increased the three-dimensional features, which
possibly resulted in the selective enhancement of the “happy face features”. I foresee new make-up
foundations that can only emphasize and develop the “happy face feature”.
S1-2-2
The role of inversion and Thatcherization in matching own- and other-race faces
Kazuyo Nakabayashi(University of Hull)In the Thatcher illusion a face in which the eyes and mouth are inverted looks grotesque when shown upright but not when inverted. Two experiments examined the contribution of feature-based and configuralprocessing to matching normal and Thatcherized pairs of isolated face parts (i.e., the eyes and mouth), andhow perceptual matching would be influenced by the race of face and inversion (better performance for
upright than inverted faces). White British and native Japanese groups made same/different judgements toisolated face parts. Experiment 1 had the same identity pairs, encouraging feature-based processing while
Experiment 2 having different identity pairs, which induced configural. Across experiments, effects of inversion and Thatchierzation were found, but these effects varied depending on the race of observer and therace of stimulus face. In addition, eye movements demonstrated increased sampling of inverted comparedwith upright faces and for Thatcherized compared with normal faces. The findings demonstrate that perceptual biases, shaped by culture-specific strategies and task-based attentional demands, can determine
sensitivity to feature-based and local configural information during perceptual encoding.
—9—S1-2-3
Matching faces: the facial features are important, but so DO the whole face. . Change ‘DOES’ to‘DO’
Alejandro J. Estudillo, Nate Frida(University of Nottingham Malaysia)
Matching two unfamiliar faces is of paramount importance in forensic scenarios but the cognitive
mechanisms behind this task are poorly understood. In fact, in contrast to the notion that faces are processed at holistic level, it has been suggested that face matching is driven by featural processing. The
present study looks to shed light on this issue by exploring the role of holistic and featural processing
for match (i.e., both faces depict the same identity) and mismatch (i.e., both faces depict different identities). Across two experiments, observers were asked to decide whether a pair of faces depicted thesame or two different identities, while their eyes were being tracked. In Experiment 1, a gaze-contingent
paradigm was used to manipulate holistic/featural processing. In Experiment 2, in addition to a standard
face matching task, observers also performed a part/whole task, which provides an index of holistic
processing. Results showed that both holistic and featural processing are important for face matching
and that neither of them individually suffices for face matching.
S1-2-4
When Brad Pitt is more refined than George Clooney: The role of stability in developing parsimonious facial representations
Christel Devue(Victoria University of Wellington)
Most people can recognise large numbers of faces, but the facial information we rely on is unknown
despite decades of experimentation. We developed a theory that assumes representations are parsimonious and that different information is more or less diagnostic in individual faces, regardless of familiarity. Diagnostic features are those that remain stable over encounters and so receive more representational weight. Importantly, coarse information is privileged over fine details. This creates cost-effective
facial representations that may refine over time if appearance changes. The theory predicts that representations of people with a consistent appearance (e.g., George Clooney) should include stable coarse
extra-facial features, and so their internal features need not be encoded with the same high resolution as
those of equally famous people who change appearance frequently (e.g., Brad Pitt). In three preregistered experiments, participants performed a recognition task in which we controlled appearance of actors (variable, consistent) and their popularity (higher, lower). Consistent with our theory, in less popular actors, stable extra-facial features helped remember consistent faces compared to variable ones.
However, in popular actors, representations of variable actors had become more refined than those of
consistent actors. We will discuss broader implications of our theory for the field.
S1-2-5The sustained familiarity effect: a robust neural correlate of familiar face recognition
Holger Wiese1, Simone C. Tüttenberg1, Mike Burton2, Andrew Young2(1Durham University, 2University of York)
Humans are remarkably accurate at recognizing familiar faces independent of a particular picture. However, cognitive neuroscience has largely failed to show a robust neural correlate of image-independent
familiar face recognition. Here, we examined event-related brain potentials elicited by highly personally familiar (close friends, relatives) and unfamiliar faces. We presented multiple “ambient” images per
identity, varying naturally in lighting, viewing angles, expressions etc. Familiar faces elicited morenegative amplitudes in the N250 (200–400 ms), reflecting the activation of stored face representations.
Importantly, an increased familiarity effect was observed in the subsequent 400–600 ms time range.
This Sustained Familiarity Effect (SFE) was reliably detected in 84% of individual participants. Addi— 10 —tional experiments revealed that the SFE is smaller for personally, but less familiar faces (e.g., university lecturers) and absent for celebrities. Moreover, while the N250 familiarity effect does not strongly
depend on attentional resources, the SFE is reduced when attention is directed away from the faces. We
interpret the SFE as reflecting the integration of visual with additional person-related (e.g., semantic,
affective) information needed to guide potential interactions. We propose that this integrative process isat the core of identifying a highly familiar person.

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Symposium 1-3 4 : 45 PM-6 : 45 PM Grand hall
Recent studies on the mechanisms of color vision and its role in the society
Organizers:
Ichiro Kuriki1, Kowa Koida2(1Tohoku University, 2Toyohashi University of Technology)
The main topic of this symposium is to introduce the recent progress in the studies on color representation in primate (including human) visual cortex, especially *after* the level of cone-opponent stage, tothe vision researchers in physiology, psychophysics, art, and computational field of study in Japan andother countries. Color vision is one of the fundamental features of primate vision. It is used not just in
object search and social interactions during the survival of individual, but sometimes give a soul-steering impression in fine arts. The contribution of color on our life is tremendous. On the other hand, descriptions on color-vision mechanisms in most textbooks is stopping at the level of cone-opponent
system, while it has been pointed out since early ‘90s that the outputs of cone opponent system do notdirectly correspond to pure red, blue, green, and yellow sensations (i.e., unique hues). Indeed, there has
not been a clear-cut explanation about how our color perception is processed in our brain. However,various possibilities have been proposed on the structure of color-vision and related visual-processing
mechanisms in the cortex, which may be related to our color perception (i.e., subjective experience ofcolor appearance). Three leading studies on this topic will be introduced in this symposium.
Firstly, Dr. Conway will introduce recent studies on cortical structure and functionality for the processing of color and related high-level visual features in primate cortex. Secondly, Dr. Tanigawa will introduce their recent study on the neural structure of color-vision processing mechanisms in early visualcortex. Finally, Dr. Hiramatsu will introduce the recent studies on the polymorphism of color vision inprimates using genetical and behavioral approach.
S1-3-1On the role of color in high-level vision
Bevil Conway(National Institutes of Health)
What is color for and how are color operations implemented in the brain? I will take up this question,
drawing upon neurophysiological recordings in macaque monkeys, fMRI in humans and monkeys,
psychophysics, and color-naming in a non-industrialized Amazonian culture. My talk will have threeparts. First, I will discuss results showing that the neural implementation of color depends on a multistage network that gives rise to a uniform representation of color space within a mid-level stage in visual processing. Second, I will describe work suggesting that color is decoded by a series of stages
within higher-order cortex, including inferior temporal cortex and prefrontal cortex (PFC). In a surprising twist, these discoveries reveal a general principle for the organization and operation of inferior
temporal cortex and provide evidence for a stimulus-driven functional organization of PFC. Finally, I
will describe two recent discoveries prompted by our neurobiological discoveries: a new interaction ofcolor and face perception, which suggests that color evolved to play an important role in non-verbal
social communication; and a universal pattern in color naming that reflects the color statistics of thoseparts of the world that we especially care about (objects). Together, the work supports the provocative
idea that basic color categories are an emergent property arising from the needs we place on the brain(including object recognition and the assignment of object valence), rather than a constraint determinedby color encoding.

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S1-3-2
Hue maps of DKL space at columnar resolution in macaque early visual cortex
Hisashi Tanigawa(Zhejiang University)
It is a fundamental question about color vision how cone signals are transformed into perceptual colors
in the cortex. Previous studies revealed functional structures for color processing in the early visualcortex, such as CO blobs in V1, CO thin stripes in V2, and color-sensitive domains in V4, and thesestructures are thought to play an important role in the transformation of cone signals. However, it is notknown how hue selectivities based on cone opponency is organized as spatial arrangement in early visual cortex. Here we performed optical imaging in macaque V1, V2, and V4 to examine distribution of
domains selective to individual hues of Derrington-Krauskopf-Lennie (DKL) color space that is basedon the cone-opponent axes of the lateral geniculate nucleus (LGN). We presented visual stimuli withisoluminant color/gray or color/color stripes: the hue of color stripes was chosen from eight evenly
spaced directions in an isoluminant plane of the DKL color space, in which four of them were along the
L-M and S-(L-M) cardinal axes. In this talk, I will first introduce our past results of optical imaging in
V4 and then show recent results of imaging in early visual cortex using the DKL color space.
S1-3-3Polymorphic nature of color vision in primates
Chihiro Hiramatsu(Kyushu University)
Although mammals generally have dichromatic color vision, primates have uniquely evolved trichromatic vision. However, not all primates possess uniform trichromatic vision, and diverse color vision is
ubiquitous in many Neotropical primates and human populations owing to polymorphisms of red-green
visual pigment genes. The biological significance of polymorphic color vision and how it influences
differences beyond perception are not fully understood. In this talk, I will present how color vision ispolymorphic at genetic and perceptual levels, and how these traits affect behavior and even aesthetic
impression. Then, I would like to discuss the potential influences of experience and social interaction,
which may modify conscious perception of colors.

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Symposium 1-4 4 : 45 PM-6 : 45 PM Colloquium
Modeling approaches to visual circuit function, pathology, and regeneration
Organizer:
Katsunori Kitano(Ritsumeikan University)
The main topic of this symposium is to show how a combination of highly quantitative measurements andmathematical modeling can lead to insights into higher order visual processing in the retina, retinal rhythmogenesis, and the mechanisms that underlie the re-establishment of retinal connections. In the first talk,
Dr Tachibana will describe a novel mechanism through which eye movements can dramatically change
the group signaling properties of the ganglion cell network, altering its informational content. Second, Dr.
Kitano will present a mathematical model for an unexpected oscillatory activity in degenerating retina.
The model suggests a source for the abnormal oscillations, and may allow us to devise therapeutic interventions. Finally, Dr Sher will present a quantitative analysis of how connectivity is reestablished in theadult outer retina follow the removal of a subset of photoreceptor (rod and cone) targets.
S1-4-1
Rapid and coordinated processing of global motion images by local clusters of retinal ganglion
cells
Masao Tachibana(Ritsumeikan University)
Our visually perceived world is stable, irrespective of incessant motion of the retinal image due to the
movements of eyes, head, and body. Accumulating evidence indicates that the central nervous system
may play a key role for stabilization of the visual world. Fixational and saccadic eye movements cause
jitter and rapid motion of the whole retinal image, respectively. However, it is not yet evident how theretina processes visual information during eye movements. Furthermore, it is not clear whether multiple
subtypes of retinal ganglion cells (GCs) send visual information independently or cooperatively. We
performed multi-electrode recordings and whole-cell clamp recordings from ganglion cells (GCs) of theretina isolated from goldfish. GCs were physiologically classified into six subtypes (Fast/Medium/Slow,transient/sustained) based on the temporal profile of the receptive field (RF) estimated by reverse correlation method. We found that the jitter motion of a global random-dot background induced elongationand sensitization of the spatiotemporal RF of the Fast-transient GC (Ft GC). The following rapid global
motion induced synchronous firing among local Ft GCs and cooperative firing with precise latencies
among adjacent specific GC subtypes. Thus, global motion images that simulated fixational and saccadic
eye movements were processed in a coordinated manner by local clusters of specific GCs. Stimulus
conditions (duration, area, velocity, and direction of motion) that altered the properties of the receptive
field (RF) were consistent with the characteristics of in vivo goldfish eye movements. The wide-range
lateral interaction, possibly mediated by electrical and GABAergic synapses, contributed to the RF alterations. These results indicate that the RF properties of retinal GCs in a natural environment are substantially different from those under simplified experimental conditions. Processing of global motion images
is already started in the retina and may facilitate visual information processing in the brain.
S1-4-2
Normal and pathological states generated by dynamical properties of the retinal circuit
Katsunori Kitano(Ritsumeikan University)
The retina numerous subtypes of neurons each of which, when embedded in a circuit, exhibits different
dynamical properties. These dynamical properties can influence the output of the retina under normal
conditions, and may also play a role in establishing aberrant rhythms under pathological conditions.
Indeed, an understanding the dynamical properties of pathological states may help us to understand— 14 —

dynamic neural mechanisms under more normal conditions. Compared to normal adult retina whichlacks oscillatory activity, the retina of the rd1 (retinal degeneration 1) mouse is known to exhibit spontaneous, low frequency (<10 Hz), oscillations. Two potential mechanisms for the spontaneous oscillation have been proposed. One mechanism involves the properties of a gap junction network between
cone bipolar cells (BCs) and AII amacrine cells (AII ACs) and between AII-ACs (Trenholm et al.,2012), whereas in the other, the oscillations arise from the intrinsic properties of AII-ACs (Choi et al.,2014). We studied the mechanism of spontaneous oscillation using a computational model of the AIIAC, BC, and GC network. In particular, to solve the paradoxical phenomenon mentioned above, we
incorporated a ribbon synapse model at the BC-GC synapse. Even when bipolar cells are held in the
depolarized state, neurotransmitter release was not always enhanced because of short term depression(Tsodyks and Markram, 1997). If we assume upregulation of the synapses in the inner plexiform layerof the rd1 retina (Dagar et al., 2014), our model could reproduce both the normal and abnormal neuralstates in the absence of light stimuli: no response in the normal retina and spontaneous rhythmic activity in the abnormal retina.
S1-4-3
Restoration of selective connectivity in adult mammalian retina
Alexander Sher
(University of California, Santa Cruz)
Specificity of synapses between neurons of different types is essential for the proper function of thecentral nervous system. While we have learned much about formation of these synapses during development, the degree to which adult CNS can reestablish specific connections following injury or diseaseremains largely unknown. I will show that specific synaptic connections within the adult mammalian
retina can be reestablished after neural injury. We used selective laser photocoagulation to ablate small
patches of photoreceptors in-vivo in adult rabbits, ground squirrels, and mice. Functional and structuralchanges in the retina at different time points after the ablation were probed via electrophysiology andimmunostaining accompanied by confocal imaging. We found that deafferented rod bipolar cells located within the region where photoreceptors were ablated restructure their dendrites. New dendritic processes extend towards surrounding healthy photoreceptors and establish new functional synapses withthem. To test if specific connectivity can be reestablished, we observed restructuring of deafferented
S-cone bipolar cells that synapse exclusively with S-cone photoreceptors in the healthy retina. We discovered that deafferented S cone bipolar cells extend their dendrites in random directions within theouter plexiform layer. If the extended dendrite encounters a healthy S-cone, it forms a synapse with it.
At the same time, it passes M-cone photoreceptors without making synapses. Finally, we used transgenic mice to investigate molecular mechanisms behind the observed restructuring. Our results indicatethat the adult mammalian retina retains the ability to make new specific synapses leading to reestablishment of correct neural connectivity.

— 15 —

Monday, July 29
Oral 1-1, Stereopsis
4 : 45 PM-5 : 15 PM, Conference hallModerators: Hiroshi Ban, Takao Sato
O1-1-1
Luminance-disparity interaction in human visual cortices
Pei-Yin Chen1, Chien-Chung Chen1,2

4 : 45 PM-5 : 00 PM

1Department of Psychology, National Taiwan University, Taipei, 2Center for Neurobiology and Cognitive Science, National Taiwan University

The perceived depth from disparity in random dot stereograms depends on luminance contrast in theimage (Chen et al., 2016). Here, we investigated the neural mechanisms underlying such effect by using
a block-design fMRI experiment. We measured the BOLD activation in KO and first-tier retinotopically defined visual areas as a function of luminance contrast and disparity. The test stimuli were squarerandom dot stereograms (20.16×20.26 degree) that gave the percept of either a flat surface (zero disparity) or a sinewave modulated in depth (corrugated surface). The luminance contrast ranged from 5% to80%. In the first-tier visual areas (V1, V2, and V3) and hV4, BOLD signals increased progressively
with luminance contrast but were independent from disparity modulation. In area V3A, V3B and KO,
the BOLD response was independent of luminance contrast in the zero disparity condition, but increased with luminance contrast whenever there was a visible depth modulation. In sum, the disparity
sensitive areas, such as V3A, V3B and KO, can display a contrast dependent activation but only when
there is a depth modulation in the stimuli. Such disparity specific luminance contrast activation may
relate to the luminance contrast effect on perceived depth from disparity.
Grant: MOST(Taiwan) 107-2420-H-002-029-DR
Keywords: stereopsis, fMRI, binocular vision, kinetic occipitalO1-1-2
5 : 00 PM-5 : 15 PM
Neural Substrate for Reversed-Depth Perception Generated by Anti-Correlated Random-Dot
Stereograms in the Human Brain
Bayu Gautama Wundari1, Hiroshi Ban1,2, Ichiro Fujita1,2
1Graduate School of Frontier Biosciences, Osaka University, 2Center for Information and Neural Networks (CiNet), Osaka University & NICT

Disparity-selective binocular neurons in the primary visual cortex show attenuated and inverted tuning
for binocular disparity in anti-correlated random-dot stereogram (aRDSs). Such disparity tuning resultin faint and reversed-depth perception where observers perceive “near” for uncrossed disparities and“far” for crossed disparities. Which neurons in the brain encode binocular disparity represented by that
attenuated and inverted tuning, leading to reversed-depth? We investigated this issue by measuring thebrain activities of 23 human observers with functional magnetic resonance imaging (fMRI). Throughout the fMRI scanning, they observed an engineered random-dot stereogram (RDS) that had variationin dot-contrast match level (anti-correlated, half-correlated, and full-correlated) for the RDS in thecenter and a correlated RDS (cRDS) in the surround. We performed decoding analysis on each brain
region by training a linear support vector machine with voxel patterns of cRDSs to classify near-far
disparity voxel patterns of aRDSs. Brain region V3A showed the classification accuracy significantly
below chance, suggesting that this area was associated with reversed-depth. This finding demonstrated
that the higher visual cortex exploits the representations of attenuated and inverted disparity tuningfrom the lower visual cortex. It therefore sheds new light on the hierarchical depth computation in thehuman brain.
Grant: none
Keywords: Stereopsis, Reversed-depth perception, Random-dot stereograms, Brain encoding-decoding analysis— 16 —

O1-1-3
5 : 15 PM-5 : 30 PM
Oblique effect in 3D gradient discriminations revealed by psychophysics and MEG
Huining Wu1, Yuji Ikegaya2,3, Hiroshi Ban1,3
1Graduate School of Frontier Biosciences, Osaka University, 2Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3Center for

Information and Neural Networks (CiNet), National Institute of Information and Communications Technology

Discrimination performance for oblique orientations is relatively lower compared to that for horizontal/
vertical contours (Oblique effect). Recent studies have shown that the oblique effect is not limited toorientation judgements but is commonly observed for the other visual features such as motion. To elucidate these perceptual anisotropies is important since it sheds insights on how visual neurons are organized and it can be utilized for modeling visual systems. Here we report a novel oblique effect in 3D
vision. Specifically, we found that surfaces tilted nearby the frontoparallel plane were more discriminable compared to those tilted more to the eye-sight line. We further explored the neural substrate of
the 3D oblique effect by comparing MEG (Elekta, Neuromag, 360 ch, 1 kHz sampling) responses
evoked by eight tilted surfaces (-52.5 to 52.5 deg). Multivariate pattern analyses revealed distinct peaksof the 3D gradient discrimination performance at 150, 240, and 320 ms after the stimulus onset. The
latter two peaks, which were thought to be derived from V3A, reflected the 3D oblique effect. These
results suggest that the 3D oblique effect has its ground in the middle stage of dorsal hierarchical depth
processing, not in the anisotropies of neural organizations in early areas.
Grant: none
Keywords: 3D visions, Oblique effect, MEG

O1-1-4
A deterministic approach to 3D vision from multiple cues
Jovan T. Kemp, Fulvio Domini

5 : 30 PM-5 : 45 PM

Brown University

Perceived 3D properties, such as depth, are typically modeled as an average of depth estimates fromindividual image signals (or cues) weighted by their reliabilities. Notably, it is assumed that depth cuesmust be processed independently by unbiased estimators maximizing accessible likelihood functions.
Here, we propose an alternative account to this probabilistic framework whereby a deterministic function maps a vector of scaled image signals to a depth estimate. This function maximizes depth discriminability while minimizing sensitivity to variations in image properties unrelated to changes in physicaldepth. Under this formulation we predict a fixed relationship between (1) a vector magnitude and perceived depth and (2) a change in vector magnitude and a Just-Noticeable Difference (JND). The firststudy investigating these predictions tasked participants to adjust a 2D probe to indicate the perceived
depth of a 3D stimulus. In the second study participants adjusted a series of cue-conflict stimuli until
their perceived depth matched the size of the 2D probe. The JNDs were measured in both studies, withthe second study directly comparing the predictions of our model and typical Maximum Likelihood
Estimation models. Results show that this novel approach provides the best fit of the data without freeparameters.
Grant: none
Keywords: 3D Vision, Psychophysics, Cue Combination— 17 —

O1-1-5
The width underestimation of 3D objects with image rotation
Marie Morita1,2, Yoshitaka Fujii3, Takao Sato4

5 : 45 PM-6 : 00 PM

1Department of Psychology, Ritsumeikan University, 2Research Fellow of Japan Society for the Promotion of Science, 3Research Organization ofOpen Innovation and Collaboration, Ritsumeikan University, 4College of Comprehensive Psychology, Ritsumeikan University

The gaze and body orientation of a person depicted in a portrait painting appears to follow the observer
even when observers move around. This is called the Mona Lisa effect. In addition, the face appears
thinner when this effect occurs. This is a break-down of shape constancy and suggests the physicalorientation of the image is not obtained or not used by the observer. In this study, we investigatedwhether the width underestimation of object with slanted image occurs with general 3D objects orspace, not only with human portrait. In experiments, we presented 2D images of 3D objects (car, clock
and building) and a scenery (road extending in depth direction) as test stimuli, and a H-shaped line-drawing as a reference. The rotation angle was varied in 5 steps between －30 to －30 deg. Observers wereasked to compare width of the object or road and reference H, and to judge which appeared wider. The
results showed that object width was perceived narrower with increasing rotation angle. However, roadwidth was perceived narrower, but not as much as other objects. These results suggest that width underestimation with rotation occurs only with 3D objects.
Grant: none
Keywords: depth perception, binocular vision, shape perception

O1-1-6
A joint motion/stereo constraint
Jiawei Zhou1, Yiya Chen1, Zhimo Yao1, Pi-Chun Huang2, Robert F. Hess3

6 : 00 PM-6 : 15 PM

1School of Ophthalmology and Optometry and Eye hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou

Medical University, Wenzhou, 2Dept. Psychology, National Cheng Kung University, 3McGill Vision Research, Dept. Ophthalmology, McGill
University

In clinical practice, stereo acuity isassessedonly using stationary stimuli. The purpose of this study was
to develop a novel test toexamine the effect of lateral motion on stereo acuity. In particular, 50 Gaborswith randomized position were presented in a circular display window in each eye; half of them weremoving coherently to the leftor the right and were assigned a disparity relative to fixation plane corresponding to the plane of the screen, while the other half of the elements were moving in the opposite
direction and were assigned an equal and opposite disparity. Observers were instructed to detect whether the Gabors in the front plane moved to left or right.A staircase method was used to determine thestereo acuity. Sub-pixel stereo accuracy was achieved by recomputing rather than simply shifting element position.For the range of motion speed that we measured (from 0.17 to 5.33 degree/second), weshow clear speed tuning of the stereo sensitivity in normal adults (F(5,35)=7.839, p＜0.001). This
motion/stereo constraint may reflect the processing of stereopsis within the dorsal pathway.
Grant: This work was supported by the National Natural Science Foundation of China grant NSFC 81500754, the Qianjiang Talent Project(QJD1702021) and the Wenzhou Medical University grant QTJ16005 to JZ, the ERA-NET Neuron grant (JTC2015) to RFH
Keywords: motion, stereopsis, psychophysics— 18 —

Monday, July 29
Poster:
10 : 30 AM-12 : 00 PM, 1 : 00 PM-2 : 30 PM, Event Hall
P1-1
Effects of emotional facial expression on the temporal resolution of visual processing
Misa Kobayashi1,2, Makoto Ichikawa1
1Chiba University, 2Japan Society for the Promotion of Science (DC1)

Some previous studies have shown that viewing fearful facial expressions enhances the temporal resolution of visual processing. We investigated if the magnitude of this effect would vary with positional
relationship between face and target stimuli. We presented a fearful or neutral facial stimulus for 500 ms
at the fixation point, and 100 ms after removal of the facial stimulus, we presented sequential two
35-ms-square-targets with an interval (ranging from 12 to 82 ms) at the overlapping position with thefacial stimulus or 1.5 arc deg above the facial stimulus. As an index of temporal resolution of visual
processing, we measured the threshold duration to detect the interval of the target stimuli by using themethods of constant stimuli. Only in the overlapping condition, we found that the temporal resolutionof visual processing reduced after viewing fearful face. While previous studies found enhancement in
temporal resolution of visual processing, the present study found its reduction. The duration of facial
stimulus and ISI between face and target stimulus were longer in the present study than those in theprevious studies We are proposing that the difference in these temporal factors in stimulus presentation
would cause differences in temporal resolution among studies.
Grant: Grant-in-Aid for JSPS Fellows
Keywords: ATR facial expression database, method of constant stimuli, ANOVA

P1-2
Infants’ perceptual insensitivity to the other-race-face in multisensory speech perception
Yuta Ujiie1, So Kanazawa2, Masami K Yamaguchi3
1Chukyo University, 2Japan Women’s University, 3Chuo University

Infants’ perceptual sensitivity to faces is broader in their early months, but gradually narrows to theirown-race-face during the first year of life. Such perceptual narrowing is considered a modality-general,pan-sensory process. However, it is poorly understood whether perceptual narrowing to own-race-faceappears in the development of audiovisual speech integration. Here, using functional near-infrared
spectroscopy, we demonstrated increased superior temporal region activity in response to the integration of audiovisual speech for the own-race-face speaker, but not for the other-race-face speaker, in infants aged 8–9 months. Using the familiarization/novelty preference procedure, we further show thatthese infants can integrate audiovisual speech of the own-race-face, but not that of the other-race-face.
These results imply that infants’ ability to integrate audiovisual speech narrows gradually to speech by
the own-race-face speaker by the second half year of life, supporting the hypothesis that perceptual
narrowing is a modality-general, pan-sensory process.
Grant: none
Keywords: Own-race, the McGurk effect, Infant development, fNIRS— 19 —

P1-3
Is human rapid face categorization viewpoint dependent?
Charles C.-F. Or1, Talia L. Retter2,3, Bruno Rossion2,4
1Division of Psychology, School of Social Sciences, Nanyang Technological University, 2Psychological Sciences Research Institute & Institute of

Neuroscience, University of Louvain, 3Department of Psychology, University of Nevada, 4Université de Lorraine, CNRS, CRAN, & CHRU-Nancy,
Service de Neurologie

Face-selective responses of single neurons in the monkey temporal cortex largely depend on head orientation, suggesting dominant view-dependent representations. In the human brain, however, whether
early face-selective neural responses depend on head orientation remains largely unknown. To address
this question, we presented 16 human observers with natural images of different objects alternating at afast rate (F=12 Hz), with face images appearing at F/9=1.33 Hz. Faces posed all full-frontal or at 3/4
views appeared in separate sequences. Significant face-selective responses were recorded in high-density EEG at 1.33 Hz and its harmonics mainly over the occipito-temporal regions. There were no amplitude differences between head orientations. Critically, alternating between full-frontal and ¾ views
within a sequence led to significant responses at 0.67 Hz (F/18) and its harmonics, objectively isolatingview-dependent face-selective responses over occipito-temporal regions. However, this response represented only a small (20-23%) fraction of the total face-selective activity, and did not reflect any difference in amplitude, being accounted for by a 21-ms earlier response for full-frontal than 3/4 views.
Overall, these findings point to predominant view-independent face-selective processes in the humanbrain, with face categorization achieved earlier for full-frontal than rotated faces.
Grant: This work was supported by Singapore MOE AcRF Tier 1 Grant 2018-T1-001-069 to C.O. & B.R., NTU HASS-SUG to C.O., F.R.S.-FNRS
grants to C.O. (FC 2773) & T.L.R. (FC 7159), and ERC Grant facessvep 284025 to B.R.
Keywords: Face perception, viewpoint dependence/invariance, EEG, Face detection

P1-4
Seeing money images explicitly increases people’s trust towards emotionally neutral faces of
strangers
On-Ting Lo
College of Professional and Continuing Education, The Hong Kong Polytechnic University

Is money the root of all evil? In the recent decade, studies consistently demonstrated that by merely
activating the concepts of money in mind, people would become more self-oriented and have otherpsychological consequences that do not favor social interactions. It is arguable that first impression
formation is the very first step for face-to-face social interaction. In this study, the money “self-orientation” effect was examined to test whether seeing a money image would decrease people’s trust towards
newly met strangers’ faces. 40 participants were randomly assigned into two experimental conditions.
In “money” condition, they were visually exposed to an image of banknote for 2 s then required to rateemotionally neutral faces’ (both in own race and other race) trustworthiness level. In contrast, being
required to perform the same task, a phase-scrambled money image was shown in control condition
instead. The results showed that participants rated the faces more trustworthy in the “money” condition.
In addition, the trustworthiness rating was higher in other race faces. No conditionXrace interaction
effect was found. This study demonstrated money would not necessarily promote self-orientation behaviors. By prolonging the explicit exposure time, money actually promotes prosocial behaviors suchas making a stranger’s face look more trustworthy.
Grant: none
Keywords: social vision, visual subliminal influence, visual perception— 20 —

P1-5
Self-perception induces visual size illusion
Ying Zhang1,2, Li Wang1, Yi Jiang1,2
1Institute of Psychology of the Chinese Academy of Sciences, 2University of Chinese Academy of Sciences

Previous studies have demonstrated that visual size perception is highly context-dependent and involves multiple neural computations. Here we report a novel perceptual illusion that self-face, being aunique and distinctive self-referential stimulus, can enlarge its perceived size. By using a size discrimination paradigm, we found that self-face was perceived as significantly larger than other faces of thesame size, and this size overestimation effect was not observed when a famous face was compared withother faces. Moreover, such illusion effect could extend to a cartoon face repeatedly associated with
one’s own face and further exert contextual influences on visual size perception of other objects. Thesefindings together highlight the role of self-awareness in visual size perception, and point to a special
mechanism of size perception tuned to self-referential information.
Grant: none
Keywords: self face, size perception, size discrimination paradigm, association paradigm

P1-6
Less is more—“Incomplete Beauty” of facial attractiveness perception
Cuihu Zhang, Mengliang Cao, Guomei Zhou
(Sun Yat-sen University)

Researchers have suggested that information shortage would enhance facial attractiveness rating, andthe enhancement may be due to participants’ expectation of whole face’s attractiveness. The aim of thepresent study is to further explore this hypothesis. In the current study, covered faces (faces covered bysunglass, mask, vertical hand, lean hand) and uncovered whole faces were presented as stimuli. In three
sequential sessions, participants were asked to (1) rate the attractiveness of uncovered parts of faces, (2)predict the whole face‘s attractiveness based on a covered face, (3) evaluate the facial attractiveness ofwhole faces. Our result showed that (1) attractiveness ratings of covered faces were higher than thoseof uncovered whole faces, (2) predicted attractiveness of whole faces were higher than attractiveness of
uncovered faces, (3) male participants’ predicted attractiveness of female faces were higher than theirpredicted attractiveness of male faces. Besides, these effects were modulated by attractiveness of faces.
Furthermore, we found a significant positive correlation between perceived attractiveness of uncovered
faces and predicted attractiveness of whole faces based on uncovered faces. The present findings provide further evidence to attractiveness enhancement under information shortage (we call this phenomenon as Incomplete Beauty), and support the hypothesis that the enhancement is due to participants’
expectation of whole face’s attractiveness.
Grant: none
Keywords: facial attractiveness, covers faces, information shortage, incomplete beauty

P1-7
Easterners cannot inhibit fixations to eye and nose regions in faceToshikazu Kawagoe1, Kazuki Kihara2, Wataru Teramoto2
1College of Contemporary Psychology, Rikkyo University, 2Division of Cognitive Psychology, Kumamoto University

It is known that Western observers cannot inhibit their gaze to the eye region even if they are told to doso when they observe face stimuli. This might be due to the fact that focusing on the eye region is needed for the holistic processing that is essential for face perception. However, previous studies have indicated that the nose region is also important for face processing by Eastern observers. The question asked
in this study was whether the Eastern observer can inhibit fixations on the eyes and nose. We have foundthat not only the eye, but also the nose region, automatically attracts Easterners’ gaze although they
fixate on the eyes more than on the nose. We replicated and extended previous studies, providing some— 21 —

insights into the characteristics of the Eastern observer’s cognition.
Grant: none
Keywords: face perception, eye tracking

P1-8Consistency is key: Face learning strategies in developmental prosopagnosics
Morgan Reedy, Hazel K. Godfrey, Tirta Susilo, Christel Devue
Victoria University of Wellington

Developmental prosopagnosics (DPs) have deficits in face recognition. Anecdotal evidence suggests
some DPs use extra-facial information (e.g., hair, ears, jawline) and body information (e.g., clothing) as
identity cues. These features can be diagnostic and allow identification in some cases. However, mostlaboratory-based studies use cropped images, neglecting their potential contribution, and perhaps exaggerating DPs’ deficits. This leads to the question, can DPs use extra-facial information to effectively
learn an identity, when extra-facial information is consistent across learning and test? Thirty DPs studied videos of three identities and then performed a recognition task in which extra-facial features wereconsistent with learning (i.e., same hairstyle & makeup to learning) or were inconsistent with learning.
To assess how extra-facial features contribute to recognition, half of the images were cropped to conceal
extra-facial features and half were full headshots. Consistent with self-reported deficits, DPs’ recognition was impaired when extra-facial features were absent or not diagnostic of identity. However, controls also showed impairments in these conditions, and DPs were as accurate as controls when extra-facial features matched learning. Therefore, when extra-facial features are consistent with learning, both
DPs and controls use this information to recognize face they have learned.
Grant: none
Keywords: Face Recognition, Face Learning

P1-9
The ERP Components Reveal the Interactions Between Configurations and the Other Race Effect
In Facial Expression Perception
Tsung-Tien Hsiung1, De-Syun Chang2, Chien-Chung Chen2,3
1Taipei First Girls High School, 2Department of Psychology, National Taiwan University, 3Center for Neurobiology and Cognitive Science, National

Taiwan University

We investigated the effect of feature configurations on the other-race effect (ORE), or it is more difficult
to identify a face of another race, in facial expression perception. The stimuli were frontal view imagesof 15 Asian and 14 Caucasian models in seven expressions, including neutral, happy, sad, fearful, angry,
surprised, and disgusted, in both in both upright and inverted orientations. The ERP waveform wererecorded on 20 Asians and 20 Caucasians who have stayed in Asia less than 6 months while they performed an expression categorization task. Each trial contained a brief presentation of a fixation mark,followed by a 400 ms presentation of an emotional face and a response interval in which a participant
was required to indicate the category of the expression. The ERP components at 170 ms and 200 ms
after stimuli onset (N170 and P200 respectively) showed a response intensity difference between inrace and other-race both in Asian and Caucasian Participants. However, While Asian participants
showed ORE in both upright and inverted faces, Caucasian participants only showed ORE in uprightfaces. Our results suggest that the Caucasian participants are more susceptible to facial configuration
effects than Asian participants in configuration judgements.
Grant: none
Keywords: N170, Electroencephalogram, Expression Identification, Face Inversion Effect— 22 —

P1-10The Face Inversion Effect For Facial Expression Judgement Is Culture Dependent
De-Syun Chang1, Tsung-Tien Hsiung2, Chien-Chung Chen1,3
1Department of Psychology, National Taiwan University, 2Taipei First Girls High School, 3Center for Neurobiology and Cognitive Science, National

Taiwan University

We investigated the effect of familiarity on face inversion effect (FIE), or that it is more difficult to
identify an up-side-down face, face expression perception and its neural substrates. The stimuli were
frontal view images of 15 Asian and 14 Caucasian models in seven expressions: neutral, happy, sad,fearful, angry, surprised, and disgusted, in either upright or inverted orientation. The event-related potential was recorded on 20 Asians and 20 Caucasians who have stayed in Asia less than 6 months while
they performed an expression categorization task. Each trial contained a brief presentation of a fixation
mark, followed by a 400 ms presentation of an emotional face and a response interval in which a participant was required to indicate the category of the expression. The ERP component at 170 ms after stimuli onset (N170) showed an overall difference between the upright and the inverted faces, demonstrating a strong FIE. However, the Asian participants showed such FIE only for Asian faces but not
Caucasian faces in the frontal and parietal electrodes. The Caucasian participants showed FIE in N170
for both Asian and Caucasian. In sum, such culture dependent FIE related ERP component is inconsistent with the universality theory for facial expression.
Grant: none
Keywords: Other Race Effect, N170, Expression Identification, Event-Related Potential

P1-11
Relationship between face familiarity and pupil mimicry
Licheng Zhu, Hirohiko Kaneko, Rumi Hisakata(Tokyo Institute of Technology, Department of Information and Communications Engineering)

The human eyes provide resourceful insights about the mental state. Recent studies reveal that there isa synchronicity of pupil responses during communication, which could be the result of a positive emotion (trust) (Kret et al., 2015). We considered that if pupil mimicry is due to the positive mental state,
the familiarity of faces would affect the pupil mimicry response. In the current study, we examined thispossibility. In addition, we examined the effect of luminance change due to the pupil change in theimage because Madou et al. (2018) suggested that there was a significant effect of physical luminancechange in stimuli on the pupil responses. We tested several stimuli sets, including luminance-equalized
faces of different familiarity levels and scrambled luminance-equalized image as a control. We presented two black circles changing in size on the positions of the eyes in the image to simulate pupil fluctuation. Results showed that pupil mimicry occurred in all the patterns and stronger for the face images
than for the scrambled images, indicating that the pupil mimicry was not just due to the luminancechanges in the stimuli. However, at this point, we didn’t find the difference of pupil mimicry between
the faces with different familiarity level.
Grant: none
Keywords: Human Vision

P1-12
Effect of viewing direction on the light from above-left assumption
Aki Tsuruhara1, Masashi Arake1,2, Yuko Aiba3, Takenori Nomiyama1
1Aeromedical Laboratory, Japan Air Self-Defense Force, 2Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical

College, 3Advanced Defense Technology Center, Acquisition, Technology & Logistics Agency)

The ‘lean-on-the sun’ illusion is known among aircraft pilots, in which during flight in cloud the brightest part of the cloud is regarded as ‘up’ even if the sun is not directly overhead. By contrast, previous
studies about shape-from-shading indicated human has an assumption that illumination is biased to the— 23 —

above-left rather than directly above. To elucidate this contradiction, we examined the effect of viewing
direction. Aircraft pilots usually look down the ground and clouds while the previous shape-from-shading studies presented stimuli on a frontal parallel plane. In our experiment, we measured the time thattook to detect a target within distractors under a single light that came from directly above or biased toleft. There were two conditions of object array: in one condition, the array was simulated as it werelooked down in 45 degrees; and in the other condition, in 90 degrees, that is, the object array appeared
as if on the frontal parallel plane of the participants. The results showed the shortest detecting time wasachieved under left-biased illumination in the both viewing conditions. Our results suggest that the‘leanon-the-sun’ illusion might have left-right asymmetry though action-perception dissociation must be
examined in the future study.
Grant: none
Keywords: the light from above-left assumption

P1-13
Relative contribution of S and L–M mechanisms to perceptual grouping
Lee Lin1, Chien-Chung Chen1,2
1Department of Psychology, National Taiwan University, 2Center for Neurobiology and Cognitive Science, National Taiwan University

We investigated color mechanisms in perceptual grouping with tripole Glass patterns, which consist of
randomly distributed sets of three dots, including one anchor dot and two context dots. Observers may
perceive a clockwise (CW) or counter-clockwise (CCW) spiral by grouping the anchor with one of thecontext dots. The chromaticity of the anchor and one context dots was placed at halfway between the
L–M and S axes, while that of the other dots varied between ±90° from anchor chromaticity in the DKLcolor space. The contrast of the context dots changed from one to four times of the detection threshold.
Participants were to respond whether they perceived a CW or CCW spiral. When the CCW dots contained a positive L–M component, the probability of perceiving a CW spiral, PCW, first increased andthen decreased with CW contrast. PCW saturated early when the CCW chromaticity was near the Saxis, suggesting a weak S-mechanism contribution. The result can explained by a model containing
global templates that each receives inputs from chromatic-spatial linear filters tuned to either L–M or S
mechanisms respectively. The percept is determined by the response difference between the CW and
CCW templates.
Grant: MOST(Taiwan) 106-2410-H-002-074-MY2
Keywords: perceptual grouping, color tuning mechanisms, divisive inhibition, psychophysics

P1-14
Large color contrast effect induced by a thin white-gap; evidence for interaction between colorand luminanceTama Kanematsu1, Kowa Kowa1,2
1Department of Computer Science and Engineering, Toyohashi University of Technology, 2Electronics-Inspired Interdisciplinary Research Institute(EIIRIS), Toyohashi University of Technology Department of Computer Science and Engineering

We found thin (0.031 deg) gray lines on a cyan background appeared red when the lines were surrounded by thin (0.031 deg) white-gaps. This effect was known as simultaneous color contrast, however, its
magnitude was greatly enhanced than the line without gaps. We quantified an appearance of the grayline for no-gap, white-gap and black-gap conditions. Matched color of no-gap condition showed either
color assimilation or contrast depending on its luminance, whereas that of white-gap condition weresignificantly shifted toward a complementary hue irrespective of its luminance. Almost no color shift
was observed for black-gap condition. This indicates that any explanation based on spatial frequency orproximity is insufficient. Interaction between color and luminance would be critical. The illusion wasprominent for thin lines and dots, however optical blur and chromatic aberration were not major factors.
The illusion occurred regardless of hues if the appropriate thickness of lines were used; preferred thickness was larger for S cone axis background than L-M cone axis background. This phenomenon may be— 24 —

considered as an inference of color of thin objects which exceeds spatial resolution of color by remaining luminance pattern, such as thin branches on the sky background.
Grant: none
Keywords: psychophysics, color, luminance

P1-15
Categorical perception of color in tracking depends on language
Mengdan Sun1,2, Xiaoqing Gao1, Xuemin Zhang2
1Center for Psychological Sciences, Zhejiang University, 2Faculty of Psychology, Beijing Normal University

Is our perception of the world shaped by the language we speak? This subject has provoked controversy over the past decades. Categorical perception (CP) of color suggests that cross-category colors are
discriminated better than within-category colors, initially serving as the supporting evidence for the
penetrability of language on perception. However, recent findings seem to suggest language-independent CP effects. Following our previous study that revealed CP effects in a tracking task, the current
study investigated the effects are dependent on language or not. We conducted two experiments where
two types of verbal interference task were implemented and assessed whether the CP effects in tracking
would be disrupted. In Experiment 1, the verbal interference task was an eight-digit memorization task,
while Experiment 2 replaced the digits by color words. It showed that the CP effects were not influenced
by the digit memorization task (Exp.1) but reduced by the memorization of color words (Exp.2). Our
results suggested that the CP effects in tracking derive from the use of color labels, supporting the roleof language in dynamic visual organization. Furthermore, the ability of different verbal interferencetasks differs in blocking the access to color labels.
Grant: none
Keywords: color perception, categorical perception, behavioral

P1-16
Pupillary responses to the perceived brightness of simultaneous contrast
Kei Kanari
Applied Brain Science Research Center, Brain Science Institute, Tamagawa University

It has been reported that the pupillary response depicts not only the physical intensity of the stimulus
but also the brightness of the stimulus. However, whether the perceived brightness processed in the
primary visual cortex affects the pupillary response remains unclear. Hence, this study aims to examine
whether the perceived brightness of the simultaneous contrast affects the pupillary response. The test
stimulus consisted of a test disk and a ring surrounding it. The perceived brightness was manipulated bychanging the width of the ring. Subjects responded to the brightness of the test disk by adjusting theluminance of the comparison disk. In addition, I measured the pupillary responses to the test stimuli.
Results showed that the contrast effect increased as the ring width increased only when the ring luminance was lower than the disk luminance (increment condition), and the pupillary response corresponded to the perceived brightness in increment condition. This study suggests that the pupil is modulatedby the perceived brightness processing in the primary visual cortex.
Grant: none
Keywords: brightness, simultaneous contrast, pupillary response

P1-17
Asymmetric brightness effects with dark vs light glare-like stimuli
Yuki Kobayashi1,3, Daniele Zavagno2, Kazunori Morikawa1
1School of Human Sciences, Osaka University, 2Department of Psychology, University of Milano Bicocca, 3Japan Society for the Promotion of

ScienceA white surface surrounded by luminance gradients which are darker in the outer ends appears brighter— 25 —

than an equiluminant surface surrounded by uniform gray (i.e., the glare effect). Although the glare effect has been a subject of much research, its photometrical reversal (i.e., the center is dark and the outerends of the surrounding gradients are lighter), which we dubbed as photometrical negative glare (PNG),
is still left surprisingly unexplored. In the present study, perceived luminance in the center of PNG was
examined. Twenty participants compared equiluminant central areas of a PNG target and a comparative
one, and rated how much the latter appeared to be brighter or darker than the former. Five luminancevalues were employed for the equiluminant (black and four levels of gray) and three for the background(black, dark gray, and light gray). Similar conditions were set up for the glare effect, and all stimuli wererepeated ten times in random order. We expected a darkening effect with PNG stimuli compared tobrightness enhancements experienced with glare stimuli. Results showed instead a substantial brightness enhancement for PNG, with the exception of the black target, which showed a tendency to appear
darker than the comparative one.
Grant: none
Keywords: lightness and brightness, illusion

P1-18
Luminance variability discrimination in brief presentation
Yusuke Takano1, Eiji Kimura2
1Graduate School of Science and Engineering, Chiba University, 2Department of Psychology, Faculty of Letters, Chiba University

We previously showed that, when asked to compare mean brightness of heterogeneous luminance arrays of disks, observers’ judgements were efficient but exhibited a bias toward the highest or lowest
luminance depending on task requirement (Takano & Kimura, ICVS2015). There were also some implications that luminance variation of the stimulus could be quickly extracted. This study further examined tentative visual processes that efficiently code luminance variation. In Experiment 1, we investigated luminance distribution discrimination of briefly-presented (47 ms) arrays composed ofheterogeneous 24 disks. The percentage of correct responses in the task could be described as a functionof the difference in the standard deviation (SD) between the standard and comparison luminance distributions. In Experiment 2, we specifically asked observers to discriminate luminance variability between
the standard and comparison stimulus arrays. The SD of the standard luminances was varied in fourlevels. Results showed that observers could efficiently and accurately discriminate luminance variability regardless of the level of the standard SD. Moreover, unlike in mean brightness judgements, no clear
evidence was found for relying on more readily available proxies such as luminance range. Together,
these findings suggest that luminance variability was processed in a qualitatively different fashion frommean luminance.
Grant: Supported by JSPS KAKENHI #26285162
Keywords: ensemble perception, brightness perception, method of constant stimuli

P1-19
Fast contrast adaptation in area 17
Kota S Sasaki1,2, Kohei Kurihara1, Izumi Ohzawa1,2
1Osaka University, 2CiNet

Images fade from perception when they continue falling on the same set of photoreceptors in retina
without eye movements. After experiencing this fading, sudden removal of images yields perception of
their negative images. To understand neurophysiological basis underlying this illusion, single unit activity was measured in the area 17 of anesthetized and paralyzed cats. The contrast response functions
were measured using flashed gratings by changing the contrast randomly within a limited range while
the other parameters (e.g., orientation) were customized and fixed at the optimal values for each neuron.
Stimulus in some conditions included gratings whose contrast polarity was inverted (i.e., negative contrast). In pedestal conditions where the temporal average of contrasts was not zero, the contrast response
functions shifted so that the pedestal could be cancelled almost perfectly. This adaptation completed— 26 —

much faster than well-known contrast gain control. As a result of this contrast cancellation, a blankscreen produced the strongest responses when neurons were adapted to gratings of negative contrasts.
This means that these neurons fires vigorously when adaptation to negative contrast is released by removing an adapting image. These results appear to be consistent with fading illusion and extraordinarily rapid fading reported by Coppola and Purves (1996).
Grant: KAKENHI 15H05921
Keywords: contrast, adaptation, neurophysiology, illusion

P1-20
Color naming is more reliable than position detection in peripheral visual field
Tatsuya Oikawa1, Kowa Koida2
1Department of Computer Science and Engineering, Toyohashi University of Technology, 2Electronics-Inspired Interdisciplinary Research Institute,

Toyohashi University of Technology

Detection and identification are two different aspects of visual function. How these performances differ
around threshold level stimuli? We measured the detection threshold of colored targets, and comparedwith accuracy of color appearance for the targets at the perithreshold contrast. In the detection task,
observers were asked to respond the position of colored target from 6 possible sites on peripheral visual field. Using staircase method, the psychometric functions and thresholds were determined. In theappearance task, the observers were asked to identify the name of color from 6 options (red, green,
yellow, purple, white, and black). Colored targets were determined by cone isolating axes, and the contrast was determined around detection thresholds. Contrary to expectations, the color naming performance was significantly higher than detection performance across sub- and supra-threshold levels.
These results suggest that discrete processing of detection and identification. Recent neurological studyof macaques indicates that superior colliculus-pulvinar-cortical pathway, is thought to be involved inspatial attention, also carry color information. Our results suggest that high contrast stimuli would be
required to drive pulvinar pathway.
Grant: none
Keywords: Psychophysics, Color vision

P1-21
Assessing peripheral visual function in myopia—a qCSF study
Jinrong Li1, Zhipeng Chen1, Zhong-Lin Lu2
1Zhongshan Ophthalmic Center, Sun Yat-sen University, 2Department of Psychology, The Ohio State University

Purpose: This study evaluated contrast sensitivity function in peripheral vision in myopia and emmetropia with the qCSF method. Methods: The study recruited 19 myopia subjects and 12 normal subjects.
Their BCVA were 0.00±0.00 logMAR. All subjects performed the qCSF test in foveal vision and fifteen
peripheral locations (Superior, inferior, temporal and nasal quadrants at 6, 12, 18 and 240 eccentricities)
and optical quality assessment with the double-pass Optical Quality Analysis System II, OQAS. The
myopes wore soft contact lens with best corrected visual acuity (BCVA). The cutoff spatial frequency(cutoff SF) and the area under log CSF (AULCSF), and contrast thresholds were derived from qCSF
test results. Results: Results from the OQAS assessment found that there was no significant opticalquality difference between two groups (p＞0.05). There was also no significant difference between two
groups in any of the CSF metrics in foveal vision(p＞0.05). Further analysis showed that myopes had
significantly increased AULCSF in the superior(p=0.026), inferior(p=0.024) and nasal(p=0.022) quadrants at 120, but not in other eccentricity. Conclusions: We speculate that these results may be attributed
to compensatory improvements of peripheral vision from its extensive use during near visual activities
in the emmetropization process of myopic visual system.
Grant: The National Natural Science Foundation of China (81770496) to Jinrong Li and the National Eye Institute (EY021553) to Zhong-lin Lu.
Keywords: myopia, peripheral vision, contrast sensitivity— 27 —

P1-22Sizing up the crowd when perceiving body size
Jason Bell1, Georgia Turnbull1, Joanna Alexi1, Georgina Mann1, Yanqi R Li1, Manja Engel2, Donna
Bayliss1, Simon Farrell1
1School of Psychological Science, University of Western Australia, 2Faculty of Social and Behavioural Sciences, Experimental Psychology/

Helmholtz Institute, Utrecht University

Recent research has shown that serial dependencies in perception can bias body size estimates towards
prior experience. The current study sought to build on that work by examining whether body size judgments are also biased by surrounding spatial information. To do this we created an Ebbinghaus Illusion
with bodies. We used the HTC Vive Pro to present six inducers in a virtual annulus surrounding thecentral test body. The configuration resembled a small crowd, all facing the observer. We tested two
conditions: one where the to-be-judged body was surrounded by overweight inducers and the other,
containing thin inducers. Participants (N=412) were randomly assigned to one condition each. Participants were instructed to ignore the inducers and judge the size of the central female body by clicking on
a VAS. Results were consistent with the Ebbinghaus illusion: the central body appeared larger whensurrounded by small inducers and vice versa. The nature of the interaction between the spatial (Ebbinghaus) and temporal (serial dependence) biases will also be described. Our findings shed further light on
the perceptual causes of body size misperception, as well as the processes underpinning serial dependencies in perception.
Grant: none
Keywords: object perception, serial dependencies, 3D

P1-23
Haptic Detection of Radial Frequency Patterns
Goro Maehara1, Jason Bell2
1Department of Human Sciences, Kanagawa University, 2School of Psychological Science, University of Western Australia

An old psychological controversy is whether our perceptions have their intrinsic structures as whole
entities or consist of combinations of local features. Recent studies on pattern vision addressed this issue using radial frequency (RF) patterns and suggest that a simple contour is processed globally. The
present study attempts to investigate whether the haptic system similarly globally processes the simple
RF contour shapes. We measured haptic detection thresholds of RF patterns at different numbers ofradial deformations. The mean threshold significantly decreased as the number of deformations increased for RF5 (pentagon like shape). The slope of the function was −0.49 with the 95% CI ranging
from −0.21 to −0.78. This slope was slightly steeper than the slope value of −0.33, which is predictedfrom probability summation. Since the haptic system could not simultaneously detect multiple deformations for the present stimuli, it seems reasonable to assume that haptic system globally processes
RF5 contours. On the other hand, detection thresholds were comparable among different numbers ofdeformation cycles for RF3. Here, deformation detection is equivalent to detection of a single local
curvature. We discuss the similarities and differences in contour perception between visual and haptic
perception.
Grant: none
Keywords: radial frequency, contour, psychophysics

P1-24
Seeing Sounds: The Role of Consonants in Sound Symbolism
Yang-Chen Shen1, Yi-Chuan Chen2, Pi-Chun Huang1
1Department of Psychology, National Cheng Kung University, 2Department of Medicine, Mackay Medical College

Sound symbolism refers to associations between phonemes and certain visual properties. In one classic
example, the meaningless sounds “bouba” and “kiki” are mapped onto rounded and angular shapes,— 28 —

respectively. We investigated whether the classification dimensions of English consonants (voiced/
voiceless, sonorant/obstruent, and abrupt/continent) correspond to the round/sharp contrast of visualfeatures. We adapted twenty meaningless spoken words from previous studies, ten of which belonged
to the round category and ten of which belonged to the sharp category. In each experimental trial, theparticipants heard one of the words and saw a rounded shape and an angular shape on the monitor. Participants then had to judge which shape provided a better match to the spoken word. The results of thesound–shape matches were predictable using the voiced/voiceless and sonorant/obstruent dimensions,but not the abrupt/continent dimension. Specifically, spoken words that consisted of voiced consonants
and sonorant consonants were more likely to be matched to rounded shapes. Hence, we verified soundsymbolism effects by demonstrating systematic mapping of contrasting dimensions among voiced/
voiceless consonants, sonorant/obstruent consonants, and round/sharp visual features. The English phonemes and visual shapes used in the current study provide useful tools to examine the universality ofsound symbolism in future studies.
Grant: This work was supported by Ministry of Science and Technology in Taiwan (MOST 104-2628-H-006-001-MY3 to PCH and MOST
107-2410-H-715-001-MY2 to YCC)
Keywords: sound-shape correspondence, Bouba/Kiki effect

P1-25
Perception of the Müller-Lyer illusion in budgerigars and pigeons
Sota Watanabe1, Noriyuki Nakamura2, Kazuo Fujita3
1Osaka Kyoiku University, 2Toyo Gakuen University, 3Kyoto University

Whereas budgerigars (Melopsittacus undulatus) are one of the most popular species as companion animals, little is known about their visual perception. This study explores how budgerigars and pigeons(Columba livia) perceive the Müller-Lyer illusion. We first trained our birds to choose the shorter/longerof two isolated horizontal lines. After transfer of this performance to the Judd figures, which had two
brackets on each end pointing in the same direction, and to the Müller–Lyer illusory figures, which had
two inward- (＞-＜) or outward-pointing (＜-＞) brackets at the end of the target lines, we displayednovel Müller–Lyer figures, whose lengths of horizontal lines are different from those used in the previous phase, to our birds and determined whether their discriminations were affected by Müller–Lyer illusion. The results suggest both budgerigars and pigeons perceive the Müller–Lyer illusion and theirillusionary tendency is the same as that of humans. We have confirmed that the birds’ responses could
not be accounted for by overall lengths of the figures. This tendency of budgerigars and pigeons shownin our study is consistent with those reported of pigeons in Nakamura, Fujita, Ushitani, and Miyata(2006).
Grant: none
Keywords: comparative cognition, geometric illusion

P1-26
Contrast sensitivity functions measured under different dynamic range widths
Misaki Hayasaka1, Takehiro Nagai2, Tomoharu Sato3, Tomonori Tashiro1, Yasuki Yamauchi1, Ichiro
Kuriki4
1Yamagata University, 2Tokyo Institute of Technology, 3National Institute of Technology, Ichinoseki College, 4Tohoku University

In classical studies, contrast sensitivity functions (CSFs) were measured under full adaptation to a uniform background. However, this environment is extraordinary as a visual scene as compared with thosein our daily life, which typically contain variegated regions with a wide luminance range. Here, we investigated effects of the dynamic range widths of the textured background on CSFs. The test stimulus
was a Gabor patch on a uniform square pedestal, whose luminance was randomly chosen from fivelevels (0.8 to 107.4 cd/m2) in each trial. The background was a one-dimensional (line) texture orthogonal to the test stimulus with various luminance values, randomly chosen within one of four dynamic
ranges widths, with the same mean luminance (16.4 cd/m2). In the results, the effects of dynamic range— 29 —

widths were not very pronounced in general; 1) spatial frequency profiles of CSFs were not very different across dynamic range widths, and 2) overall sensitivities were the highest around the average luminance of the background, regardless of the dynamic range widths. However, the highest sensitivity
range spanned wider luminance levels of pedestal under wider dynamic range conditions. These results
indicate that the overall sensitivity of CSF is optimized to the dynamic range of visual scene.
Grant: none
Keywords: Contrast sensitivity functions, Psychophysics, High dynamic range

P1-27
Size of global arrangement affects the perceived size of local elements
Taiichiro Uechi1, Makoto Ichikawa2
1Graduate School of Science and Engineering Chiba University, 2Faculty of Humanities Chiba University

We found that perceived size for local circular elements, which form a circular arrangement, illusorily
decreases with the expansion of the global circular arrangement (Uechi & Ichikawa, ECVP2018). In
this study, we examined the effects of the amount of elements, size of elements, and size of global circular arrangement on perceived size of the local elements. Each stimulus was presented for 600 ms at
the center of the display. After each stimulus observation, participants selected one of the circles, whichis perceptually equivalent to the size of the circular elements in the global arrangement, from a chartthat shows a row of white circles with different diameters. As we found in previous study, perceived size
for local elements reduced as the global size increases. From this result, we are proposing that the information of reduction in viewing distance, which is extracted from global expansion, would cause perceptual reduction of the elemental size in terms of the “size-distance invariant hypothesis”. Furthermore,
we found interaction of the three factors; for large elements size, perceived size of local elements increases as amount of elements increases with small global sizes. We will discuss the bases of this threeway interaction.
Grant: none
Keywords: size illusion, circular arrangement, ANOVA

P1-28
Spatial Summation on a pattern mask
Chia Hua Chen1, Chien Chung Chen2, Christopher W. Tyler3
1Department of Psychology, National Taiwan University, 2Center for Neurology and Cognitive Science, National Taiwan University; Department of

Psychology, National Taiwan University, 3Smith-Kettlewell Eye Research InstituteWe investigated the mechanisms underlying spatial summation with a masking paradigm. The targets
were Gabor patterns placed at 3 deg eccentricity to either the left or right of the fixation and elongatedalong an arc of the same radius on a concentric Gabor mask of the same radius. The observer’s task was
to indicate whether the target in each trial was on the left or the right of the fixation. The Ψ staircase
procedure was then used to measure the threshold at 75% accuracy. When the mask contrast was low,
the target threshold initially decreases with size with slope −1 until target length reached 45’ half-heightfull-width (HHFW) and further decreased with slope −1/2 on log–log coordinates. At high mask contrast, the threshold also showed a −1 slope up to 45′ HHFW. However, the threshold was constant between 45′–210′ HHFW, followed by another −1 slope drop. Our results suggest that summation acrosslocal channels, which accounts for −1/2 slope decrease, can be eliminated by a high contrast mask, but
not the summation within the receptive field of one channels, which accounts for the -1 decrease. The
second drop in threshold suggests two summation mechanisms tuned to different size.
Grant: none
Keywords: ideal observer, threshold, contrast detection, gain control— 30 —

P1-29Neural Networks for Computing Touch Topology
Keiji Miura1, Kazuki Nakada2
1Kwansei Gakuin University, 2Tsukuba University of Technology

While tactile or visual image data have been conventionally processed via filters or perceptron-likelearning machines, the advent of computational topology enabled us to extract the globally consistentfeatures from the local pixelwise data. For example, the invariants under continuous deformation suchas the number of islands or holes in an image are informative for digits discrimination. However the realtime computation is still hard and the parallelized algorithms are desired for the quickness to achieveinteractive touch screens. We show that the invariants (#islands or #holes), irrespective of detailed
touch shapes, can be obtained in a recurrent neural network after the iterative updates of its state (IEEE
Access, 2014). Here we can count not only isolated touches but also “overlapped” touches by the Euler
integral (1). When you only need the difference (#islands#holes), it suffices to instantly count the Poincare–Hopf indices only for a handful of salient pixels (IEEE Access, 2015, 2017), as if only a few
sensory neurons activated and mattered for global consistency. These neural implementations of computational topology may give a hint for the consistency-based sensory signal processing in the brain.
Grant: KAKENHI 18K11485
Keywords: image processing, touch screens, topology, object recognition

P1-30
A new demonstration of amodal completion implied in Oyama’s (1960) figure-ground reversible
image
Kentaro Usui, Akiyoshi Kitaoka
Ritsumeikan University

When an object is occluded by another one, the occuded part is invisible but the object is perceived asa perfect one. The visual function to fill in the lacked part is called ‘amodal completion.’ In many cases,
T-junctions are regarded as a critical cue of occlusion. In this contex, the area above the horizontal barof ‘T’ appears to be closer to the observer and to occlude the ‘stem’ of ‘T.’ Here we propose a new typeof amodal completion phenomenon that accompanies T-junctions in a different fashion, in which eitherside of the ‘stem’ appears to be closer.
Grant: none
Keywords: amodal completion

P1-31
Angular Tuning of Tilt Illusion depends upon Duration
Saki Takao1,2, Colin WG Clifford2, Katsumi Watanabe1,2
1Waseda University, 2University of New South Wales

Brief presentation induces larger simultaneous contrast effects (Kaneko et al., 2017), including the tilt
illusion. This was explained in that the brief presentation led to higher uncertainty in determining theorientation of the test stimulus, which enhanced contextual modulation. Here, we examined the effectof duration on the tilt illusion with a wider range of center-surround orientation differences to examine
whether higher uncertainty changes the angular tuning function. Centre and surround gratings were
presented for 10 to 640 ms. Surround orientation was manipulated between ±7.5 to ±75 degrees for each
duration. An interleaved Bayesian adaptive staircase method adjusted the orientation of the central
grating to estimate a point of subjective verticality for each combination of duration and surround orientation. The results showed that the surround orientation at which the tilt illusion peaked changed withduration. Specifically, as the duration became shorter, the illusion became larger and the peak shifted
toward a larger center-surround difference. These results suggest that presentation duration influences
not only the magnitude but also the orientation profile of the processes underlying the tilt illusion.
— 31 —

Grant: none
Keywords: visual perception, contextual effect, psychophysics

P1-32
The transfer of perceptual learning to a physically and orientation different stimulus requires
triple training
JunYun Zhang, Guo-Zhen Liu, Cong Yu
School of Psychological and Cognitive Sciences, Peking University

Perceptual learning becomes transferrable with double-training. However, Vernier learning transferred
to a new location only when the training and transfer stimuli shared the same orientation. A second
exposure to a suprathreshold-orthogonal-Vernier was necessary to enable cross-orientation learningtransfer. Here we investigated whether orientation learning transfer between orthogonal gratings andsymmetric-dot-patterns also requires such triple training (training-plus-double-exposures). Observers
learned orientation discrimination of a grating/symmetric-dot-pattern, and the learning transfer to theother-orthogonal-stimulus was tested. We found (1) Baseline: Grating orientation learning (35o/125o)
had little effect on orthogonal dot-pattern orientation discrimination; (2) Double-training: Additional
exposure to the orthogonal-dot-patterns via a brightness-discrimination-task produced incomplete
learning transfer to orthogonal-dot-patterns; (3) Triple-training: Observers received exposure of bothnew orientation and new stimulus via two separate tasks: grating-brightness-discrimination at the orthogonal orientation, and dot-pattern-brightness-discrimination at the same/orthogonal orientation. After triple training, complete transfer of grating orientation learning to the orthogonal symmetric-dot-patterns was evident. The brain might perform two remapping to transfer perceptual learning. One remaps
learning to an orthogonal-orientation of the same stimulus. The other remaps learning to a physicallydistinct stimulus.
Grant: none
Keywords: perceptual learning

P1-33
Velocity of self-induced optical flow contributes to body control through unconscious speed estimation of self-motion during rotational movement
Ryo Tokuyama, Rumi Hisakata, Hirohiko Kaneko
Dept. of Information and communications Engineering, Tokyo Tech.

In tune with VR technology development, some recent studies have revealed the effects of visual information on body control. For example, Langbehn et al. (2018) demonstrated that the under-thresholddistortion of the virtual path induced subconscious bending of walking trajectory. Most people will beable to image visual information affects body control, however, how visual information has an impact
on body control is still unclear. To investigate this issue, we focused on optical flow and body movement during self-rotation about the yaw axis. We manipulated the relative velocity of optical flow
during self-rotation and instructed the subjects to keep rotating at constant speed. The subjects wore ahead-mount display (HTC VIVE) and observed a spherical space composed of floating dots. The subject’s movement was detected by the VIVE-tracking system, resulting in that we could manipulate thesubject’s optical flow velocity in real time. Because the subjects were asked to ignore the visual stimulus, they were presumed to keep the physical speed of self-rotation. However, the physical velocity ofself-rotation decreased as the relative velocity of optical flow increased, namely they couldn’t ignore it.
The result suggests that the estimation of the velocity of the self-rotation is inevitably affected by visual information even if enough information from the vestibular system is available during self-rotation.
Grant: none
Keywords: perception of self-motion, optic flow, self-rotation, body-control— 32 —

P1-34
Motion priming reveals visual instability under sudden change in ambient light level
Sanae Yoshimoto1, Tatsuto Takeuchi2
1Hiroshima University, 2Japan Women’s University

When you dance on a club floor under heavily flashing lights, you might feel as though your body is
floating while the world around you is shaking. Since spatiotopic representation in the brain is key tothe perception of visual stability, we speculate that a sudden change in ambient light level deteriorates
the construction of spatiotopic representation. This hypothesis was examined using a phenomenon
called visual motion priming, in which the perceived direction of a directionally ambiguous test stimulus is influenced by the moving direction of a priming stimulus. Participants performed saccades after
the termination of the primer and then judged the perceived direction of the test stimulus. A test stimulus
was presented in the retinotopic location or screen-based spatiotopic location. The average luminanceof the display changed from photopic to mesopic level or vice versa at a time point between primer
offset and test onset. We found that when the average luminance was changed, spatiotopic priming
disappeared, whereas retinotopic priming was not influenced. The different responses of cones and rods
to luminance change would contribute to the disappearance of spatiotopic priming—a signature of the
disturbance in construction of spatiotopic representation—which would eventually lead to visual instability.
Grant: none
Keywords: motion perception, visual stability, eye movement, ambient light level

P1-35
Development of human infants’ receptive field mechanisms in visual motion processing
Yusuke Nakashima1, So Kanazawa2, Masami K Yamaguchi1
1Department of Psychology, Chuo University, 2Department of Psychology, Japan Women’s University

Perceiving motion direction is more difficult when the size of high-contrast motion stimuli is increased.
This perceptual phenomenon is considered to reflect surround suppression, a receptive field property
observed in MT neurons. Here, we demonstrate that this phenomenon can be observed in human infants. We measured motion direction discrimination with small and large drifting gratings in 3- to
8-month-old infants using familiarization/novelty-preference procedure. Infants at 7–8 months of age
showed higher sensitivity for a small motion stimulus than for a large one. However, infants under 6months showed the opposite result; motion sensitivity was higher for a large stimulus. These results
suggest that suppressive surround regions beyond classical receptive fields develop in the second halfof the first year. Moreover, we investigated the size of receptive fields using this phenomenon and foundthat the center region of receptive fields was larger in 3–4-month-old infants than in 7–8-month-old
infants. Our findings suggest that receptive fields related to motion processing are broad and do not haveextra-classical receptive fields in early infancy, and that they become narrower and acquire suppressive
surround regions in the first year of life.
Grant: none
Keywords: visual development, motion, infant

P1-36Interactions between luminance-defined and orientation-defined visual rotations on visually induced self-rotation illusion (roll vection)
Shinji Nakamura
Nihon Fukushi University

Uniform motion of large visual display which mostly occupies observer’s field of view can induce illusory self-motion perception toward the opposite direction (visually induced self-motion perception,
also known as vection). Our previous studies have been indicated that visual rotation defined by orien— 33 —tations of visual elements (fractal rotation) can effectively induce roll vection, even in the situation
where the visual inducer didn’t contain any luminance modulations (APCV 2017). The present investigation further examined the effects of the non-luminance-based motion, using a visual situation where
the luminance-defined (luminance rotation) and orientation-defined (fractal rotation) visual rotations
were convoluted with each other and employed as a visual inducer. Psychophysical experiment with 13
participants revealed that in the condition where the luminance and the fractal rotations were contradicted, the luminance rotation became dominant to determine perceived strength and direction of roll vection. The fractal rotation cannot overcome the dominating effects of the luminance rotation even if its
luminance contrast was quite low, but still seems to have modifying effects on visual self-rotation perception in some cases.
Grant: none
Keywords: self-motion perception, vection

P1-37
Interaction between form and motion processing: neural basis investigated with Glass patterns
and repetitive TMS
Rita Donato1, Andrea Pavan2, Massimo Nucci1, Gianluca Campana1
1University of Padova, 2University of Lincoln

Glass patterns (GPs) are a class of visual stimuli useful to investigate global form perception and theinteraction between form and motion processing. GPs are dot patterns formed by applying different
geometric transformations to change the spatial relationship between dot pairs (dipoles), to create visual patterns that convey a specific global form. A rapid succession of different GPs also gives the impression of motion (dynamic GPs). In the present study, we investigated the neural basis of circular dynamic GPs by interfering with the use of repetitive transcranial magnetic stimulation (rTMS). Rotating
random dot kinematograms (RDKs) were used as control stimuli. Participants performed a 2-interval
forced choice task and had to discriminate between the presentation of GPs (or RDKs) vs. a random
pattern (i.e., noise). The results showed that rTMS over V1/V2 interfered with the processing of bothdynamic GPs and RDKs, while rTMS over V5/MT only interfered with motion processing, but not withthe processing of dynamic GPs. These findings suggest that partially different neural substrates subtend
the processing of dynamic GPs and circular motion.
Grant: none
Keywords: Circular motion, Dynamic Glass patterns, Form-motion processing, repetitive transcranial magnetic stimulation

P1-38
Representation of spatial feature of complex motion in areas MT and FST
Takahisa M Sanada
Kansai Medical University

Spatial feature of visual motion in natural scene is typically non-uniform. For example, in liquid flows,
various directions/speeds of motion vectors are spatially distributed in a complex manner. Recently, it
was reported that the spatial smoothness of local motion vectors, characterized using the mean discrete
Laplacian of motion vectors, correlated with rated liquidness impression by human psychophysics(Kawabe et al., 2015). Neurons in area FST are selective to spatial structure defined by motion (Mysore
et al., 2010), and we hypothesized that FST neurons represent spatial features of complex motion by
integrating multiple motion components. In the present study, we tested this possibility by recording
responses of FST neurons to complex motion stimuli with various degrees of spatial smoothness. 8
different levels of spatial smoothness of motion were generated by manipulating mean discrete Laplacian of motion vectors. Sixty-four stimuli were prepared in combination of 8 spatial smoothness and 8
directions. If a neuron is related to representing spatial feature of complex motion, it should respond atparticular Laplacian levels. We found that subset of FST neurons which showed broad direction selectivity responded when the spatial smoothness was high, suggesting that spatial feature of complex— 34 —

motion might be represented in area FST.
Grant: This research is supported by JSPS (JP16H01681, JP16K00384, JP18H05016)
Keywords: Electrophysiology, Motion, Shitsukan

P1-39
The disappearance of global apparent rotational motion with local drifting sinusoidal gratings
Hoko Nakada, Katsuhito YAMoto, Ikuya Murakami
Department of Psychology, The University of Tokyo

Apparent rotational motion is perceived when Gaussian blobs of two different luminances are alternately arranged to configure a ring and switch their luminances. We added local sinusoidal gratings drifting
upward or downward to each blob and switched their motion directions simultaneously with their luminance switching. We found that the appearance of rotational motion was significantly decreased andsometimes completely abolished. This indicates that correspondence matching, motion energy, etc.,
necessary for perceiving a global apparent rotational motion, are obscured by local sinusoidal gratings
drifting in vertical directions, not along the trajectory of apparent rotation. One possibility is that thetemporal frequency power in the first-order motion masks the frequency of the luminance switching.
However, this is unlikely because, regardless of the frequency of the switching, the apparent rotationalmotion was suppressed by the sinusoidal gratings drifting above certain speed. We will discuss otherpossibilities that may be related to the disappearance of apparent rotational motion, such as local motion
directions and the synchronization of luminance switching, aiming to elucidate the mechanisms underlying the global perception of apparent rotational motion.
Grant: Supported by JSPS KAKENHI (JP18H05523).
Keywords: motion

P1-40
Decoding image motion using deep neural network features
Ken U Shirakawa1, Yukiyasu Kamitani1,2
1Graduate School of Inforoto University, 2ATR Computational Neuroscience Laboratories

While visual images are represented in hierarchical neural representations with diverse complexity,
motion information is often assumed to be processed by detecting monolithic spatio-temporal features.
To explore diverse neural representations of image motion, we used spatio-temporal features derived
from a deep neural network (DNN) model pre-trained to classify action in a moment. The DNN feature
values of natural movie stimuli were predicted (decoded) from the fMRI responses in the visual corticalareas, and the decoding performance was compared across the combinations of DNN layers and visualareas. We found that low-/high-layer DNN feature values were predicted better from the brain activity
patterns in low-/high-level visual areas, respectively, replicating the hierarchical homology static image
features found in our previous work. Decoded feature patterns were useful to identify seen movies.
These results suggest that diverse motion-related features could be represented in the hierarchical visual cortical areas.
Grant: none
Keywords: Brain decoding, Image motion, deep neural network

P1-41
Visual confidence on global motion depends on local motion ambiguity and type of motion noiseAngela M.W. Lam, Alan L.F. Lee
Department of Applied Psychology, Lingnan University

Perceptual confidence has been found to correlate with task performance in general, and is believed to
be independent of stimulus features. However, certain stimulus feature could induce a subjective senseof uncertainty, which could potentially influence confidence judgments beyond task performance. The— 35 —

present studies aimed at assessing the effects of the ambiguity of local motion signals on perceptual
confidence on a global-motion task. Participants first discriminated the global motion directions of two
multiple-aperture, global-motion patterns, one generated using multiple Gabor elements and the otherusing multiple Plaid elements. They then performed a two-interval, forced-choice confidence task bychoosing which of the two perceptual responses they were more confident in being correct. In Experiment 1, when perceptual performance was controlled by varying coherence, we found that participantschose plaids more often than Gabors, even with perceptual performance matched between the twopatterns. In Experiment 2, when perceptual performance was controlled by varying luminance contrast
of noisy pixels in every motion frame, such “plaid preference” in confidence bias was significantly
weakened. Our results show that, at the same level of objective task performance, subject perceptual
confidence depends on both the ambiguity of local motion signals and the type of noise.
Grant: Direct Grant from Lingnan University (DR18A7)
Keywords: Motion, Psychophysics, Motion integration, Visual confidence

P1-42
Visual confidence depends on serial task difficulty and explicit report of confidence judgments
Frankie H.F. Law, Alan L.F. Lee
Department of Applied Psychology, Lingnan University

In a series of hundreds of trials, confidence on a visual task demonstrates serial dependence. However,it remains unclear what serial factors give rise to such serial dependence. In the present study, we addressed this question by building a series of motion-discrimination tasks based on trial sequences withmanipulated properties. In every trial, participants performed a left-right, direction-discrimination task
on a random-dot motion pattern, and simultaneously indicated their confidence on a four-point scale.
We first calibrated task difficult to individual participants’ discrimination sensitivity. Then, we manipulated serial task difficulty by controlling motion coherence, so that a trial with medium difficulty level
was preceded by either easy trials or hard trials. In Experiment 1, we found that confidence rating forthe medium-difficulty trial was higher when it was preceded by easy trials than when preceded by difficult trials, although direction-discrimination accuracy remained constant. In Experiment 2, such serial
dependence on task difficulty was found to weaken significantly when participants were instructed tojudge motion speed instead of to give confidence judgment in the preceding trial. Our findings suggestthat both task difficulty and explicit report of confidence in preceding trials contribute to the serial dependence of judgments on visual confidence.
Grant: Direct Grant from Lingnan University (DR18A7)
Keywords: psychophysics, serial dependence, motion, visual confidence

P1-43
The effect of the relative depth positions of disparity-defined objects for apparent motion perception and object tracking
Hidetoshi Kanaya1, Marie Morita2, Takao Sato1
1College of Comprehensive Psychology, Ritsumeikan University, 2Department of Psychology, Graduate School of Letters, Ritsumeikan University

We examined the effect of depth positions of the stimulus for both perception of apparent motion andobject tracking. The stimulus was disparity-defined rectangular objects that were generated within adynamic random-dot stereogram. In Experiment 1, perception rates were measured for two-frame apparent motion. The two rectangular stimuli were located either near or far relative to the fixation plane,
and were successively presented with an ISI varied between 0 and 533.3 ms. The disparity was plus orminus 12.24 min. It was found that motion perception rates were lower for far object than for near objects when ISIs were less than 100 ms. In Experiment 2, object tracking scores in multiple object tracking task were measured when the tracked objects were located either near or far. ISI was fixed at 0 ms.
It was found that the tracking scores were significantly lower for far objects than for near objects. In
sum, the performance was worse with far objects for both motion perception and object tracking. These— 36 —

results indicate both motion and tracking were mediated by mechanisms that distinguish depth, andsuggest that mechanisms underlying the two tasks are not the regular second-order motion mechanism.
Grant: none
Keywords: motion, binocular vision, psychophysics, tracking

P1-44
Perceived spatial alignment of moving objects varies with properties of abrupt events
Junji Yanagi, Makoto Ichikawa
Chiba University

When two moving objects reverse their directions abruptly and asynchronously, the perceptual alignment of their reversal locations is systematically affected according to the temporal relationship between two events. For instance, the second reversal tended to be perceived to overshoot against the firstreversal (Fechner Day 2017). In this study, we investigated whether this effect of the temporal asynchrony on the spatial alignment perception was specific to the motion reversal. Instead of the two motion reversals, we used motion offset (termination) and onset (initiation) as the two events to be judged
their spatial alignment. Using the method of constant stimuli, we measured the spatial shift of the two
events to be perceived as spatially aligned under various conditions of their temporal relationships. The
results did not coincide with that of the motion reversals. The termination location tended to be perceived to undershoot against the initiation when the termination occurred after the initiation. Furthermore, there were large individual differences. These tendencies were quite contrasting with those found
for the motion reversals. These results suggest that the perceptual process of the motion reversals should
be different from that of other types of motion events. We will discuss the underlying mechanisms ofthese phenomena.
Grant: none
Keywords: psychophysics, motion, spatial alignment

P1-45
The relationship between eye-dominance for motion perception and postural control
Toshiki Fukui1, Miyuki G. Kamachi2
1Graduate School of Engineering, Kogakuin University, 2Faculty of Informatics, Kogakuin University

Humans in the standing position utilize visual information related to body sway to maintain a stableposture. Previous studies have shown that visual stimuli caused forward or backward slanting, thus resulting in body sway. In this study, we investigated whether body sway deviation could be attributed tothe difference in a person’s eye dominance when perceiving motion directions and/or velocities. We
conducted experiments to investigate how the participant’s body sway changed when vection occurredby viewing a visual motion stimulus. Visual movement velocities of 0.25, 1.0, and 4.0 deg/s were utilized as velocity parameters. Visual motion stimuli were monocularly presented independently on amonitor. Real-time data at 50 Hz was recorded for gravity centers with each participant in the standing
position during stimulus presentation. The results showed that the body sway deviation was greater
when a motion stimulus was presented to the non-dominant eye than to the dominant eye. Moreover, thesway occurred even when the velocity of the motion stimulus was almost undetectable (0.25 deg/s).
More sensitive body sways were generated by visual processing of information presented to thenon-dominant eye, suggesting that our visual system may obtain environmental information from thenon-dominant eye.
Grant: none
Keywords: motion perception, eye dominance, body sway, peripheral vision— 37 —

P1-46Visual and Tactile Perception of the Wind in the Virtual Reality environment
Yuya Nishimaki1, Naokazu Goda2, Miyuki G. Kamachi3
1Graduate School of Engineering, Kogakuin University, 2National Institute for Physiological Sciences, 3Faculty of Informatics, Kogakuin University

We can get a realistic sensation by integrating visual and tactile information in the virtual reality (VR)environment. Since many VR devices are attached to our body directly, if their synchronization is temporally imbalanced, users’ realistic sensations are going to be low. On the other hand, environmental
winds around users can be presented without any direct devices. The integration process of visual andtactile perceptions for wind is unknown. We conducted experiments to explore the integration intensity
under the combination of the two senses. We compared perceived intensity of wind under the conditionsof visual only, tactile only, and a combination of visual and tactile senses, using the HMD and/or winddisplays. We focused on intensities and directions of wind in visual (a flapping flag) and tactile (windfrom fans) information as experimental parameters. In experiments 1 and 2, the sensitivity of each modality was measured. Results showed that humans can accurately discriminate the intensity of wind, if
the information is presented independently. In experiments 3 and 4, we measured whether human sensitivity is affected according to the difference of matched and mismatched directions between visual
and wind stimulations. Results showed that visual presentation influences intensity of wind perception.
Grant: none
Keywords: virtual reality, realistic sensation, multi-sensory integration, wind perception

P1-47
Relationship between Occurrence of 2D- and 3D- Footsteps Illusion and “The Law of Inertia”
Hypothesis-based Bidirectional Reinforcement Learning in Human Perception
Naoya Torisato, Hiromaru Nakagawa, Yoshitaka Fukaya, Shoko Hira, Sakuichi Ohtsuka
Kagoshima University

Visual illusions offer good cues for elucidating how perception normally works and why it sometimes
fails. In this study, we examined the footsteps illusion (FI) in occluded- and non-occluded-conditions in
2D and 3D environments. A 24 inch stereo LCD (BENQ ZL2420T) was employed. Ten observers, who
had adequate dynamic stereoscopic acuity, participated in the experiments. First, all results showed that
FI onset delay in all non-occluded-conditions was long enough that the observers were assured of being
able to discriminate low-contrast contours clearly. Taking into account that the delay was longer in 3Dthan in 2D- non-occluded-conditions for the complete camouflage condition (Kumasaki 2015), it issuggested that the observers adopted “the law of inertia” hypothesis with highest priority if they wereable to perceive full contours of the target, real or subjective, at a distance offset from the referenced
plane. Next, the variation in onset delay between in 2D- and 3D- occluded-conditions strongly depended on observer history. In conclusion, it is suggested that (1) object contours are essential for perceiving
FI, and (2) the illusion is not the simple consequence of edge contrast deterioration but is triggered by
top-down reinforcement learning, both positively and negatively, as developed by attention experience.
Grant: none
Keywords: visual illusion, perception, psychophysics, motion

P1-48
Motion aftereffects with different adaptation duration investigating color- and luminance-motion
processes
Wakana Koshizaka2, Weijing Ren2, Ichiro Kuriki1,2, Yasuhiro Hatori1,2, Chiahuei Tseng1,2, Satoshi Shioiri1,2
1Research Institute of Electrical Communication, Tohoku University, 2Graduate School of Information Sciences, Tohoku University

While separate pathways for processing color and luminance signals have been identified physiologically, perceptual interactions between luminance- and color-defined motion (LM and CM) were report— 38 —

ed in several behavioral studies. How are the functional interactions of LM and CM signal take place inthe cortical loci of visual information processing? To address this question, we investigated motion aftereffects (MAEs) by using functional magnetic resonance imaging (fMRI) technique. After presenting
CM for 21s as adapting stimulus, we found evoked responses to the adapted direction larger than thatto opposite direction, which is peculiar in MAE experiments and inconsistent with MAEs that we perceptually confirmed in the same condition. When adaptation period was 3s, following a previous study
that showed normal MAEs for LM stimuli, we found normal MAE which is consistent with perceptualones. These results suggest that the interaction between CM- and LM-processing mechanisms strongly
depends on the duration of pre-adaptation. It might be the case that the interaction takes place at multiple loci, and some of them are irrelevant with perception.
Grant: none
Keywords: motion aftereffect, fMRI, color, luminance

P1-49
The perception of motion direction for deformation-defined flow
Takahiro Kawabe
NTT Communication Science Laboratories

In natural scenes, a transparent water flow deforms image information of its background scene andconsequently produces deformation-defined flow. It is still unclear how human observers perceive deformation-defined flows. The purpose of this study was to check whether the human visual system
discriminated the motion direction of the deformation-defined flow. To generate a deformation-defined
flow, a natural scene image was deformed by means of deformation maps to which one of three spatial
frequencies and a fixed translation speed were given. The task of observers was to judge whether the
deformation-defined flow translated leftward or rightward. As a result, the observers reported the correct motion direction of the deformation flow when the spatial frequency of image deformation was
relatively high. On the other hand, the observers robustly reported incorrect (that is, reverse) motion
direction when the spatial frequency was relatively low. A deformation-defined flow possibly contains
deformation-specific image features that contribute to motion direction discrimination. Otherwise, human observers possibly judge motion direction on the basis of the dominant first-order motion signals.
Grant: none
Keywords: Motion perception, Deformation perception, Material perception

P1-50
Influence of uniform body rotation on perceived speed of visual moving objects
Ryosuke Fukasaku, Rumi Hisakata, Hirohiko Kaneko
Department of Information and Communications Engineering Course Tokyo Institute of Technology

When we observe moving objects, we can perceive the actual velocity while we are moving, indicatingthat our visual system estimates it with taking the body movements into account. Hogendoorn et al.
(2017) showed that visually perceived velocity changed depending on the direction of acceleration
when the observer’s body rotated. However, it’s not clear whether the effect is due to the acceleration
signals from the vestibular/somatosensory systems or other factors. Here, we examined the motion
perception under the situation where there was no acceleration on the body along the direction of visual motion. Two circular objects moving to the left and right were simultaneously presented as visual
stimulus and the observer judged which object moved faster. The observer’s body was rotated about thevertical axis with a constant angular velocity using a rotating platform. Results showed that they perceived the object moving in the same direction as the body faster under the condition of no acceleration
along the direction of motion. This result suggested that the effect of body motion on the velocity perception is not due to the acceleration signals from vestibular/somatosensory systems and probably due
to the mechanism to calculate the velocity on the spatial coordinates.
Grant: none

— 39 —

Keywords: motion, multi sensory perception

P1-51
Motion detection sensitivity in the same direction as motion parallax decreases depending on thebinocular disparity and head movement
Rumi Hisakata, Hirohiko Kaneko
Tokyo Institute of Technology, School of Engineering

A static target appears to move in synchrony with head movement depending on the apparent distances(e.g., Tietz & Gogel, 1978). The direction of the concomitant motion is the opposite (same) to that ofself-movement when observed at far (near) distance (e.g., Ono & Ujike, 2005). Based on the phenomenon, we presumed that visual motion sensitivity to horizontal directions would change depending on
the distance from observers during head movement. The visual stimulus was a vertical Gabor patch with
2D noise. A moving chin rest guided subjects’ head movement. Both the Gabor and fixation point weremoving in synchrony with the head movement, resulting in that the visual stimulus was almost static on
the retina and there was no pursuit eye movement. We added binocular disparity to both the Gabor and
2D noise to define their depth relative to the display. Subjects answered which stimulus contained motion, former or later, with 2IFC. The result showed that the velocity of detection thresholds in the opposite direction from the head movement was greater on the near depth plane than the far depth plane. We
will discuss about the possibility that visual system suppresses the motion signal concomitant with
self-movement presented on the depth plane consistent with the motion parallax cue.
Grant: none
Keywords: motion, psychophysics, head movement, binocular disparity

P1-52
The role of internal state in monocular deprivation-induced ocular dominance plasticity
Zhifen He1, Yiya Chen1, Peng Zhang2, Robert F. Hess3, Jiawei Zhou1
1School of Ophthalmology and Optometry and Eye hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou

Medical University, 2Institute of Biophysics, Chinese Academy of Sciences, 3McGill Vision Research, Dept. Ophthalmology, McGill University

It is well known that there are characteristic differences in internal state when eyes are open versus eyes
closed in the dark. It is however not clear, how the alternation in the internal state affects stimulus induced plasticity. In this study, we directly addressthis question by comparing the monocular deprivation-induced ocular dominance plasticity under conditions were the patched eye is either open or closed
under the patch. Previous studies have shown that 2.5-hour of monocular deprivationtemporarily
strengthens the previously patched eye’s contribution to binocular perception. Here, we show that thisform ofvisual plasticity is enhancedif the patched eye behind theoccluder is kept open, eventhough thevisual input is unchanged. We document these enhancements using both binocular combination andbinocular rivalry end point measures. This effect could not be accounted for in terms of the change inthe spontaneous alpha power in the eyes open/eyes close condition and may involve a separate change
in internal state at a binocular site.
Grant: This work was supported by the NSFC 81500754 to JZ, the ERA-NET Neuron grant (JTC2015) to RFH, and the Wenzhou Public Welfare
Science and Technology Project (Y20170765) to ZH
Keywords: visual plasticy, ocular dominance, psychophysics

P1-53
Smallest detectable depth difference on multiview autostereoscopic displays
Vincent Nourrit1, Di Zhang2, Peng Wang3, Xinzhu Sang3, Jean-Louis de Bougrenet de la Tocnaye1
1IMT Atlantique, 2Communication university of China, 3Beijing University of Posts and Telecommunications

Autostereoscopic technology can provide an immersive viewing experience compared with 2D technology. Studies have shown that the number of views could impact the viewing experience but little infor— 40 —

mation is available on the relation between the number of views and depth perception. In this study, wemeasured, in 14 healthy subjects (23.8±2.5 years old), the smallest detectable depth difference (SDDD)
in normal viewing conditions on a multiple view autostereoscopic 3D display to assess the influence ofthe number of views on the measurement, as well as the nature of the stereogram stimulus (contour or
randots). According to our results, the number of views and the stimuli has a significant impact on
SDDD. When clinical measurements are conducted on such displays, 7 views is the minimum numberof views required to ensure that the ability to perceive small disparities (30″) is tested effectively. Also,
the use of random dots stereogram can lead to significantly better performances when compared tocontour stereograms when the number of views is small (＜7). For this reason, random dots stereograms
should be chosen over contour stereograms when the view number is small, such as 2 views or 4 views.
Grant: none
Keywords: 3D Displays

P1-54
Distance and Orientation Effects on Perceived Slant of Physical and Artificial Stimuli
Fletcher John Hammond1, Andrew Hill2, Mark Horswill1, Philip Grove1
1University of Queensland, 2Clinical Skills Development Service, Royal Brisbane & Women’s Hospital

We investigated the differences in distance and orientation effects for physical and artificial stimuli.
Previous studies have shown that changes in viewing distance and orientation lead to depth distortions
for artificial 3D stimuli that do not occur for physical stimuli. This is because changes in distance andorientation lead to changes in the left and right eyes’ images of a real object that are different fromchanges in the images from an artificial 3D image (e.g., anaglyph). We investigated how the perceived
slant of an anaglyph 3D stimulus scales with viewing distance and orientation in comparison to analogous physical stimuli. Participants viewed physical and artificial stimuli depicting two vertically abutting surfaces slanted relative to one another. Participants manually estimated the slant between the two
surfaces with an unseen probe. We found that an increase in viewing distance led to a significant increase in perceived slant. We found no effect of orientation, with all viewing angles yielding similarreports of slant. Finally, there were no effects of viewing distance or orientation for the analogous
physical stimuli. Constancy breaks down for artificial stimuli with changes in viewing distance but notorientation. Constancy holds for physical stimuli under similar viewing conditions.
Grant: University of Queensland Postgraduate Scholarship
Keywords: Stereoscopic Vision, Constancy

P1-55
The disparity tuning symmetry explains the degree of solving the correspondence problem in
macaque visual areas MT and V4
Toshihide W Yoshioka1,2, Takahiro Doi3, Mohammad Abdolrahmani4, Ichiro Fujita1,2
1Grad Sch Front Biosci, Osaka Univ, 2CiNet, Osaka Univ and NICT, 3Dept Psychol Univ of Pennsylvania, 4Lab for Neural Circuits and Behavior,

RIKEN Brain Sci InstTo use binocular disparity as a depth cue, the visual system should find the corresponding visual features between the two eyes that originate from the same surface point in the 3D space. This correspondence problem is not solved at the first binocular stage in the primary visual cortex (V1). Here we examined the degree of solving the correspondence problem in areas MT and V4 of the monkeys byanalyzing neural responses to graded anti-correlation of binocular visual stimuli. The responses of V4
neurons were more consistent with the solution to the correspondence problem than those of MT neurons. In each area, neurons with even-symmetric tuning curves tended to show a higher degree of correspondence computation than neurons with odd-symmetric ones. We further found that MT neurons
exhibited a variety of disparity tunings ranging from odd-symmetric to even-symmetric and that mostV4 neurons were even-symmetric. The latter two findings, together with an assumption of output nonlinearity following the initial disparity computation in V1, explain the difference in the degree of solv— 41 —

ing the correspondence problem. Thus, the mid-tier stages of the dorsal and ventral pathways, MT and
V4, implement a common mechanism (i.e., disparity tuning shape) for distinct representations of stereoscopic depth.
Grant: KAKENHI JP (23240047,15H01437, 17H01381)
Keywords: binocular stereopsis, neurophysiology, MT, V4

P1-56
Discrimination of 3D spaces generated by binocular disparity and pictorial cues
Satoko Ohtsuka
Saitama Institute of Technology

It is plausible that perceptual 3D space generated from different depth cues, i.e., binocular disparity andpictorial cues, have different nature. This research was designed to seek to evidence suggesting thedifference in characteristics of resultant 3D spaces between binocular and pictorial cues. Here we employed a modified compatibility technique. A target in the first experiment was painted in red or green,
and was displayed in front of or behind the fixation plane with binocular or composite pictorial cues.
Participants responded the target’s color by keys which were arranged in the depth direction. While
results in the disparity condition showed a significant compatibility effect, they were not in the pictorial cues condition. The targets in the second experiment was manipulated to be in depth positions withthe cues as in the previous experiment, further their depth position was indicated by 3D arrows. The
participants responded the target’s position. The result showed an effect of the arrows on the participants’ response. A manipulation of temporal property of depth information presentation, to separate thatwas indicated by the cues and arrows, revealed distinct compatibility curves among the cues. Thesesuggests the action-oriented nature for disparity while is not for the pictorial cues.
Grant: none
Keywords: depth, psychophysics

P1-57
Common cortical representation of convex–concave shapes from different depth cues
Zhen Li1, Hiroaki Shigemasu2
1Graduate School of Engineering, Kochi University of Technology, 2School of Information, Kochi University of Technology

We investigated whether common representation of convex–concave shapes from different depth cues
(binocular disparity or perspective) were involved in ROIs by assessing shape classification accuracy
using multi-voxel pattern analysis. ROIs included retinotopic areas and higher visual areas. Shapes
which consisted of two slanted planes were depicted by three types of stimuli separately (random dot
stereogram; black–white dotted lines with disparity; black-white dotted lines with perspective). Two
different disparity stimuli types were used to examine whether shapes from disparity using different
elements share common representation. We evaluated the accuracy of transfer classification between
combinations of stimuli. Results showed that accuracy was significantly higher than chance level for all
types of classification in dorsal intraparietal sulcus (DIPS). To further investigate whether the high accuracy was based on global shape information or the orientation information of the slanted planes, threesimilar types of stimuli were used to depict slanted planes in two different orientations on which transfer classification to distinguish orientation was performed. Results showed classification accuracy wasaround chance level. In summary, DIPS may be involved in global shape representation from different
cues and this is not based on the orientation of slanted plane itself.
Grant: none
Keywords: Shape perception, 3D VISION, MVPA, fMRI

— 42 —

P1-58Generalized Representation of 3D Object Orientation in Human Visual Cortex
Thanaphop Threethipthikoon1, Zhen Li1, Hiroaki Shigemasu2
1Graduate School of Engineering, Kochi University of Technology, 2School of Information, Kochi University of Technology

The representation of three-dimensional (3D) orientation is a fundamental feature of human vision
which has been broadly studied in recent years. The cortical representation of stereoscopic 3D surface
was investigated in our previous study, and the result showed that some regions of interest (ROI) in
intraparietal sulcus (IPS) had a tendency for 3D shape orientation classification. Since it is well known
that IPS area is involved in vision for action such as visually-guided pointing, grasping, and object
manipulation, we adopted different stimuli that were expected to produce a better classification. We
used 3D objects related to action for orientation classification with two different types of orientation, (1)slant-tilt 3D orientations and (2) 2D rotations, while the blood oxygen level-dependent signal was recorded from visual cortices. Multivariate pattern analysis classification was utilized to find relation
between object orientation and ROIs in visual cortices. The results showed that some areas in IPS haveconsistency of prediction accuracy for 3D orientation while other ROIs showed high prediction in 2D
orientation but had low accuracy in 3D orientation. These results suggested that IPS area is likely torepresent 3D object orientation in human cortices.
Grant: none
Keywords: object orientation, 3D orientation representation, MVPA, fMRI

P1-59
Can changing brightness with head movement deliver depth perception like as motion parallax?
Masataka Kurokawa, Masahiro Furukawa, Taro Maeda
Osaka University

It is widely known that motion parallax delivers quite strong depth perception. Our question is whether
the gradually and brightness change provide motion parallax cues. The display was placed in a darkroom and subjects observed the light spots while actively moving their heads. The distance between twolight spots was reduced and measured the threshold for depth perception. Two methods were compared
as a method of presenting images. The first was a conventional method of causing two light spots tofollow the movement of their head. In the second method, one light spot followed their head movement
as in the conventional method. Another light spot was presented by extracting two points on the trajectory along which the light spot moves, and using the two points alone to gradually change the brightnessof each other based on their head position.
Grant: This research was supported by collaborative with research Komatsu MIRAI Construction Equipment Cooperative Research Center.
Keywords: depth perception, motion parallax, head movement

P1-60
How does body analogy help mental rotation? Disentangling bottom-up and top-down processes
Hiroyuki Muto1,2
1Research Organization of Open Innovation and Collaboration, Ritsumeikan University, 2Japan Society for the Promotion of Science

Object-based mental rotation can be easily performed when a to-be-rotated object is likened to a humanbody. Such body analogy is known to be effective when human bodies are used as stimuli instead of
abstract objects and when a to-be-rotated abstract object is merely regarded as a human body, as bottom-up and top-down processes, respectively. The present study aims to evaluate the bottom-up andtop-down contributions of body analogy to mental rotation in a same-different judgment task. Forty-four participants performed mental rotation of human-like objects (human-shaped cubes with a pattern like a human head) and abstract objects (human-shaped cubes with a nonsense pattern) in counterbalanced order. We assumed that those who completed the human-like condition first would takeadvantage of body analogy in a top-down manner for the subsequent abstract objects while those who— 43 —

completed the abstract condition first would not. Results showed faster mental rotation in the human-like condition, suggesting that the bottom-up process was beneficial. However, the condition order
did not affect mental rotation speed, suggesting that the top-down process made a negligible contribution. These findings indicate that body analogy helps mental rotation via the bottom-up rather than topdown process at least during a same-different judgment task.
Grant: none
Keywords: spatial cognition, mental rotation, embodied cognition

P1-61
Object-motion and self-motion differently affect peripersonal space representation
Naoki Kuroda, Wataru Teramoto
Department of Psychology, Graduate School of Social and Cultural Sciences, Kumamoto University

Peripersonal space (PPS) is the space around the body parts. The present study investigates how object-motion and self-motion affects the range of PPS, using visuotactile interaction. Visual stimuli were
presented through a head-mounted display to the participants in the study. These participants were thenrequired to detect vibrotactile stimuli delivered to their chest as quickly as possible while watching anapproaching object (Experiment 1) or while approaching a static object by a visually-induced self-motion (Experiment 2). The object was presented at various distances from the participant’s body (120,240, 360, 480, and 600 cm). In the baseline condition, a tactile stimulus was delivered without the approaching object. PPS was defined as the range at which tactile detection was facilitated by the approaching visual object. Two approaching speeds was compared: 1.5 m/s and 6.0 m/s. The results
showed that the PPS was larger for the faster speed condition when static participants watched the approaching object. This is consistent with a previous single-unit recording in monkeys. In contrast, whenparticipants approached the static object by self-motion, the PPS expanded more than the distancetested in the present study, irrespective of the speed. These results suggest that the mechanisms underlying the PPS expansion were different for object-motion and self-motion.
Grant: This work was supported by JSPS KAKENHI Grant (17K00263)
Keywords: multisensory integration, self-motion, peripersonal space, psychophysics

P1-62
Relationship between vection and head displacement in sitting and standing postures
Kanon Fujimoto, Hiroshi Ashida
Graduate School of Letters, Kyoto University

Visual optic flow that simulates self-motion often causes standing observers to adjust their postures aswell as to perceive self-motion illusion (i.e., vection). Previous research has suggested common neuralmechanisms underlying visually induced postural response and vection. Although body postures suchas standing or sitting could affect both postural responses and vection, the relationship between these
responses has not been sufficiently studied in non-standing postures. In this study, we presented radialor lateral optic flows through an Oculus Rift CV1 head-mounted display and tracked head displacementin sitting and standing postures. Vection was also measured concurrently. For radial optic flow, wefound head displacement bias in the opposed direction as stimulus motion in the sitting condition, while
we found a tendency of head displacement bias in the same direction as stimulus motion in the standing
condition. Similar but less clear tendency was found for lateral optic flow. Vection measures were notsignificantly different across conditions. Our results showed that postural responses to optic flow aremodulated by the body postures, whereas vection is not substantially changed, suggesting partially
distinct neural mechanisms underlying postural control and vection.
Grant: JSPS
Keywords: vection, posture, sitting, optic flow

— 44 —

P1-63
Influence of pre- and post-saccadic contrast on displacement detection across saccades
Shuhei Takano1,2, Kazumichi Matsumiya2, Chia-huei Tseng1,2, Ichiro Kuriki1,2, Heiner Deubel3, Satoshi
Shioiri1,2
1Research Institute of Electrical Communication, Tohoku University, 2Graduate School of Information Sciences, Tohoku University, 3Department

Psychology, Ludwig-Maximilians-Universität München

The visual system is less sensitive to displacement of visual stimuli during saccadic eye movements
than that during fixation (saccadic suppression of displacement or SSD). SSD may have an importantrole to realize perceptually stable world with drastic retinal changes due to saccade. We measured theeffect of stimulus contrast to investigate how pre- and post-saccadic stimulus influence displacement
detection respectively and compared accuracy of saccade for ten individuals. Experimental results
showed that increase of post-saccadic stimulus contrast decrease the detection rate, which suggests that
SSD is an active suppression after saccade. We analyzed the correlation between the strength of suppression during saccade and saccadic accuracy, and found that the person with larger saccadic errors
had stronger suppression of displacement. This may show that the active suppression during saccade
have an important role for stabilizing perceived world under the condition with large retinal changes
due to saccade.
Grant: none
Keywords: eye movement, saccade, visual stability, psychophysics

P1-64
Measuring cognitive impairment using a test of visual scene comprehension
Stephanie Reeves1, Victoria L Williams3, Deborah Blacker2,4, Russell L Woods1,5
1Schepens Eye Research Institute, 2Gerontology Research Unit, Mass General Hospital, 3Department of Neurology, Harvard Medical School,
4Department of Psychiatry, Harvard Medical School, 5Department of Ophthalmology, Harvard Medical School

The process of interpreting and acting upon the visual environment requires functioning cognitive andvisual systems. The Information Acquisition (IA) method is an objective measure of the ability to perceive and understand a visual scene, using verbal descriptions in response to an open-ended question.
Previously, we showed that subjects with central vision loss and hemianopia have reduced IA scores.
Since the task requires functional working memory and linguistic fluency, we asked if IA could be applied to cognitively impaired populations. We recruited 56 participants across the spectrum from normal cognition to mild dementia (mean age 81, 66 to 99 years) at Massachusetts General Hospital,
Boston, Massachusetts. Subjects watched twenty 30-second video clips and described the visual content without time constraints. Each response was compared to a control group of responses using a“wisdom of the crowd” natural-language approach that generated a score for each response. Linear
mixed models accounted for random effects of education, gender, and age. IA decreased with increasinglevels of cognitive impairment with a dose response effect. This suggests that this test might be appliedin cognitive as well as visually impaired populations for longitudinal monitoring. Additional analyses
show relationships between specific cognitive domains and IA performance.
Grant: none
Keywords: visual perception, cognition, impaired populations

P1-65
Effective visual space for a simplified first-person shooter game in a VR environment measured
by visual masking method
Daiki Matsushita1, Yasuhiro Seya2, Hiroyuki Shinoda1
1Ritsumeikan University, 2Aichi Shukutoku University

Virtual reality (VR) headset provides a wearer a visual display of an entire field of view. However, thespatial extent of the visual field in which observers can utilize visual information is generally limited,— 45 —

and such a visual field associated with particular visual tasks is called an effective visual space (EVS).
The present study examined EVS for a simplified first-person shooter game presented in a VR environment. The peripheral visual field was restricted by masks of various sizes, while participants played thegame in which normal (Experiment 1) and horizontally inverted images (Experiment 2) were presented.
The EVS was defined as the smallest size of the restricted field of view where a game score (i.e., numberof hits) reached a plateau at the same level as that measured without visual masking. Experiment 1
showed that the game score increased with increasing the size of observable area of visual masking. The
score reached a plateau at 80 degrees. Similar results were found in Experiment 2, even though the task
was more demanding than in Experiment 1. From both experiments the EVS was estimated to be about
80 degrees in diameter.
Grant: none
Keywords: Effective visual space, VR, visual masking method

P1-66
Human Factors in Navigating within Train Stations
Zac Je Sern Yeap, Nidhi Deepu Rajan, Hong Xu
Nanyang Technological University

Successful and efficient navigation is often influenced by the design of the environment, including signage, lighting, or distinctive color schemes. In this study, we investigated the human factors influencing
wayfinding in train stations in Singapore. Using focus groups discussions, a field survey, and a lab experiment using psychophysical methods, we investigated how brightness and color temperature affects
people’s perception and judgment of wayfinding in the stations. We found that subjects preferred thestation lights to be dimmer at night, contrary to current literature on lighting conditions in stations.
Warmer light temperatures were preferred in small enclosed spaces, whereas cooler temperatures werepreferred in large open spaces. We also found that using color schemes in stations increases identification accuracy, and training subjects to rely on color schemes rather than signage results in faster reaction
times to identify the stations. Thus, our findings suggest that lighting temperature and color are important human factors in efficient wayfinding. While these findings would be useful in architectural design,
it provides insights for using virtual reality to investigate such questions. Replicating our behavioral
results in virtual reality would open up avenues for behavioral experiments without the constraints of aphysical environment.
Grant: Nanyang Technological University
Keywords: Visuospatial navigation, Visual identification, Psychophysics, Virtual Reality

P1-67
Cyber Sickness was Affected by Apparent Gravity of Virtual Environment at Side-lying Position
Yue Song1, Toshiya Tsuchihasi1, Jyumpei Matsumura2, Masaki Ogawa1, Atsuo Kawai1, Naoki Isu1
1Department of Information Engineering,Graduate school of Engineering, Mie University, 2Department of Information Engineering, Faculty ofEngineering, Mie University

In sensory conflict theory, conflict of visual and vestibular inputs is a cause of cyber sickness. One example is “vection”, which is visually induced self-motion perception. In present virtual reality technology, we often experience this phenomenon and sometimes experience cyber sickness. In the previous
study, we found that a sensation of attitude change relative to the gravity (SACRG) has important effects on cyber sickness. In this study, we investigate what effect gravity (true gravity, subjective gravity,
etc...) has on cyber sickness. There were two conditions about the virtual environment (VE): axes andbody axes (same with real environment, 90 degree side-lying from real environment). Three types ofcombination of them (VE and body axes were same with real environment, body axes were rotated, andboth VE and body axes were rotated) were examined. Additionally, there were 2 conditions of virtualenvironment’s motion from participant (yaw, pitch), so totally 6 conditions in this experiment. Threesubjective evaluations (discomfortness, vection strength, SACRG strength) were measured. Results— 46 —

showed that subjective values were increased with a sensation of attitude change relative to the “virtualenvironment’s” gravity. It should be confirmed by experiment that employs another virtual environmentthat has no apparent gravity.
Grant: This work was supported by JSPS KAKENHI Grant Number 18K11395
Keywords: cyber sickness, vection, side-lying position, sensation of attitude change relative to the gravity

P1-68
Covariance Structure Modeling of Biosignal for Detection of Cyber Sickness
Takumi Nara1, Tomoya Kai1, Yuichiro Suzuki2, Masaki Ogawa1, Atsuo Kawai1, Naoki Isu1
1Department of Information Engineering, Graduate School of Engineering, Faculty of Engineering, Mie University., 2Department of Information

Engineering, Mie University

Recently, virtual reality technology is increasing and becoming pervasive to our daily life. However, thepresent virtual reality technology come with the problem of causing cyber sickness. There is need for amethod for quantitatively expressing the discomfort of cyber sickness, but it was difficult and we needmore time to study for it. Thus, as a first step, we aimed at detecting the onset of cyber sickness. In thisresearch, we tried to make a covariance structure model of biosignals. Twelve biosignals and threesubjective evaluations were measured. Participants operated a driving-simulator in seven types of scene
and made responses every two minutes about subjective discomfort, arousal levels, and stress levels.
Covariance structure analysis was conducted to measured biosignals and subjective evaluations. In theanalysis, three common factors corresponding to discomfort, arousal levels, and stress levels were employed. Results were estimated by three indices (goodness of fit index.983, normed fit index.895, androot mean square error approximation.032), and we concluded this model is good but still improvable.
Especially, we identified scope for improvement by clustering of individual differences. In fact, there
was a better model than the result model when we consider about a personal model.
Grant: This work was supported by JSPS KAKENHI Grant Number 18K11395
Keywords: Cyber sickness, Biosignal, Covariance structure analysis

P1-69
Research on Onboard Movie Showing Methods to Suppress Seasickness
Akihiro Emoto1, Ryota Ishikawa2, Hikaru Hasegawa1, Masaki Ogawa1,2, Atsuo Kawai1,2, Naoki Isu1,2
1Department

of Information Engineering, Mie University., 2Department of Information Engineering, Graduate School of Engineering, Mie

University

In order to suppress sensory inconsistencies that are the cause of motion sickness, we have created amethod to suppress seasickness by watching a movie displaying an image that makes the visually perception of own motion together with the movie. A virtual environment (VE) that reproduces a landscapethat allows subjects to perceive the horizontal and vertical were displayed / projected with a movie.
Because the VE was counter-moving to the ship’s motion (rolling, pitching, and yawing), horizontal
and vertical axes of the VE were perceived as static, like a distant view. Our previous report, this method were succeed to suppressed discomfortness to about 70% of that of the control (non VE) condition.
In this study, effect of scale factor of VE’s motion was investigated in two experimental environments(actual ship and onboard theatre simulator). Our purpose was that make clear the best scale factor ofcounter-motion of the VE to ship motion. Results for both experimental environments showed tendency
that the best scale factor is at about 50% of ship motion. However, these results were not supported bystatistical indices (Dunnett test: alpha level is .05). The reasons of these results were discussed.
Grant: This work was supported by JSPS KAKENHI Grant Number 18K11395
Keywords: Seasickness, Onboard Movie, Virtual Reality— 47 —

P1-70Contributions of 3D Circular Images to Incidence of Visually Induced Motion Sickness
Toshiya Tsuchihashi2, Kenta Taniyama2, Kyohei Koike1, Naoki Isu2, Masaki Ogawa2, Atsuo Kawai2
1Department of Infomation Engineering, Mie Univercity, 2Department of Infomation Engineering, Graduate School of Engineering, Mie Univercity

A factor of great importance in Visually Induced Motion Sickness (VIMS) during 3D viewing is thevisually induced self-motion sensation called vection. When the vection is felt, there is a mismatch
between vestibular and visual sensation. On the sensory conflict theory, this mismatch generates VIMS.
On the other hand, our previous work showed another important factor about VIMS: The sensation of
attitude change relative to the gravity (SACRG). SACRG is difficult to explain in words, but easy tofeel when playing on the bar. However, at the first report of a SACRG, there were many factors to modulate VIMS. In this study, we employed three factors: orientation of circular vection, axes of virtualenvironment, and moving speed. Participants answered to subjective evaluations discomfort, vection
strength, and SACRG strength. The result of the experiment indicates that SACRG is one of the mostimportant factors of VIMS. Results of regression analysis, specifically in the orientation of circular
vection was roll condition, SACRG was larger effects than vection. We should confirm the effects of
SACRG with more experiments to investigate the mechanisms of VIMS.
Grant: This work was supported by JSPS KAKENHI Grant Number 18K11395.
Keywords: motion sickness, virtual reality, vection

P1-71
The Role of Parahippocampal Cortex in Scene Integration
Seoyoung Lee, Olivia S Cheung
New York University Abu Dhabi

Humans perceive a coherent visual world across time and space. To update incoming sensory information while maintaining a stable representation of the environment, previous studies have suggested therole of the parahippocampal place area (PPA) in scene processing and ensemble processing. Using
functional magnetic resonance imaging, we examined how the PPA might integrate information by relying on continuous spatial-temporal sequence of information flow, or mere shared elements in a scene.
We used scene images that were divided into three segments, with 66% overlap between the first andsecond segments and 33% overlap between the first and the third segments. Participants (N=17) viewed
the three scene segments either sequentially or in a displaced order, identical segments for three times,or three completely different scenes. We found that the bilateral PPA not only showed significantly
stronger activations for different scenes than identical scenes (p’s＜.0001), but also for different scenes
than three segments of the same scenes (p’s＜.03). Moreover, the sequence order of the three segments
did not affect the response amplitude (p’s＞.56). These results suggest that although the PPA may not
be sensitive to the sequence of information flow, it appears to integrate segments with shared elements
to form a coherent representation. Event hall
Grant: none
Keywords: scene perception, neuroimaging, PPA— 48 —

Tuesday, July 30
Symposium 2-1 9 : 00 AM-11 : 00 AM Grand hall
On the border of implicit and explicit processing
Organizer:
Shao-Min (Sean) Hung
(James Boswell Postdoctoral Scholar, California Institute of Technology)
Implicit processing plays an important role in maintaining visual functions. After all, at a given moment, our phenomenal experience is inherently limited by various factors, including attention, working
memory, etc. In the current proposal, we will tackle major questions in the field and challenge intuitions
on implicit/unconscious processing. These questions include the fundamental relation between attention and consciousness, using the level of visual processing as a delineation of explicit and implicit
processing, and how implicit decision making perturbs the explicit sense of agency.
Naotsugu Tsuchiya will show recent findings on how attention tracks suppressed stimulus under binocular rivalry. Shao-Min Hung will provide evidence from unconscious language processing, substantiating high-level implicit processing. Daw-An Wu further discusses how TMS alters our attribution of
motor decision making.
These topics will be integrated by Shinsuke Shimojo, providing an overall view of the current challenges and advances in the field, including “postdiction.” Some of these challenges can be better dealt withonce we are equipped with more suitable views on implicit processing, such as a dynamic interaction
among visual items across time, utilizing both predictive and postdictive factors.
S2-1-1
Implicit processes are dynamic and interactive
Shinsuke Shimojo(Gertrude Baltimore Professor of Experimental Psychology, California Institute of Technology)
Can the implicit level of mind execute only simple sensory/cognitive functions? And is the bottleneck
to consciousness single, or multi-gated? These questions are elusive, especially considering examples
such as implicit semantic priming, and implicit stroop effect (Hung talk in this symposium). I will aim
for taxonomy and integration of related findings including my own, to have a clearer overview. First,
there are multiple definitions of implicit processing on top of “subliminal”, as exemplified in causal
misattribution in action (Wu talk), and attention vs. consciousness (Tsuchiya talk). Second, the implicit/
explicit distinction will NOT map onto the lower-/higher-levels of cognitive function (Hung talk). Rather, there are multiple gates to consciousness as indicated in the binocular rivalry debate (80s, up tonow), and also quick interplays between implicit and explicit processes. Third, the implicit process may
be dynamic spreading over time, operating predictively and postdictively. Auditory-visual “rabbit” effect would be a great example where implicit postdictive process leads to a conscious percept (Shimojotalk),. The implicit process is also based on separate dynamic sampling frequencies. Some evidence
comes from interpersonal bodily and neural synchrony (Shimojo talk), and dependence of perceptualchanges upon allocation of attention relying on different temporal frequencies (Tsuchiya talk). Thus all
together, we may need to abandon several simplistic ideas of implicit processes, and rather take a more
dynamic and interactive view.
S2-1-2
Attention periodically samples competing stimuli during binocular rivalry
Naotsugu Tsuchiya(Monash University)
The attentional sampling hypothesis suggests that attention rhythmically enhances sensory processing
when attending to a single (~8 Hz), or multiple (~4 Hz) objects. Here, we investigated whether attention— 49 —

samples sensory representations that are not part of the conscious percept during binocular rivalry.
When crossmodally cued toward a conscious image, subsequent changes in consciousness occurred at~8 Hz, consistent with the rates of undivided attentional sampling. However, when attention was cued
toward the suppressed image, changes in consciousness slowed to ~3.5 Hz, indicating the division of
attention away from the conscious visual image. In the electroencephalogram, we found that at attentional sampling frequencies, the strength of inter-trial phase-coherence over fronto-temporal and parieto-occipital regions correlated with changes in perception. When cues were not task-relevant, these effects disappeared, confirming that perceptual changes were dependent upon the allocation of attention,and that attention can flexibly sample away from a conscious image in a task-dependent manner.
S2-1-3
Language processing outside the realm of consciousness
Shao-Min (Sean) Hung1,2(1California Institute of Technology, 2Huntington Medical Research Institutes)
The concept “Out of sight, out of mind” has been repeatedly challenged by findings that show visual
information biases behavior even without reaching consciousness. However, the depth and complexityof unconscious processing remains elusive. To tackle this issue, we examined whether high-level linguistic information, including syntax and semantics, can be processed without consciousness.
Using binocular suppression, we showed that after a visible sentential context, a subsequent syntactically incongruent word broke suppression and reached consciousness earlier. Critically, when the sentential context was suppressed while participants made a lexical decision to the subsequent visible word,
faster responses to syntactically incongruent words were obtained. Further control experiments showthat (1) the effect could not be explained by simple word-word associations since the effect disappeared
when the subliminal words were flipped and (2) the effect occurred independent of accurate localizationof the subliminal text.
In another study we utilized a “double Stroop” paradigm where a suppressed colored word served as aprime while participants responded to a subsequent visible Stroop word. In the word-naming task, we
showed that word but not color inconsistency slowed down the response time to the target, suggestingthat semantic retrieval was prioritized. However, when asked to name the color, the same effect was
obtained only after a significant practice effect on the color naming (i.e. reduction of response time)occurred, suggesting a competition of attentional resources between the current conscious task andunconscious stimulus. These findings were later replicated in separate experiments.
Across multiple studies we showed that high-level linguistic information can be processed unconsciously and exert an effect. These findings push the limit of unconscious processing and further show that aninterplay between conscious and unconscious processing is crucial for such unconscious effect to occur.
S2-1-4
The feeling of volition as a retrospective observational inference.
Daw-An Wu(California Institute of Technology)
We generally assume that intentions and decisions cause our voluntary acts: We form a conscious intention to do something, and then this mental act leads to a bodily act. Neuroscientific research into thetimeline of volition faces the challenge of measuring and reconciling events along many unstably related timelines - external, neural and mental. We use motor TMS stimulation to create a reference event,allowing for single-trial temporal order judgements to be meaningful across all the timelines.
1) We use electromyography (EMG) to monitor the participant’s (e.g.) thumb. 2) TMS is targeted to
motor cortex so as to elicit an involuntary thumb movement. 3) The participant is asked to relax, and at
a time of their own choosing, to flex their thumb (a voluntary movement). When the EMG detect theinitiation of this movement, it triggers the TMS to activate.
In many cases, the participants report that the TMS click and its resulting thumb movement happened— 50 —

prior to their own volition. Some describe it as if the machine was reading their mind, and just as they
were about to decide to act, the TMS beat them to it. The way we have set up the system, however, theTMS cannot be triggered until the voluntary muscle movement has physically begun.
The initiation of a voluntary act is not a discrete, early event to which we have direct mental access.
Instead, it is a process that continues to consolidate after the initiation of movement. Our perception of
our intentions depends not only on neural signals generated at initiation onset, but also on the integration of information gathered later. This may be analogous to the role of re-entrant feedback to visualcortex in visual consciousness. Contrary to the Cartesian assumption that our introspective awarenessis direct, our sense of agency is inferred based on predictive and postdictive inferences about its most
likely cause.

— 51 —

Tuesday, July 30
Oral 2-1, Physiology
9 : 00 AM-11 : 00 AM, Colloquium
Moderators: Hiromasa Takemura, Ryusuke Hayashi
O2-1-1
9 : 00 AM -9 : 15 AM
Bifurcation pathway in the macaque fovea for unifying the left and right halves of a visual fieldYoshihiko Tsukamoto1,2, Naoko Omi2
1Hyogo College of Medicine, 2Studio EM-Retina

The left half of a visual field is represented in the right visual cortex, and the right half in the left cortex.
The fact that we can perceive a uniform visual field with no discontinuity can be attributed to the complex cells that combine the simple cells representing the identical orientation and the identical visuotopic location from both left and right hemispheres via the corpus callosum. Correspondingly, a groupof ganglion cells along the midline border project onto either the right or the left hemisphere as a cue
for left-and-right unification. However, this currently postulated mechanism hardly explains the ultimate precision at the foveal center of the primate retina under the Hebbian rule of synaptic plasticity.
By serial section transmission electron microscopy, we have found a novel pathway of bifurcation froma midget bipolar cell to two (so-called parvocellular or midget) ganglion cells. Two almost same copiesof the single-cone driven neuronal activity are thought to be conveyed to both right and left hemispheres. The synchronously occurring and highly correlated neuronal activities of these two cells may
contribute to the formation of synapses between correctly paired simple cells and a complex cell for
left-and-right unification at the highest resolution.
Grant: none
Keywords: neural circuits, foveal retina, electron microscopy, Hebbian ruleO2-1-2
9 : 15 AM -9 : 30 AM
White matter connections of the human cingulate sulcus visual area (CSv)
Maiko Uesaki1,2,3, Michele Furlan4, Andrew T Smith5, Hiromasa Takemura6,71Open Innovation & Collaboration Research Organization, Ritsumeikan University, 2Japan Society for the Promotion of Sciences, 3School of Social

Sciences, Nanyang Technological University (NTU), 4Scuola Internazionale Superiore di Studi Avanzati (SISSA), 5Department of Psychology,
Royal Holloway, University of London, 6Center for Information and Neural Networks (CiNet), National Institute of Information Communications
Technology, abd Osaka University, 7Graduate School of Frontier Biosciences, Osaka University

Human cingulate sulcus visual area (CSv) is located in the posterior part of the cingulate sulcus, andresponds selectively to visual (Wall & Smith 2008) and vestibular (Smith et al. 2011) cues to self-motion. Understanding of the structural connections associated with CSv could shed light on its roles inself-motion perception and locomotion. To this end, Smith et al. (2017) studied the structural connectivity of CSv using diffusion MRI. While their probabilistic method suggests cortical endpoints of CSv
connections, it does not reveal the trajectories of the white matter tracts adjacent to CSv. Here, we investigate the white matter connections of CSv, in relation to known white matter tracts and association
fibres by analysing data from Smith et al. (2017). We found that some CSv connections estimated bytractography likely belong to the superior longitudinal fasciculus I and cingulum, which are associatedwith motor planning and visuospatial processing (Thiebaut de Schotten et al. 2011; Kantarci et al.
2011). We also observed short-range tracts connecting CSv with areas in the parieto-occipital sulcus,
superior parietal lobule and insula. Our findings provide further evidence for CSv’s role in guiding locomotion, by demonstrating its spatial proximity to the white matter tracts supporting relevant functions.
Grant: none
Keywords: Human cingulate sulcus visual area, White matter tracts, Diffusion MRI, Functional MRI— 52 —

O2-1-3
9 : 30 AM-9 : 45 AM
Attentional State Modulates Connectome-Based Predictions of Cognitive Performance
Christopher L. Asplund1,2,4,5,6, Esther X.W. Wu1,2, Gwenisha J. Liaw2, Rui Zhe Goh1, Alisia M.J. Chee3,
Tiffany T.Y. Chia2, B.T. Thomas Yeo2,3,4,6
1Divisionof Social Sciences, Yale-NUS College, 2Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore,

3Department of Electrical and Computer Engineering, Faculty of Engineering, National University of Singapore, 4Clinical Imaging ResearchCentre, Yong Loo Lin School of Medicine, 5Department of Psychology, Faculty of Arts and Social Sciences, National University of Singapore,
6Centre for Cognitive Neuroscience, Duke-NUS Medical School

PURPOSE: Individual differences in sustained attention (Rosenberg et al., 2016), selective attention(Rosenberg et al., 2018), and fluid intelligence (Finn et al., 2015) can be linked to neural patterns
through Connectome-based Predictive Models (CPMs; Shen, 2017). Here we tested whether these predictions held when fMRI-based functional connectivity data were collected during a demanding task,
the attentional blink (AB). METHODS: fMRI data were collected during resting state and again while
performing the AB task, for which participants (n=73) searched for two items in a stream of distractors.
Outside the scanner, sustained attention (Gradual Continuous Performance Task), selective attention(Attention Network Task; ANT) and fluid intelligence (Raven’s Progressive Matrices) were assessed.
CPMs based on resting state (rs-fcMRI) and the AB task state (task-fcMRI) were used to account for
behavioral task performance. RESULTS: In general, AB magnitude and selective attention could be
best predicted from task-fcMRI, whereas fluid intelligence could be best predicted from rs-fcMRI. Sustained attention could be predicted by both rs-fcMRI and task-fcMRI. Strikingly, the functional connectivity patterns that predicted better AB performance predicted worse selective attention (ANT) performance, and vice versa. CONCLUSIONS: Attentional state is an important modulator of CPM-basedtask predictions from fMRI data.
Grant: Yale-NUS startup grant, DSO National Laboratories grant
Keywords: visual attention, fMRI, attentional state, individual differencesO2-1-4
9 : 45 AM-10 : 00 AM
Probing contextual influences in macular degeneration: is the reduced inhibition a sign of corticalreorganization?
Giulio Contemori1,2,3, Luca Battaglini1,2, Clara Casco1,2
1Department of General Psychology, University of Padova, 2Neuro.Vis.U.S. Laboratory, University of Padova, 3Université de Toulouse-UPS,

Centre de Recherche Cerveau et Cognition

Complete bilateral central vision loss leads macular degeneration patients (MD) to develop a preferredretinal locus for fixation (PRL) that presumably undergoes some use-dependent cortical changes overtime. In this study, we challenge this hypothesis by comparing spatial integration in the PRL, in a symmetrical retinal position (non-PRL) and in a region with matched eccentricity in a control group. To dothis, we probed the contextual influences by measuring the contrast gain for a vertical Gabor target,
flanked by two high-contrast collinear masks with respect to the orthogonal baseline condition. Surprisingly, the between-groups analysis revealed that in both PRL and non-PRL, at the shortest target-to-flankers distance (2λ), the contextual influence was facilitatory rather than inhibitory as in controls. Further
analysis with data collapsed across groups showed that this effect depends on the individual contrast
sensitivity at the baseline. When the target-to-flankers contrast ratio increases the inhibition decreases
and then switch to facilitation. However, when ratio surpasses 1 the facilitatory effect progressively
reduces and then disappear. This relationship is well expressed by a ‘dipper’ function similar to thosepreviously reported by Zenger and Sagi (1996) for normal vision. Contrary to previous interpretations,
we concluded that this modulation reflects neither a phenomenon of spontaneous nor use-dependent
cortical plasticity.
Grant: University of Padova
Keywords: psychophysics, macular degeneration, brain plasticity, contrast sensitivity— 53 —

O2-1-5
10 : 00 AM-10 : 15 AM
Combined use of intrinsic optical imaging and 2-photon Ca2+imaging for determining distribution of stimulus-specific responses across macro-architecture in macaque visual cortex
Yang Fang1,2, Gaku Hatanaka1, Mikio Inagaki1,2, Ryosuke F Takeuchi1, Ken-ichi Inoue3, Masahiko
Takada3, Ichiro Fujita1,2
1Graduate School of Frontier Biosciences, Osaka University, 2Center for Information and Neural Networks (CiNet), Osaka University and National

Institute of Information and Communications Technology (NICT), 3Primate Research Institute, Kyoto University

Area V2 is a key stage where various types of visual information are routed to the dorsal and ventral
streams. V2 CO stripes, thick, thin and pale, have their specific input/output routes. Elucidation of functional neurons distributed across stripes provides a clue for understanding the visual processing along
the two streams. To relate individual neuron responses to micro-architecture of V2 stripes, we combine
intrinsic signal optical (ISO) imaging and 2-photon Ca2+imaging in macaque visual cortex. We implanted an imaging chamber in a monkey (Macaca fuscata) and injected adeno-associated virus vector
carrying a calcium indicator (GCaMP6s) downstream of CaMKIIα or Syn. We first performed ISO
imaging, using different visual cues to activate and identify V2 stripes. Calcium responses recordedwith wide-field single-photon imaging appeared locally (～2 mm) at the virus injection sites. Orientation maps and color blob patterns in V1 and orientation specific stripes in V2 in these regions were
spatially matched to those visualized with ISO imaging. This combined application of multiscale imaging will be useful to resolve the questions on the functional architecture of area V2 and to obtain insights into the question of exactly how different visual cues are segregated into the dorsal and ventral
streams.
Grant: Ministry of Internal Affairs and Communications; KAKENHI JP18H05007; JST JPMJPR1683; AMED JP18DM0307021
Keywords: Macaque visual cortex, Multiscale calcium imaging, Genetically Encoded Calcium IndicatorO2-1-6
Cross-inhibition and cross-pattern detectors in macaque V1
Cong Yu, Shu-Cheng Guan, Nian-Shen Ju, Shi-Ming Tang

10 : 15 AM-10 : 30 AM

Peking University

V1 neuronal responses to a grating are suppressed by a superimposed orthogonal grating. This cross-inhibition effect suggests divisive normalization, a crucial computation that determines the non-linearity
in neuronal contrast response functions. There is also sporadic evidence that some V1 neurons may
respond to cross grating patterns. We used two-photon calcium imaging to record the responses of superficial-layer neurons to a single Gabor or a cross pattern (two orthogonal Gabors) in macaque V1.
Many V1 neurons (～70%) were orientation-tuned, and the peak responses to a 0.32-contrast gratingwere suppressed by an orthogonal grating at the same or lower (0.08) contrasts. There was no evidence
for a winner-take-all effect, in which responses to a 0.32-contrast grating would be unaffected by a0.08-contrast grating. The remaining neurons (～30%) showed weak and orientation non-selective responses to a 0.32-contrast single grating, but strongly responded to 0.32+0.32 cross gratings with pattern orientation tuning. The two groups of neurons formed a bimodal distribution in terms of their responses to single gratings and cross grating patterns, suggesting distinctive neural subpopulations in
V1. The cross-pattern neurons cannot be revealed via traditional single-unit recordings that first map theRFs with oriented stimuli, and then assess the responses to cross gratings.
Grant: none
Keywords: visual cortex / 2-photon imaging— 54 —

O2-1-7
10 : 30 AM-10 : 45 AM
Neural ensemble representation of view orientation in monkey inferior temporal cortex: A comparison between face and object processing
Ryusuke Hayashi
Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)

Previous studies have revealed an extensive network devoted to face and object recognition along ventral visual pathway in monkey brain. Within this network, several interconnected areas where face selective neurons are clustered have been functionally distinguished by the way of coding view orientation and individual identity difference (Freiwald & Tsao, 2010). However, it remains unclear how the
representation of face orientation and identity changes depending on image morphing toward the facesof different species or other objects. To address this question, I implanted three multi-electrode arrayson the surface of area TE and recorded multi-unit activities in response to the images randomly presented on a computer monitor. The images of 3D photorealistic models of human faces, monkey faces, cars,
foods and shoes (4 exemplars per category) and their intermediate morphed models (25-75, 50-50, and75-25% of two different categories) viewed from 5 different angles in azimuth were used as stimuli.
Then, I analyzed the representational similarity (Kiegeskorte et al., 2008) change of the recorded neuraldata as a function of categories and morphing level. The results showed the different neural ensemble
representation of orientation between face and other object images, as well as own-species bias of face
identity representation.
Grant: MEXT KAKENHI (Grant-in-Aid for Scientific research) Grant numbers JP16K13117, JP18H05019, JP18H04208 and a NEDO grant in Aidof Research.
Keywords: face recognition, object recognition, electrophysiology— 55 —

Tuesday, July 30
Symposium 2-2 9 : 00 AM-11 : 00 AM Conference hall
The early development of face and body perception
Organizers:
Jiale Yang1, Yumiko Otsuka2(1Department of Life Sciences, University of Tokyo,
2 Department of Humanities and Social Sciences, Ehime University)
Human possess remarkable capacities to process face- and body-related signals. Prior studies consistently reported visual sensitivities to face and body at birth (e.g., Filippetti et al., 2013; Johnson et al.,1991). Moreover, culture specific experience shapes the development of the visual system to develop
expertise for specific types of faces and bodies (e.g., own-race faces and communicative body gestures).
Furthermore, it is well known that the development of face and body perception is at the foundation of
more complex perceptual and cognitive abilities, such as learning and social skills.In this symposium,
we will present 5 talks focusing on the early development of face and body perception from infancy tochildhood by using a broad range of research methods: skin conductance, electroencephalogram (EEG),
eye-tracking, and psychophysics measurements.
Xiao will show how experience of face-race determines early development of infants’ social perception,social learning, and stereotype formation. Chien will show that the pervasive own-race face experience
shapes the development of fine-grained and efficient face perception across childhood, which further
links to biased social development in childhood. Nava examines the development of multisensory integration from early infancy to childhood and its contribution to the development of body representation.
Yang will show tactile information facilitates visual processing in infants, and how body representation
modulates this multisensory enhancement. Hirai will talk about infants’ perception of body movements
and bodily gestures, and its role in social learning.
In sum, this symposium brings together the latest findings regarding face and body perception acrossvarious stages of life and in different culture settings. These studies shed insights into the current advances and future directions of the field of early development of face and body perception.
S2-2-1
Biased early social development by perceptual experience: Evidence from mono-racial Asian
countries
Naiqi G. Xiao
(Princeton University)
Convergent evidence shows that experience shapes early perceptual development. For example, infants
who grow up in a mono-racial environment would develop biased perceptual capabilities for own- vs.
other-race faces. However, it is unclear regarding the breadth of experiential impacts on early development. To this end, we explored how face-race experience affects early social development.
In three lines of research, we investigated the impacts of face-race experience in Asian countries,
where people mostly see Asian faces, but rarely see faces of other-races. Thus, the mono-racial environment in Asian countries provides an ideal tool to examine whether infants’ social development is biased
by asymmetrical face-race experience.
We first studied how face-race affects infants’ social perception via their associations of face-races
with different emotional signals (happy vs. sad music). With increased age, infants gradually associatedown-race faces with happy music, but other-race faces with sad music, which were evident at 9 monthsof age. To probe how this biased social perception further influences infants’ social interactions, weinvestigated infants’ social learning behaviors via learning to follow other’s gaze. Seven-month-olds
tended to learn from own- but not other-race adults under uncertain situations. Moreover, similar racebased social learning bias was found when infants learned from multiple own- vs. other-race adults:
infants formed a stronger stereotype from a group of other-race adults as opposed to a group of own— 56 —

race adults. Together, these evidence convergently demonstrate social consequences of asymmetricalface-race experience in infancy. These findings stress the broad experiential impacts on early development beyond perceptual domains.
S2-2-2The development and challenges of becoming a native face expert: Insights from Taiwanese children
Sarina Hui-Lin Chien(China Medical University)
People are remarkable at processing faces. In a split second, one can recognize a person’s identity, gender, age, and race. Importantly, such face processing expertise is not equally prominent for all classesof faces; it works the best for faces belonging to one’s own racial group. In this talk, I will highlight thedevelopment and challenges of becoming a native face expert based on my recent studies with Taiwanese children. First, despite many cross-cultural studies reported an early emergence of the own-race
advantage (ORA) in the first year of life, adult-like proficiency in discriminating own-race faces is not
fully manifested until late childhood. Second, although encoding of race is fast and automatic, categorizing racially ambiguous faces is biased and cognitively taxing. Adults and children with racial essentialist beliefs tend to categorize ambiguous bi-racial faces as other race. Third, when do children judge
people by their races? We found that a rudimentary race-based social preference emerges in late preschool years, and the influence of social status becomes increasingly important as children go to elementary school. In sum, the collective findings suggest that our perception of race emerges early in lifeand continues to develop through childhood. Lastly, the implications for race-based perceptual and social biases and avenues for future research will be discussed.
S2-2-3
Multisensory contributions to the development of body representation
Elena Nava
(University of Milan-Bicocca)
The representation of the body and the sense of body ownership are the product of complex mechanisms, and adult studies have suggested that a crucial role is played by multisensory interactions ofbody-related signals, such as vision, touch and proprioception. In my talk I will present a series ofstudies conducted at different stages of development (from infancy to childhood) that suggest that multisensory cues not only shape body representation but play either a facilitating or constraining role depending on age. In particular, I will show that very early in life, infants are able to extract the amodal
invariant that is common across senses (e.g., rhythm, tempo), and this predisposes them to be naturally
attracted to redundant multisensory stimuli. Infants can also extract the social component conveyed bymultisensory stimuli, as observed in a recent study in which we found that 4 months-old infants showless arousing responses (as indexed through skin conductance response) to slow/affective touches coupled with a female face than to multisensory non-social stimuli (a discriminative-type of touch coupledwith seeing houses). Interestingly, I will show that later in development, children lack to integrate thesenses, and this prevents them from being susceptible to classical multisensory body illusions, such as
the rubber hand illusion. Finally, I will show that sensory experience, such as vision, contributes to thedevelopment of multisensory interactions, and that lack of visual input – as in congenital blindness –prevents blind individuals to have a typical body representation.

— 57 —

S2-2-4
The effect of tactile-visual interactions on body representation in infants
Jiale Yang
(University of Tokyo)
The representation of the body, which is closely related to motor control and self-awareness, relies uponcomplex multisensory interactions. Humans new born have been observed to perceive their own bodies(Rochat, 2010), and recent studies showed that visual tactile interactions facilitate the body perception
in the early months of life (Filippetti et al., 2013; Freier et al., 2016). In the present study, we used thesteady-state visually evoked potentials (SSVEP) to investigate the development of tactile-visual cortical interactions underlying body representations in infants. In Experiment 1, twelve 4-month-old andtwelve 8-month-old infants watched a visual presentation in which a hand was stroked with a metal
tube. To elicit the SSVEP, the video flashed at 7.5 Hz. In the tactile-visual condition the infant’s own
hand was also stroked by a tube whilst they watched the movie. In the vision-only condition, no tactile
stimulus was applied to the infant’s hand. We found larger SSVEPs in the tactile-visual condition thanthe vision-only condition in 8-month-old infants, but no difference between the two conditions in the
4-month-olds. In Experiment 2, we presented an inverted video to 8-month-old infants. The enhancement of tactile stimuli on SSVEP was absent in this case, demonstrating that there was some degree ofbody-specific information was required to drive the tactile enhancements of visual cortical processing
seen in Experiment 1. Taken together, our results indicate that tactile influences on visual processing of
bodily information develops between 4 and 8 months of age.
S2-2-5Development of bodily movement perception in preverbal infants
Masahiro Hirai(Jichi Medical University)
Understanding another’s actions or behavior is one of the vital abilities that allows us to live in a dynamic and socially fluid world. In this talk, two aspects of body perception in preverbal infants will be
discussed. The first aspect concerns the developmental mechanisms that underlie the perception of
bodily movements—particularly the visual phenomenon of “biological motion” (Johansson, 1973),
whereby our visual system detects various human actions through point–light motion displays. The
second aspect concerns the cognitive mechanisms of the communicative aspect of bodily movement.
The theory of natural pedagogy (Csibra & Gergely, 2009) proposes that infants use ostensive signals
such as eye contact, infant-directed speech, and contingent responsivity to learn from others. However,
the role of bodily gestures such as hand-waving in social learning has been largely ignored. We exploredwhether four-month-old infants exhibited a preference for horizontal or vertical (control) hand-waving
gestures. We also examined whether horizontal hand-waving gestures followed by pointing gestures
facilitated the process of object learning in nine-month-old infants. Results showed that four-month-old
infants preferred horizontal hand-waving gestures to vertical hand-waving gestures. Further, horizontal
hand-waving gestures enhanced identity encoding for cued objects, whereas vertical gestures did not.
Based on our series of studies on body perception in preverbal infants, I will discuss the developmental
model of body perception and its role in social communication.

— 58 —

Symposium 2-3 3 : 00 PM–5 : 00 PM Grand hall
Novel developmental, metabolic, and signaling mechanisms in the retina
Organizers:
Chieko Koike1, Steven H. DeVries2(1Ritsumeikan University, 2Northwestern University)
The retina is a laminarly organized, self-contained, and accessible piece of the central nervous systemthat performs the task of early visual processing. The ability to isolate piece of the nervous system thatremains fully functional allows us to examine intact pathways including those that underlie development, metabolism, and neural circuits. This symposium will present recent progress in our understanding of mammalian retinal function and development in the areas of cell fate determination, regeneration, synaptic function, and hibernation by vision researchers in the United States. In this symposium,
Dr Seth Blackshaw will exploit both transcriptomics and cross-species comparisons to identify thepathways that are essential for retinal cell fate determination and regeneration capacity. Dr Wei Li will
focus on the thirteen-lined ground squirrel and describe metabolic pathway adaptations that permit theretina to tolerate long periods of time at near freezing temperatures during hibernation. Finally, Dr Steven DeVries will focus on the cone circuitry in the cone-dominant retina of the ground squirrel anddescribe how parallel processing pathways get their start.
S2-3-1
Seeing in the cold: vision and hibernation
Wei Li(National Institutes of Health)
The ground squirrel has a cone-dominant retina and hibernates during the winter. We exploit these two
unique features to study retinal biology and adaptations during hibernation. In this talk, I will discuss
an optic feature of the ground squirrel retina, as well as several forms of adaptation during hibernationin the retina and beyond. By exploring the mechanisms of adaptation in this hibernating species, wehope to shed light on therapeutic tactics for retinal injury and diseases, which are often associated withmetabolic stress.
S2-3-2
Building and rebuilding the retina: one cell at a time
Seth Blackshaw(Johns Hopkins University School of Medicine)The retina is an accessible system for identifying the molecular mechanisms that control CNS cell fatespecification and is a prime target for regenerative therapies aimed at restoring photoreceptors lost toblinding diseases. I will discuss our recent large-scale single-cell RNA-Seq analysis of multiple vertebrate species that is aimed at identifying gene regulatory networks that drive the acquisition of neuronaland glial identity in the developing retina. I will discuss our identification of transcription factors that
control both temporal identity and proliferative quiescence, new tools we and our collaborators havedeveloped to identify core evolutionarily-conserved gene regulatory networks controlling retinal development, and mechanisms controlling injury-induced neurogenic competence in retinal glia.

— 59 —

S2-3-3
Parallel signal processing at the mammalian cone photoreceptor synapse
Steven H. DeVries(Northwestern University)
The brain has a massively parallel architecture that supports its prodigious computational abilities. In
the visual system, parallel neural processing begins at the cone photoreceptor synapse. At this synapse,
an individual cone signals to ~12 anatomically distinct bipolar cell types that comprise two main classes, On and Off, each consisting of about 6 types. To better understand the first steps in parallel visualsignaling, we record in voltage clamp from synaptically connected pairs of cones and identified Off
bipolar cells in slices from the cone-dominant ground squirrel retina. At the same time, we capture thedetailed structure of the recorded synapse using super-resolution microscopy. Our results show how themolecular architecture of the synapse, including the placement of ribbon transmitter release sites, glutamate transporters, and postsynaptic ionotropic glutamate receptors, can enable the flow of different
signals to the different bipolar cell types.

— 60 —

Tuesday, July 30
Symposium 2-4 3 : 00 PM–5 : 00 PM Colloquium
Studying attention without relying on behavior
Organizers:
Yaffa Yeshurun1, Satoshi Shioiri2(1University of Haifa,2Tohoku University)
Attention—the selective processing of relevant information at the expense of irrelevant information—
has been subject to scientific inquiry for over a century. One fundamental challenge to the study of attention is that most of our current knowledge was established using paradigms that depend on assumptions regarding the fate of unattended information, or rely in some other way on properties of theparticipants’ responses (e.g., accuracy or response time). Yet, the assumptions on which these paradigms are based may not always hold, and in general participants’ response can be influenced by manyother factors than attention allocation, including response history, biases, higher-level strategies, experience, and so on. Moreover, response time, which is likely the most prevalent measurement in attention
studies, is also linked to motor preparation, not just perception. Fortunately, several recent studies were
set out to study attention with novel and exciting methodologies that do not rely on the participant’s
response, and therefore provide a more objective measure of attentional deployment. Some of thesenovel methodologies rely on measurements of brain activity (e.g., SSVP, ERP) instead of accuracy or
response time, while other methodologies rely on pupil size or eye movements. The four presentations
included in this symposium illustrate how such methodologies can be utilized to overcome obstacles
that prevail with more traditional paradigms.
S2-4-1
The characteristics of the attentional window when measured with the pupillary response to lightYaffa Yeshurun(University of Haifa)
This study explored the spatial distribution of attention with a measurement that is independent of performance - the pupillary light response (PLR), thereby avoiding various obstacles and biases involved
in more traditional measurements of spatial covert attention. Previous studies demonstrated that when
covert attention is deployed to a bright area the pupil contracts relative to when attention is deployed toa dark area, even though display luminance levels are identical and central fixation is maintained. We
used these attentional modulations of the PLR to assess the spread of attention. Specifically, we examined the minimal size of the attentional window and how it varies as a function of target eccentricity andthe nature of other non-target stimuli (i.e., distractors). We found that when the target was surroundedby neutral task-irrelevant disks (i.e., bright/dark disks that did not include response-competing information) the attentional window had a diameter of about 2º. However, when the disks included competing
information this size could be further reduced. Interestingly, the size of the attentional doesn’t seem tovary as a function of eccentricity, but it is affected by stimuli size. Finally, we also examined whether
the spatial spread of attention is influenced by perceptual load. Load levels were manipulated by the
degree of stimuli heterogeneity or task complexity. We found that the size of the attentional window waslarger when load levels were low than when load levels were high. These findings demonstrate theflexibility and constraints of spatial covert attention.

— 61 —

S2-4-2
Differences in attention modulations measured by steady-state visual-evoked potentials and by
behaviors.
Satoshi Shioiri(Research Institute of Electrical Communication, Tohoku University)
One of well-established methods to investigate spatial attention of the human visual system is to ask
subjects to attend on a location intentionally (endogenous attention). The modulation in attention has
been observed by subjective method such as reaction time and detection rate, and objective method
such as electroencephalogram (EEG), fMRI or others. We have been comparing several aspects of spatial attention between behavioral measures and EEG measures, focusing on steady state visual evoked
potential (SSVEP). Steady state visual evoked potential (SSVEP) is a technique to realize measurementof attentional effect at unattended locations with stimuli tagged by temporal frequency. We have succeeded to measure spatial and temporal characteristics of visual attention using SSVEP. The measurements showed both similarity and differences between the behavioral and EEG measurements and also
between different measures of EEG measures. The EEG measures we compares were amplitude of
SSVEP and phase of SSVEP as well as event-related potential (ERP). Time course of spatial attention
shift estimated by detection rate is similar more to that by SSVEP phase than others, spatial spread ofattention is similar to P3 of ERP but very different of either of SSVEP amplitude or SSVEP phase.
Measurements of object-based attention showed similar object effect between SSVEP and reaction
time. These results suggest that attention modulation is not at a single site of the visual process, but
perhaps at multiple processes. Different effects of attention at different processes may be related todifferent role of attention at different processes.
S2-4-3
Unified Audio-Visual Spatial Attention Revealed by Pupillary Light Response
Hsin-I Liao
(NTT Communication Science Laboratories)
Recent evidence shows that pupillary light response (PLR) reflects not only the physical light input tothe retina, but also the mind’s eye, i.e., where covert visual attention is directed to (see review in Mathôt& Van der Stigchel, 2015). While visual and auditory systems rely on different peripheral mechanisms
to represent locations of distal stimuli in the environment, it remains unclear how the spatial representations of the visual and auditory objects are formed in the brain, and how attention plays a role there.
Do audio- and visual-spatial attention share the common mechanism or not? To investigate the issue,
we examined whether PLR also reflects spatial attention to auditory object. In series of studies, participants paid attention to an auditory object, which was defined by a spatial (e.g., sounds presented in theleft or right ear) or non-spatial (e.g., voices from a male or female talker) cue. Results showed that PLR
reflected the focus of spatial attention regardless of whether the auditory object was defined by thespatial or non-spatial cue. Furthermore, the amount of spatial attention induced PLR was modulated by
the reliability of the spatial information of the auditory object. Cognitive effort (e.g., task difficulty) or
physical gaze position could not explain the result. Taken together, the overall results indicate that PLR
reveals not only the focus of covert visual attention but also that of auditory attention. Auditory objects
share the common space representation associated with visual spatial attention.

— 62 —

S2-4-4
Estimation of attentional location based on the measurement of unconscious eye movements.
Hirohiko Kaneko1, Kei Kanari2(1Tokyo Institute of Technology, 2Tamagawa University)
Eye and attentional locations are closely related but they are not always the same. Although many eye
tracking systems have been developed and used to roughly estimate the location of attention in thescene, but attention tracking system to accurately estimate the location of attention has not been developed yet. In our series of studies, we found that the relationships between the characteristics of eye
movements and stimulus properties can be used to estimate attentional location. One of the examples is
the relationship between optokinetic nystagmus (OKN) and motion in attention area. We presented twoareas with different directions of motion arranged on the left and right, top and bottom, or center andsurrounding (concentric) areas in the display. Observers kept their attention to one of the areas by anattention task, which was to count targets appearing on the area. The results indicated that attention
enhanced the gain and frequency of OKN corresponding to the attended motion. Another example issmall vergence eye movements that occurs when paying attention to an approaching or receding object
while fixating a stationary object. The magnitude of the eye movements when paying attention to acertain area was smaller than those when directing eyes to the area, but the relationships between thecharacteristics of eye movements and stimulus were the same in both cases. Using these relationships,
it is possible to determine the attentional location in the visual scene containing objects with various
depth and motion. We also mention some applications of the present method for estimating attentional
location based on the measurement of unconscious eye movements.

— 63 —

Tuesday, July 30
Oral 2-2, Engineering
3 : 00 PM-5 : 00 PM, Conference hallModerators: Izumi Ohzawa, Juno Kim
O2-2-1
3 : 00 PM-3 : 15 PM
Centrifugal signal to the avian retina improves stimulus detection and target discrimination
Hiroyuki Uchiyama, Hiroshi Ohno, Takuto Kawasaki, Yuhki Ohwatari, Takahiro Narimatsu, Yusaku
Miyanagi, Taiga Maeda
Kagoshima University

The centrifugal pathway to the avian retina is composed of three serially-connected neurons; 1) tecto-isthmo-optic (tecto-IO) neurons in the optic tectum (OT), 2) isthmo-optic (IO) neurons in the isthmo-optic nucleus (ION) and 3) IO target cells (IOTC) in the retina. Furthermore, the IOTCs may contact with a particular kind of bipolar cells that are immunoreactive for protein kinase C (PKC-BCs). The
IO neurons are passively activated by visual stimuli and are also voluntarily activated just before head
movements oriented toward their receptive fields. The activity of the IO neurons, or the centrifugal
signal to the retina, facilitates visual responses of the retinal ganglion cells (RGCs) transiently and locally via the IO target cells and perhaps the PKC-BCs. Inactivation of the IO neurons during search andpeck task revealed that the centrifugal signal to the retina improved stimulus detection and target discrimination by the intraretinal facilitation mechanisms. Then, topographically-biased distribution of
RGCs’ population activity with a peak at the target location may correctly induce orienting to the target
through visuomotor transformation probably by tecto-bulbar neurons.
Grant: KAKENHI
Keywords: optic tectum, retina, centrifugal projection, attentionO2-2-2
3 : 15 PM-3 : 30 PM
Animal experiment platform with wireless multi-channel microstimulation system usable for cortical vision prosthesis
Yuki Hayashida, Yuichi Umehira, Naoki Satoshiro, Kosuke Takayama, Shinnosuke Ishikawa, Tetsuya
Yagi
Graduate School of Engineering, Osaka University

We have been studying on intra-cortical visual prostheses, in which spatiotemporal microstimulation
corresponding to the visual scene is delivered to the cortices in visually impaired people in order toprovide artificial vision. In this study, we aimed to build a platform of animal experiments that is indispensable to determine the optimum range of stimulation parameters in the visual prosthesis. Thus far,
we have designed and prototyped a VLSI chip with the stimulation output of 64 channels, and wirelesselectronic modules that can control this up to 64 chips. Utilizing the voltage-sensitive dye imaging of
the visual cortex in head-fixed rodents in vivo, we verified that microstimulation with high accuracy canbe achieved as designed by using our stimulator chip. In addition, the quantitative relationship between
the stimulation intensity and the cortical response was obtained from the imaging experiments, and thestimulation parameters considered to be effective for the visual prosthesis were determined. Subsequently, the above-mentioned electronic modules were modified to be wearable in order to conduct, as
the next step, behavioral experiments in free-moving rodents. We are currently developing a basic control program for the wearable system and a behavioral experiment environment to demonstrate thesystem’s operation.
Grant: Grant-in-Aid for Scientific Research from MEXT, Japan (25282130 and 18K12059 to Y.H. and 16717084 to T.Y.), and Grant-in-Aid for
Challenging Exploratory Research from MEXT, Japan (25560197 to T.Y.)
Keywords: Visual prosthesis, Electronic system, Physiological experiment— 64 —

O2-2-3
OSX and iOS applications for vision science education and research
Izumi Ohzawa1,2, Koichiro Nishi1, Naoharu Iwai1, Takuma Hanaya1

3 : 30 PM-3 : 45 PM

1Osaka University, 2CiNet

We have developed a number of applications for educational and research purposes for vision research.
These applications will be available via App Store. [1] Two-dimensional Fourier transform and image
filtering application (for OSX and iOS). This application allows loading an arbitrary image in standard
formats and applies filtering in the 2D Fourier domain. Filters such as low-pass, band-pass and orientation
filters are available. These filter parameters such as cut-off frequencies and orientations may be manipulated by mouse, and filtered images are displayed immadiately. [2] Real-time Visual Neuron Simulator(OSX) allows applying Fourier-domain filtering to video camera input in real-time in the 3D spatiotemporal frequency domain. By loading spatiotemporal receptive field data to the simulator, reponses of visual neurons are simulated. [3] Dynamic Random-Dot Stereogram for testing stereoacuity (iOS) allows
using iOS devices such as an iPhone to perform measurements of stereoacuity by using the device as a
low-cost head-mount display. Results of measurements may be sent via email to a specified address.
Grant: KAKENHI 15H05921
Keywords: neurophysiology, visual neuron simulator, OSX and iOS application, Fourier filteringO2-2-4
3 : 45 PM-4 : 00 PM
Gamification of vision test improves usability for internet experiments
Kenchi Hosokawa1, Kazushi Maruya1, Shin’ya Nishida2, Satoshi Nakadomari3,5, Masayo Takahashi4,51NTT Communication Science Laboratories, 2Kyoto University, 3Kobe City Eye Hospital, 4RIKEN Center for Biosystems Dynamics Research,

Laboratory for Retinal Regeneration, 5NEXT VISION

Conventional methods in vision science cannot be applied in internet-based experiments due to longexperiment time and requirements of special environment. We developed a test battery which can beused in vision experiments over internet. The test consists of a set of video games (contrast sensitivity
function (CSF), visual field, multiple object tracking and character identification). We modified protocols of conventional test and embedded them into those game-tests. Next, we evaluated usability andvalidity of our game-tests. Thirteen persons participated in the evaluation experiment. They playedgame-tests, and evaluated subjective enjoyability, operability and difficulty. The playing times and performances were also recorded. The same participants performed experiments with conventional methods. As a results, more than 90% players finished every game-tests within 3 minutes. Subjective evaluation scores were higher in the game-test than in the conventional-tests. CSFs measured in the game-test
were comparable to those of conventional tests if the players are familiar with the games (Hosokawa etal., VSS2019). In other tests, the performance decreased as game’s difficulty level increased, suggestingthat players adequately performed tasks and their performance were correctly reflected on the data.
Those results shows potential usability of the our tests for the internet experiments.
Grant: none
Keywords: psychophysics, big data, gamification

O2-2-5
4 : 00 PM-4 : 15 PM
Effects of display compensation, speed and stereopsis on motion perception in an immersive virtual environment viewed on a head-mounted display (HMD)
Wilson Luu1,2, Barbara Zangerl1,2, Michael Kalloniatis1,2, Juno Kim1
1University of New South Wales, 2Centre for Eye Health

We used the Oculus Rift (CV1) HMD to better understand motion processing in participants with andwithout clinically-defined global stereopsis. We assessed the impacts of immersion, perceived scene rigidity and cybersickness on the seated perception of illusory self-motion in depth (i.e., vection) by manipulating simulated speed and display compensation for active lateral head movements. During active— 65 —

head movements, the display either presented pure radial optic flow (active uncompensated viewing) or
a combination of radial and lamellar flow consistent with a constant spatial direction of self-motion (active compensated viewing). We also performed a control condition with viewing of pure radial flow
(passive viewing). Eye movements and patterns of retinal motion were controlled with a static fixation
point rendered on the display at the lower portion of the flow field. Interestingly, active head-movement
displays with and without compensation generated equally superior vection strength, compared with
passive viewing of pure radial flow in stereo-normal participants. However, stereo-impaired participants
reported vection advantages in active uncompensated viewing conditions compared with active compensated and passive viewing conditions. Both stereo-impaired and stereo-normal participants also reported
poorer rigidity in active viewing conditions compared with passive viewing conditions.
Grant: None
Keywords: Motion Perception, Virtual Reality, Stereopsis

O2-2-6Perceived scene stability predicts presence and cybersickness
Juno Kim1, Stephen Palmisano2

4 : 15 PM-4 : 30 PM

1University of New South Wales (UNSW Sydney), 2University of Wollongong

Cybersickness is the adverse experience of oculomotor discomfort, disorientation or nausea commonly
reported by users of head-mounted displays (HMDs). We instructed participants to generate pitch head
movements in response to a metronome at either 0.5 Hz or 1.0 Hz. We systematically increased the display lag of the Oculus Rift CV1 above its benchmark latency (＜9 ms). We found that increasing display
lag increased perceived scene instability, and this perceived scene instability increased with the speedof head movement. Participants who reported greater perceived scene instability also reported weakerspatial presence (i.e., the illusory experience of being “there” in the virtual environment). Severity ofcybersickness was also predicted by the magnitude of perceived scene instability. These findings suggest that the human visual system’s sensitivity to display lag depends on perceived scene instability,
which in turn depends on the speed of head movement.
Grant: Australian Research Council (ARC) Future Fellowship
Keywords: Virtual Reality, Presence, Cybersickness, Psychophysics

O2-2-7
AR/VR Safety Implications for Training
Logan B. McIntosh, Guy M. Wallis, Philip M. Grove

4 : 30 PM-4 : 45 PM

University of Queensland

Virtual Reality Head-Mounted Displays and their application in virtual reality (VR) have increased in
popularity. However, user discomfort and sickness hinder more widespread use. Although “cybersickness” is common in VR, individuals differ in how quickly or severely they are affected, given the same
virtual environment. One explanation for these differences is that they are, at least in part, due to differences in sensory processes across individuals. We investigated whether individual differences on fivebinocular sensory processes were related to reports of past experiences with sickness stimuli. 108 participants completed a sickness history questionnaire, and psychophysical measures (interleaved staircase) of vergence eye movement duration, vergence latency, vergence range, range of fusible disparities, and static stereoacuity. Thresholds on all measures varied across participants, though thequestionnaire data was markedly negatively skewed. We found a relationship between Gender andsusceptibility to cybersickness, replicating previous studies. We did not find relationships between stereoacuity and cybersickness nor between the eye movement measures and cybersickness. One explanation for the null results is the inaccuracy and skew of the introspective, retrospective questionnairemeasure.
Grant: none
Keywords: Virtual Reality, Cybersickness, Visual Perception, Psychophysics— 66 —

O2-2-8
Sensory feedback reduces Weber’s law in perception and action tasks
Ailin Deng, Evan Cesanek, Fulvio Domini

4 : 45 PM-5 : 00 PM

Brown University

Weber’s law—the variability scales with physical stimulus magnitude—has been widely observed inperceptual responses. Recent studies have shown that action is immune to this law, which has been
touted as a feature of specialized vision-for-action processing, separate from perceptual processing. In
this study, we investigated the alternative hypothesis that sensory feedback plays a central role in the
reduction of scalar variability. First, we investigated the role of online visual feedback and final haptic
feedback in grasping. Weber’s law was only observed without either type of feedback. Instead, introducing visual feedback or haptic feedback substantially diminished scalar variability. In the two follow-up studies, we also tested the effect of sensory feedback on manual size estimation (MSE) — a
widely used perceptual task. In one experiment we found that repeated exposure to feedback during
grasping reduced the Weber’s law in MSE followed the grasping session. Remarkedly, we also foundthat indicating the accuracy of an MSE task through explicit visual feedback dramatically reduced scalar variability. We conclude that sensory feedback plays a central role in the reduction of scalar variability, regardless of any functional distinction between perception and action tasks.
Grant: National Science Fundation (#BCS 1827550)
Keywords: sensorymotor, goal-directed action, perception and action— 67 —

Tuesday, July 30
Poster:11 : 00 AM-12 : 30 PM, 1 : 30 PM-3 : 00 PM, Event Hall
P2-1
Cue categories but not cue identities modulate the sequence effects of cueing paradigm
Qian Qian1, Chen Cai1, Yunfa Fu1, Miao Song2, Keizo Shinomori3
1Kunming University of Science and Technology, 2Shanghai Maritime University, 3Kochi University of Technology

An influence of previous cueing status on the current cueing RTs has been found in symbolic cuingtasks: VV＜IV＜II＜VI, while IV represents the RTs of a valid trial preceded by an invalid trial. As aresult, cueing effects are larger after a valid trial than after an invalid trial. This sequence effect has been
explained by some researchers as feature integration of low-level features of cues and targets. The present study investigated the influence of cue identity and cue category on the sequence effect. In experiment 1, two different arrow cues (along with different targets) pointed horizontally or vertically to thepossible target locations, respectively. In experiment 2, arrow cues and gaze cues were tested instead oftwo different arrow cues. Sequence effects were not totally abolished when both stimuli (two different
arrows along with different targets) and cueing axes (horizontal or vertical) were manipulated in Experiment 1, but it was indeed abolished when different cue categories (gaze and arrow) were presented ascues in Experiment 2. The findings support the task-file theory which considers sequential modulationsof attentional tasks as multi-level processes within specific task contexts, rather than the feature-integration hypothesis.
Grant: none
Keywords: visual attention, attention orienting, cueing effects, sequence effects

P2-2
Does attribute amnesia occur with the presentation of complex, meaningful stimuli? The answer
is “it depends”
Jiahan Yu, Yingtao Fu, Ping Zhu, Wei Li, Jifan Zhou, Mowei Shen, Hui Chen
Department of Psychology and Behavioral Sciences, Zhejiang University

Attribute amnesia (AA) refers to the phenomenon whereby participants fail to report a salient attributeof a simple stimulus (e.g., the color or identity of a target letter) on which their attention has just been
focused during a prior task. The current study sought to explore boundaries of AA by investigating
whether it persists when participants encounter complex, meaningful stimuli (e.g., pictures) that hold an
advantage in cognitive processing and memory. In Experiments 1a–1d, we examined whether AA wasobserved with different types of complex stimuli. In Experiments 2a–b, 3a–b we linked the type ofstimuli (simple vs. complex and meaningful stimuli) to the other two potential boundary factors of AA(i.e., repetitiveness of target stimulus and set effects of Einstellung) to see whether there were interactions between these boundary factors. The results demonstrated that AA persisted for complex stimuli
in a typical AA paradigm wherein participants encountered many trials and the targets were repeatedacross trials. However, this effect appeared only for simple stimuli when target stimuli were never repeated through the experiment, or when the surprise test appeared on the first trial of the experiment.
These findings have crucial implications in understanding the boundaries of AA.
Grant: NNSF (No.31771201); National Science Foundation for Distinguished Young Scholars of Zhejiang Province, China (No. LR19C090002);
Humanities and Social Sciences Foundation of the Ministry of Education of China (No.17YJA190001)
Keywords: working memory, attention, expectation— 68 —

P2-3
The correspondence between monkey visual areas and layers in DCNN saliency map model for
representations of natural images
Nobuhiko Wagatsuma1, Akinori Hidaka2, Hiroshi Tamura3,4
1Toho University, Faculty of Science, 2Tokyo Denki University, School of Science and Engineering, 3Osaka University, Graduate School of Frontier

Biosciences, 4Center for Information and Neural Networks (CiNet)

Recent saliency map models based on deep convolutional neural networks (DCNNs) represent thehighest performance for predicting the location of attentional selection and human gaze. However, therelationship between artificial and neural representations for determining attentional selection and predicting gaze location has not been unveiled. In order to understand the mechanism of the saliency map
model based on DCNN and the neural system of attentional selection, we investigated the correspondence between layers in DCNN saliency map model and monkey visual areas about representations fornatural images. We compared the characteristics of the responses on each layer of DCNN saliency map
model to that of neural representation on visual areas V1, V4 and IT. Irrespective of the level of the
DCNN layer, the characteristics of responses on the DCNN saliency map model were consistent withthat of neural representation in the primary visual area V1. Intriguingly, we found marked peaks ofcorrespondence of V1 at early-level and higher-intermediate-level layers of saliency map model basedon DCNN. These results suggested that the neural representations in V1 played an important role fordetermining saliency mediating attentional selection and for predicting human gaze location.
Grant: KAKENHI, Japan (no. 17K12704)
Keywords: Deep Convolutional Neural Networks, Saliency Map, Visual Areas

P2-4
Taller individuals may see our visual world better than the rests: Influence of different eye-heights
on visual short-term memory performance
Yageum Ka1, Hyeonbin Gwon2, Juyeong Lee3, Joo-Seok Hyun1
1Department of Psychology, College of Social Sciences, Chung-Ang University, 2School of Computer Science and Engineering, College ofComputer Science and Software, Chung-Ang University, 3School of Electrical Electronics Engineering, College of ICT Engineering, Chung-Ang
University

Height differences between tall and short individuals may derive different visual experiences against
the same visual scene. Based on this idea, the present study examined the influence of different eyeheights on visual short-term memory (VSTM) performance for a simplified visual scene. In the experiments, a memory array of 3 or 6 colored boxes was displayed in each trial, and participants had to remember their colors. The boxes were placed across different depth positions selected under one of threelinear perspectives representing views from different eye heights. After the memory interval of about 1
second, the same array or an array with one of the boxes changing its color was displayed as a test arrayupon which participants had to report presence or absence of the color change. The results showed asubstantial drop in change detection performance in the lowest eye-height condition if the array set size
was 6, but showed no such drop if it was 3. The results indicate that, as the eye-height became lower,
sensory interference among memory items increased to impair VSTM encoding process. They further
suggest that different eye-heights have a clear influence on the cognitive process subsequent to VSTM
encoding process.
Grant: This work was supported by the National Research Foundation of Korea Grants funded by the Korean Government (NRF2016S1A5A2A01026073 & NRF-2017R1D1A1B03033965)
Keywords: visual short-term memory, visual perception, change detection, individual difference— 69 —

P2-5
Comparison of attentional bias to negative and positive stimuli between people with and without
sleep disturbance using the dot probe task and the Implicit Association Task(IAT)
Siyung Chin1, Yung Jae Suh2, Kyong-Mee Chung3
1Yonsei University, 2Yonsei University, 3Yonsei University

The purpose of this study is to compare the attentional bias of negative stimuli between people who
self-reported mild, severe, or no sleep disturbance. A total of 52 participants were included in the study.
Among 51 recruited participants (aged 18-65), 21 people reported having mild or severe sleep disturbance symptoms, while 30 people reported having no sleep disturbance symptoms. In order to compare
the attentional bias to negative and positive stimuli between the two groups, the participants completed
a pictorial dot-probe task under two conditions, Neutral-Sleep positive and Neutral-Sleep negative, anda word Implicit Association Task(IAT) under two conditions, Me-Sleepy vs. Others-Active and Me-Active vs. Others-Sleepy. An independent t-test was conducted to determine the differences of reaction
time on each condition of the dot-probe task and the IAT. As a result, there was a significant difference
between the two groups in the IAT, while there was no significant difference between the two groups forthe dot probe task. The results implied that people who had sleep disturbance symptoms, spend lesstime categorizing sleep relate words with self. The study implied that people may have an attentional
bias with words, rather than pictures, in a self-reporting setting.
Grant: none
Keywords: attention, bias, stimuli, sleep disturbanceP2-6
The effect of representation structures on visual working memory retrieval
Pengpeng Liu, JiFan Zhou, MoWei Shen
Department of Psychology and Behavioral Science, Zhejiang University

Visual information is encoded into structured mental representation to enter visual working memory.
The current study examined the effect of representation structures on the retrieval process. Participants
were required to memorize a colored image that has several parts with a hierarchical structure, and retrieve two parts of the image in a specified order. By manipulating the structural distance between two
parts, we found that the retrieval performance of the second part decreased with the distance to the first
part. And this effect could not be triggered by merely priming of the first part, indicating that retrievalof the first part is necessary for the effect of mental structure to occur on the second part. Those findings
suggested that the retrieval of information stored in visual working memory is based on the structured
representation, the retrieval performance could be impaired when the retrieval structure is inconsistent
with the structure of representation.
Grant: none
Keywords: visual working memory, mental representations, hierarchical structures, memory retrieval

P2-7
Effects of visual working memory on individual differences in echolocation performance
Tomoki Maezawa, Jun Kawahara
Department of Psychology, Hokkaido University

Echolocation is a method to localize objects based on the reflection of sound. Sighted individuals canuse echolocation following suitable training, while the performance of echolocation shows considerable
individual difference. Several factors, such as working memory and processing of visual images are
involved in this difference;(e.g., Ekkel, van Lier, & Steenbergen, 2017). Thus, visual spatial componentof working memory should be involved in echolocation. The present study examined the association
between echolocation performance in sighted individuals and visual working memory capacity. Subjects performed an object detection task by using echolocation at different target distances (20, 30, 40,— 70 —

or 50 cm) across three-separated days, and completed a visual working memory task in the third day.
The results indicated that the subjects improved the performance of the detection task across the initial
two days, while the performance showed large individual differences. We found a significant positive
correlation (r=0.62) between the performance and the visual working memory capacity. The present
results reflect that visual spatial processing is involved in an object detection using echolocation forsighted individuals. We suggest that visual working memory capacity would be predictive of higher
performance of the detection task.
Grant: none
Keywords: visual working memory, echolocation, individual difference

P2-8
Long-term Retention of Multi-Attribute Stimulus-Response Mapping
Yumiko Fujii1, Hiromi Morita2
1Graduate School of Library, Information and Media Studies, University of Tsukuba, 2Faculty of Library, Information and Media Science, Universityof Tsukuba

The human visual system processes different attributes of an object separately and then integrates themto elicit a specific response. Ishizaki et al. (2015) proposed a paired-attribute model in which boundfeature pairs are units of multi-attribute stimulus-response associations. However, our previous study ofstimulus-response mapping suggested that color and shape are bound and associated with a response,
whereas location is not, when added to the association; consequently, we proposed the location-singleton model. The present study aims to confirm that location is not bound with other attributes in the retention stage after learning, as observed for the learning stage. One week after participants learned themapping of eight stimuli comprising color (red/green), shape (circle/triangle), and location (left/right)
to four responses, they were tested with the same mapping. As a result, they could respond as accurately and quickly as they did immediately after learning. Moreover, their responses to the color–locationand shape–location pairs were more difficult than their response to the color–shape pair as observed
immediately after learning. The results suggest that the location-singleton model is applicable to therepresentation of multi-attribute stimulus–response mapping during the retention period.
Grant: JSPS KAKENHI Grant Number 17K00200
Keywords: experimental psychology, memory, learning, feature integration

P2-9
The interaction of grouping and salience in visual search: The electrophysiological evidence forthe collinear masking effect
Li Jingling1, Chia-huei Tseng2,3, Shin Ono2,3, Satoshi Shioiri2,3
1Graduate Institute of Biomedical Sciences, China Medical University, 2Research Institute of Electrical Communication, Tohoku University,
3Graduate School of Information Sciences, Tohoku University

Visual search is impaired when neighboring items to a target are aligned (i.e. collinear visual searchmasking, Jingling and Tseng, 2013). To elucidate its involved mechanisms, we measured the event-related potential when 16 participants completed the search task. The display was filled with the samevertically- (or horizontally-) oriented bars, except for one distractor column consisting of bars orthogonal to the others. The bars in the distractor column were grouped by collinearity or by similarity at equalchance, and the distractor location was task-irrelevant. The target, a tilted bar, was located at threepossible locations with equal likelihood (1/3 overlapping with distractor column and 2/3 not). Results
showed that the distractor column, in both collinear and similarity grouping, elicited a strong P1 component at around 100 ms and a Pd component around 200 ms after display onset. This indicated that thewell-grouped distractor was salient but suppressed during search. The target, regardless of overlappingwith distractor or not, elicited an N2pc component at 200-300 ms, suggesting focused attention on target
processing. Interestingly, targets overlapped with a collinear distractor reduced P3 amplitude thannon-overlapping conditions, implying additional cognitive processing other than suppression contribut— 71 —

ed to the collinear search impairment.
Grant: FY2018 RIEC Nation-wide Cooperative Research Projects, MOST106-2420-H-039-002-MY3
Keywords: visual search, ERP, perceptual grouping, N2pc

P2-10
Gaze Cues Stored in Working Memory Trigger Automatic Attentional Orienting
Haoyue Ji1,2, Yi Jiang1,2, Li Wang1,2
1Institute of Psychology, Chinese Academy of Sciences, 2University of Chinese Academy of Sciences

Previous research has shown that social cues including eye gaze can readily guide our focus of attention. Here, we demonstrate that merely maintaining social cues in working memory (WM) can elicit asimilar attentional orienting effect. Using the delayed-match-to-sample paradigm combined with the
dot-probe task, we found that holding a face image with task-irrelevant averted eye gaze in WM could
automatically induce attentional orienting to the gazed-at location. Importantly, such WM-induced attention effect could not be explained by the perceptual attentional process, because the identical gazecues that were only passively viewed and not memorized in WM didn’t trigger attentional orienting
beyond the time window of typical social attention. Furthermore, non-social cues (i.e., arrows) held in
WM also failed to elicit the automatic attentional orienting effect. Taken together, the current study
provides clear evidence that social but not non-social cues stored in WM can guide spatial attention akinto that with actual presentation of stimuli, and highlights the uniqueness of brain mechanisms underlying social attention as compared to non-social attention.
Grant: none
Keywords: social attention, working memory, eye gaze, arrows

P2-11
How professional stereotype and warning work in episodic memory: modulation of morality
Minye Li, Aiqing Nie
Department of Psychology and Behavior Science, Zhejiang University

Previous research on stereotypes indicates that in general, the effect of source memory of the contents
conforming stereotypes is better. However, negative or immoral contents that violate stereotypes comewith even better source memory. There has been no systematic study to illustrate the roles of ethics on
the influence of stereotypes on source memory. We assume that in contrast to the situation of conforming professional ethics, violating them will result in better source memory. Therefore, we add the professional ethics factor in our study to explore its regulation effect on the influence of stereotypes onsource memory. The results show that: (1) contents that conform professional stereotypes have bettersource memory; (2) contents that conform professional ethics have better memory; (3) there has beeninteracting effect between professional ethics and professional stereotypes and professional ethics havea regulation effect.
Grant: none
Keywords: source memory, social cognition, stereotype, morality

P2-12
Attentional cueing effect by pointing hand and other cues: differences and interactions
Ryosuke Niimi
Niigata University

Images of pointing hand act as attentional cue and guide spatial attention. Is this attentional effect identical to that of other cues (arrows, eye gaze)? Experiment 1 (standard Poster paradigm with pointing
hand and arrow cues) demonstrated that pointing hands, either upright or inverted, yielded cueing effectcomparable with arrow cues. In Experiment 2, a pair of pointing hand and eye gaze served as cue stimuli. Validity of the hand cues and eye gaze cues was manipulated independently; the hand and eye gaze
— 72 —

were in the same direction in some trials, while in other trials they were conflicting with each other.
Results showed that the cueing effect of eye gaze almost disappeared if the pointing hand cue was invalid, and vice versa. The cueing effect by pointing hands is basically equivalent with that of arrows,
while it interacts with gaze cueing effect.
Grant: This work was supported by a grant for InterdisciplinaryJoint Research Project from Brain Research Institute, Niigata University.
Keywords: attention, body perception, object perception

P2-13
The visual cocktail party problem: Enhancement of visual selective attention through phase entrainment to auditory streams
Xiangyong Yuan1,2, Xilei Zhang1,2,3, Ying Wang1,2, Yi Jiang1,2
1State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of

Psychology, Chinese Academy of Sciences, 2Department of Psychology, University of Chinese Academy of Sciences, 3School of Biological
Sciences and Medical Engineering, Southeast University

One’s auditory selective attention under noisy conditions, such as in a cocktail party, can be facilitatedby congruent visual inputs. Here we demonstrate that in a “visual” cocktail party situation, visual selective attention can be significantly enhanced through phase realignment to a concurrent auditory stream.
In an EEG experiment, participants were asked to discriminate a visual object among distractors, in the
meanwhile they were presented with an auditory stream that changed either congruent or incongruent(i.e., in- or out-of-phase) with one of the visual features embedded in the target object. We found thatthe presentation of a congruent auditory stream not only improved the target discrimination accuracy
but also increased the power of the parieto-occipital neural oscillations specifically entrained to theauditory-congruent feature of the target object. Moreover, the functional connectivity between the parieto-occipital and fronto-central regions, which reflects the phase coherence between audiovisual oscillations, could significantly predict the behavioral discrimination accuracy when accompanied by congruent sounds. Taken together, our findings suggest that a congruent auditory stream can enhancevisual selective attention by boosting the neural entrainment through strengthening the phase coherence
between the auditory and visual neural activities.
Grant: none
Keywords: multisensory integration, selective attention, neural oscillation

P2-14
Early VEP reflects affective priming modulated by temporal attention
Takuya Imani, Hikaru Ishisaka, Tomokazu Urakawa, Yuki Kurita, Osamu Araki
Department of Applied Physics, faculty of Science, Tokyo University of Science

Orienting attention to specific timing of an upcoming visual event has been reported to enhance visual
processing of the event. By recording visual evoked potentials (VEPs), the present preliminary study
tried to elucidate temporal profile of visual processing relevant to the affective priming effect enhancedby temporal attention (tAPE). In the experiment, we employed a stimulation paradigm of subliminal
affective priming for face. At the beginning of each trial, participants were informed about the presentation timing of primer with a visual cue (Short or Long). A primer was either a happy or a fearful face,and participants then judged the affect of a neutral face target following the primer. Our results for behavioral data showed that tAPE was not consistently observed across participants. However, in terms of
the inter-individual differences in behavioral and VEP data, we found, for the trials with happy primer,that a diminishment of N75 (a negative VEP component at a latency of around 75 ms) significantly
correlated with an increase of tAPE across participants. This finding suggests, by focusing on interindividual differences, that the affective priming effect enhanced by temporal attention is reflected as early
as about 75 ms following the primer’s onset.
Grant: none
Keywords: temporal attention, VEP, consciousness— 73 —

P2-15The effect of aging on gaze-induced Inhibition of Return
SyuanRong Chen1, Li Jingling2
1China Medical University, 2China Medical University

Inhibition of return (IOR) is an inhibition mechanism of attention orienting. Previous studies showedthat aging did not alter the size of IOR induced by peripheral cues (the tradition IOR). The goal of thisstudy aimed to explore how aging alter the size of gaze-induced IOR. Two experiments were carriedout, each collected 30 younger (age ranged from 20 to 30 years old) and 30 older adults (older than 65
years old), in total 120 participants. Both experiments were localization tasks using photographs of real
faces to introduce gaze cues. The cues validity was set as uninformative. Experiment 1 followed theclassical cue-target paradigm and Experiment 2 used the target-target paradigm. Results showed thatboth younger and older adults can reach high accuracy (above 95%). Younger adults showed facilitation
at 200 ms and IOR at 2400 ms SOA. Nevertheless, older adults did not have statistical significant differences between valid and invalid trials in any SOA conditions. Since traditional IOR did not altered withaging, our data thus did not support for the hypothesis that gaze-induced IOR was elicited by the same
inhibition mechanism from that elicited by periphery cues.
Grant: MOST106-2410-H-039-001-MY2
Keywords: inhibition of return, gaze cue, age, the cueing effectP2-16
Attentional shift to the newer object in the preview and simultaneous search
Takayuki Osugi
Yamagata University

When some distractors (old items) appear before others (new items) during an inefficient visual searchtask, observers exclude the old items from the search (preview benefit). Previous studies demonstrated
that preview benefit occurred when items were presented in two-time steps (i.e., the first and second
displays). However, it remains unclear whether observers can shift their attention to newer object if thetarget appeared after the onset of the other new items; the target includes in the third display. To test this,we compared search times for the target in the third display under the preview condition and the simultaneous condition in which no items were presented in the first display (i.e., blank display). In twothirds of the trials, the target was included in the second display, and it appeared in the third display on
the remaining trials. The results indicated that preview benefit occurred when the target appeared in thesecond display, but target detection in the third display was slower under the preview condition relative
to the simultaneous condition. It suggests that attentional shift to the newer target requires more time if
search items were already divided into two groups by temporal information.
Grant: JSPS KAKENHI Grant Number 17K13960
Keywords: Visual search, Inhibition, attentional control

P2-17
Working Memory is Corrupted by Strategic Changes in Search Templates
Garry Kong, Jessica Meehan, Daryl Fougnie
New York University Abu Dhabi

When searching for an item, we often conjure an image of that item to act as a search template. Thissearch template is thought to be stored as, and is no different from, a visual working memory representation. Evidence for this primarily comes from studies demonstrating that the contents of working memory influences search behavior. However, whether this interaction applies in both directions is unknown.
Here, we present evidence that changes in search templates can influence working memory. Participants
remembered the orientation of a target line and on some trials (75%) performed a visual search for thatorientation, but on other trials (25%) recalled the target’s orientation. Critically, we manipulated the— 74 —

search template by introducing a predictable context—distractors in the search task were always clockwise (or counterclockwise) from the search target. We found that the context biased search away fromthe distractors (i.e., counterclockwise), t(27)=15.00, p＜.001, Cohen’s d=2.83, and crucially, also similarly biased orientation reports during recall, t(27)=2.97, p=.006, Cohen’s d=0.56. This demonstrates
that working memory and search templates were not held as separate, isolated representations, supporting the conclusion that search templates are equivalent to memory representations.
Grant: none
Keywords: Visual Working Memory, Visual Search, Attention, Psychophysics

P2-18
Involvement of visual mismatch negativity in access to visual consciousness
Yuki Kurita, Tomokazu Urakawa, Osamu Araki
Department of Applied Physics, Graduate School of Science, Tokyo University of Science

Electroencephalographic brain response to a violation (or a change) of preceding sequential regularityof visual events, called visual mismatch negativity (vMMN), has been well known to reflect automatic
visual change detection. A recent study using a modified version of binocular rivalry paradigm reported
that the vMMN was evoked even when a violation occurred during binocular rivalry suppression (Jacket al., 2017). In the present study, we report that vMMN’s occurrence under binocular suppression isrelevant to rendering an invisible image evoking vMMN visible. In stimulation, we intermittently presented a sinusoidal grating and abruptly changed its orientation by 90 degrees (a violation of precedingvisual sequence) during binocular suppression. Under this scheme, vMMN under binocular suppression
was recorded and the proportion of perceptual switch from before to after the presentation of the violation was calculated. With a focus on the inter-individual differences in the behavioral index and vMMN’s
amplitude, we found that an enhancement of vMMN significantly correlated with an increase of the
proportion of perceptual switch across participants. We propose, besides visual change detection in theabsence of consciousness, that visual processing underlying vMMN is relevant to triggering access tovisual consciousness.
Grant: none
Keywords: visual mismatch negativity, visual awareness, EEG

P2-19
Quick buildup of suppression revealed by eye-swapping technique in continuous flash suppression
Motomi Shimizu1, Eiji Kimura2
1Graduate School of Advanced Integration Science, Chiba University, 2Department of Psychology, Faculty of Letters, Chiba University

Continuous flash suppression (CFS) can render a static stimulus in one eye invisible by presenting a
dynamic stimulus in the other eye. To elucidate the underlying mechanism of CFS, we investigated theeffects of the eye of presentation (which eye receives which stimulus) by using an eye-swapping technique. If CFS is mediated by an eye-based process, swapping the stimuli between the eyes should disrupt suppression. To test this possibility, we measured the time it takes for a suppressed stimulus to be
detected, with manipulating the frequency of eye swapping. Results showed that the detection time was
not much affected and the suppression was strong when the swapping frequency was low (1.2 Hz).
However, the detection time was significantly reduced when the swapping frequency was high (3.5 Hz).
Further investigation with measuring detectability of a briefly presented target revealed that the suppression was weak just after an eye swap but became stronger by the time of the next eye swap in the
1.2-Hz eye-swapping condition. These results can be understood by the contribution of an eye-based
process that exhibits a quick buildup of suppression to CFS.
Grant: Supported by JSPS KAKENHI (26285162 & 18K18686)
Keywords: binocular vision, continuous flash suppression, psychophysics— 75 —

P2-20Effects of eyeblinks on perceptual switching during continuous flash suppression
Ryoya Sato1, Eiji Kimura2
1Chiba University Graduate School of Science and Engineering, 2Chiba University Graduate School of Humanities

Eyeblinks have been reported to modulate perceptual switching during multistable perception, but theirreported effects were not unequivocal. This study investigated how different types of eyeblinks, i.e.,
spontaneous (unintentional) and voluntary (intentional) eyeblinks, modulate perceptual switching
during continuous flash suppression (CFS). CFS refers to an experimental paradigm, where a high-contrast dynamic Mondrian stimulus presented to one eye renders invisible a static target stimulus presented to the other eye. In the experiments, we gradually increased target contrast after exclusive dominanceof the dynamic Mondrian had been established, and measured the time required for the suppressed target to break through the suppression. Results showed that spontaneous eyeblinks that occurred before
target detection increased the detection time, relative to that found on the control trials where no eyeblinks occurred. By contrast, voluntary eyeblinks generated in response to a visual cue shortened thedetection time. In the present paradigm, physical blackout, which had comparable timing and duration
to eyeblinks, did not significantly affect the detection time. Moreover, a close temporal relation was
found between voluntary eyeblinks and target detection; the frequency of target detection was peaked
0.5 sec after the eyeblinks. These findings suggested that extra-retinal signals associated with voluntary
eyeblinks induce perceptual switching.
Grant: Supported by JSPS KAKENHI (26285162 & 18K18686)
Keywords: Eyeblink, multistable perception, awareness

P2-21
The spatial profile of interocular suppression is modulated by mask speed
Egor Ananyev1, Gerrit Maus1, Po-Jang (Brown) Hsieh2
1Nanyang Technological University, 2Duke-NUS

Interocular suppression is a phenomenon where a salient stimulus in one eye (mask) suppresses visualawareness of another stimulus (target) presented to the other eye. Despite the popularity of the paradigm
in the study of unconscious processing, the mechanism of interocular suppression is yet unclear. It is
assumed that the interocular suppression is spatially uniform, and that this should not depend on mask
speed. To test this assumption, we manipulated mask speed, target speed, and target eccentricity. We
found that the masking strength varied with all three factors. Slower masks were more effective in suppressing slow, centrally presented targets. Faster masks were more effective in suppressing fast, peripherally presented targets. To account for this phenomenon, two explanations are considered: neurophysiological dichotomy between parvocellular and magnocellular pathways and a computational model ofdivisive normalization.
Grant: none
Keywords: interocular suppression, divisive normalization, motion, binocular rivalry

P2-22
ON response does not reflect access to visual consciousness: A VEP study
Erika Takahashi, Tomokazu Urakawa, Yuki Kurita, Osamu Araki
Department of Applied Physics, Faculty of Science, Tokyo University of Science

Automatic detection of a visual change in relation to a preceding sequential regularity of visual eventsis reflected in electroenephalograpgic brain response, called visual mismatch negativity (vMMN). Our
recent study using a modified version of binocular rivalry found that vMMN’s occurrence driven by thechange under binocular suppression is relevant to rendering an invisible image evoking vMMN visible.
In the present study, we further attempted to determine whether ON-response, evoked by a visualchange without a preceding sequential regularity, under binocular suppression would also be related to— 76 —

triggering access of a perceptually-suppressed image to consciousness. In stimulation, a sinusoidal
grating was presented under binocular suppression and its luminance was abruptly increased. With thisscheme of experiment, P1 and N1 (visual evoked potentials, VEPs) were recorded and the proportionof perceptual alternation was calculated. By focusing on the interindividual differences in VEP’s amplitude and the behavioral index as in our preceding study regarding vMMN, our current results showedthat each amplitude of P1 and N1 did not significantly correlate with the facilitation of perceptual alternation across participants. We propose that vMMN but not ON response is relevant to triggering accessto visual consciousness.
Grant: none
Keywords: VEP, ON response, binocular rivalry

P2-23
Dissociating Conscious and Unconscious Privileges of Temporal Structures in Visual Competition
Ruichen Hu1,2, Peijun Yuan1,2, Yi Jiang1,2, Ying Wang1,2
1State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of

Psychology, Chinese Academy of Sciences, 2Department of Psychology, University of Chinese Academy of Sciences

Dynamic events with regular changing patterns provide abundant sources of temporal structures in ourenvironment. Among them, we have previously demonstrated that feature- and semantics-based temporal structures, relative to their non-structured counterparts, prolonged the predominance of dynamic
information streams during the competition for visual awareness. Here we disentangled the underlying
mechanisms for these multi-source facilitation effects, especially regarding their reliance on conscious
processing. During binocular rivalry, temporal structures built on dynamic change of visual features
held an advantage largely attributable to reduced durations when suppressed from awareness, whereas
those emerging from semantic-level regularities benefited mainly from prolonged perceptual durations
while dominating awareness. A further experiment using the bCFS paradigm yielded consistent resultsthat only the feature-based structured streams, when initially suppressed, gained privileged access toawareness over the random counterparts, indicating a benefit for unconscious processing. Together,
these findings provide evidence for dissociable mechanisms to prioritize different types of temporal
regularities for conscious experience. Extraction and utilization of semantic-level temporal structures
engage conscious information processing, compared with that of perceptual-level temporal structures
may occur even without awareness, pointing to their distinct privileges and functional roles in conscious and unconscious processes.
Grant: none
Keywords: binocular rivalry, visual awareness, temporal structure, unconscious processing

P2-24
Can Semantic Information be Temporally Integrated Under Interocular Suppression? An fMRI
study
Yung-Hao Yang1,2, Tsung-Ren Huang1,4,5, Su-Ling Yeh1,3,4,5
1Department of Psychology, National Taiwan University, 2Human Information Science Laboratory, NTT Communication Science Laboratories,

Nippon Telegraph and Telephone Corporation, 3Graduate Institute of Brain and Mind Sciences, National Taiwan University, 4Neurobiology andCognitive Science Center, National Taiwan University, 5Center for Artificial Intelligence and Advanced Robotics, National Taiwan University

Awareness of visual stimuli in one eye can be interocularly suppressed by high-contrast masks from theother eye; such interocular suppression provides a powerful tool to examine the function of consciousness along visual pathway. We used fMRI to investigate whether multiple words presented sequentiallycan be unconsciously integrated into higher-level meanings. Temporal sequences of four characters
were manipulated to form either a Chinese idiom or a meaningless random sequence. Word sequencesfrom one eye were accompanied with or without masks from the other eye to render the unaware oraware condition, respectively. BOLD signals showed reliable activation in bilateral fusiform areas regardless of temporal sequence and visual awareness, suggesting processing of single word form. Criti— 77 —

cally, despite idiom judgment task showed chance level performances in the unaware condition, theactivation patterns of contrast between random and idioms were nevertheless modulated by awarenessstate: In the unaware condition, Chinese idioms generated higher activation than random sequence inbilateral inferior frontal gyrus (IFG), while the same contrast in the aware condition showed higher
activation in bilateral superior temporal gyrus (STG). The distinct neural mechanisms between unconscious and conscious processes suggest that different semantic processing was modulated by conscious
states.
Grant: none
Keywords: Semantic integration, Interocular Suppression, unconscious processing, functional magnetic resonance imaging

P2-25
Establishing a Massive-Report paradigm to reveal the richness of consciousness
Naotsugu Tsuchiya1, Jasmine Walter1, Alon Loeffler1, Zhao Koh1, Jeroen van Boxtel1, Shinji Nishimoto2
1Monash University, 2Osaka University

While conscious perception of the world seems rich, this richness has proven difficult to verify in traditional experiments. One of the problems with traditional psychophysical studies is that they used tasks
which primarily reflected participants’ capacity for recalling specific items of interest (e.g., letters).
Here, we implemented a novel approach for gauging experiential richness, the Massive-Report paradigm to overcome many limitations of previous experiments. This paradigm allows people to demonstrate the richness of their experience to a far greater extent than previous methods. Participants viewed
briefly-displayed natural images (133 ms) and were asked to demonstrate their detailed experience of
the image through answering a Massive series of questions (640+). Each question consisted of a word
which may or may not be an appropriate description of some component of the image. Participants
could express what they experienced in a way that was at least 35 times richer than in traditional paradigms. The Massive-Report paradigm has the potential to bring significant revision to our view on thenature of consciousness.
Grant: Australian Research Council Discovery Project DP180100396 and DP180104128
Keywords: psychophysics, natural scene, consciousness

P2-26
Perceptual decision for average orientation over space and time
Ryuto Yashiro1, Hiromi Sato1, Takumi Oide2, Isamu Motoyoshi1
1Department of Life Sciences, The University of Tokyo, 2Department of Integrated Sciences, The University of Tokyo

The visual system can rapidly compute spatial statistics in stochastic stimuli. The present study investigated mechanisms underlying average-orientation discrimination over space and time. Six observers
viewed a dynamic texture (4 or 32 frames of texture patterns with Gabor elements serially presented at
30 Hz) and indicated whether its average spatiotemporal orientation was tilted clockwise or counter-clockwise. The spatial mean orientation of each frame was varied according to a Gaussian distribution with a particular mean and a temporal SD of 0–8 deg. Element orientation in each frame was varied
according to a Gaussian distribution with a spatial SD of 0–16 deg. We found that discrimination thresholds increased as a function of spatial SD if temporal SD was small but remained nearly constant if
temporal SD was large. Reverse correlation analysis revealed that observers put emphasis on the lastfew frames when judging spatiotemporal average. The results are inconsistent with visual mechanismsthat integrate local information equally over space and time but support distinct spatial and temporalmechanisms: a sensory mechanism that rapidly averages spatial orientation and a perceptual decision
mechanism that accumulates averaged signals over time.
Grant: Supported by the Commissioned Research of NICT, and by JSPS KAKENHI JP15H05916, JP15H03461 and JP16J07259.
Keywords: perceptual decision making, psychophysics— 78 —

P2-27
Reverse-correlation analysis of real-time perceptual decision for dynamic visual stimuli
Hironori Maruyama, Hiromi Sato, Ryuto Yashiro, Isamu Motoyoshi
Department of Life Sciences, The University of Tokyo

To understand how humans utilize information until the moment when they make a decision for visual
events, the present study applied a reverse correlation analysis to the behavioral response in a reaction-time task for stochastic stimuli. The observers viewed a dynamic texture (15 Hz frame rate) composed of Gabor elements whose orientation randomly varied according to a Gaussian noise both inspace and time. During the stimulus presentation, they pressed a button as immediately as possible toindicate whether its average spatiotemporal orientation was tilted clockwise or anti-clockwise. We calculated logistic regression coefficients of the observer’s response to the spatial mean orientation at eachtemporal frame with respect the moment of reaction time, which ranged from ～500 to ～2000 ms. The
analysis revealed a sharp peak in the regression coefficient at 300-400 ms before the manual response.
The peak was less profound for trials with longer RTs. The subsequent analysis also showed that withina temporal period at around this peak, SD of orientation was lower than the other periods. These results
indicate that, at least under urged situations, human perceptual decision is triggered dominantly by information 200-400 ms before behavioral response.
Grant: Supported by the Commissioned Research of NICT, and by JSPS KAKENHI JP15H05916, JP15H03461 and JP16J07259.
Keywords: psychophysics, descion making

P2-28
Analyzing eye fixation patterns to explore the factors affecting visual balance in visual art withdepth perspective
Cong-Wei Ho1, Shwu-Lih Huang1,2
1Department of Psychology, National ChengChi University, 2Research Center for Mind, Brain & Learning, National Chengchi University

It is well known that even distribution of visual weight in a frame will achieve visual balance. However,this phenomenon has not been thoroughly studied. Also little research has been done to examine thefactors that influence visual weight empirically. In this study, we aimed to verify Arnheim’s (1974)
claim that an element with greater depth will carry more visual weight in a picture. Using eye-tracker
as a tool, we conducted our research on visual balance first with real visual art—photography, and gradually simplified the research stimuli to rule out confounding variables. Normalized eye fixation measures were used to estimate the visual weight. The visual balance of three kinds of colorful photographswith two objects was compared, including (1) larger near-object and small far-object (Arnheim-consistent), (2) small near-object and larger far-object (Arnheim-violated), (3) unbalanced control. We foundthat both Arnheim-consistent and Arnheim-violated photographs can achieve visual balance. Larger
visual weight of far-object than near-object was observed in the Arnheim-consistent condition, but itreversed in the Arnheim-violated condition. Our results implied that Arnheim’s balance theory of spatial depth is not totally complete. Background knowledge of the real size of objects also is an importantfactor to influence visual balance.
Grant: none
Keywords: eye-tracker, visual balance, depth perspective, art

P2-29
Bayesian Optimal Decision Making in Risk-Return Trade-off under Spatiotemporal Motor Variability
Qirui Yao, Yutaka Sakaguchi
Graduate School of Informatics and Engineering, University of Electro-communications

Are humans capable of achieving optimal motor planning in controlling the risk-return tradeoff under
their own motor variability? Two experiments adopting different motor decision tasks were conducted— 79 —

to tackle this problem. In the temporal task, participants were asked to reproduce the target interval as
accurately as possible by mouse click on a semi-circled ring. The spatial task required participants toclick on an arched ring as proximate to its midline (hidden from view) as possible within a predefinedtime window. In both tasks, participants received a “gain” according to the task performance determined by temporal/spatial accuracy, where the steepness of gain function (high-risk high-return vs.
low-risk low-return) was modulated by the click position. Participants were asked to choose the risk-return configuration (i.e., the click position) so as to maximize the gain. Performance of individual participants was evaluated by a Bayesian decision-making model. We found that participants’ performancereached and maintained the Bayesian optimality within the experimental session of 210 trials in amanner of balancing the risk/return, both in the temporal and spatial tasks. The present result indicatesthat humans can achieve the optimal motor planning for risk-return control under spatiotemporal motor
variability.
Grant: none
Keywords: Bayesian Modeling, Movement Planning, Decision Making

P2-30
Impacts of spatial and verbal cognitive activities on SNARC effectShena Lu1, Yongchun Cai1, Shuangxia Li1,2
1Department of Psychology and Behavioral Science, Zhejiang University, 2Institute of Education, Henan Normal University

The spatial numerical association of response codes (SNARC) refers to the observation that responses
are faster for small numbers (1–4) with left-side response buttons and faster for large numbers (6–9)
with right-side response buttons. The underlying mechanism remains controversial. The SNARC effectcan be interpreted either as the association between number and space (i.e., small and large numbers areassociated with left-side and right-side spatial locations, respectively) or as the association between
number and linguistic concept (i.e., small and large numbers are associated with the “left” and “right”
concepts, respectively). Here, participants were required to perform either a spatial rotation task or averbal fluency task. The SNARC effect was measured both before and after this task. If the SNARC
effect was due to the spatial/conceptual association, it would be enhanced after the spatial rotation/verbal fluency task accordingly. When the SNARC effect was measured by the magnitude comparisontask (numerical information was explicitly processed), it was enhanced only after the spatial task. When
the SNARC effect was measured by the parity judgment task (numerical magnitude was implicitly
processed), it was enhanced after both the spatial and verbal tasks. Results suggested that the SNARC
effect was mainly modulated by spatial operations.
Grant: This work was supported by Project of Humanities and Social Sciences, Ministry of Education of China (18YJA190011, 18YJA190001),
Zhejiang Provincial Natural Science Foundation of China (LY18C090001), National Natural Science Foundation of China (61876222)
Keywords: numerical cognition, the spatial numerical association of response codes effect (SNARC)

P2-31
Drifting head movement in a micrometer order during visual fixation
Yasuto Tanaka1, Hiroyuki Fujie2, Taro Maeda3
1Neuromathematics Laboratory, 2Miki Holdings, 3Osaka University

Micro-meter order drifting head movement is found during visual fixation. The video oculography wasused to detect miniature head movement together with eye movement. Three markers on the forehead
together with left and right corners of each eye were shot by the high speed camera with 300 Hz. The
image was processed by the SURF algorithm yielding sub-micrometer resolution. Affine transformation
was used to match the three data points that determines the vector components of head motion. Subjects
were asked to move their head within a tiny amount towards the right, left, upper, and lower direction
from the central fixation. Visual feedback was given by a red central fixation spot. The motion trajectories at the foreheads and two corners of eye exhibited the directions of left, right, up, and down with thevelocities of 1.9 deg/sec, with the movement vector size 5.75+/−0.06 deg(average+/-SE) , correspond— 80 —ing saccadic elements of eye. During the stopping period (targeting location and back-fixation position),a slower component was found with 13 Hz frequency with the magnitude 0.5+/−0.09 arcmin(average+/−SE). The trajectory patterns were topologically identical between the position, indicating that the
subject shifted their head intentionally. Such drifting head movement is to be utilized for exact fixation,
attentional orienting, and vestibular ocular reflex (VOR) in a micrometer scale together with eye movement.
Grant: none
Keywords: visiomotor coordination, head movement, eye movement

P2-32
The effect of word’s visual complexity distribution on saccade targeting in reading chinese sentences
William Alberto Cruz Molina1, Jie Li Tsai2, Chia Hsing Chen3
1National Cheng Kung University, 2National Cheng Chi University, 3National Cheng Chi University

Previous studies about the factors that influence the decision about where to move the eyes next suggest
a strong influence from low-level features; some studies also assume that this decision involves thecomputation of a saccade target before the oculomotor program is executed. In order to test whether the
distribution of visual components within Chinese words influence the saccade targeting mechanism, we
devised a new parameter that reflects the distribution of visual information along 2-character words’
area: the Visual Complexity Distribution (VCD) index. Three groups of words with a marked VCD index were identified and embedded in natural sentences; the eye movement of Chinese native speakers
was recorded in order to contrast first-pass duration, position and probability eye movement measures
between conditions. The experimental effects were estimated through contrast between conditions using Linear Mixed Models, providing evidence about the VCD index’s influence on both, the decision
about when and where to move the eyes next. These results indicate that the luminance patterns within
2-character Chinese words can influence the specification of a saccade target when those words areabout to be fixated as well as modulate the fovea load when those words are currently fixated.
Grant: Embedding the VCD as regressor in Linear Mixed Models for different oculomotor measures resulted significant for some conditions
Keywords: Saccade Targeting Mechanism, Initial Landing Position, Reading Chinese

P2-33
Analysis of the relationship between eye movement and performance during dance rotation using
a wireless eye movement measurement device
Takuya Sarugaku, Yasuyoshi Kobayashi, Reiko Koyama, Shinya Mochiduki, Mitsuho Yamada
Tokai University

Sports science is attracting a lot of attention along with the Tokyo Olympics and Paralympics near athand in 2020. In particular, analyzing gaze movement during sports is considered to commit insights
into the athlete’s excellent performance, and is supposed to be useful for coaching athletes. For gaze
analysis during sports, particularly those sports in which the athlete moves vigorously, a wireless eye
movement measurement device is indispensable. Previous eye movement measurement devices were
expensive and often difficult to use outside of a laboratory. In recent years, compact and easy-to-use
measuring devices have been put into practical use, but these experimental devices cannot operate thedevices after the start of measurement. For athletes who exercise and move vigorously, the calibration
may shift during the experiment, so it can be said that the experimenter can remotely control the device
during the measurement is ideal to analyze eye movement while an athlete move quickly. We have developed a wireless eye movement measurement device that can be operated remotely while the athlete
is wearing it. In this paper, we describe the outline of this wireless measurement device and the relationship between head, body and eye movement during dance rotation measured using the device.
Grant: none
Keywords: Wireless eye movement measurement device, Sport, Gaze movement— 81 —

P2-34
A real time fatigue evaluation with standard deviation of the gaze point during calculation task
Yuki Kurosawa, Shinya Mochiduki, Yuko Hoshino, Mitsuho Yamada
Tokai University

In Japan, it is said that the eyes are the window of the mind. The eyes condition is often used as an indicator of feeling and physical condition. Among eye movements, the small involuntary eye movementsthat continually occur even during gazing are known to be particularly important for the vision. In addition, these movements can be sorted into micro-saccades, drifts and tremor components, also a visual
image cannot be maintained without these movements. However, few reports have measured changes
in small involuntary eye movements during a task in real time and analyzed them. Therefore, in thisstudy, we measured the eye movements within the gaze points while the subjects are performing a calculation task and examined the relationship between the standard deviation of eye movements and thecritical fusion frequency (CFF) value, which is used as an indicator of fatigue. As a result, it was shownthat the change in the eye movements within gaze point can be an effective parameter to evaluate thelevels of fatigue and concentration.
Grant: none
Keywords: Eye movement, fatigue, CFF

P2-35
Examination of physiological evaluation by investigation of influence of movies on eye movement
and CFF
Takahide Otomo1, Shinya Mochiduki1, Eriko Ishii2, Yuko Hoshino1, Mitsuho Yamada1
1Tokai University, 2Kagoshima Prefectural College

Nowadays, we can enjoy many video contents such as movies in various ways with advancement of
information technologies and an opportunity and time for watching images was increased. Therefore, it
can be said that analysis of influence from watching video contents on eye movement is an importanttask. As a major way to analyze influence when watching movies, measurements of electroencephalogram are often used and reported. However, few reports have been studied changes in eye movement
caused by watching video contents. Research using various parameters in addition to eye movement isdesirable. We used two types of movie contents to analyze influence on physiological parameters suchas eye movement and Critical Fusion Frequency. As a result, it was confirmed that watching movies
affected the latency of the saccade and the variance degree of fixation eye movement. Moreover, constant changes by each movie content were confirmed in several subjects. This study examined the influence that a different movie gave to an audience by the change of eye movement and that of physiological parameter. Moreover, the possibility of evaluating physiological information such as arousal levelwith eye movements was seen from the change tendency.
Grant: none
Keywords: Eye movement, Image, CFF, Saccades

P2-36
Examination of gaze characteristics while displaying vibrational motion stimuli in the peripheral
field of vision
Takahiro Ueno, Minoru Nakayama
Information and Communications Engineering, Tokyo Institute of Technology

Perceptual reactions to vibration stimuli orientated in 12 directions were analyzed in order to examine
human gaze characteristics while vibrational motion stimuli were displayed in the peripheral field ofvision. In the experiment, viewers were asked to detect the vibrational motion of a white circle shaped
stimulus in their peripheral field of vision while they conducted a RSVP task using letters positioned in
the central field of vision to examine the characteristics during the gaze. Viewer’s eye movements were
— 82 —

also measured at a sampling rate of 400 Hz in order to examine the change in attention level during task
execution. Fields of view were classified into three regions using cluster analysis of the percentage ofcorrect detection of the direction of vibrating stimuli. Perception ability was higher for movement in ahorizontal direction and for the area immediately below this. Results of cross spectral density analysis
of eye movement during the presentation of vibration stimulus also suggested that the cross spectral
power increase in the frequency band below 4 Hz shows the relationship between the dispersion of attention and activation of eye movement.
Grant: none
Keywords: eye movement, peripheral vision field

P2-37
An invisible target caused by backward masking induces a saccadic eye movement
Takuto Araki1, Yasuaki Tamada1, Masayuki Sato1, Keiji Uchikawa2
1Graduate School of Environmental Engineering, The University of Kitakyushu, 2Human Media Research Center, Kanagawa Institute of Technology

It is known that eye movements and visual perception are processed in separate neural pathways. One
might expect that a target, made invisible due to backward masking, could still cause a saccadic eye
movement. To verify this expectation, we measured a saccade latency between a stimulus presentationand the saccade onset. We presented a circular target at 10 deg either in the right or in the left visual fieldfrom a fixation point, then an annular mask at a certain stimulus onset asynchrony (SOA). Subjects
made a saccade to the target (or to the mask) as soon as possible. It was obtained that the saccade latency was 235 ms when subjects could not detect the target due to the mask with SOA of 60 ms, and that itwas 202 ms for the mask only. The saccade latency should be 262 (=202+60) ms if the mask only would
cause the saccade. This indicates that the invisible target contributed to the saccade. Furthermore, whensubjects could detect the target the saccade latency was 215 ms, shorter than when the target only waspresented (234 ms), suggesting that the mask enhanced the eye movement signal of the visible target.
Grant: none
Keywords: eye movement, psychophysics

P2-38
Influence of frequency of eye movements on decision making
Dan Uemura, Kenji Yokoi
National Defense Academy of Japan

There had been a controversial issue about the relationship between eye movements and decision making in the gaze cascade effect. In our previous study, we demonstrated the involvement of eye movements in preferential decision by using the gaze-contingent method, in which stimuli were shifted according to the gaze while keeping the retinal image constant irrespective of saccades (Uemura et al.,2019). The results also suggested that the frequent eye movements to the chosen face might reinforce
the preference bias. So, in this study, we investigated the influence of frequency of eye movements on
preference formation. Similar to the previous studies, two faces were presented alternatively with different durations (900 ms or 300 ms) and the participants selected the more attractive one. To manipulate
the frequency of eye movements, the longer-presented face was moved in a circular trajectory up to six
times within 900 ms and the participants were asked to chase it. The relationship between the frequency
of eye movements and preferential bias was discussed in relation to the proposed gaze cascade model.
Grant: none
Keywords: gaze cascade effect, eye movements, decision making, face recognition— 83 —

P2-39Change in posture and body sway by looking down
Masahiro Ishii
Sapporo City University

An eccentric visual target, which requires a large lateral gaze shift to project it onto the fovea, elicits not
only an eye and head movement but also a trunk and foot movement in the same direction (Hollands, etal., 2004; Land, 2004; Solomon, et al., 2006). Although the temporal and spatial characteristics of the
body movements while gazing at eccentric targets have been studied, it seems that none has studied the
body movements while looking down. In this study, the posture and the center of foot pressure of subjects were measured while they were looking down. The posture was measured using a video camera,
and the center of foot pressure was measured using a sway meter device. The downward angle from thehorizontal to a line of sight from the observer to the visual target was 70 degrees. We found that the
subjects moved their shoulder forward and their buttocks backward while looking down. We also foundthat the center of foot pressure shifted posterior with deteriorated postural stability.
Grant: none
Keywords: eye-body coordination

P2-40
Automatic detection of oculomotor disorders
Jean-Louis de Bougrenet1, Mathieu Lamard2, Johanne Bolloch1, Vincent Nourrit1
1IMT Atlantique, 2University of Western Brittany (UBO)

Assessment of oculumotor functions is a key part of any eye examination and several studies haveshown that it could also help in the diagnostics of various neurological conditions. Objective measurement of oculomotor performances using eye tracking is however little used in orthoptics or clinicalpractice, perhaps partly because current eye tracking tools provide raw or little processed data that areof limited value without deeper analysis. The aim of this study was to develop more sensitive tests andanalysis tools to be able to identify automatically patients with oculomotor disorders. 40 subjects (25normals and 15 orthoptics patients) participated to the study at Brest University Hospital. Subjects had
to perform series of 3 different orthoptics exercises (fixation, saccades, small pursuit) during which
their eyes’ movements were recorded with a Tobii Pro Spectrum eye tracker. The spatial and temporal
statistics of the trajectories were analysed using conventional metrics and a recurrent neural network.
The study shows that an eye tracker is a valuable tool to quantify oculomotor performances in orthoptics practice. The results of this study open up interesting possibilities for the use of the various algorithms in future work.
Grant: none
Keywords: eye tracking, Orthoptics

P2-41
Do ‘no’ responses arise from the same processing as ‘yes’?: A two-stage model for object detection
using fragmented contours
Kosuke Taniguchi1, Kana Kuraguchi2, Yukuo Konishi1
1Center for Baby Science, Doshisha University, 2Faculty of Psychology, Otemon Gakuin University

In an object detection task, participants respond ‘yes’ when an object is detected, or ‘no’ when no object
is detected. Previous studies have not argued significant differences in the processing of yes/no responses in the 2-alternative forced choice task. In this study, we investigated whether yes/no responses differ
in response time and accuracy by controlling the task difficulty through fragmented contours (short andlong length) and stimulus duration (50, 100, and 200 ms). The results showed a significant difference inthe processing of yes/no responses, in that ‘yes’ responses were accurate regardless of task difficulties,
whereas ‘no’ responses differed by task difficulty. Here, accurate and slow ‘no’ responses correlated— 84 —

with easy task difficulty, and inaccurate and fast ‘no’ responses correlated with difficult tasks. Therefore, we suggest a two-stage model involving early and later processing. In the early processing stage,inaccurate and quick ‘no’ responses are generated when information received is insufficient. In the late
processing stage, accurate ‘yes’ and delayed ‘no’ responses are generated as a result of object processing, such as grouping. Thus, ‘yes’ responses arise as a result of accurate decision making, whereas ‘no’responses, depending on task difficulty, arise from both intuitive and accurate decision making.
Grant: none
Keywords: yes/no response, contour detection, 2-alternative forced choice, decision making

P2-42
Influence of optical flow on unconscious horizontal- and cyclo-vergence
Kenji Murase1, Yusaku Takeda1, Toshihiro Hara1, Hirohiko Kaneko2
1Mazda Motor Corporation, 2Tokyo Institute of Technology

In order to present appropriate visual information while driving an automobile, it is necessary to know
the behavior of unconscious eye movement in addition to the intentionally controlled gaze direction. In
this study, we measured and analyzed horizontal- and cyclo-vergences, while observing optical flow
simulating the visual stimulus when driving an automobile. In the experiment, randomly scattered white
dots on a black background were presented on the display and they moved to simulate the optical flow
when moving forward in a three-dimensional virtual space. The velocity and spatial configuration were
stimulus variables. As a result, we found that unconscious out-cyclovergence (right and left eyes moveclockwise and counter clockwise, respectively) occurred when observing the optical flow while moving
forward. This result indicates that the shape of horopter, which is the spatial locus producing the images on the corresponding points of two eyes, is different during driving and during stopping and then thehuman space perception would also change. Based on this results, it will be possible to define the appropriate positions for presenting visual information in the cockpit of an automobile by measuring or
predicting unconscious eye movements due to the optical flow while driving.
Grant: none
Keywords: eye movement, vergence, optical flow

P2-43
Infant Brain Detects Inconsistency between Belief and Action: An Electroencephalography Study
Yu-Ju Chou1, Jung-Tai King2
1Department of Early Childhood Education, National Tsing Hua University, 2Brain Research Center, National Chiao Tung University

The ability to predict the actions of others on the basis of their perspectives is crucial to successful social interactions. A current debate concerns whether preverbal infants possess this ability; the ability canbe investigated by examining their dynamic brain activity. In this study, we manipulated the inconsistency between others’ beliefs and subsequent actions to examine the conflict detection ability of preverbal infants with respect to the beliefs and actions of others. We examined the mid-frontal theta-band
power activation of 18 six-month-old infants when they were presented with two false-belief scenariosthat led to different action consequences. An additional eleven infants were excluded from the analysis
because they failed to complete the task or had high EEG noise. The results showed that ten infants’frontal theta-band power significantly increased after the onset of an agent’s action in the incongruent
condition compared with the congruent one. These findings indicate that six-month-old infants alreadypossess the ability to represent an agent’s intended action and detect a different outcome. Other factors,
such as parent–child interaction quality and infant temperament, may also influence the time at which
this ability develops and must be studied further.
Grant: none
Keywords: infant, belief-based action prediction, conflict detection, electroencephalography— 85 —

P2-44
A Normative Formalism for Internal Criterion Inference and Its Validation in Human VisualClassification and Brain Activity
Heeseung Lee1, Kyoungwhan Choe2,3, Sang-Hun Lee1
1Department of Brain and Cognitive Sciences, Seoul National University, 2Department of Psychology, The University of Chicago, Chicago,
3Mansueto Institute for Urban Innovation, The University of Chicago

Everyday life requires humans to make discrete decisions on continuous perceptual quantities. To thisend, we learn and apply ‘criterion’ that partitions the continuous perceptual quantities into discreteclasses. Reflecting this intuition, criterion has been an essential theory constituent on perceptual decision-making. However, criterion has mostly been assumed simply as a constant lacking a computational rigor commensurate to other theory constituents such as ‘stimulus’ and ‘decision variable’. Here, weredressed this inconsistency by developing a unified computational model that has the optimal inference
process also for criterion not only for the other theory constituents, and the normative interplay between
them. The criterion inference manifested its empirical impacts in a decision, decision time, and neuralactivity concurrently by revealing the relativity in decision-making and discerning neural loci for eachtheory constituents. Therefore, we hope to supersede the conventional constant-criterion framework insystems neuroscience by the comprehensive framework with a criterion inference.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: decision-making, internal criterion, Bayesian inference, fMRI

P2-45
Learning Decision Criteria from Feedback for Visual Classification
Hyang-Jung Lee, Sang-Hun Lee
Department of Brain and Cognitive Sciences, Seoul National University

Every day we perform numerous decision-making tasks, with a specific goal for each. To maximize
performance, one must learn the true structure of contingencies imposed by the environment, typically
based on feedback. The contributions of feedback to such learning in perceptual decision-making remain elusive, compared to those in reward-based or motor decision-making. The present work focuseson how people utilize feedback to learn decision criteria for a visual classification task. While people
classifying ring stimuli of different sizes into ‘small’ and ‘large’ over consecutive trials, we stochastically sampled criteria used for giving ‘correct’ or ‘incorrect’ feedback. Taking a Bayesian approach, we(i) developed a generative model—people’s causal account for the statistical structure of our task, (ii)created several Bayesian agents who differ in the way of propagating the information provided by feedback to infer decision criteria, and (iii) examined which agent’s inference best matched those of people
by comparing psychometric and chronometric curves. We found one strong winning agent, who ‘rationally’ resolves the logical inconsistency between her own decision (e.g., ‘small’) and feedback (e.g.,‘large’) by allowing neither her own decision nor feedback to propagate over her generative model
when inferring decision criteria.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: psychophysics, computational modeling

P2-46
Chromatic information modifies gaze patterns in visual search
Natsuko Wasaki1, Tatsuto Takeuchi1, Sanae Yoshimoto2
1Japan Women’s University, 2Hiroshima University

Experts in comprehension of visualization, who engage in deliberate practice, such as radiologists,
perform very well in tasks involving finding targets from images. Superior visual search skills general— 86 —

ly accompany the modification of gaze patterns while searching. Meanwhile, chromatic information is
known to enhance the comprehension of various types of images, such as metro maps, and therefore,
finding a target is easier on a colored map than on a gray-scale map. The question is whether gaze patterns on a colored map is similarly modified as that of experts. In this study, participants searched atarget station on the colored or gray-scale metro map seen for the first time. We found that the gaze
patterns for the colored map were modified as follows: reduced time to first fixation, shorter fixation
duration and dwell time, and fewer fixation counts. However, these patterns were dependent on the areas of interest and the saccade amplitude did not differ between the colored and gray-scale maps. No
significant effect of practice was found for the colored map. These results indicate that the gaze patterns
could be modified by adding color, but the underlying mechanisms enabling performance enhancementof visual search by color and practice would be different.
Grant: none
Keywords: visual search, eye movement, color, learning

P2-47
Visual hallucinations in Parkinson’s disease – Understanding fixation potentials in a free-viewing
face detection experiment
Gajanan S. Revankar1, Noriaki Hattori1, Tomohito Nakano1, Yuta Kajiyama1, Etsuro Mori2, Hideki
Mochizuki1
1Department of Neurology, Graduate School of Medicine, Osaka University, 2Department of Psychiatry, Graduate School of Medicine, Osaka

University

In Parkinson’s disease (PD) patients a precursor phenomenon to Visual hallucinations (VH) known as
Pareidolia occurs. These are misperceptions of meaningful objects/faces arising from ambiguous forms.
The main purpose of this study is to understand the mechanism of VH in PD, using Pareidolias as amarker to elucidate the temporal dynamics of brain in face recognition and misperceptions. We performed co-registered eye-tracking – electroencephalography (EEG) recordings in 20 PD patients and 12
age matched healthy controls using a computer based modified Noise pareidolia test which involves
identifying faces from noisy images. To assess cognitive status, a series of neuropsychological assessments were done. Half of the PD patients (n=10) showed pareidolic responses (misperceptions) whereas the other half did not. Those with pareidolias had much higher pareidolias when compared to eithergroup. Fixation related parameters showed poorer accuracy and increased latency in PD patients. Presaccadic potential was seen to be less negative in PD compared to controls explaining the failure ofvisual encoding and transfer of attention during visual exploration. Fixation potentials changes between
the groups did not correlate well with neuropsychological examination. We describe the potential use ofpareidolias as early markers for identifying PD patients prone to hallucinations.
Grant: none
Keywords: Eye-tracking, Electroencephalography, Unconstrained visual exploration, Eye-fixation related potentials

P2-48
Proposal of new evaluation method of mental work-load using eye-head coordination
Kimihiro Yamanaka1, Kenji Kobayashi2
1Intelligence and Informatics, Konan University, 2Graduate School of Natural Science, Konan University

Experiments on mental work-load and eye-head coordination were carried out to propose the evaluationindex of mental work-load on the task, without distracting subject’s main task. Eye and head movement
was measured by non-contact device under the condition which subject’s mental work-load was controlled. In particular, Subjects performed tasks which are three kinds of numerical task such as hard,
middle and easy for inducing an increase the mental work-load, and driving task for inducing eye-headcoordination. In the experiment, subjective work-load and the ratio of correct answers for numericaltask were measured. As a result of consideration on numerical task, it was found that subject’s mental
work-load was increased under numerical task of hard conditions. Also, the ratio of correct answers was— 87 —

decreased. As a result of eye and head movement, it was found that eye-head coordination to visualtarget was influenced by mental work-load. Eye movement precedes on viewing to visual target which
under numerical task of easy conditions. On the other hand, head movement precedes on viewing tovisual target under numerical task of hard conditions.
Grant: none
Keywords: eye and head movement, visual information processing, mental work-load

P2-49
Suitable dwell time for eye-gaze-based object selection with eye tracking
Yesaya Tommy Paulus1, Gerard B Remijn2
1Kyushu University, Graduate School of Design, Department of Human Science, 2Kyushu University, Faculty of Design, Department of Human

Science

Dwell time refers to the time needed to select specific objects on a screen with eye-gaze-based input, forexample with eye tracking. This study investigates the dwell time necessary to select objects on a display for three types of visual password formats. The formats were an alphanumeric format, a patternformat, and a picture format. The participants were asked to memorize a 4-object or a 6-object password
and register, confirm, and log in the password using eye-gaze-based input, with a minimum dwell time
set at 250 ms, 500 ms, 1000 ms, and 2000 ms per object. The task was performed on 4 grids, consistingof 3×4, 4×3, 4×5, and 5×4 cells (columns-by-rows), respectively. The participants were also asked toevaluate each dwell time with a rating scale. The results showed that the participants required more time
to authenticate a 4-object or 6-object password as the dwell time increased, but with fewer input mistakes for each of the three password formats. These results suggest that a dwell time in between 500 and1000 ms is suitable for visual password object selection using eye-gaze-based input, depending on individual performance and preferences.
Grant: none
Keywords: dwell time, eye-gaze-based input, eye tracking, visual password

P2-50
A social interaction-based model for human locomotion
Mingcheng Miao1, Chen Zhou1, Yifei Hu1, Xinran Chen1, Shuguang Kuai1,2
1Shanghai Key Laboratory of Brain Functional Genomics, Key Laboratory of Brain Functional Genomics, Ministry of Education, School of

Psychology and Cognitive Science, East China Normal University, 2NYU-ECNU Institute of Brain and Cognitive Science, New York University
Shanghai

As social animals, people tend to keep a comfortable distance with other ones, named as personal space.
When people bypass others, they are not only avoiding a physical collision, but also avoiding intruding
personal spaces of others. Here, we conducted three experiments to testify the hypothesis and established a social interaction model to predict human walking behaviors in a social environment. In Experiment 1, participants were asked to steer towards a pillar while a virtual human was standing halfway
between the pillar and participants in a virtual environment. We found that participants tend to bypass
the virtual human from the side with weaker potential social interaction. In Experiment 2, participants
were asked to bypass a virtual human who was oriented to different directions. We then quantitatively
measured the space participants avoided during their walking. Based on that, we built a social interaction model to predict walking routes. In Experiment 3, we asked participants to bypass virtual human at
random positions and with different orientations. The social interaction model achieved a good performance in predicting the routes, supporting the robustness and generalization of the model. Our results
indicate that human walking behavior is influenced by the perception of others’ personal space.
Grant: National Natural Science Foundation of China Grants (No. 31771209)
Keywords: Perception and action: Locomotion, Behavior/Psychophysics— 88 —

P2-51The Presence of Pupillary Responses Confounded by Eyeblink, and a Statistical Solution for That
ConfoundSang-Hun Lee, Kyung Yoo
Department of Brain and Cognitive Sciences, Seoul National University

Pupillometry has become one of the most popular measurement tools among cognitive and systems
neuroscientists, earning an honorable sobriquet “window for cognition.” Pupillometry indeed has many
merits as indirect measures of internal cognitive states. Despite its popularity and merits, however, users
must be warned of the fact that potential factors that influence pupil size have not been fully catalogued,
and, more importantly, that it is currently unknown how those factors interact with one another. The
present work notes ‘eyeblink’ as one of so far unattended yet substantive factors and demonstrates theoretical and empirical repercussions of failing to handle ‘eyeblink’ properly. Our findings are threefolds. First, we show that each blink triggers a specific temporal profile of pupil size change, 1-second
long period of constriction followed by slower recovery, which we named BPR (blink-locked pupillary
response). Second, we demonstrate that BPR confounds pupillary changes caused by cognitive factors
by showing that the prevalence of eyeblink is associated with cognitive factors such as working memory loads. Lastly, we develop a statistical toolbox that corrects pupillary responses for BPR. We expect
the work to help users of pupillometry recognize the presence of BPR and fix the confounds due to BPR
effectively.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: pupillometry, eyeblink, deconfounding

P2-52
Usability of gaze control: Visual search in a gaze-contingent foveated imaging window with temporal delay
Junhui Kim, Takako Yoshida
Applied Brain Science Laboratory Engineering, School of Engineering, Tokyo Institute of Technology

Foveated imaging is an image processing technique that varies the image resolution based on the viewer’s gaze position. This enables wide field-of-view and retina-level resolution for a human observer
while only requiring limited image processing resources and information of the image presentation
system. However, at high resolutions, a spatio-temporal mismatch between the gaze movement and thecontingent window can degrade the user’s visual experience such as immersion, comprehension of theimage, and so on. We evaluated the correlation between the usability of the gaze-contingent of the window and the temporal delay from the gaze shift of the human participant to the shift of the high-resolution window. The task was a simple visual search for a Chinese character. The results indicated that thesense of agency for the window was maintained when the temporal delay was within about 500 ms. Thissensation was completely lost at about 3000 ms. Our results indicate that there is some critical temporaldelay to disrupt the user’s sensation that they are controlling the window with their gaze.
Grant: JSPS for TY
Keywords: vision cognition, eye gaze

P2-53
Patterned silencing of parvalbumin neurons in rodent visual cortex
Akira Masuda, Susumu Takahashi
Doshisha University

Stimulation of visual cortex can induce artificial sense of vision, called phosphenes, and be utilized forrecovery of visual loss. Optogenetic stimulation promises higher resolution and more specific neuraltargets than other forms of stimulation including mechanical, electrical, or magnetic ones. However, few— 89 —

studies tested which combination of cell-types and optogenetic proteins is applicable for the visual restoration. Here, in rats, we electrophysiologically characterized optogenetic silencing of parvalbumin(PV) positive inhibitory neurons in monocular region of primary visual cortex (V1 m) to locally disinhibit neural activity. We used PV-Cre rats which had given adeno-associated virus (AAV) fused with
DIO-NpHR3.0 into V1 m. Red LED light (630 nm) was emitted from photo-stimulator system consistingof mini-LED (8×8 pixels in 20×20 mm, 2.8 mm pitch) and two convex lenses (biconvex and pleno-convex lens) installed above the V1 m. We recorded physiological responses evoked by illumination (optogenetic stimulation) or visual stimuli with high-density neural probes on the anesthetized conditions. We
found that large number of excitatory neurons showed phasic increase in response to illumination. Thissuggests that the optogenetic silencing PV neurons is an applicable strategy of artificial vision.
Grant: none
Keywords: visual cortex, optogenetics, artificial vision, electrophysiology

P2-54
Using macromolecular tissue volume mapping to identify subdivisions in human lateral geniculate nucleus
Hiroki Oishi1,2, Hiromasa Takemura1,2, Kaoru Amano1,2
1Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology and Osaka University,
2Graduate School of Frontier Biosciences, Osaka University

Lateral geniculate nucleus (LGN) consists of magnocellular (M) and parvocellular (P) subdivisions.
While these subdivisions have different anatomical properties, identifying these subdivisions from living human brain using structural MRI has been difficult, partly due to their small size and image inhomogeneity in a standard T1-weighted image. In this study, we tried to identify human LGN subdivisions
using macromolecular tissue volume (MTV) mapping (Mezer et al., 2013), which provides quantitative
map corrected for image inhomogeneities. We first identified the entire LGN from four healthy participants using high-resolution proton density-weighted image. We then collected MTV data and classified
20% of voxels with the lowest MTV to the M-group and the remaining 80% of voxels to P-group. This
classification is because the area size of P-group is roughly four times larger than that of M-group (Andrews et al., 1997). As a result, we found that estimated M- and P-group voxels are clearly separated
and are located ventromedial and dorsolateral respectively in all participants. These patterns were consistent with LGN anatomy for human and primates. This result suggests that MTV mapping provides
stable parcellation for LGN subdivisions, which will be useful to study human LGN anatomy with respect to retinal disorders or visual functions.
Grant: Japan Society for the Promotion of Science (JSPS) KAKENHI (JP17H04684, H.T)
Keywords: Lateral Geniculate Nucleus, Quantitative MRI, Tissue segmentation

P2-55
Inter-individual deep image reconstruction
Tomoyasu Horikawa1, Yukiyasu Kamitani1,21Department of Neuroinformatics, ATR, 2Graduate School of Informatics, Kyoto University

Recent studies demonstrated the utility of deep neural networks (DNNs) for characterizing visual representations in the brain, offering opportunities to develop advanced applications via brain–DNN interfacing. By decoding brain activity measured by functional MRI into DNN feature patterns, it has become possible to reconstruct visual images via decoded feature patterns (“deep image reconstruction”).
However, modeling the relationship between DNNs and the brain requires large amounts of data (several hours of measurements) from each individual, limiting the generalizability of such brain–DNN
technology. Here, we examined whether models for deep image reconstruction can generalize acrossindividuals by functionally aligning brain data. We used hyperalignment techniques to construct a common representational space from brain activity patterns of multiple individuals, using identical sequences of natural scene stimuli. Reconstruction was performed using one individual’s data for model train— 90 —ing and another’s for testing. The inter-individual analysis successfully reconstructed viewed images
with recognizable silhouettes of objects even with ～30 min brain data for functional alignment. Our
results demonstrate that functional alignment with a small amount of data preserves detailed visualfeature representations across individuals, providing an efficient way to create visual image reconstructions without training data from each individual.
Grant: none
Keywords: brain decoding, visual image reconstruction, deep neural networks, functional magnetic resonance imaging

P2-56
The response property and efficacy of prosthetic retinal stimulation by single-unit analysis
Tomomitsu Miyoshi1, Hiroyuki Kanda2, Takeshi Morimoto2, Takashi Fujikado2
1Dept. Integrative Physiology, Graduate School of Medicine, Osaka University, 2Dept. Applied Visual Science, Graduate School of Medicine, Osaka

University

We have been developed a novel retinal prosthesis, Suprachoroidal Transretinal Stimulation (STS) for
photoreceptor degenerating diseases. The stimulating electrode array of STS is implanted into scleraand do not directly contact retinal tissue to avoid physical damage. To investigate the response properties by STS, we recorded the single-unit activities from cat lateral geniculate nucleus (LGN) relay
neurons. The size of each electrode head in the implanted array was 0.5 mm in diameter and 0.3 mm inheight, which was the same as the clinical device. The waveform of single pulse was biphasic, 0.5 or 1
mA amplitude, and 0.5 ms/phase duration. The single pulse STS elicited the burstic discharges, which
occurred alternately on ON and OFF cells. This burstic response was due to the prolonged change of
excitability by the interaction in the stimulated retinal circuits. With the continuous stimulation, theelicited number of spikes was not proportional to stimulating frequency. The maximum discharges per
second was achieved by the stimulation not greater than 50 Hz, suggesting that high frequency stimulation may less effective.
Grant: none
Keywords: retinal prosthesis, electrophysiology

P2-57
The double representation of the fovea, if there are ipsilateral connection from the eye to the
LGN, why is there no cortical representation?
Mark Matthias Schira
University of Wollongong

The debate about a double representation of the fovea in human visual cortex is still ongoing (Jordan etal. 2014). Ipsilateral connections from the retina to the LGN exist and are reasonably well described(Stone 1973, Bunt & Minkler 1977, Fukuda et al. 1989). The retinotopic representation of the foveal
confluence in human visual cortex, specifically the central 0.5 degree, is substantial with more that2000 mm2 for V1, V2 and V3 alone (Schira et al. 2009) exclusively representing the contralateral visual field. No ipsilateral visual field representation can be seen in V1. Reanalysing the data by Bunt &Minckler and Fukuda et al., only a very small count between 110 and 130 cells was estimated. For
conscious perception it needs be considered: Firstly, while the ipsilateral overlap is relatively large inthe periphery (up to 15 degree), close to the fovea it is either less 0.5 degree or absent. Secondly, there
are a substantial number of transcallosal fibers along the representation of the vertical meridian at theboundary of V1 and V2, especially in the foveal confluence (Zeki et al. 1969, Van Essen et al. 1986)
suggesting a double representation would be superfluous. Finally, macular sparing, clearly cannot bewell explained by an ipsilateral representation of the visual field. Many patients with hemianopia haveno macular sparing whatsoever (Reinhard &Trauzettel-Klosinski, 2003), which is irreconcilable with asignificant ipsilateral representation.
Grant: none
Keywords: Foveal vision, Anatomy, Retinotopy, Physiology— 91 —

P2-58Quantifying the Impacts of Transcranial Electrical Stimulation on Cortical Activity in Human
Visual Cortex
Jeongyeol Ahn1, Juhyoung Ryu1, Sangjun Lee2, Chany Lee3, Chang-Hwan Im2, Sang-Hun Lee1
1Department

of Brain and Cognitive Sciences, Seoul National University, 2Department of Biomedical Engineering, Hanyang University,

3Department of Structure & Function of Neural Network, Korea Brain Research InstituteTranscranial electrical stimulation (tES) has become a popular interventional method of stimulating
human brains noninvasively. Despite reports of modulation of membrane potentials or BOLD responses by tES, it is far from conclusive whether and how tES affects neural activity. One prominent factor
contributing to this inconclusion is that the baseline variability of noises intrinsic to measurements,
which occur with diverse origins not just between but also within experimental sessions, have not been
properly handled in previous studies. For example, the intrinsic variability of hemodynamic responses
within and between scans causally confounds tES and thus complicates the attribution of observed effects in BOLD. To overcome this problem, we developed an experimental protocol that allows for statistically dissecting tES effects and other intrinsic noises in BOLD activity. By applying this protocol tohuman visual cortex, we demonstrate that tES induces substantial changes not only in the temporal
dynamics of hemodynamic response function (HRF) but also in cortical population responses to dynamic stimuli, which cannot be reduced to the changes in HRF. Our findings imply that tES, when applied in protocols with statistical rigor and power, can manifest its impacts on BOLD signals in much
more complicated and nuanced ways than previously reported.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: Transcranial Electrical Stimulation, Visual Cortex, fMRI

P2-59
Quantitative analyses of cortical responses to prosthetic microstimulations using voltage-sensitive
dye imaging on mice
Celine Audrey Vergne, Lucas de Levy Oliviera, Tamas David Fehervari, Keisuke Morisada, Naofumi
Suematsu, Yuki Hayashida, Tetsuya Yagi
Graduate School of Engineering, Osaka University

Microstimulation with penetrating electrodes is now considered to be one of the key technologies invisual cortical prosthetics for restoring visual function in blind patients. However, it is still not wellunderstood how the excitation distributes and propagates in the cortical circuits in response to the microstimulations, although it is crucial to design the cortical prostheses. The purpose of the study is toelucidate a quantitative relationship between the microstimulation and the spatiotemporal properties ofcortical response. We applied a single pulse and repetitive pulse stimulations to the mice primary visual cortex and imaged the responses using voltage-sensitive dye imaging. The response induced by asingle pulse spread in wide region of the primary visual cortex. In contrast, the spreading region of response to repetitive stimulation gradually shrank following the transient propagation to wide region. We
modeled these spatiotemporal properties of cortical responses with a combination of excitatory andinhibitory synaptic responses. The present results quantified the spatiotemporal properties of corticalresponses to microstimulations and thus provides critical insight to evaluate the efficacy of the stimulation patterns for evoking phosphene perception.
Grant: Grant-in-Aid for Scientific Research from MEXT, Japan (25282130 and 18K12059 and 16717084), and Grant-in-Aid for Challenging
Exploratory Research from MEXT, Japan (25560197)
Keywords: Visual prostheses, Microstimulation, Imaging, Model analysis— 92 —

P2-60Wearable phosphene image simulator for cortical visual prosthesis
Fumiaki Nakao, Nobuaki Kishigami, Jinhwhan Choi, Yuki Takano, Naofumi Suematsu, Tetsuya Yagi
Graduate School of Engineering, Osaka University

Previous clinical and animal experiments suggeted that microstimulations delivered to visual cortex
with multi-electrode induced apparent image consisting of phosphenes, which could partially restore
the visual function in blind patients. In order to evoke appropriate perception that is useful for object
recognition, self-navigation and so on, the electrode arrangement in the cortical area and current stimulation patterns must be designed so that phosphene image should effectively convey the image information of surrounding world. However, it is not straight forward to predict the feasible phophene images, since the visuo-topic map from the visual field to the cortical surface is not simple. In the present
study, we built a wealable phosphen image simulator consisting of an image processing unit, a visualcortex model expressed with the wedge-dipole formulation and a HMD. The phosphene images werereconstructed in real time on the HMD while modifing the electrode arrangemet and current stimulation
patterns in the cortex model. We conducted psychophysical experiments on normally sighted subjects
wearing the phosphen simulator to assess the effective and feasible electrode arrangement and stimulation patter. The phosphen simulator deviced in the present study accelerates the development of thecortical prosthesis.
Grant: Grant in Aid for Scientific Rsearch (C), MEXT (16k01354)
Keywords: VIsual prosthesis, Phosphene image, Simulation, Psychophysics

P2-61
In vitro Comparison of Orbital Preadipocyte Adipogenesis between Pediatric and Adult Graves’
Ophthalmopathy
Jung Hyo Ahn
Pusan National Universtiy Medical College

Purpose: To evaluate whether orbital preadipocytes obtained from pediatric Graves ophthalmopathy(GO) patients differ from that from adult GO under lipopolysaccharide (LPS)-induced inflammatory
condition. Materials and methods: The pediatric and adult orbital preadipocytes were differentiated inadipogenesis media without LPS intervention. The remaining pediatric and adult orbital preadipocytes
were stimulated to differentiate into mature adipocytes with LPS intervention. The expression of adipogenic transcription factor, peroxisome proliferator-activated receptor-gamma (PPAR-γ), and CCAAT-enhancer-binding protein α (C/EBP-α) were determined by real-time PCR. The cells were stained with oil
red O to observe the intracellular lipid accumulation. Results: Without LPS-induced inflammation, thepediatric orbital preadipocytes showed increased expression of PPAR-γ, C/EBP-α, and accumulation of
intracellular lipids than the adult orbital preadipocytes. When treated with LPS, both pediatric and adultpreadipocytes showed increased expression of adipogenesis as compared to without treatment. Especially, the pediatric orbital preadipocytes had increased expression of PPAR-γ, C/EBP-α, and accumulation of intracellular lipids than adult orbital preadipocytes. Conclusions: Adipogenesis of the pediatricorbital preadipocytes was more affected and up-regulated as compared to that of the adult preadipocytes
in GO by LPS-induced inflammation.
Grant: none
Keywords: orbit— 93 —

P2-62
Female Bias in Face Memory
Jenna Jaewon Lee1,2, Koyo Nakamura2,3,4, Katsumi Watanabe2,5
1Johns Hopkins University, 2Waseda University, 3Japan Society for the Promotion of Science, 4Keio Advanced Research Centers, 5UNSW Sydney

People tend to expect to see male than female faces under perceptual uncertainty (Watson et al., 2016).
On the other hand, people are better at recognizing female faces when attention is less available during
encoding (Palmer et al., 2013). Many previous studies of gender bias in face memory focused on theencoding stage of face memory. In the present study, we examined whether any gender bias would exist
in storage and/or retrieval stages in memorization of faces. In the first experiment, participants memorized faces and chose the corresponding face from an array of face stimuli morphed along the sexual
dimorphism spectrum. We found that both male and female participants tended to choose the slightly
feminized stimuli on the spectrum than what they actually had seen. In the second experiment, we prepared pairs of original and slightly feminized face stimuli. Participants memorized an original face andthen the two faces were presented side by side: one original and the other feminized face. We observed
similar effects on face memory, namely, the bias to choose feminized faces as remembered ones. Overall, these results suggest that there is a significant bias toward feminine faces in the storage and/or retrieval stages in face memory.
Grant: none
Keywords: Cognitive Science, Memory, Face

P2-63
Cultural Differences in the Generalization of the Mere Exposure Effect
Hidekazu Yarimizu1,2, Koyo Nakamura3,4,5, Katsumi Watanabe3,6, Masami Kanazawa Yamaguchi1
1Faculty of Letters, Chuo University, 2Faculty of Psychology, Meijigakuin University, 3Faculty of Science and Engineering, Waseda University,
4Japan Society for the Promotion of Science, 5Keio Advanced Research Centers, 6Art & Design, University of New South Wales

This study investigated the cultural differences in the generalization of the mere exposure effect, which
was examined using Asian face stimuli for Asians. The generalization of the mere exposure effect refers
to the increase in liking of a previously exposed face evaluated again later, regardless of face directions
presented earlier. Exposure to upright and inverted faces was compared to confirm that the face is specific in the generalization of the mere exposure effect. The vertical orientation (upright and inverted)and the horizontal angles (0, 45, 90 degrees) of Asian faces were manipulated, and those faces were
presented to Asian participants. The participants then evaluated their liking of the upright face presented at 0°. Regarding upright faces, exposure at 45° increased their liking when the face was evaluatedlater than at 0°; however, there was no difference between 0 and 90 degrees. Inverted faces did notchange the participants’ liking for them depending on the angles. These results show that exposure to
inverted faces increases liking of the same faces in upright orientation in Asians, which is different fromthe result of a previous study with Caucasians.
Grant: none
Keywords: Face, Cultural Difference, The Mere Exposure Effect

P2-64
Activation Pattern Classification Revealed Facial Expressions Encoding in N170 and P200
Ka Lon Sou1, Manuel Seet2, Hong Xu1
1Psychology, School of Social Sciences, Nanyang Technological University, Singapore, 2Singapore Institute of Neurotechnology (SINAPSE),

National University of Singapore

How does the brain encode emotional stimulus? It has been debated whether the activation of theface-sensitive N170 is modulated by emotion. Most previous studies focused on the peak activation of
the N170, but largely ignored the activation pattern of the N170 or P200 which is often overlooked inemotion perception. In this study, we investigated whether the activation patterns of the N170 and P200
— 94 —

can predict the emotion category of the presented face stimuli. Fifteen subjects were recruited to complete an emotional face categorization task, while EEG signals were recorded simultaneously. We
trained the support vector machine to classify emotion of the presented emotional faces based on the
N170 activation pattern and the P200 activation pattern. Three main findings emerged: 1) The P200
peak amplitude was less negative for happy faces. 2) Both the N170 activation pattern and the P200
activation pattern could predict the emotion category of the presented face above chance level. 3) Neutral faces were more accurately classified than angry faces with the P200 activation pattern. Our results
argue that the N170 and the P200 might be both activated in facial emotion perception but play different
roles in emotion categorization.
Grant: none
Keywords: Emotional face perception, EEG, Pattern classification analysis

P2-65
Unattractive faces are identified more easily than attractive ones
Kana Kuraguchi1, Hiroshi Ashida2
1Otemon Gakuin University, 2Kyoto University

Attractive faces capture our gaze and we can judge facial attractiveness immediately even in peripheral
vision. These previous studies suggest that attractive face is detected easily but that unattractive face israther ignored. We hypothesize that perceiving unattractiveness precedes perceiving attractiveness for
distracting attention from unattractive faces and then focusing on attractive ones. To test this idea, weinvestigated whether facial attractiveness affects performance of face identification. In this study, we
conducted a face identification task, in which participants judged whether a face matched one of the two
faces presented earlier, and then compared the hit rates of attractive and unattractive faces. Result
showed that hit rate of unattractive faces was significantly higher than of attractive ones, which suggeststhat facial attractiveness affects face identification. This effect of facial attractiveness on face identification, however, appeared only when both attractive and unattractive faces were presented and weredirected attention to. Identification of unattractive faces with comparative ease may facilitate directing
our gaze to attractive faces, which is considered adaptive behavior.
Grant: This study was supported by JSPS KAKENHI Grant Number 17K13901.
Keywords: face

P2-66
Data-driven mathematical modeling reveals hidden cues to attractiveness: Are attractive faces
always feminine-looking?
Koyo Nakamura1,2,3, Katsumi Watanabe1,4
1Faculty of Science and Engineering, Waseda University, 2Japan Society for the Promotion of Science, 3Keio Advanced Research Centers, 4Art &Design, University of New South Wales

Facial attractiveness is judged through a combination of cues. Sexual dimorphism (facial differences
between the sexes that emerge at puberty) is an important factor influencing perceived attractiveness.
Previous studies have demonstrated that female-looking faces are often preferred over male-looking
ones among both males and females. However, it remains unclear how critically facial femininity affects attractiveness judgments, relative to other facial features. To examine the relationship between
facial attractiveness and sexual dimorphism, we applied data-driven mathematical techniques to theratings of attractiveness and sexual dimorphism for computer-generated male (n=200) and female(n=200) faces, provided by Japanese observers. Then, we built a quantitative model for how facial
shape and texture may vary on attractiveness, while controlling for perceived femininity. As per themodel, we generated faces manipulated on attractiveness, while keeping femininity constant. We founda positive correlation between attractiveness and femininity, but we were still able to identify facial
features contributing to attractiveness, even after controlling for perceived femininity. This suggeststhat femininity affects perceived attractiveness, but attractive faces are not always feminine-looking.
— 95 —

Grant: none
Keywords: Face perception, Facial attractiveness, Data-driven mathematical modeling

P2-67
Serial dependence in facial appearance along the attractiveness dimension
Aki Kondo1,2, Koyo Nakamura2,3,4, Katsumi Watanabe3,5
1Department of Advanced Fibro-Science, Kyoto Institute of Technology, 2Japan Society for the Promotion of Science, 3Faculty of Science andEngineering, Waseda University, 4Keio Advanced Research Centers, 5Art & Design, UNSW)When we make attractiveness judgment for sequentially presented faces, each judgment assimilates
toward the judgment for the preceding trial (Kondo et al, 2012). Recent studies have suggested that theassimilation effect also occurs at the perceptual level; the facial appearance of a person is assimilated
toward that of another person presented in the preceding trial (Liberman et al, 2014). In the present
study, we examined whether the perception of the facial attractiveness is also assimilated toward thefacial attractiveness for the preceding trial. Nine facial images that differed in attractiveness levels weregenerated from two different identities by using a computational model of facial attractiveness (Nakamura & Watanabe, 2017). On each trial, a randomly selected target face was presented, and participants were asked to match the adjustment face to the target face by changing facial appearance along
the attractiveness dimension. The results showed that the facial appearance of the adjusted faces was
assimilated toward that of the target attractiveness appeared in the preceding trial. This finding suggeststhat the serial dependence of face attractiveness occurred at the perceptual level.
Grant: This research was supported by Japan Society for the Promotion of Science (JSPS) under Grant-in-Aid for Scientific Research (KAKENHI)
grant numbers 15K16008
Keywords: Serial dependence, Attractiveness perception, Face perception

P2-68
Spatial Frequency Manipulation Reveals Impaired Ensemble Coding of Facial Attractiveness inHigh Autistic Traits
Wenxuan Cheng, Haojiang Ying, Hong Xu
Nanyang Technological University

We are able to perceive the attractiveness of a group of faces through ensemble coding. Manipulating
spatial frequency of the faces can highlight the local curvature or global information. How does thismanipulation affect ensemble coding? In the present study, 58 participants rated the attractiveness of 4
unattractive and 4 attractive faces individually or in a group with 1) High Spatial Frequency (HSF; ＞32
cycles per face), 2) Low Spatial Frequency (LSF; ＜8 cycles per face) and 3) Original Full Bandwidth(FB). We found significant positive correlations between grouped and individual faces ratings, in both
unattractive (all rs＞.65, ps＜.001) and attractive (all rs＞.55, ps＜.001) conditions, confirming theoccurrence of ensemble coding. Past research suggested autistic population demonstrated distinct faceprocessing and preference for HSF. Here we measured participants’ autistic traits by Autism-Spectrum
Quotient (AQ). Results showed AQ scores were significantly correlated with the rating difference between the FB and LSF unattractive face ensembles (r=.417, p=.001). It thus suggests the distinct ensemble coding of facial attractiveness in high autistic traits individuals who extract the local high spatial
frequency information more than the global low spatial frequency information.
Grant: none
Keywords: Ensemble Coding, Autistic Traits, Spatial Frequency, Facial Attractiveness— 96 —

P2-69The Effect of Implicit Racial Bias on Recognition of Own- and Other-Race Faces
Araz Aslanian1, Olivia S. Cheung2
1New York University Abu Dhabi, 2New York University Abu Dhabi

Previous research has established a possible link between recognition performance and implicit racial
bias of other-race faces. Here we further examined how recognition of own- and other-race faces might
be modulated by observers’ face recognition ability, social experience, and implicit racial bias. Caucasian participants (N=53) completed a memory task for Caucasian and Asian faces, an implicit association test and a questionnaire on social experience towards Caucasians and Asians, and a face recognition ability test (Cambridge Face Memory Test). The memory performance for own-race faces was
positively predicted by increased face recognition ability (β=.54, t(49)=4.49, p＜.0001), whereas thememory performance for other-race faces were positively predicted by increased face recognition ability (β=.45, t(48)=4.14, p=.0001), social experience with Asians (β=.33, t(48)=2.77, p=.008), and negatively predicted by increased positive bias towards Asians (β=-.32, t(48)=−2.67, p=.01), which wasmodulated by an interaction between face recognition ability and implicit bias (β=−.36, t(48)=−3.3,
p=.002) with the effect of bias observed only in observers with high face recognition ability. Thesefindings suggest the complexity in understanding the perceptual and socio-cognitive influences on theother-race effect, and that observers with high face recognition ability may involuntarily allocate sparecognitive resources to evaluate racial factors when recognizing other-race faces.
Grant: none
Keywords: Face recognition, Other-race effect, Implicit racial bias, Psychophysics

P2-70
Exploring Visual Processing Strategies of Self-Face and Other-Face Recognition
Jasmine Lee Kar Wye, Alejandro J. Estudillo
University of Nottingham Malaysia

Some studies have shown an advantage for the processing of the self-face compared to other familiar
and unfamiliar faces. However, it is largely unknown whether the self-face is also processed qualitatively different to other faces. With an eye tracking study, we explore the visual processing strategies for
self-face, age- and gender- matched personally familiar face and age- and gender- matched unfamiliar
face. Thirty individuals freely explored face images presented on screen without performing any task
demands. Images were presented in two different conditions: vertical (i.e., inverted or upright) andhorizontal orientation (i.e., mirror-inverted or normal). While in Experiment 1, external features of thefaces (i.e., jawline, hairline) were concealed with an oval mask, in Experiment 2, internal features andshape information of the faces were available. In comparison to familiar and unfamiliar faces, self-facereceived generally more fixations. Interestingly, observers showed a preference for the mouth region
when seeing the own face, and for the nose region when seeing unfamiliar and familiar faces. These
results might suggest that the self-face is processed in a distinct manner to other faces, wherein self-faces may be processed in a more featural manner than both familiar and unfamiliar faces.
Grant: none
Keywords: self face recognition, eye-tracking— 97 —

P2-71The N170 component fluctuations between upright/inverted face processing might predict behavioral performance of holistic face processingPeter Kuan-Hao Cheng1,2, Jun-Hua Lai1,3, Chao-Chih Wang1, Gary C.-W. Shyi2,4, Tzu-Hua Wang1,5
1Research Center for Education and Mind Sciences, National Tsing Hua University, 2Department of Psychology and Center for Research in

Cognitive Sciences, National Chung Cheng University, 3Department of Educational Psychology and Counseling, National Tsing Hua University,
4Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, 5Department of Education and Learning

Technology, National Tsing Hua University

In this study, the neurophysiological face-sensitive N170 component of the event-related potential(ERP) were explored through an orientation discrimination task using natural faces, face-like emoji,
and scenes. After one month later, the participants were called back to evaluate their face processing
ability using composite task. About ERP results, the mean amplitude of the N170 component located in
the bilateral occipito-temporal region (P7/P8) was analyzed. The participants elicited an occipito-temporal N170 component for the faces and emoticons, and the N170 is significantly larger for the inverted
faces than upright faces while this effect was not appeared in emoticons. And the effect of orientation
for faces on P8 (right hemisphere) is more significant than the effect on P7 (left hemisphere). For thecomposite task, participants performed significantly better with congruent than with incongruent trials
only in the aligned condition, but not in the misaligned condition. Correlation analyses revealed thatparticipants with greater N170 fluctuations between upright and inverted face processing demonstrated
better performance on the aligned composite task, suggesting that individual differences in global/holistic perceptual processing of faces as early as the N170 time-window constructing a neural representation of faces that might predict behavioral performance of holistic face processing.
Grant: Yin Shu-Tien Educational Foundation
Keywords: Face perception, Composite task, N170 Component, EEG/ERP

P2-72
Recognising Own- and Other- Race Faces through Static versus Dynamic Stimuli: Chinese, Malay and Indian Compared
Hoo Keat Wong
University of Nottingham Malaysia

To date, many face-related studies have used static images as stimuli; however, faces that we encounterin the real world involve dynamic motions that may affect the way how faces are processed. Previous
face studies involving dynamic stimuli in naturalistic settings have revealed a different eye movement
pattern, with more fixations directed toward the mouth (e.g., Pillai et al., 2012; Russo et al., 2011; Vo etal., 2012). This study aims to employ own- and other-race face stimuli that closely represent naturalsocial situations to study the own-race bias (ORB) in face memory (for a review, see Meissner &Brigham, 2001). In a classic old-new recognition paradigm, we investigated (a) to what extent observers’ recognition memory is affected by dynamic facial motions and (b) whether observers of different
races in a multi-racial population use different eye movement strategies when instructed to recognise
dynamic faces as compared to static faces. Our findings revealed that, regardless of stimulus race, dynamic faces not only yielded better recognition performance, but also greater number of fixations on thenose and mouth regions than static face images did. Most interestingly, despite the weak ORB, we detected statistically significant, though subtle, differences in eye movement pattern between race groups.
Grant: none
Keywords: face recognition, eye-tracking— 98 —

P2-73
Corss-cultural Differences in Sensitivity Detection of Yawning Faces
Kazufumi Sato1, Hassan Matout1, Meingold Chan2, Yasuhiro Hatori1, Ichiro Kuriki1, Satoshi Shioiri1,
Chiahuei Tseng1
1Research Institute of Electrical Communication, Tohoku University, 2Ohio State University

Yawning is a universal action that involves very distinct facial and body expressions, but why we yawn
remains a topic of debate. Past theories emphasized on its physiological functions (e.g. respiratory circulation, brain temperature regulation, arousal), while a newly emerging view suggests a possible social
communication function. In this study, we examine the social communication hypothesis by asking
whether yawning expression processing shares similar features as other emotional expressions (e.g.
happiness, anger). We used the standardized yawning expression stimuli developed by Chan and Tseng(2017) to examine the detection sensitivity in 40 Japanese and Hong Kong students. We discovered thatHong Kong participants had a significantly lower success rate to identify a yawning face than Japaneseparticipants, especially at high intensity images. But such difference was exclusive in yawning expression, not in other types of facial emotion detections (i.e., happiness, anger). Historical literature hassuggested that yawning contains different meanings across culture, but whether this contributes to theobservation in our behavioral experiment remains unclear. We suggest to follow-up with eye-tracking
studies to further elucidate this interesting phenomenon.
Grant: Cooperative Research Project Program from Research Institute of Electrical Communication at Tohoku University, and Grant-in-Aid for
Scientific Research on Innovative Areas (No.18H04180) “Keywords: Face, Social

P2-74
Effects of Object Category and Visual Representations on Recognition Accuracy
Chun-Cheng Hsu
Institute of Applied Arts, National Chiao Tung University

Some graphics can be easily distinguished and desired, while some cannot be desired or comprehended
by the general public. What are the causes behind such outcomes? Relevant investigations in great deal
have been found in the gestalt theory, design discipline, ergonomics, and object recognition theory. The
purposes of this study are centered on understanding the means of measuring whether a graphic can beeasily recognized. A 2×2×9 mixed factorial design (N=360) was conducted to investigate the effect of
the three independent variablessimplification designs, object category, and participant profile- on thevisual recognition. Based on the evaluation results generated from the dependent variablerecognition
accuracy, the most optimal graphic simplification values could be comprehended. Analysis results of
the ANOVA for total scores indicated that the visual recognition accuracy was both significantly impacted by the main effects and interactions of ‘the simplification designs’ and ‘the object category’. The
results of this study shown that graphic details were conducive for the facilitation of promoting visual
recognition accuracy, however, the visual recognition accuracy could no longer be enhanced, even withan increase in the graphic details, after reaching a certain threshold value. We would recommend thedesigners pay exceptional attention to the effects exerted by the object category on the recognition accuracy when simplifying the design, especially the simplification of components of natural objects.
Grant: none
Keywords: Graphic Design, Degrees of Simplification, Shape Feature, Recognition Accuracy— 99 —

Wednesday, July 31
Symposium 3-1 9 : 00 AM-11 : 00 AM, Grand hall
Neural oscillations and behavioral oscillations
Organizers:
Kaoru Amano1, Rufin VanRullen2(1Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), 2Centre de Recherche Cerveau et Cognition (CerCo), CNRS)Neural oscillations, such as delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and gamma (30–100 Hz),are widespread across cortical areas and are related to feature binding, neuronal communication, andmemory. Accumulating evidence suggests that alpha oscillations correlate with various aspects of visual processing. Typically, the amplitude of intrinsic alpha oscillation is predictive of the performance on
a visual or memory tasks, while the frequency of intrinsic occipital alpha oscillations is reflected in
temporal properties of visual perception. Other lines of evidence suggest that behavioral performancesuch as detection thresholds oscillates at the theta or alpha frequencies. While the connection between
neural oscillations and behavior seems to be tight, the underlying mechanisms of these phenomena are
not fully understood.
In this symposium, five researchers will present their recent studies on neuronal and/or behavioral oscillations and will discuss the possible functional roles of these oscillations. Dr. Amano will show thecausal relationship between intrinsic alpha oscillations and a visual illusion called the motion-induced
spatial conflict, possibly suggesting cyclic processing at the frequency of alpha oscillations. Dr. Nakayama will report discretized motion perception at 4–8 Hz, which may reflect the slow attentional
process. Dr. Ding will present about the relation of temporal attention to sensorimotor processes. Dr
Luo will present the evidence suggesting the causal role of temporally ordered reactivations in mediating sequence memory. Finally, Dr. VanRullen will present perceptual echoes originating from alphaoscillations and their relation to predictive coding.
S3-1-1Illusory jitter perceived at the frequency of alpha oscillations
Kaoru Amano(Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT))
Although accumulating evidence suggests that alpha oscillations correlate with various aspects of visual processing, the number of studies proving their causal contribution to visual perception is limited.
Here we report that illusory visual vibrations are consciously experienced at the frequency of intrinsic
alpha oscillations. We employed an illusory jitter perception termed the motion-induced spatial conflictthat originates from the cyclic interaction between motion and shape processing. Comparison between
the perceived frequency of illusory jitter and the peak alpha frequency (PAF) measured using magnetoencephalography (MEG) revealed that the inter- and intra-participant variations of the PAF are mirroredby an illusory jitter perception. More crucially, psychophysical and MEG measurements during amplitude-modulated current stimulation showed that the PAF can be artificially manipulated, which results
in a corresponding change in the perceived jitter frequency. These results suggest the causal contribution of neural oscillations at the alpha frequency in creating temporal characteristics of visual perception. Our results suggest that cortical areas, dorsal and ventral visual areas, in this case, are interacting
at the frequency of alpha oscillations. Possible neuroanatomical basis of the inter-individual differencesin the PAF and the peak alpha power (PAP) will also be discussed.

— 100 —

S3-1-2
Temporal continuity of vision and periodic feature binding
Ryohei Nakayama1, 2(1The University of Sydney, 2Center for Information and Neural Networks (CiNet), National Institute ofInformation and Communications Technology (NICT))
Psychophysical and physiological evidence reveal that sensory information is processed periodicallydespite the subjective continuity of perception over time. How does the visual system accomplish thesubjectively smooth transitions across perceptual moments? To address this issue, we analyzed a novelillusion: a continuously moving Gabor pattern appears temporally discrete when its spatial window
moves over a carrier grating that remains stationary or drifts in the opposite direction. This discretization depends on the speed difference between window and grating, but the apparent rhythm is constantat 4–8 Hz regardless of the stimulus speeds (Nakayama, Motoyoshi & Sato, 2018). In the light of recent
studies reporting the theta-rhythmic function of attention, we hypothesize that different dimensionalfeatures of window and grating whose positional estimates are biased by opposite directional motions
would be bound in a periodic manner. Accordingly, we found that temporal binding of visual features isperformed periodically at ~8 Hz between spatially separated locations, while depending on pre-stimulus
neural oscillatory phases locked by voluntary action (Nakayama & Motoyoshi, under review). (As one
would expect from previous studies on pre-attentive binding, such a periodicity was not observed between superimposed locations.) Therefore, periodic attention serves to bind sensory information acrossdifferent dimensions and locations to produce unified perception, subserved by neural oscillations insynchrony with action. The present combined results imply that slow attentional process can cause thediscretized perception, while perhaps fast automatic process may underlie the temporal continuity ofvision.
S3-1-3
Temporal attention requires sensorimotor mechanisms during visual and auditory processing
Nai Ding(Zhejiang University)
We live in a dynamic world and sensory information comes rapidly and overwhelmingly. Temporal attention provides a mechanism to preferentially process time moments that carry more critical sensory
information. It has been proposed that the motor system is critical to implement temporal attention andhere I will present recent evidence that temporal attention involves sensorimotor processes. It is shownthat blinks and related eyelid activity are synchronized to temporal attention. When processing a visualsequence, a task is used to force the participants to attend to specific time moments. We find that blinks
are suppressed at the attended time moment and the blink rate rebounds about 700 ms after the attended
moment. This phenomenon can be interpreted as a form of active sensing that actively avoids the lossof important visual information caused by blinks. Nevertheless, further evidence from the auditorymodality shows that attention-related eyelid activity is a more general intrinsic property of the brain. It
is shown that blinks are similarly modulated by temporal attention in auditory tasks. Even when theeyes are closed, eyelid activity measured by EOG is still suppressed at the attended time moment. Furthermore, when listening to speech and performing a speech comprehension task that does not explicitly requires temporal attention, eyelid activity is synchronized to spoken sentences. Taken together, theseresults suggest that the motor cortex is activated when allocating attention in time and activity in motor
cortex can be reflected in eyelid activity.

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S3-1-4
Serial, compressed memory-related reactivation in human sequence memory: neural and causal
evidence
Huan Luo(Peking University)
Storing temporal sequences of events in short-term memory (i.e., sequence memory) is fundamental to
many cognitive functions. However, it is unknown how the sequence order information is maintained
and represented in human subjects. I will present two studies in the lab to address the question. First,
using electroencephalography (EEG) recordings in combination with a temporal response function(TRF) approach, we probed the item-specific reactivation activities in the delay period when subjects
held a sequence of items in working memory. We demonstrate that serially remembered items are successively reactivated, in a backward and time-compressed manner. Moreover, this fast-backward replay
is strongly associated with recency effect, a typical behavioral index in sequence memory, thus supporting the essential link between the item-by-item replay and behavior. Based on the neural findings, we
further developed a “behavioral temporal interference” approach to manipulate the item-specific reactivations in retention, aiming to disrupt and change the subsequent sequence memory behavior in recalling. Our results show that the temporal manipulation on the replay patterns – synchronization and orderreversal –successfully alters the serial position effect, as typically revealed in sequence memory behavior. Taken together, the results constitute converging evidence supporting the causal role of temporallyordered reactivations in mediating sequence memory. We also provide a promising, efficient approach
to rapidly manipulate the temporal structure of multiple items held in working memory.
S3-1-5Alpha oscillations, travelling waves and predictive coding
Rufin VanRullen(Centre de Recherche Cerveau et Cognition, CNRS)
Alpha oscillations are not strictly spontaneous, like an idling rhythm, but can also respond to visual
stimulation, giving rise to perceptual "echoes" of the stimulation sequence. These echoes propagate
across the visual and cortical space with specific and robust phase relations. In other words, the alphaperceptual cycles are actually travelling waves. The direction of these waves depends on the state of thesystem: feed-forward during visual processing, top-down in the absence of inputs. I will tentatively
relate these alpha-band echoes and waves to back-and-forth communication signals within a predictive
coding system.

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Wednesday, July 31
Symposium 3-2 9 : 00 AM-11 : 00 AM, Colloquium
Science of Facial Attractiveness
Organizer:
Tomohiro Ishizu(Senior Research Fellow, University College London)
Visual attraction pervades our daily lives. It influences and guides our moods, behaviours, and decisions.
Scientists apply psychological and cognitive neuroscientific methods to disentangle the seemingly complex attractiveness evaluation, and the rigorous scientific findings are growing quickly. Facial attractiveness has been a central interest in the science of attraction. In this symposium, we present new insights
on attractiveness judgments with a focus on face perception from a wide range of methods including
behavioural testing, computational modelling, neuroimaging, and brain-stimulation. We anticipate that it
will engage interests of the APCV attendance and that it will draw a large and lively audience.
Firstly, we show a data-driven mathematical modelling which reveals physical features of a face contributing to attractiveness judgments (Nakamura). We, then, present a study which visualises a ‘mental
template’ of attractive faces by applying the reverse correlation technique and deep convolutional neuralnetwork (Naito). The first two talks can elucidate physical and measurable features of attractive faces
and what contributes to the judgment. Secondly, we show how facial attractiveness judgment can beformed. We present evidence that attractiveness judgment is a dynamic process in which each facial
feature (e.g., eyes, nose, hairstyle) is integrated over time to construct a final evaluation (Saegusa). Next,
we discuss the brain systems, that are possibly underlying in attractiveness judgment on faces and compare them with non-facial/non-biological stimuli in relation to cortical-subcortical networks (Ishizu).
Finally, we demonstrate the ‘causal role’ of those brain sites when judging attractiveness of faces andother visual stimuli with the application of non-invasive brain-stimulation techniques (Cattaneo). Understanding attractiveness evaluations and the impact of visual experiences is an indispensable part of understanding human interaction with the visual world. This symposium, showcasing diverse methods toapproach the question, will provide new insights into the studies on attraction and attractiveness.
S3-2-1
Data-driven mathematical modeling of facial attractivenessKoyo Nakamura1,2,3(1Waseda University, 2Japan Society for the Promotion of Science, 3Keio Advanced Research Centers)
Facial attractiveness can be assessed in a rapid and spontaneous manner, long before we can tell whatfeatures make a face attractive. Faces vary in many different ways and many of these variations affectfacial attractiveness judgments. In this talk, I will present a series of studies that examine how people
judge facial attractiveness from a combination of multiple cues such as facial shape and skin properties.
To identify important cues to attractiveness, we first sampled many different East-Asian faces and collected ratings on their attractiveness, then built a data-driven mathematical model for how facial features vary on attractiveness. The results revealed that faces with larger eyes, smaller noses, and brighter
skin are judged as more attractive, regardless of the sex of the faces. Furthermore, our model allows forquantitatively manipulating the attractiveness of any arbitrary faces by transforming such facial features, thus helping discover as yet unidentified cues to attractiveness. The attractiveness manipulation
technique provides a tool to produce well-controlled East-Asian face stimuli that quantitatively differ inattractiveness, which can be used to elucidate further the visual processes related to attractiveness judgments.

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S3-2-2
Transplantation of taste for facial attractiveness of individuals to deep convolutional neural network
Tomoyuki Naito(Osaka University)
Deep convolutional neural network (DCNN) has a lot of attention for its capability of image categoryclassification that is comparable to that of human. A recent study reported that the DCNN obtained hierarchical representations and learn the concept of facial attractiveness. However, it is still unclear
whether the judgment mechanisms of the DCNN under the facial attractiveness judgment was similar
with humans or not. In this study, we show that from facial attractiveness judgment scores of individuals, DCNN learned the taste of individuals with high accuracy. Then, we reconstructed visual mental
template of facial attractiveness of both participants and the DCNN using psychological reverse correlation technique. For all participants and corresponding DCNN, the visual mental template was successfully reconstructed. We confirmed that the mental template of DCNN was significantly correlatedwith that of the participant who provided the facial attractiveness scores for learning. Our results suggested that the DCNN that learned one’s taste for facial attractiveness reconstructed similar judgments
mechanisms with humans in it.
S3-2-3
Judgments of facial attractiveness as a dynamic combination of internal/external parts
Chihiro Saegusa1, Katsumi Watanabe2,3, Shinsuke Shimojo4, Janis Intoy4(1Kao Corporation, 2Waseda University, 3The University of Tokyo 4California Institute of Technology)
Although the importance of facial attractiveness has been widely researched, how attractiveness of internal/external facial parts and whole interacts in a time course of attractiveness judgment is still unclear. In our research, visual information integration in the facial attractiveness judgment has been investigated in a series of psychological experiments in which presentation of facial images to beevaluated their attractiveness was constrained spatially and/or temporally. Attractiveness evaluation ofbriefly-presented facial images demonstrated that 1) contribution of the eyes to the whole facial attractiveness judgment remains high even after short exposure duration as 20 milliseconds to the face, while
contribution of other facial parts changed over time, and 2) either the gaze of the face is directed to or
averted from the evaluator affected the dynamic integration of facial parts information to the judgmentsof whole facial attractiveness. Different experiments examining the influence of external feature on theperceived facial attractiveness revealed the mutual, but not symmetrical influence between facial attractiveness and hair attractiveness. These findings together suggest the dynamic feature of facial attractiveness judgment where information from internal/external features is integrated over the time while it isaffected by social cue such as gaze direction of the faceS3-2-4
Varieties of attractiveness and their brain responses
Tomohiro Ishizu(University College London)
Over the past decade, cognitive neuroscience of attractiveness has been maturing and has found thatexperiencing something as attractive, such as viewing a beautiful face, engages brain's reward circuit,
namely the medial orbitofrontal cortex/ventromedial prefrontal cortex (mOFC/vmPFC) and structuresin the ventral striatum (VS). Interestingly, these core regions are thought to be stimulated by attractiveness regardless of their source and to encode a 'common neural currency' (Levy & Glimcher, 2012).
This is not contradicting to daily experiences: we feel pleasure when we find something attractive.
However, assuming that attractiveness is closely related and intertwined to pleasure, it gives rise to thequestion; the activation within the mOFC/vmPFC and the VS with attractiveness experience may be— 104 —

merely attributed to the pleasurable experience, and it is little to do with attractiveness per se. To address this question, I propose to categorise attractiveness into two types; attractiveness derived from
biologically-based stimuli, such as faces, bodies, or nutritious foods (biological attractiveness), and one
derived from higher cognitive processes, such as art appreciation or a person with good morality (higher-order attractiveness). The stimuli categorised in the former relate to the fulfilment of biologicalneeds, such as mating, having sex, intake of nutrition (primary rewards), whereas, stimuli of the latter
category do not require biological needs and primary rewards. Recent findings and discussions from ourlab and others (e.g. Wang et al., 2015; Ishizu & Zeki, 2017) suggest that judgments of both biologically-based attractiveness (i.e. facial attractiveness) and higher-order attractiveness (i.e. moral attractiveness) similarly engage both the mOFC/vmPFC and VS, but that the higher-order attractiveness alone
lacks the VS activity. These findings suggest that, even though attractiveness is hardwired to pleasure,it may not be a one-to-one relationship and different types of attractiveness may engage dissociablebrain mechanisms.
S3-2-5The impact of brain stimulation in modulating visual preference for faces and paintings
Zaira Cattaneo(University of Milano-Bicocca)
Neuroimaging evidence has shown that beauty appraisal correlates with activity in a complex networkof brain areas involved in sensory processing, reward, decision making, attentional control, and the retrieval of information from memory. In my talk, I aim to present an overview of a series of recent experiments I conducted with non-invasive brain stimulation (both transcranial magnetic and transcranial
direct current stimulation) that shed light on the causal role of different brain regions in underpinningaesthetic appreciation for different stimulus categories, ranging from faces to paintings. By informing
about whether the activation of a particular cortical site is necessary (vs. epiphenomenal) for an ongoingtask, brain stimulation critically adds to the correlational evidence provided by neuroimaging techniques, and may be a promising tool in the field of neuroaesthetics.

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Wednesday, July 31
Moderators: Hiroshi Tamura, Chiahuei Tseng
Oral 3-1, Texture
9 : 00 AM-10 : 15 AM, Conference hallO3-1-1The tuning of early visual cortex to the fractal structure of natural scenes
Zoey J Isherwood1, Colin WG Clifford3, Mark M Schira1,2, Branka Spehar3

9 : 00 AM-9 : 15 AM

1University of Wollongong, 2Neuroscience Research Australia, 3UNSW Sydney

Despite large differences in their visual appearance, natural scenes share many statistical regularities.
Firstly, they have similar photometric properties as they share a unique distribution of luminance intensity variations known as the 1/fα amplitude spectrum (α ≈ 1). Secondly, they are similar in their geometric properties as they share a similar density of structure across spatial scales—a property that makes
them fractal (e.g., how the branching pattern of a tree is similar across scales). It is currently unclear
whether the visual system is reliant on photometric characteristics which change depending on the illumination of a scene—or whether it is tuned to geometry which remains stable. Here we use psychophysics and fMRI to measure responses to three different stimulus image types—greyscale, thresholded, andedges. Each image type shares the same geometric properties, but differ in their photometric properties.
Sensitivity and BOLD activity (in visual areas V1–V4) display a characteristic dependency on the geometric properties of an image, peaking for stimuli that had the most natural geometry across all image
types despite differences in their photometric properties. This suggests that the visual system is critically reliant on the fractal structure of nature—which remains stable irrespective of scene illumination.
Grant: none
Keywords: natural scene statistics, fMRI, fractal, early visual cortex

O3-1-2
9 : 15 AM-9 : 30 AM
Antagonistic receptive-field structure of V4 neurons detects local figure-ground organization innatural image patches
Kouji Kimura1, Yukako Yamane2, Hiroshi Tamura2, Ko Sakai1
1University of Tsukuba, 2Osaka University

Figure-ground (FG) processing has been suggested to take place in the intermediate-level visual areas.
Recently, we have reported that approximately one-third of V4 neurons exhibit the response modulation
based on the organization of FG in natural images with respect to their CRF location. To investigate theneural mechanisms underlying the FG modulation, we estimated the spatial structure of their responsive
regions corresponding to FG (the receptive field and surrounding region with respect to FG). We presented natural image patches that extended approximately three times larger than the CRF and theirvariants to the monkeys, and recorded from V4 with 32-channel electrodes. To extract the preferred FG
structure of the neurons, we tagged luminance intensity with figure. Specifically, we grouped the natural
images with figure regions brighter than ground (bright-figure set), or vice versa (dark-figure set).
Spike-triggered average (STA) was computed from each set of stimuli, and the difference was taken tocancel out contrast dependence. The estimated STA showed a facilitative region on the preferred (figure
or ground) side including the CRF center, and a suppressive region on the other side, indicating theantagonistic structure for the detection of FG organization in and around the CRF.
Grant: none
Keywords: Receptive-field estimation, Figure-ground organization, V4, Electrophysiological experiment— 106 —

O3-1-3
Parietal tACS at beta frequency improves visual crowding
Luca Battaglini1, Clara Casco1, Andrea Ghiani1, Luca Ronconi2

9 : 30 AM-9 : 45 AM AM

1University of Padova, 2Vita-Salute San Raffaele University

Crowding can be described as the deleterious influence of nearby contours on visual discrimination.
Beta cortical oscillations were found to play a key role in crowding, with a higher beta amplitude related to better crowding resilience. In the present study, we tested the effect of right parietal-tACS at 10 Hz(within the alpha band), 18 Hz (within the beta band) and sham on a letter crowding task, with the prediction that by increasing parietal beta activity would improve performance. Resting electroencephalography was measured before and after stimulation to test the influence of tACS on neural oscillations.
An increment in the participants’ performance for parietal 18-Hz tACS, as compared to 10-Hz tACS
and sham was measured. This improvement was found specifically in the hemifield contralateral to thestimulation site and was accompanied by increased amplitude of EEG beta oscillations. Furthermore,correct discrimination was associated with a specific phase angle of the ongoing beta tACS at the single
trial level. These results support a causal relationship between beta oscillations and visual crowding.
Furthermore, they provide evidence that tACS at relevant frequencies can improve crowding-related
performance, paving the way for application in clinical conditions such as dyslexia and amblyopia thatare severely impaired by crowding.
Grant: none
Keywords: Crowding, tACS, oscillations

O3-1-4
9 : 45 AM-10 : 00 AM
The interaction between attention and perceptual grouping revealed by contrast masking paradigm
Chiahuei Tseng1, Chien-Chung Chen2, Satoshi Shioiri1
1Research Institute of Electrical Communication, Tohoku University, 2Department of Psychology, National Taiwan University

Attention and perceptual grouping both enhance visual efficiency by selecting relevant information forfurther processing. They share similar modulations on mid- and high-level visual phenomena and it islikely that they share common mechanisms. In this study, we quantitatively investigated the underlying
mechanisms for both attention and grouping. We measured participants’ detection thresholds of a target(2.5 cpd vertical Gabor) on pedestals with same spatial profile but different contrasts. A valid or invalid
location cue was presented before the target appeared at one of the four possible locations. Several
u-shapes outlines were arranged in a way that they can be grouped into competing configurations basedon the applied grouping principles (e.g., similarity and closure). This allows us to assess the relative
grouping strength quantitatively. The target threshold vs. pedestal contrast (TvC) function for valid cues
was a vertical downward shifted copy of that for the corresponding invalid cue conditions, suggestingthat that attentional cueing effect originated from excitatory sensitivity enhancement, not from uncertainty reduction. The TvC functions for grouped and ungrouped conditions showed difference only inhigh pedestal contrasts, implying a change of divisive inhibition level. Thus, the interaction between
attention and perceptual grouping is readily observed by the change of TvC function changes.
Grant: Tohoku RIEC Collaborative Research Grant
Keywords: Attention, Psychophysics, Perceptual Grouping— 107 —

O3-1-5
10 : 00 AM-10 : 15 AM
More efficient semantic than phonological extraction in reading Chinese/Kanji for Taiwanese/
Japanese skilled readers
Su-Ling Yeh1, Jen-Tse Dong1, Pokuan Ho1, Shuo-Heng Li1, Te-Chi Huang1, Shiho Hirai2, Yoshiyuki
Ueda3, Jun Saiki4
1Department of Psychology, National Taiwan University, 2Faculty of Education, Kyoto University, 3Kokoro Research Center, Kyoto University,
4Graduate School of Human and Environmental Studies, Kyoto University

Previous reading models, regardless of written forms, have largely assumed sequential processing in theorder of orthography, phonology, and semantics. However, we found evidence against such assumption
from a novel approach, which brings the hierarchical nature of previous models into question. We adopted a visual crowding paradigm where a prime word was crowded by meaningless flankers in the
periphery, and it was either a homophone or non-homophone (or semantically related/unrelated) to thetarget word. In the isolated condition, an isolated prime word was used to compare with results from thecrowded condition. Results showed that, while semantic priming occurred in both crowded and isolated
conditions, phonological priming was found only in the isolated condition. That is, semantic extraction
survives visual crowding and thus semantic priming occurs even with unrecognizable (crowded) primes,
but word recognition is required for phonological extraction in reading Chinese. When Japanese participants were tested with Kanji characters in the isolated condition, semantic priming was found but notphonological priming. Taken together, our results indicate better efficiency of semantic than phonological extraction in reading Chinese/Kanji characters, and Chinese/Kanji characters are excellent tools fortesting general reading models (e.g., Perfetti, Liu, & Tan, 2005) across different writing systems.
Grant: none
Keywords: reading, visual crowding, psycholinguistics, Chinese/Kanji characters— 108 —

Wednesday, July 31
Oral 3-2, Attention
3 : 00 PM-5 : 00 PM, Colloquium
Moderators: Hsin-I Liao, Hirohiko Kaneko
O3-2-1
Motion extrapolation and time compression during eye blinks
Gerrit Maus1, Hannah Letitia Goh1, Matteo Lisi2

3 : 00 PM-3 : 15 PM

1School of Social Sciences, Nanyang Technological University Singapore, 2School of Health Sciences, City University of London

Eye blinks cause disruptions of the visual input that generally go unnoticed. The brain uses active suppression to prevent awareness of the gaps, but it is unclear how suppression would affect the perceptionof dynamic events, when visual input changes across the blink. Here we studied the perception of moving objects around the time of eye blinks. In Experiment 1, we presented a moving stimulus that disappeared upon detection of a blink, and instructed participants to indicate the last perceived location of thestimulus. We observed that when motion terminates during a blink, the last perceived location is extrapolated ahead. In Experiment 2, a similar moving stimulus jumped either backward or forward by avariable amount during a blink. Participants were instructed to indicate the perceived direction of thejump. We found that motion trajectories were perceived as more continuous when the object jumped
backward during the blink, cancelling a fraction of the space it travelled. This suggests a subjective
underestimation of the duration of a blink. These results reveal the strategies used by the visual system
to compensate for disruptions and maintain perceptual continuity: time elapsed during eye blinks isperceptually compressed and filled with extrapolated information.
Grant: none
Keywords: eye blinks, motion, time perception, psychophysics

O3-2-2
3 : 15 PM-3 : 30 PM
Microsaccades reveal anticipation of cognitive conflict in a cued-flanker task
Mario Dalmaso, Luigi Castelli, Giovanni Galfano(University of Padova)

Microsaccade are tiny and rapid eye movements that we perform during fixation. In the last years, several studies reported a link between microsaccadic frequency and higher-level cognitive processes, suchas attention and memory. Here, we investigated whether microsaccade can be shaped by anticipatedcognitive conflict. A version of the flanker task was administered, which is known to elicit cognitive
interference. In more detail, at the beginning of each trial, a central colour cue informed the participant
regarding the upcoming target frame. In two thirds of the trials, the colour cue reliably informed theparticipants that in the upcoming trial the flankers either matched the central target letter (e.g., HHH) ornot (e.g., HSH). Hence, participants could accurately anticipate whether cognitive conflict would ariseor not. In the remaining one third of trials, the colour cue provided no useful information. Taken together, the results showed that microsaccadic rate, time-locked to colour cue onset, was reduced on trials inwhich an upcoming cognitive conflict was expected. In conclusion, this study shed fresh light on thepossible top-down modulations of microsaccade dynamics.
Grant: none
Keywords: eye movements, microsaccades, cognitive control— 109 —

O3-2-3
Attentional blink in 7- to 8- month-old infants
Shuma Tsurumi1, So Kanazawa2, Masami K Yamaguchi1, Jun Kawahara3

3 : 30 PM-3 : 45 PM

1Chuo University, 2Japan Women’s University, 3Hokkaido University

Cognitive models of visual attention propose that perception relies on two-stage processing. The rapid
initial stage processes all stimuli as representation followed by the slow resource limited consolidation
stage involving working memory (Chun & Potter, 1995). Although this model has been tested in adults
and children, it was unclear whether this model applies to preverbal infants’ cognitive systems. To address this question, we investigated the infants’ encoding of working memory during viewing rapid
serial visual presentation. First, we examined infants’ ability to identify a target face embedded in visual streams at a rate of 100 ms/item, and found that 7- to 8- month-olds could identify a target face. Next,
we tested the attentional blink effect, in which identification of the second of two brief targets is impaired when inter-target lags are short. The temporal lag between the first and second targets were 200
or 800 ms. We found that they could identify both targets at the longer lag but failed to identify thesecond target at the shorter lag, representing attentional blink comparable to adults. These results suggest that the working memory in 7- to 8 month old infants functions with the same temporal parameters
as adults.
Grant: none
Keywords: attention, development, working memory

O3-2-4
3 : 45 PM-4 : 00 PM
Perceptual learning induces lower alpha power to nonsalient irrelevant shapes
Yulong Ding1, Chupeng Zhong2, Zhe Qu2
1School of Psychology, South China Normal University, 2Department of Psychology, Sun Yat-Sen University

Usually, attentional capture is provoked by salient-but-irrelevant stimuli. Our recent study showed that,a nonsalient shape can attract attention automatically as a consequence of perceptual learning. Thisbottom-up capture of attention was indexed by an involuntary N2pc component, which began at around170-180 ms after stimulus onset and was predictive of stimulus-specific behavioral improvement. Here,by reanalyzing the electrophysiology data, we investigate whether any earlier top-down attentional effect is generated as a result of perceptual learning of nonsalient shapes. Time-frequency analysis showed
that, after perceptual learning, alpha power around the period of stimulus onset was smaller under the
trained condition than under the untrained condition. Importantly, this alpha effect was also predictiveof stimulus-specific behavioral improvement. However, this alpha effect was not correlated with thefollowing involuntary N2pc effect, and was irrespective of whether the target was presented or not.
These results suggest that, after perceptual learning, top-down attentional system could be well prepared for the target ahead of time, and such attentional preparation is specific to the trained shape.
Different from the involuntary N2pc, the voluntary effect indexed by alpha power could be considered
as another neural mechanism underlying the behavioral improvement after perceptual learning of nonsalient shapes.
Grant: National Nature Science Foundation of China (No. 31471070) ; Leading Talents in BaiQianWan Project of Guangdong Special Support
Program (No. 201626026)
Keywords: visual attention, event-related potential, alpha power, perceptual learning— 110 —

O3-2-5
Spatial spread of visual attention on a uniform random-dot field
Lin Shi1, Søren K. Andersen2, Satoshi Shioiri3

4 : 00 PM-4 : 15 PM

1Kunming University of Science and Technology, 2University of Aberdeen, 3Tohoku University

Visual attention plays a critical role in selecting important information from the large amount of retinal
inputs. Basic factors of selection in retinal inputs are the location and extent. Shioiri et al reported spatial spread of visual attention measured by steady-state-visual-evoked-potential (SSVEP). However, it
is possible that their measurements include effect of object based attention because the disks should beperceived as eight objects or as one group object, which may influence the extent of spatial attention.
Here, we designed a stimulus without salient features to shape objects and measured spatial spread ofvisual attention by a similar paradigm as Shioiri et al. The stimulus is random-dot pattern divided into
eight sectors flickering with different temporal frequencies. The random-dots suppresses the visibilityof borders between sectors so that the stimulus appears to be uniform to the observer. Observer’s detected infrequent targets in a rapid serial visual presentation (RSVP) at attended locations. The spatial
profile of visual attention was similar to that found in Shioiri’s independently of task difficulties. These
results suggest that visual attention spreads spatially broadly in the absence of salient objects or borders.
Grant: none
Keywords: Visual attention

O3-2-6
4 : 15 PM-4 : 30 PM
Transient Attention Does Change the Appearance: Excluding the Response Bias
Fang Zhang1, Yongchun Cai2,3, Liufang Zhou2,3
1Zhejiang University, 2Zhejiang University, 3Huanan Normal University

Previous studies have shown that transient attention enhances the perceived contrast of a low-contrast
stimulus but attenuates the perceived contrast of a high-contrast stimulus. However, it is still unclear
whether such an effect was genuinely perceptual or was due to response bias. In this study, participants
were shown with a pair of grating stimuli, following a peripheral cue which directed exogenous attention to the left or the right. After the grating offset, an additional response cue was introduced to determine the response direction: participants were asked to report which stimulus looks higher or lower incontrast. This response cue was designed to eliminate the response bias as no particular response tendency towards left or right should be made before the instruction. By using psycho-physical methods,
the apparent contrast of a standard stimulus was measured and compared when attention was directed
to its location or its opposite location. The results successfully replicated previous findings, showing anenhancement effect at a low contrast level (attended 26.81% vs. unattended 22%) and an attenuation
effect at a high-contrast level (attended 51.66% vs. unattended 60%). Furthermore, our results offeredempirical evidence for supporting the view that human perceptual experience is modified by attention.
Grant: none
Keywords: psychophysics, attention

O3-2-7
Perceived time and the accrual of visual information
Kielan Yarrow1, Isla Jones1, Alan Johnston2, Derek H Arnold3

4 : 30 PM-4 : 45 PM

1Department of Psychology, City, University of London, 2School of Psychology, University of Nottingham, 3School of Psychology, The Universityof Queensland

When people time intervals, they may be integrating some quantity directly related to the richness of
sensory information (e.g., memories; change). This perspective suggests that (illusory) temporal dilation is corollary to an increase in the rate of information uptake. Such an increase in “bit rate” formed
the original explanation for the temporal oddball illusion (TOI), where an infrequent stimulus embedded in a sequence of repeating standards appears of relatively greater duration. To test this account, we— 111 —

measured the TOI for the final stimulus in a sequence (contrasting oddballs with repetitions). We thenassessed contrast discrimination (d’) under identical conditions. Critically, we also measured the linear
increase in d’ that occurs when sub-second exposure duration is varied. This allowed us to predict how
the subjective dilation implied by each participant’s TOI should affect discriminability, if both depend
on identical information. The TOI was accompanied by increases in d’. However, this discriminability
boost significantly exceeded predictions. Furthermore, the two effects failed to correlate across participants. We conclude that one or more factors (e.g., exogenous attention; repetition suppression) influenced two independent mechanisms (an internal clock, and a contrast detector) rather than a coupledsystem.
Grant: none
Keywords: time perception, psychophysics

O3-2-8
4 : 45 PM-5 : 00 PM
Reading direction influences the deployment of visual attention during word processing
Honami Kobayashi, Hirokazu Ogawa
Kwansei Gakuin University

Previous studies demonstrated that the orthographic property of a N+1 word can be processed in parallel with the lexical processing of a currently attended N word. This bias towards the right-side word has
been hypothesized to be consistent with a reading direction in alphabetical languages. We tested thishypothesis by using the flanker lexical decision task with Japanese words that were aligned horizontally or vertically. The results demonstrated that the traits of target words affected lexical decision, whichis in line with the previous studies in alphabetical languages. In addition, the flanker words right of or
below the target (i.e., N+1 words) were processed to the orthographic level in parallel with the target,
in contrast to the previous studies that showed the lack of parallel processing of the word presented
below a target. The contrast may be due to the fact that, unlike alphabetical languages, Japanese language can be written both vertically and horizontally. These findings highlight the possibility that variation in writing systems influences how attention is allocated during word processing.
Grant: none
Keywords: word processing, attention— 112 —

Wednesday, July 31
Symposium 3-3 3 : 00 PM–5 : 00 PM, Grand hall
Two-photon calcium imaging of architecture and computation of primate visual cortex
Organizers:
Ichiro Fujita 1, Kristina Nielsen2, Ian Nauhaus3(1Osaka University,2Johns Hopkins University,3University of Texas Austin)
We aim to bring together researchers working actively on the primate visual system using 2-photon
calcium imaging and related techniques. Two-photon imaging is now a standard tool in systems neuroscience. It provides unique advantages for addressing questions at multiple levels of function and structure which are not accessible by other techniques; e.g., high temporal resolution of detecting signals
originating from single action potentials and high spatial resolution of determining the position anddistribution of individually monitored neurons. These technical merits allowed us to reveal the functional microarchitecture of the visual and other cortices. Thus far, the vast majority of two-photon imaging studies in the mammalian brain have been performed in the rodent. However, the primate is thepreferred animal model for linking cells and circuits to more sophisticated sensory, motor, and cognitive
functions. This holds true especially for visual functions which has evolved elaborately in primates.
Given the merit and potential, there currently is a large push to overcome the technical challenges of
performing two-photon imaging in primates. In this symposium, we provide a platform for discussing
and sharing the scientific impacts, current technical advancement, and ideas of future directions in thisresearch field. The speakers include researchers from Asia (Fujita, Ohki, Tang) and USA (Nauhaus,
Nielsen, Priebe), working on various stages of the visual cortical hierarchy (V1, V2, V4) in macaqueand marmoset monkeys. All speakers have agreed to participate in this symposium. The symposium
will start with a brief introduction (5 min) by one of the chairs followed by 20-min presentation of the
6 speakers.
S3-3-1Zooming in on neural circuits in macaque visual cortex
Shiming Tang
(Peking University)
My lab focuses on the neural mechanisms of visual object recognition and the development of techniques for neuronal circuit mapping. We have established long-term two-photon imaging in awake
monkeys — the first and critical step toward comprehensive circuit mapping — to identify single neuron functions. We have systematically characterized the V1 neuronal responses with unprecedented
detail in awake monkeys. We found a large percentage of V1 neurons exhibit complex pattern selectivity beyond orientation tuning, to sparsely responded to natural scenes. This finding suggests an earlystage of local complex pattern detection in V1 in the visual object recognition hierarchy. Recently, we
performed high resolution dendritic imaging in macaque monkeys, and mapped the fine spatiotemperal
organization of excitatory inputs on dendrites of macaque V1 neurons. Our results suggested V1 neurons integrate rich and heterogeneous inputs for complex local pattern detecting. With these modern
imaging technologies now functioning in macaque monkeys, we can untangle the neuronal micro-circuits in visual cortex and finally uncover fundamental computational principles in visual information
processing.

— 113 —

S3-3-2
Neural tuning in superficial V1 as a function of scale invariant inputs
Ian Nauhaus(University of Texas Austin)
Recent imaging studies in macaque primary visual cortex (V1) have revealed maps of spatial frequency(SF) preference that systematically align with maps of orientation preference and ocular dominance.
Additional V1 maps are predicted under the assumption of “scale invariance”, whereby scale parameters - RF size, SF bandwidth, SF preference – are proportional to one another. However, prior studies
show that scale invariance fails for “complex cells”, which make up the majority of our two- photon
recordings in layer 2. Given that scale parameters cannot be predicted from SF preference for complex
cells, a general model of the V1 architecture is still lacking for superficial V1. Here, we compared mapsof SF preference to maps that would be correlated under scale invariance (RF size and SF bandwidth),in addition to maps that would be independent from SF under scale invariance (orientation and phaseselectivity). In each case, the data deviated from scale invariance much more strongly than a populationof V1 simple cells. Finally, we are fitting a model whereby scale invariant simple cells converge to build
for a population of RFs like the ones in our data. In summary, we have provided a more complete description of V1 architecture in L2/3 – the principal output layer - that provides improved constraints to
decoding models over basic assumptions of scale invariance.
S3-3-3Clustering of 3D and 2D shape information in area V4
Kristina Nielsen(Johns Hopkins University)
long the ventral pathway, image information is converted into object and scene understanding. Area V4,
an intermediate stage in this pathway, has previously been shown to represent 2D contour shape. We
have recently demonstrated that a substantial fraction of V4 neurons are more responsive to 3D volumetric shape (shape-in-depth) than to 2D shape in the image plane. Here, using 2-photon functional
microscopy, we investigate the spatial organization of 3D and 2D shape tuning in V4. Our results
demonstrate that neurons with 2D and 3D shape tuning form segregated clusters in V4.
We used realistic shading cues to render simple volumetric shapes (Cs and Vs with cylindricalcross-sections and smoothly curved joints and endcaps), presented at a range of 3D orientations. In
addition, we measured responses to the 2D silhouettes of the same stimuli. More precisely, for each 3D
stimulus there was a matching 2D stimulus that shared the same 2D contours. While in the 3D casethese contours appeared as self-occlusion boundaries of volumetric objects, they appeared as sharpedge boundaries of planar shapes in the 2D case.
3D and 2D stimuli were used to probe the responses of V4 neurons in 2-photon experiments in anesthetized animals, in which neurons were labeled with the calcium indicator Oregon Green BAPTA-1AM. In each imaging region, we consistently observed strong local clustering of 3D- and 2D-responsive neurons in separate patches on the order of several hundred microns. At the same time,neighboring 3D and 2D patches were most responsive to congruent 3D and 2D shapes. These results
suggest that derivation of 3D volumetric shape from 2D image information is a major constraint on
micro-organization in area V4.
S3-3-4
Functional architecture for processing visual texture in V4
Ichiro Fujita(Osaka University)
Visual texture is an important clue for recognizing objects. Representing a texture requires computationof a collection of products between V1-like filter outputs across scales, orientations, and positions (i.e.,— 114 —

higher-order image statistics). Previous studies using static texture stimuli demonstrate that neuronalselectivity for higher-order image statistics is not evident in V1, and gradually develops in mid-level
ventral visual areas, V2 and V4. Here, we aimed to extend our understanding on the processing of texture in V4 by examining the functional architecture of texture representation. We recorded activity ofV4 neurons with the aid of in vivo 2-photon calcium imaging in two immobilized macaque monkeys
under opiate-analgesia. We presented naturalistic movie stimuli, in which higher-order image statistics
dynamically changed. We evaluated contributions of higher-order image statistics on V4 responses byusing a general encoding-model approach in which regularization and cross-validation were implemented. Consistent with the previous studies, V4 neurons overall preferred higher-order image statistics
over low-level image statistics (i.e., V1-like filter outputs), whereasV1 neurons recorded from the same
animals preferred spectral stimulus features such as orientation and spatial frequency. The 16 different
sites we examined in V4 exhibited a variety in preference for higher-order image statistics. Most sites
contained many neurons preferring higher-order image statistics. Some other sites were abundant withneurons preferring low-level image statistics, and thus were indistinguishable from V1 sites. From theseresults, we conclude that neurons representing higher-order image statistics are locally clustered in V4,
and the cluster size is between several hundreds of micrometers (size of a recording site) and several
millimeters (distance between recording sites). Together with known functional structures in V4 forcolor and orientation with this scale, we suggest that V4 consists of mosaic-like compartments (~mmsize) each responsible for a specific visual feature such as color, orientation, and texture.
S3-3-5Multiscale calcium imaging of the visual cortex in marmoset monkeys
Kenichi Ohki
(The University of Tokyo)
Primate neocortex analyzes visual scenes with a hierarchical neuronal network. To understand how
such network interactively process visual scenes, we developed a method to monitor neuronal activity
at multiple spatial scales. Based on Tet-off system (Sadakane et al., 2015), we first designed new
AAV2/9 vectors which contain TLoop system (Cetin and Callaway, 2014) or two in-tandem of GCaMP,
and successfully increased the level of GCaMP expression in a large volume of the marmoset neocortex.
Using the improved vectors, we first performed wide-field 1-photon calcium imaging. In addition toorientation map in the primary visual cortex (V1), we found that full-field luminance increment anddecrement evoked regular patches of responses in V1 (luminance polarity map). We then studied cellular activity using 2-photon imaging. In addition to orientation-selective cells, we found “non-tuned
cells” that were responsive to drifting gratings but not selective for orientation, and “non-responsive
cells”. Interestingly, non-tuned cells selectively responded to the luminance increment, whereas non-responsive cells selectively responded to the luminance decrement.
The present method is applicable to higher visual areas beyond V1. Smooth neocortex of marmosets
allowed us to monitor neuronal activity in multiple brain areas spanning occipital to parietal cortices
These results demonstrate usefulness of the marmoset brain to study the visual cortical network.
S3-3-6
The functional organization of area MT neurons revealed by 2-photon
Nicholas Priebe, Jagruti Pattadkal and Boris Zemelman(University of Texas at Austin)
Area MT contains neurons that are exquisitely sensitive to visual motion and, based on extracellular
recordings, is functionally organized for direction. To uncover the fine-scale functional architecture ofarea MT and assay the selectivity of inhibitory neurons, we used the marmoset (Callithrix jacchus).
These primates have lissencephalic brains in which we have access to activity of large neuronal populations. We used 2-photon microscopy to record from several hundred neurons at single-cell resolution— 115 —

over a 1 mm2 region of area MT in awake marmosets. GCaMP expression was induced by injecting
AAV constructs with promoters that provided specific expression in interneurons within area MT.
GCaMP signals from inhibitory neurons revealed similar degrees of motion selectivity as that foundfrom excitatory neurons (median DSI=0.38, n=301 cells). Nearby neurons tend to share direction preference, forming a map of direction preference with a period of approximately 300 microns. Finally, we
found that the degree of orientation selectivity in MT neurons is weaker (median OSI=0.13) than direction selectivity. In sum, we have revealed the fine functional organization of area MT using 2-photon
microscopy in awake marmosets and have demonstrated that MT inhibitory neurons are as direction
selective as their excitatory neuron counterparts.

— 116 —

Wednesday, July 31
Oral 3-3, Appearance
3 : 00 PM-4 : 45 PM, Conference hallModerators: Eiji Kimura, Takashi Suegami
O3-3-1
3 : 00 PM-3 : 15 PM
Divisive inhibition determines orientation discrimination threshold after adaptation to center-surround sinusoidal stimuli
Yih-Shiuan Lin1, Chien-Chung Chen2,3, Mark W. Greenlee1
1Institute of Psychology, University of Regensburg, 2Department of Psychology, National Taiwan University, 3Neurobiology and Cognitive Science

Center, National Taiwan University

Ample evidence supports the claim that center-surround interactions in spatial vision is subject to a normalization process. We studied such lateral modulation in peripheral vision with an adaptation paradigm.
Previously, we found that orientation discrimination thresholds of Gabor targets elevated after adaptation
to a sinusoidal-grating adapter. Moreover, adding a surround annulus to the adapter decreased the adaptation effect, suggesting a center-surround inhibition during adaptation. To investigate whether this inhibition is orientation-specific, we varied the center and surround orientations of the adapter independently from 0° (vertical) to 90° (horizontal) in the counter-clockwise (CCW) direction. We found that the
CCW threshold was the greatest when the adapter center had an orientation of 11.25°, regardless of thesurround orientation. The threshold decreased as the adapter surround orientation approached that of thecenter. Our results indicate that the magnitude of lateral inhibition depends on the surround orientation.
We fitted a divisive inhibition model to the data. The model contains an array of orientation selective
mechanisms whose response corresponds to the stimulus elicited excitation, raised by a power, divided
by an inhibitory component plus a constant. The surround modulation in the adapter is represented by amultiplicative parameter that captures sensitivity modulation between center-surround mechanisms.
Grant: none
Keywords: spatial vision, computational model, lateral inhibition, psychophysics

O3-3-2
3 : 15 PM-3 : 30 PM
Falling pitch imitating Doppler shift facilitates detection of visual motion in the extreme-periphery
Takashi Suegami1,2, Mark Changizi3, Christopher C Berger2, Daw-An J Wu2, Shinsuke Shimojo2
1Yamaha Motor Corporation U.S.A., 2California Institute of Technology, 32ai Labs

Previous studies demonstrated that concurrent auditory stimuli can bias visual motion perception in the
periphery more than in the fovea (e.g., Takeshima & Gyoba, 2013), and auditory becomes crucial whenreliability of vision is reduced (e.g., Schmiedchen et al., 2012). We investigated if auditory affects detecting extreme-peripheral visual motion from behind, which is possibly one of the most salient situations since visual ambiguity is very high and detecting such motion can be ecologically critical to survive. In the experiment, a sequence of three 204 ms dots (255 ms SOA) was presented in theextreme-periphery (individually set by the largest eccentricity with 75% detection); each dot was presented at 3 adjacent locations with 2˚ distance so as to have apparent motion forward, or at the same
location. As auditory stimuli, we employed concurrent beep with falling pitch, which roughly imitated
Doppler pitch shift for passing-by object. We employed concurrent beep with rising pitch as a control,
in addition to another no sound control. The results showed the concurrent beep with falling pitch increased the hit rate for motion detection, relative to that with no sound and rising pitch beep. Underlying
mechanism was discussed with signal detection analysis.
Grant: Yamaha Motor Corporation U.S.A.
Keywords: periphery, cross modal, motion detection, visual perception— 117 —

O3-3-3
3 : 30 PM-3 : 45 PM
Motion-generated optic flow facilitates perception when visual images are blurry
Jing Pan1, Hongge Xu1, Xiaoye M Wang2, Geoffrey P Bingham2
1Sun Yat-sen University, 2Indiana University

Traditionally, visual functioning is thought to correlate with visual acuity, and clear images precede
successful event or scene identification. In natural viewing, however, there are two sources of opticalinformation: static images and motion-generated optic flow. Each specifies spatial structures. Eachfunctions largely independently of the other. When optic flow and blurry images coexist, they interact
and yield effective and stable perception, because the detection of flow is unaffected by image blur andoptic flow compensates for the loss of image details. In two studies, we tested how events and scenes
were identified when visual images were blurry and with relative motions between observers and world
structures. We found that observers did not identify events or scenes from static blurry images (as anexperimental manipulation), but they did when motion, and thus optic flow, were added. We quantified
optic flow strength and showed that it correlated with identification performances. Once observers had
identified the events or scenes with motion, they continued to identify them from static blurry images,
which previously did not afford identification. We replicated these results in age-related macular degeneration and amblyopic patients. Thus, optic flow and visual images should both be considered in visualassessment and rehabilitation.
Grant: National Science Foundation of China 31571116
Keywords: Optic flow, Low vision, Event perception, Scene perceptionO3-3-4
3 : 45 PM-4 : 00 PM
Eye movement correlates of accurate recognition of balanced painting composition
Piotr Francuz, Iwo Zaniewski, Paweł Augustynowicz, Natalia Kopiś, Tomasz Jankowski
The John Paul II Catholic University of Lublin

Aesthetic experience is a result of many factors accompanying the appreciation of a work of art. Two ofthem seem particularly important: the quality of the work of art and the level of expertise of the viewer.
We were interested in whether visual arts experts more accurately recognize a balanced composition in
one of the two paintings being compared simultaneously, and whether people who correctly recognize
harmonious paintings are characterized by a different visual scanning strategy than those who do notrecognize them. In other words, the aim of this study was to search for eye movement correlates ofexpertise in visual arts. We found that the eye movements of people who more accurately appreciatedpaintings with balanced composition differ from those who more liked their altered versions due todwell time, first and average fixation duration and number of fixations. The familiarity of paintings
turned out to be the factor significantly affects both the aesthetic evaluation of paintings and eye movement. To sum up, the experimental manipulation of comparing pairs of paintings, whose composition isat different levels of harmony, has proved to be an effective tool for differentiating people because of
their expertise in visual art.
Grant: The National Science Center (Poland, UMO-2013/11/B/HS6/01816) and the Polish Ministry of Science and Higher Education (1/6-1-17-0501-8126) grants.
Keywords: expertise in visual arts / eye movementO3-3-5
McCollough-effect induced illusory colour biases binocular rivalry
Shuai Chang1,2, Joel Pearson1

4 : 00 PM-4 : 15 PM

1School of Psychology, University of New South Wales, 2School of Psychology, South China Normal University

McCollough effect is a visual phenomenon that after adapting to two orthogonal gratings with complementary colour, individuals will have subjective experience of colour once they are presented with anachromatic grating in the orientation of either of the two prior stimuli. The colour experience induced— 118 —

by the McCollough effect can be categorised as a form of phantom colour, since it was not directlybased on the external colour stimuli. After viewing the McCollough phantom colour for 4 seconds
against a dark background, participants reported a significant perceptual bias in the subsequent colour
rivalry perception, but the bias decreased to chance level when it was on a bright background. Further
experiment showed that the direction of the perceptual bias depended on the contrast of the grating inducers. Whereas medium contrast induced a facilitatory effect, higher contrast induced suppression. In
addition, the perceptual biases in the rivalry perception induced by neon phantom colour and voluntarily imagined colour had significant correlation, but neither of them correlated with the bias induced by
McCollough effect. The current study demonstrates the perceptual nature of involuntary phantom vision and suggested that there were similarities and differences between voluntary and involuntary formsof phantom vision.
Grant: none
Keywords: McCollough Effect, Phantom vision, binocular rivalry, visual perceptionO3-3-6
4 : 15 PM-4 : 30 PM
Light sources as scene components: estimating light source direction in scenes with multiple objects
Lindsay M Peterson1, Daniel J Kersten2, Damien J Mannion1
1UNSW Sydney, 2University of Minnesota

Humans can identify properties of a light source from an image of an illuminated object. However, it isunclear whether this capacity is based on an inference about the light source as a scene component or
about the lighting conditions that are local to an object. We predicted that the precision of a scene-based
light source representation would be enhanced by the presence of multiple objects. We presented observers (n=28) with rendered scenes containing 1, 9, or 25 unfamiliar blob-like objects and measured
their capacity to discriminate whether a directional light source was left or right of the vantage point.
Consistent with a scene-based lighting representation, we find that the presence of more objects was
associated with an increase in discrimination accuracy. However, we also find that renderings without
cast shadows were associated with a decrease in discrimination accuracy with more objects. We suggestthat the presence of more objects reduces the fidelity of the information from each object, and that thisreduction occurs to an extent in the absence of cast shadows that outweighs the benefits from integrating
across multiple objects. Future experiments will use equivalent noise methods to distinguish these contributions to illumination direction estimation accuracy.
Grant: none
Keywords: illumination, psychophysics

O3-3-7
4 : 30 PM-4 : 45 PM
The effect of color temperature on the color-dependent Fraser–Wilcox illusion
Akiyoshi Kitaoka
Ritsumeikan University

The color-dependent Fraser–Wilcox illusion is a motion illusion observed in stationary images that ischaracterized by perceptual dimorphism (Kitaoka, 2014). The direction of illusory motion is reversed
depending on illuminance when we observe printed images. Here I report a new finding that this perceptual dimorphism is affected by color temperature. High color temperature promotes the motion illusion observed in a bright condition, while low color temperature enhances the illusion observed in adark condition.
Grant: none
Keywords: motion, color, illusion— 119 —

Wednesday, July 31
Poster:11 : 00 AM-12 : 30 PM, 1 : 30 PM-3 : 00 PM, Event Hall
P3-1
Visual Working Memory Load Affects Visual Detection: Attention Resource Competition or Cortical Resource Competition?
Nailang Yao1, Yang Guo2, Zaifeng Gao3
1nlyao@zju.edu.cn, 2guoyang_psy@zju.edu.cn, 3zaifengg@zju.edu.cn

It has been revealed that visual working memory (VWM) load reduces the detection of a low-priority
target. This fact has been explained in terms of VWM load competes visual attention with the detection
task (visual attention hypothesis). However, an alternative explanation existed for this finding: since
processing visual representations in VWM requires the involvement of primary visual cortices, which
also plays a key role in visual detection, the reduced detection was due to the competition of the resources of visual cortex (cortical resource hypothesis). To test this alternative, we required the participants to memorize both color and shape of the stimuli (feature load), or the bindings between color andshape (binding load). Moreover, a low-priority task was added in the maintenance phase of VWM. It
has been found that extra attention was required to process binding representations than the constituent
single features. The visual attention hypothesis predicted that the detection performance in the binding
load was worse than that in the feature load condition, whereas the cortical resource hypothesis predicted a non-difference between the two conditions since the same visual cortices were employed. In linewith the prediction of cortical resource hypothesis, we did not find any difference between the two loadconditions. Meanwhile, once the memory load was manipulated in terms of number of visual features,
we re-established the impaired detection under high feature load.
Grant: National Natural Science Foundation of China (No. No.31771202)
Keywords: Visual working memory load, Visual detection

P3-2
Active suppression of nonsalient irrelevant shapes induced by perceptual learning
Zhe Qu1, Liping Hu1, Yulong Ding2
1Department of Psychology, Sun Yat-Sen University, 2School of Psychology, South China Normal University

Visual attention can be attracted by salient-but-irrelevant features, a phenomenon called attentional
capture. Accompanying with attentional capture, a top-down inhibitory mechanism is usually enacted
to suppress the attentional shift. Our recent study showed that, a nonsalient shape can also provoke arobust capture of attention as a consequence of perceptual learning. It remains unclear, however, whether the brain would initiate an active suppression process to a nonsalient irrelevant shape which could
capture attention. Here, we show that detectability of a shape may be a key factor determining whether
the shape would be actively suppressed or not. After extensive training as a target in visual search, anonsalient shape could elicit an N2pc when it was an irrelevant stimulus in a visual search task or an
RSVP task, indicating a capture of attention induced by perceptual learning. Following the N2pc, a Pd
would be elicited by the irrelevant shape only if its detectability is relatively high. These findings suggest that an active suppression process could be applied not only to salient features, but to nonsalient
shapes. A nonsalient shape could improve its salience through perceptual learning and would be actively suppressed when its learned salience reaches to some certain level.
Grant: National Nature Science Foundation of China (No. 31471070) ; Leading Talents in BaiQianWan Project of Guangdong Special Support
Program (No. 201626026)
Keywords: visual attention, perceptual learning, event-related potential, Pd— 120 —

P3-3
The effects of attentional area size and its mean luminance on pupillary response
Xiaofei Hu, Rumi Hisakata, Hirohiko Kaneko(Department of Information and Communications Engineering/Tokyo Institue of Technology)

It has been shown that pupil constricted more when people attended to a narrow area compared with aspread area for the same stimulus. It was explained by the effect of selective attention area. However,another possibility was that the mean luminance within the attended area decided the magnitude of pupillary response and it was the higher luminance that elicited a smaller pupil when people narrowed theirattention in the Navon figure used. In this study, we focused on both the attentional area and its mean luminance. In Experiment 1, we controlled participant’s attentional area by presenting two imaginary circles with different radiuses consisting of eight disks placed equidistantly. The radius of the small circle
was fixed and that of the large circle varied. They were presented simultaneously and participants were
instructed to attend to one of them. In Experiment 2, the radiuses of the circles were fixed and the size ofouter disks varied to change the mean luminance. Results showed that the attentional area didn’t affectpupillary response, while the distribution of stimulus luminance did. We conclude that the pupillary response is independent of the selective attention area itself, at least for the present stimulus condition.
Grant: none
Keywords: pupillary response, attention, psychophysics

P3-4
Attentional updating of perceived position can account for a dissociation of perception and action
Ryohei Nakayama1,2, Alex O. Holcombe1
1School of Psychology, The University of Sydney, 2Center for Information and Neural Networks (CiNet), NICT

It has been proposed that the neural pathways for perception and action depend on distinct visual information. In support of this notion, recent studies reported that although internal grating motion can accumulate over seconds into a large illusory position shift, this position shift is not reflected in saccadetargeting (action). Another possibility however is that rather than saccades and other actions having
privileged access to the correct position, the attention shift thought to precede saccades resets the accumulated position shift to zero. Here we found that the accumulation of illusory position shift is reset bytransients near the moving object, resulting in a striking impression of the object jumping back to its
actual position. The object motion is also perceived as having a veridical direction rather than a shifted
direction when transients are given repetitively. The position shift however accumulates to alter theperceived direction despite repetitive transients when observer’s attention is removed by a concurrent
letter identification task. These results suggest that attention can update the perceived position of moving objects and mediate the previously reported dissociation between perception and saccades.
Grant: none
Keywords: motion, attention, psychophysics

P3-5
Individual differences of the collinear masking effect in visual search
Pei-Chen Ye1, Li Jingling2
1China Medical University, 2China Medical University

The ability to inhibit irrelevant distractors is crucial in efficient visual search, and was shown to varywith individual’s working memory capacity and anxiety. The current study examined whether such individual differences also exist in the collinear masking effect, which refers to the phenomenon that atarget can be concealed when it overlaps with a salient but task-irrelevant collinear structure. Sixty
participants completed a visual search task to probe the collinear masking effect, the Chinese Mandarin
version State-Trait Anxiety Inventory Y form to estimate personal anxiety, and the backward digit span
to probe working memory capacity. Results showed that the larger the collinear masking effect, the— 121 —

stronger the state anxiety score, r=.74, p=.XX. Meanwhile, trait anxiety score and backward digit span
performance did not correlate to the size of the collinear masking effect. Our results suggest that thecollinear masking effect, similar to the distractor suppression or attentional capture effect in visual
search, related to current anxiety strength. Thus we concluded that the ability to inhibit the search for
distractors may be the cause of individual differences in collinear masking effects. Our study may thus
reveal the individual differences on camouflage.
Grant: none
Keywords: Attentional capture, working memory capacity, anxiety, distractor suppression

P3-6
Attempt on the measurement of spatial extent of audiovisual attention by EEG
Shin Ono1, Shuichi Sakamoto1,2, Ryo Teraoka1, Yoshiyuki Sato2,3, Yasuhiro Hatori1,2, Chiahuei Tseng1,2,
Ichiro Kuriki1,2, Satoshi Shioiri1,2,3
1Graduate School of Information Sciences, Tohoku University, 2Research Institute of Electrical Communication, Tohoku University, 3Advanced

Institute for Yotta Informatics, Tohoku University

Several studies of crossmodal attention showed that attention to a visual stimulus facilitates the processing of an auditory stimulus that was presented at the same location, and vice versa. Since these crossmodal facilitation in behavioral performance depends on the spatial distance between visual and auditory stimuli, spatial characteristics are important to understand the mechanisms of crossmodal attention.
Here, we developed an experimental procedure to measure the spatial extent of crossmodal attention
with Steady-State Responses (SSRs) of electroencephalogram. In our experiments, participants were
presented with letters as visual stimuli and vowels as auditory stimuli simultaneously. Participant’s task
was to attend one location to detect either visual or auditory target appearing at the attended location.
SSRs of visual and auditory stimuli at multiple locations were measured simultaneously to estimate thespatial extent of attention. We succeeded to measure the spatial extent of unimodal attention peaking
near the attend location, while no clear crossmodal attention was found in the present condition. This
failure to find the crossmodal attention was possibly because the binding between audio and visual
stimuli was weak in our experimental conditions.
Grant: none
Keywords: crossmodal attention, EEG, visual, auditory

P3-7
Task difficulty at fixation location modulates attentional bias caused by head direction
Ryoichi Nakashima1,2, Takatsune Kumada2,3
1The University of Tokyo, 2RIKEN, 3Kyoto University

During eccentric gaze, visual perception of a stimulus appearing in front of the head is facilitated. This
indicates that attention is biased toward the natural eye direction, which is an involuntary attentional
bias based on eye movement control by ocular-muscle constraints. The present study examined whether the intention to attend to a specific position influences the attentional bias caused by head direction.
We conducted a target identification task where visual stimuli briefly appeared to the left and right of a
fixation point, and manipulated the head direction relative to the fixation position. We included filler
trials where a target stimulus appeared at the fixation position (the central task), manipulating the sizeof the stimulus (large/small) to vary the difficulty of the central task. It was assumed that observers
would intend to focus more attention on the fixation position when the central task was difficult. Results
confirmed the attentional bias based on the head direction under both conditions. However, the degreeof this effect was smaller in the difficult central task condition than in the easy central task condition.
These findings indicate that the influence of head direction on visual attention during eccentric gaze ismodulated by intentional attention control.
Grant: none
Keywords: attention, visual perception— 122 —

P3-8
Does Visual Experience abolish Search Asymmetry?
Chia-Chun Tsai1, Sung-En Chien1, Yoshiyuki Ueda2, Jun Saiki3, Su-Ling Yeh1
1Departmentof Psychology, National Taiwan University, 2Kokoro Research Center, Kyoto University, 3Graduate School of Human andEnvironmental Studies, Kyoto University

Search asymmetry is a change in search efficiency when target and distractors switch roles, and it has
been considered as a diagnosis of basic feature or signal strength. However, most studies recruitedwestern participants and indeed, found faster reaction times and shallower slopes in searching a longline among short lines than vice versa. Yet, this phenomenon was not observed in Japanese participants(Ueda et al., 2018), suggesting that visual experiences may affect the performance in search asymmetry.
In Experiment 1, Taiwanese participants were asked to perform a line length search task. In Experiment2, a session of English digit search where participants searched for Arabic number among English letters was added before each line search task, inducing a priming experience of English letters. Resultsfrom Experiment 1 showed no search asymmetry, similar to Japanese data from Ueda et al. (2018).
Critically, we found faster reaction times for short lines than long lines, opposite to the results obtained
from English users. In Experiment 2, Taiwanese participants still showed no search asymmetry but thedifference in reaction times between the two kinds of lines disappeared. Conventional theories of search
asymmetry need to modify to accommodate the malleable nature of search performance.
Grant: none
Keywords: search asymmetry, culture

P3-9
Agent Identity Affects the Encoding of Biological Motion into Visual Working Memory
Quan Gu, Jingyin Zhu, Mowei Shen, Zaifeng Gao
Zhejiang University

To recognize and predict social interactive behaviors, we have to encode human biological motions(BMs, e.g., walking and waving), into visual working memory (VWM). Critically, each BM in real life
is produced by a distinct person, carrying a dynamic motion signature (i.e., identity). Whether the agent
identity influences VWM processing of BMs remains unknown. Here we addressed this question by
examining whether memorizing BMs with different identities promoted the VWM processing of task-irrelevant clothing colors. Two opposing hypotheses were tested: (a) VWM only stores the target action(element-based hypothesis), and (b) VWM stores both action and irrelevant clothing color (event-based
hypothesis), interpreting each BM as an event. We required the participants to memorize actions thateither belonging to one agent or distinct agents, while ignoring clothing colors. Then we examined
whether the color was also extracted into VWM by probing a distracting effect: If the color was extracted, the change of color in probe would lead to a significant distracting effect on the action recognition.
We found that VWM encoding of BMs was adaptive: Once the memorized-actions had different identities, VWM adopted an event-based encoding mode regardless of memory loads and probe identity.
However, VWM used an element-based encoding mode when memorized-actions shared the same
identity. Overall, these findings suggest that agent identity information has a significant effect on VWM
processing of BMs.
Grant: none
Keywords: identity, biological motion, visual working memory, adaptive processing— 123 —

P3-10
An fNIRS-based investigation of brain activity related to focal attention
Tomoki Matsumoto, Aoi Kobayashi, Hisashi Yoshida, Takeshi Kohama
Kindai University

In order to establish a neuro-rehabilitation evaluation method for attentional dysfunction, we evaluatedbrain activity in right hemisphere during a dual-cued target detection task using functional near-infrared
spectroscopy (fNIRS). It is well known that the impairment of the maintenance of focal attention brings
various interferes in everyday life or social life. In the neuro-rehabilitation for attentional dysfunction,
recovering the function in the brain area related to maintain focal attention is considered effective. In
this study, we conducted a dual-cued target detection task which controls subjects’ attentional allocation
with sequential presentation of a symbolic-cue and a direct-cue in the same trials. Two experimental
conditions were implemented: (1) ignore direct-cue and maintain attention toward symbolically cued
location and (2) redirect attention to directly cued location and ignore symbolic-cue. After confirming
the cue effects based on the response time, fNIRS measurements were carried out. The results indicatethat when subjects intentionally maintain their focal attention to the symbolically cued direction, theactivity in the right prefrontal cortex increased and in the right temporo-parietal region decreased. Thissuggests that brain activation related to maintain focal attention can evaluate based on the fNIRS measurements.
Grant: none
Keywords: fNIRS measurement, attention, Frontal lobe region, Prefrontal cortex

P3-11
The effect of bottom-up attention in the frequency of microsaccade
Shogo Noguchi, Chinatsu Toriyama, Hisashi Yoshida, Takeshi Kohama
Kinki University

In order to investigate the properties of bottom-up attention induced microsaccades, we conducted anexperiment in which subjects’ maintain their fixation while passively viewing of randomly presented
peripheral spot lights. It has been suggested that focusing or reallocating of attention while actively
fixating visual stimuli modulate the frequency of microsaccades. However, little is known about attentional modulation on the frequency of microsaccades in regards to passively viewing condition. In our
experiment, the subjects instructed to fixate a crosshair pattern presented on the center of a LCD display
and passively viewed peripherally displayed targets. The brightness of the target was changed stepwise
around the predetermined perceptual threshold of each subject. The number of targets presented in eachtrial was randomly determined between 3 and 5. Microsaccades were detected by using a order-statistic
time-window analysis (Ohtani et al. 2016) and the frequency transitions of microsaccades associatedwith the onset of the target were analyzed. The results indicate that around 300 ms after the onset of thetarget, the occurrence of microsaccades show transient suppression and rebound. The property of thefrequency transition of microsaccades in this study consists with that in actively viewing condition
shown in previous studies.
Grant: none
Keywords: Microsaccade, attention, fixation eye movement, passive visionP3-12
An autoregressive mathematical model of neuronal spiking responses
Suguru Hirai1, Akihiro Masaoka2, Takeshi Kohama1
1Kindai University, 2Tamagawa University

Higher-order brain functions such as visual cognition are extremely complex. Recent studies haveshown that constructive approaches are highly advantageous to understanding such brain mechanisms.
Masaoka & Kohama (2018, in Japanese) described a neuron network model which reproduces the at— 124 —tentional modulation in several brain regions using an autoregressive mathematical representation. Thismodel is configured with several functional unit which is correspond to specific brain regions. Suchbrain regions are actually constructed by networks of many individual neurons. Masaoka model, however, is a macroscopic expression of the regional brain activity and does not consider individual neuron
responses. In this study, we proposed a modified Masaoka model to reproduce various spiking properties of individual neurons which can share mathematical expressions between macroscopic and microscopic brain functions. We evaluated the output of our proposed model by comparing with the output ofIzhikevich model, which is known to be highly reproducible of neuron responses. The simulation results show that our model reproduces the various spiking response of neurons sufficiently.
Grant: none
Keywords: Neuron model, Spike response, Autoregressive mathematical expression, Constructive aproach

P3-13
Eye movement patterns when driving in virtual reality environment
Bo Du1, Yiik Diew Wong2, Hong Xu1
1Psychology, School of Social Sciences, Nanyang Technological University, 2Centre for Infrastructure Systems, School of Civil and Environmental

Engineering, Nanyang Technological University

Human errors are the major cause of most traffic accidents. Previous studies have investigated drivers’
visual features in hazardous driving conditions (e.g., tunnel and raining). However, few studies attempted to link drivers’ visual attention and mental workload under those situations. The current study examines drivers’ eye movement patterns in various roads and aversive weather conditions. We tested thedriving behaviour and eye movement of 18 drivers when driving in virtual environment by a highly
controlled driving simulator. The driving scenarios were simulated based on real driving route in Singapore and included open road and underground tunnel in rainy and sunny conditions. We found larger
perceived saccadic velocity/acceleration/dispersion in open road than tunnel driving in both weather
conditions; larger pupil size and longer blink duration in tunnel than open road in rainy condition. Thesefindings indicate higher mental workload in tunnel than open road driving. Moreover, larger pupil size
but fewer fixation numbers (negatively correlated with fixation duration) was observed in rainy thansunny driving in open road, indicating higher mental workload in rainy than sunny condition. Our findings of increased mental workload in tunnel and rainy driving than open road and sunny driving provide
insights for autonomous vehicle designs.
Grant: none
Keywords: Visual attention, Virtual Environment, Mental Workload, Human-vehicle interaction

P3-14
Age-related effects of cross-modal duration perception
Fang Jiang, Dustin Dutcher, Daniela Lemus, Alexandra N Scurry
University of Nevada

Reliable duration perception of external events is necessary to perform daily functions, such as perception and action coordination and speech discrimination. Visual duration perception can be heavily influenced by concurrent auditory signals, however age-related effects on this cross-modal influence hasreceived minimal attention. Recently, we examined the effect of aging on cross-modal duration perception by quantifying 1) duration discrimination thresholds, 2) auditory temporal dominance, and 3) visual duration expansion/compression effects induced by an accompanying auditory stimulus of longer/
shorter duration. Natural aging did not impact duration discrimination thresholds or auditory dominance over visual duration perception, however older adults did perform worse than young adults whencomparing durations of two target stimuli (e.g., visual) in the presence of distractors from the othermodality (e.g., auditory). Older adults also exhibited more robust visual duration expansion over a wider range of auditory durations compared to their younger counterparts, likely due to age-related enhancement in multisensory integration or inflexible decision strategies. Follow up experiments in young— 125 —

adults reveal expanded visual expansion percepts for more complex stimuli that allow a wider window
for audiovisual integration. Results are discussed in terms of multisensory integration and possible decision strategies that differ with age.
Grant: EY023268 to FJ, 5U54GM104944, and P20 GM103650
Keywords: Cross-modal duration perception, Aging, Multisensory integration

P3-15
Manual reproduction of visual and auditory pulse sequence
Gaku Sugawara, Ikuya Murakami
The University of Tokyo

Studies have shown features of sensorimotor synchronization for periodical pulses and mechanisms
underlying the perception of short durations. We examined how accurately subjects reproduced thefrequency (i.e., pulses per second) of visual and auditory pulses in three conditions: visual flashes periodically presented at the same position, visual flashes periodically presented at different positions fromflash to flash, and auditory periodical clicks. In each trial, the ISI was chosen from six varieties within
140～490 ms, and the subjects were requested to reproduce the frequency with finger tapping right after
the stimulus sequence. In all conditions, reproduced frequencies in different ISI conditions differedfrom each other despite ISI difference being 40 ms at the minimum. Between the visual and auditory
conditions, the reproduced frequencies exhibited significant differences at the three shortest ISIs, withthe frequency being slightly under-reproduced for the visual flashes. However, the position(same/different) of the flashes made no difference. These results suggest that the mechanism underlying periodicity
perception accurately retains timing information even if motor synchronization is not performed during
stimulation, and that the responsible mechanism in the visual pathway is well above the level of temporal-frequency filtering that is only sensitive to events occurring within small receptive fields.
Grant: Supported by JSPS KAKENHI (JP18H05523).
Keywords: Psychophysics

P3-16
Color and Motion Together Lead to Effective Perception of Blurry Events
Hongge Xu1, Jian Wang1, Xiaoye Michael Wang2, Jing Samantha Pan1
1Department of Psychology, Sun Yat-sen University, 2Department of Psychological and Brain Sciences, Indiana University, Bloomington

Events consist of objects in motion. When viewing events, observers simultaneously receive static image information projected from objects and dynamic optic flow generated by motion. We investigate
how the two contribute to perceiving blurry events. In Experiment 1, observers first identify common
events from blurry colored images. The rate of identification was 49% and the eye fixations overlappedwith saliently colored areas. When seeing blurry events in colored animations, accuracy increased to97%. After motion stopped, when observers saw static blurry colored images again, the rate of identification was 94%. In the motion and post-motion conditions, observers’ fixations were mainly in areas
with strong optic flow. This suggested that optic flow helped identifying blurry events and the effect offlow was preserved in blurry images. In Experiment 2, we removed colors and found similar trends.
When first viewing static blurry grayscale images, observers identified 0.07% of events. By adding
motion, this rate increased to 72%. After motion stopped, when seeing static blurry grayscale images
again, the rate was 61%. Eye movement analysis suggested that when fixated on areas with strong optic
flow, identification was better. Comparing the two experiments, optic flow enabled perceiving blurry
events, but color made it better.
Grant: none
Keywords: event perception, optic flow, eye tracking, low vision— 126 —

P3-17
Effect of stimulus duration on audio-visual temporal recalibration
Yaru Wang, Makoto Ichikawa
Chiba University

If visual and audio stimulus are repeatedly presented with a certain temporal gap for a few minutes, theperceived temporal gap between the stimuli would be reduced. This phenomenon is called as “audio-visual temporal recalibration”. Many previous studies found significant audio-visual temporal recalibration for stimuli with short duration while effects of stimulus duration on the audio-visual temporal recalibration. Here we investigated how the presentation of different durations of auditory sound andvisual flash affects the audio-visual temporal recalibration. We prepared the short duration condition(500 ms visual flash was combined with 520 ms auditory sound) and long duration condition (20 ms
visual flash was combined with 20 ms auditory sound). After exposure to a fixed time lag(0 ms or
230 ms) between the auditory and visual stimuli for about 3 minutes, participants judged whether the
onset of the visual flash or that of auditory sound is the first. We found that the audio-visual recalibration
for the short duration condition was larger than that for the long duration condition. These results suggest that the long duration of audio-visual may inhibit the audio-visual temporal recalibration. The
bases of the effect of stimulus duration upon the audio-visual temporal recalibration will be discussed.
Grant: none
Keywords: constant method, probit analysis, point of subjective equality

P3-18
Temporal judgements under conditions with and without conscious perception
Sofia Lavrenteva, Taro Miura, Ikuya Murakami
The University of Tokyo, Department of Psychology

When an odd stimulus is presented in a train of visual stimuli each having the same duration, the perceived duration of the oddball is longer than that of other standard stimuli. We investigated whether thiseffect requires conscious perception of the difference between standard and oddball stimuli. We presented stimulus trains consisting of digital letters in the periphery of the visual field. The target letter
was presented either alone (“single” condition), or with two flanker letters located laterally in a way thatthe target letter could or could not be identified (“multiple” and “crowding” conditions respectively).
The first three stimuli in each train were standard letters, and the last letter was the test letter, similar tothe standard in half of trials and different (oddball) in the other half. We asked participants to judge
whether the test letter had a longer or shorter duration than the standards and then to discriminate thetest letter. The perceived duration was longer for the oddball stimulus, and in the crowding condition,
this dilation effect positively correlated with the correct response rate in the discrimination task. These
results emphasize the importance of conscious perception in temporal judgements.
Grant: none
Keywords: time perception, psychophysics

P3-19
Audiovisual synchrony perception for music and body movement
Tsukasa Uehara, Akira Takehana, Yutaka Sakaguchi
Graduate School of Information Science and Engineering, University of Electro-Communications

Synchronization between music and body motion is an essential issue affecting the artistic impressionof human body performance. However, it has not been well elucidated how people perceive their synchrony. To answer this question, we examined the characteristics of synchrony perception in observing
the performance of Japanese Radio Calisthenics (i.e., body exercise to music). We performed psychophysical experiments using the video clips of exercise performance presented with different onset asynchronies between visual and auditory streams. Participants were asked to judge the synchrony of visual— 127 —

and auditory stimuli. Synchrony was perceived when the timing of endpoints or lowest points of thehand/foot motion agreed with the music beats, which implies that these feature points serve as the visual reference for synchrony judgement. On the other hand, interestingly, the participants were able tojudge the synchrony even when these feature points were invisible, suggesting that some prediction
mechanism contributes to the synchrony perception. We would like to discuss the role of the above
feature points in synchrony perception, from the viewpoints of motor prediction and “common-codingof action and perception.”
Grant: none
Keywords: Audiovisual synchrony perception, Human body movement, Psychophysics

P3-20
Unconscious non-target stimuli can compress the perceived duration of visual stimuli
Riku Asaoka
Kanazawa University

A visual stimulus is perceived as shorter when a non-target stimuli is presented immediately before andafter the visual target than when the visual target appears alone. The present study examined whether
the time compression effect (TCE) can occur even when a participant is unaware of the presentation of
the non-target stimuli. In order to manipulate the visibility of the non-target stimulus, we manipulated
the luminance contrast between the target and non-target stimuli. We assumed that the participants
could not perceive the non-target stimuli when the luminance contrast was low while they can could
when the contrast was high. A white circle was presented as the target stimulus while a light gray (lowcontrast), dark gray (medium contrast) or black circle (high contrast) was presented before and after thetarget as non-target stimuli. The participants were asked to reproduce the perceived duration of thetarget while ignoring the non-target stimuli. The results showed that the perceived duration of the target
was shorter when the non-target stimuli were presented than when they were not presented (control),suggesting that TCE occurred when the participants could not perceive the non-target stimuli. We canconclude that unconscious non-target stimuli can affect time perception.
Grant: JSPS KAKENHI Grant Number JP50825057
Keywords: time perception, luminance contrast

P3-21
Effects of exogenous and endogenous attention on duration perception
Ryosuke Katsumata, Makoto Ichikawa
Chiba university

We investigated how each of exogenous and endogenous attention affects perceived duration for a visual stimulus. By combining target search task with duration judgment task, we examined the relationship between reaction time (RT) in target search task and duration perception. In target search task,
spatial attention was controlled by pre-cueing method; exogenous attention was directed 100 ms before
target onset by luminance increase while endogenous attention was directed 400 ms before target onset
by orientation of a square space holder. In each trial, participants responded to the target stimulus onset
as soon as possible, and then, judged whether target stimulus duration was longer than a pre-learned
standard duration. We found a significant correlation between the RT and perceived duration only forexogenous attention, and that perceived duration in the valid condition was longer than that in the invalid condition only for exogenous attention although cost, benefit, and difference in RT between theinvalid and valid conditions were significant for both exogenous and endogenous attention. These results suggested that perceived duration for a visual stimulus would be affected more directly by exogenous attention than by endogenous attention. The bases of effects of visual attention on perceived duration would be discussed.
Grant: none
Keywords: cognitive psychology, time perception, spatial attention, pre-cueing method— 128 —

P3-22
Perceived (in)congruency of audiovisual stimuli using Gabor patches
Natalia Postnova, Gerard B. Remijn
Human Science Department, Kyushu University

In numerous audiovisual studies Gabor patches have often been combined with various auditory signals, mostly simple modulated tones. These combinations were used to create “congruent” or “incongruent” audiovisual stimuli, based on correlations between manipulated spatial and temporal frequencies. The congruency factor is highly important in multisensory integration research, however, little
systematic empirical studies describing the differences in perceptual congruency of Gabor patches andauditory tones have been performed. The nature of Gabor patches suggests that similar stimuli in theauditory domain should be modulated noises or pure tones, where modulating frequency corresponds
either to spatial frequency of a Gabor patch, its phase-changing rate or its flickering rate (in case of anon-static patch). Here we conducted a congruency experiment where moving and flickering Gaborpatches of various spatial frequencies were presented to participants accompanied by amplitude-modulated or frequency-modulated tones. Participants rated the perceived congruency of each stimulus on ascale from 1 to 7, resulting in congruency curves for various audiovisual stimulus parameters. The data
could be used as a reference when designing experiments and conducting studies in audio-visual perception.
Grant: none
Keywords: Audio-visual perception, Psychophysics, Perceptual psychology, Multisensory research

P3-23
The intentional binding of auditory and visual action effects
Takumi Tanaka, Hideaki Kawabata
Keio University

Intentional binding is a subjective compression of the temporal interval between a voluntary action andits external sensory consequence, which is composed of two illusions in time perception called “action
shift” and “outcome shift” (Haggard, Clark, & Kalogeras, 2002). Given the sensorimotor aspects ofintentional binding, we could not ignore the effect of different sensory modalities, such as temporal
resolution. Moreover, recent studies revealed that such compression could occur in the space perception
as well as temporal perception. Although several studies have used auditory stimuli while others usedvisual or somatic cues, the effects of outcome modalities have not been sufficiently investigated(Hughes, Desantis, & Waszak, 2013). Therefore, in two experiments with different procedures to measure intentional binding, we directly compared the binding effects between auditory and visual effects.
Our results showed that binding effects for auditory and visual could have different temporal characteristics, indicating the independent bases of these phenomena.
Grant: none
Keywords: time perception, psychophysics

P3-24
Normal Visuo-Auditory and Visuo-Tactile Processing in High Functioning Adults with Autism
Spectrum Disorder
Iris H. E. Loh1, Takashi Obana2,3, Tze Jui Goh4, Elysia J. W. Poh2, Christopher L. Asplund1,2,3,5,6
1Department of Psychology, Faculty of Arts and Social Sciences, National University of Singapore, 2Division of Social Sciences, Yale-NUS

College, 3Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 4Institute of Mental Health, National HealthGroup, 5Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, 6Centre for Cognitive Neuroscience, Duke-NUS Medical School

PURPOSE: Individuals with autism spectrum disorder (ASD) have been found to have anomalous or
reduced multisensory processing as compared to typically-developing (TD) controls. Such differences
may account for the social and linguistic impairments in ASD. Here we test whether visuo-tactile pro— 129 —cessing is also different in those with ASD. METHODS: High-functioning adults who had been previously diagnosed with ASD (n=23) and matched TD controls completed three temporal order judgement(TOJ) tasks. Participants were presented with pairs of simple stimuli (flashes, beeps, or vibrations) withvarious relative temporal offsets and reported which stimulus appeared first. Different pairings (visuo-visual, visuo-auditory, or visuo-tactile) were presented in separate blocks of trials. RESULTS: Psychometric functions were fit to the data for parameter estimation. Temporal precision, temporal bias
towards a given modality, and reaction times were comparable across groups (TD, ASD) for each of the
TOJ tasks. Visuo-auditory and visuo-tactile judgments had similar precision, and both were less precise
than visuo-visual judgments. No significant temporal biases were observed. CONCLUSIONS: Multisensory processing for some individuals with ASD appears to be in the normal range, despite differences on other measures. Such individuals may have had normal multisensory processing throughout development or caught up to TD individuals by adulthood.
Grant: Yale-NUS College Start up grant
Keywords: multisensory, temporal perception, autism spectrum disorder

P3-25
Visual and cross-modal association skills predict music sight-reading
Pu Fan1, Yetta Kwai-Ling Wong2, Alan Chun-Nang Wong1
1Perception and Experience Lab, Department of Psychology, the Chinese University of Hong Kong, 2Learning and Perception Lab, Department of

Educational Psychology, Faculty of Education, the Chinese University of Hong Kong)

Can visual skills explain variations in music sight-reading (SR) performance? This study delineated ahierarchical cognitive structure behind SR with an emphasis on visual skills and visual-to-auditory andvisual-to-motoric transformation abilities. Music sight-reading refers to playing a piece of music atsight fluently and accurately without practice. The task is extremely complex, involving a series ofperceptual, motoric, and cognitive processes under strict time constraints. Although previous studies
proposed various component skills as building blocks of SR ability, this study is among the first to include visual skills and visual-related transformation skills as component predictors. In a multiple regression model, performance in seven perceptual-cognitive tasks explained over 50% of variance in SR
performance of 143 pianists. The most important predictors were the visual perceptual fluency for sequential matching of musical notes, the visuoauditory association ability, and the visuomotor association ability. Visual perceptual fluency for numbers, trilling speed, executive functions, or working memory capacity did not significantly predict SR performance. Theoretically, this study speaks to thecontribution of basic visual skills in complex domains of expertise, such as skilled reading. Practically,
the model sheds light on the utilization of perceptual learning paradigms in SR training and complex
skill development generally.
Grant: none
Keywords: visual perceptual fluency, visuoauditory association, visuomotor association, individual differences

P3-26
Word information influences unconscious processing of single Chinese character under interocular suppression
Jiane Bai1,2,3, Jinfu Shi1,2,3, Yiming Yang1,2,3,4
1School of Linguistic Sciences and Arts, Jiangsu Normal University, 2Jiangsu Collaborative Innovation Center for Language Competence, 3Jiangsu

Key Laboratory of Language and Cognitive Neuroscience, 4Institute of Linguistic Sciences, Jiangsu Normal University

Word superiority effects indicated that word level information plays an important role on single character recognition. Although single Chinese character often has meaning by itself, two-character words arevery common in Chinese reading matrials. In this study, we examined whether word information canaffect the unconscious processing of single Chinese character under interocular suppression. In eachtrial, a visible prime Chinese character was presented to subject’s two eyes for 2 s,then a high-contrast
dynamic noise pattern was presented to one eye meanwhile a target Chinese character was presented to— 130 —

the other eye. For half trials, prime and target characters can combine into a two-character word and forthe other half trials, prime and target were unrelated. We measured how long it took for the target characters to overcome suppression induced by the dynamic noise patterns. We found that compared tounrelated condition, when the prime and target can be combined into a word, it took less time for thetarget character to break from suppression. This result indicated that word information can influence
unconscious processing of single Chinese character during interocular suppression.
Grant: Supported by National Natural Science Foundation of China(31400866,31671170),Natural Science Foundation of Universities in Jiangsu
Province (14KJB180006), Jiangsu Provincial Foundation for Philosophy and Social Sciences (12YYC015)
Keywords: unconscious perception, Chinese Character, Interocular suppression, behavioral experiment

P3-27
The Effects of Fonts on the Chinese Reading Performance in Adults with Low Vision
Li-Ting Tsai1, Chiun-Ho Hou2, Yi-Ling Peng3, Kuan-Chun Liu4, Kaun-Jen Chen2, Chia-Yuan Chan2
1School of Occupational Therapy, College of Medicine, National Taiwan University, 2Department of Ophthalmology, Chang Gung Memorial

Hospital, 3Department of Endocrine and Metabolism, Zhong-Xiao branch, Taipei City Hospital, 4Shi-Pai Shi-He Rehabilitation Clinic

It is well accepted that font affects text readability, especially for patients with low vision. We investigated the reading performance using the traditional Chinese reading charts in adults with low vision.
Four types of character fonts (SimHei, Microsoft JhengHei, Jingxihei, and Biauki) were used. Participants were adults (n=27, age 41-84) with best-corrected visual acuity (BCVA), not more than 0.5 decimal unit. We also performed stratified analysis by acuity level (VA≦0.5 and VA≦0.3) to investigate
the effects between fonts and acuities. Eye diseases were the causes of low vision. Three indexes,
reading acuity (RA), critical print size (CPS), and maximum reading speed (MRS), were used to estimate reading performance. The viewing distance was 40 cm, and the illuminance was kept around 680
to 720 lux. The RA of all participants was higher across four types of fonts than the BCVA (e.g., RA of
SimHei=0.89 logMAR, BCVA=0.48 logMAR). Significant differences were showed between the RA of
SimHei and Microsoft JhengHei fonts and CPS of SimHei and Biauki fonts. For the sub-group(VA≦0.3), there was a significant difference between the MRS of SimHei and Biauki fonts (n=11).
Further application is discussed.
Grant: none
Keywords: low vision

P3-28
Associations between grapheme and gender in Japanese people
Yan Zhang, Na Chen, Katsumi Watanabe
Waseda University

Some synesthesia was involved with cognitive constructs, such as graphemes associated with personalities or genders (also known as ordinal linguistic personification, OLP). However, little has been knownwith the grapheme-personality associations in a normal population. In the present study, we investigated grapheme personification with gender using a questionnaire survey in Japanese non-synesthesia
people. 214 participants (174 males, Mage=18.9, SD=0.55) were asked to make a gender judgment toeach grapheme (including 48 Hiragana and Katakana, 10 numbers in Arabic and Japanese Kanji form,and 26 English alphabets in uppercase and lowercase forms). Those results showed that some graphemes were significantly associated with specific genders, for example, Katakana and Kanji numbers are
considered more as male gender. Besides, the gender judgments between hiragana and its counterpart
katakana alphabets, Arabic and Its kanji members, uppercase and lowercase English alphabets showedstrong consistence. Those results suggested that there might exist some nonrandom grapheme-genderassociations in non-synesthesia people, and the sound of graphemes might contribute more to those
associations.
Grant: none
Keywords: grapheme, gender, Japanese— 131 —

P3-29Developmental dyslexia: a deficit in magnocellular-parvocelluar co-activation, not simply in puremagnocellular activation
Ambra Ciavarelli1, Giulio Contemori1,2, Luca Battaglini1,2, Clara Casco1,2, Michele Barollo2
1Department of General psychology, University of Padua, 2NeuroVis.U.S. laboratory, University of Padua

The magnocellular deficit theory of dyslexia predicts selective impairment in contrast detection of stimuli involving pure magnocellular response (for example, 0.5 c/deg, 30 Hz, low contrast). A recent alternative hypothesis posits that dyslexia may be associated with a reduction of the facilitation expected innormal readers with stimuli relying on low-level magno-parvo co-activation, with respect to stimuli
eliciting pure magno activation. According to this hypothesis, any advantage in contrast sensitivity,
produced both by decreasing stimuli temporal frequency (from 30 to 10 Hz, Experiment 1) or using
static stimuli of increasing spatial frequency (from 0.5 to 4 c/deg, Experiment 2), would be ascribed tothe coexisting responses of both systems. Differently from controls, dyslexic individuals, while showing no deficit in the unmixed magnocellular response, showed also no advantage when the relative
weight between magnocellular and parvocellular inputs, was thrown off balance in favor of the latter.
Our results point out that in dyslexia, the relative contribution of these two systems to visual processing
is perturbed and this may have a detrimental consequence in word processing, both within the parafovea
and the fovea, during fixation. Collectively, these data may give a contribution to the advancement of
diagnostic and training protocols for developmental dyslexia.
Grant: none
Keywords: Developmental dyslexia, magnocellular, parvocellular, contrast sensitivity

P3-30
Effect of microsaccades on global processing of shape
Ken Wei Sheng Tan, Elizabeth M. Haris, Neil W. Roach, Paul V. McGraw
University of Nottingham

The sensitivity of the human visual system to subtle changes in shape are often attributed to the existence of global pooling mechanisms, which integrate local form information across space. While global
pooling is typically demonstrated under conditions of steady fixation, other work suggests that prolonged fixation leads to a collapse of global structure. Here we ask whether small ocular movements
during periods of fixation affect global processing of radial frequency (RF) patterns—closed contours
created by sinusoidally modulating the radius of a circle. Observers were asked to indicate which of two
peripheral patterns was deformed from circular, while fixational eye movements were recorded binocularly at 500 Hz. Global processing was assessed as the rapid fall in discrimination thresholds as cycles
of modulation increased, whereas changes in mean threshold was used as an index of overall performance. Microsaccades were detected using a velocity-based algorithm, allowing trials to be sorted according to the relative timing of stimulus and microsaccade onset. Results indicate that microsaccades
have a generally detrimental effect on task performance, consistent with previous demonstrations ofsaccadic suppression. In contrast, the presence of global processing was unaffected, suggesting its relative robustness to small eye-movements.
Grant: none
Keywords: Shape processing, Psychophysics, Fixational eye-movement— 132 —

P3-31
Aspect-Ratio Discrimination Thresholds for Objects Defined by Short-Range Motion and Luminance Contrast
Andrew Lachlan Stark, Philip MacVicar Grove
School of Psychology, The University of Queensland, Australia

Existing studies on spatial form defined by short-range motion (SRM) predominantly focus on the conditions necessary to yield the perception of a discrete object. However, the spatial acuity of our perception of such objects remains unknown. We measured aspect-ratio discrimination thresholds for objects
made visible through a single iteration of SRM and compared them with thresholds for luminance defined objects. Participants viewed random-dot patterns where a central rectangular section was madevisible through SRM or luminance contrast. In the SRM condition, two random-dot patterns were presented in rapid succession. The surrounding dots were identical for each presentation. However, thecentral section was shifted horizontally, making it briefly visible through SRM. In the luminance condition, mean luminance of the surrounding dots was increased to make the central section discernible.
Target aspect-ratios ranged from 0.88 to 1.12. Participants indicated which dimension was greater,height or width. Thresholds were determined using the method of constant stimuli. For equated stimulus
display times, no significant differences in aspect-ratio discrimination thresholds were found between
the SRM and luminance conditions. We conclude that aspect-ratio discrimination thresholds for SRM
are similar to those of luminance, a first-order visual perception pathway.
Grant: None
Keywords: Spatial vision, Short-range motion, Psychophysics

P3-32
Neural correlates of semantic priming under visual crowding: An MEG study
Sung-En Chien1, Yung-Hao Yang2, Shohei Teramoto3, Yumie Ono3, Su-Ling Yeh1
1Department of Psychology, National Taiwan University, 2Human Information Science Laboratory, NTT Communication Science Laboratories,

Nippon Telegraph and Telephone Corporation, 3Meiji University

Visual crowding refers to impaired object recognition when a peripheral visual target is closely surrounded by flankers. Yeh et al. (2012) found that semantic priming survived visual crowding: Faster
response times in the semantically related (vs. unrelated) condition with unrecognizable (crowded)
prime words. We used magnetoencephalography (MEG) to investigate the neuronal mechanisms ofsuch semantic priming effect when an isolated or a crowded prime preceded an isolated target, and theprime and target was either semantically related or not. Participants were asked to judge whether thetarget was a word in a go/no-go lexical decision task. Results showed theta-band (4-7 Hz) activation
when contrasting between unrelated and related primes in the left inferior frontal gyrus (left-IFG)
during 300-500 ms after the onset of the target for isolated primes, but during 450-750 ms for crowded
primes. Thus, the semantic priming effect with crowded primes was delayed compared to isolated
primes. The phase locking values analysis showed difference in synchronization of theta-band between
left- and right-IFG regardless of whether the primes were isolated or crowded. These findings provide
neural evidence for semantic priming under visual crowding and additionally indicate a cross-hemisphere interaction in semantic relatedness for crowded and isolated primes.
Grant: none
Keywords: visual crowding, Magnetoencephalography, semantic processing— 133 —

P3-33
Influence on spatial resolution by dual task and illuminance level
Toru Sugiura1, Hiroyuki Shinoda2
1Graduate School of Information Science and Engineering, Ritsumeikan University, 2College of Information Science and Engineering, Ritsumeikan

University

Eyewitness testimony in a crime scene is treated as an important evidence in a trial. Accuracy of eyewitness testimony has been studied from various perspectives. Most of the studies took account of theinfluence of environments of sighting. For instance, color response was shown to be inconsistent because color recognition was affected by illuminance, stimulus size and observation duration. In actual
sighting situations, however, witnesses happen to see an accident or an event in the midst of executionof other irrelevant tasks such as driving. In other words, witnesses may not completely concentrated onsighting. In the present study, experiments were conducted to examine how spatial resolution changes
due to dual task. A participant discriminated the orientation of a Landolt ring presented at random times
while tracking a moving target using a mouse. The illuminance of an experimental booth was set atvarious levels from photopic to scotopic visions. The luminance of the Landolt ring, the moving target,
the mouse cursor and the background were modulated on a display according to the illuminance level.
The result showed a degradation in the orientation discrimination due to dual task. The performancedegradation was larger at mesopic illuminance levels than other illuminance levels.
Grant: none
Keywords: eyewitness testimony, psychophysics, visual acuity

P3-34
A Novel Kind of Suppression in Human Visual Cortex: Orientation-specific Surround Suppression in Polar Space
Juhyoung Ryu, Sang-Hun Lee
Department of Brain and Cognitive Sciences, Seoul National University

Active vision—adaptive sampling of visual information for an impending task—creates intricate regularities in image statistics, which can be utilized as prior knowledges for efficient visual processing. We
note one such prior in active vision of visual search for objects: circular arrays of concentrically oriented contours become prevalent as a meaningful object (e.g., human face) enters the fovea. As one wayof exploiting this prior, we hypothesize that human visual system modulates the excitation-vs-inhibition(EI) balance between receptive-field center and surround in a manner specific to the orientation definedin polar space, such that concentric contours induce salient population neural representations. We (i)acquired BOLD responses from V1 to ‘concentrically’ versus ‘radially’ oriented bars in ring- or wedgeshape apertures that drifted over space along the polar axis, (ii) developed several V1 models that differ
in the way of implementing the orientation-specific EI balance, and (iii) examined which model best
explains the observed BOLD time series. The best model supported our hypothesis by exhibiting pronounced surround suppression for concentric unit along the radial axis, implying that human visualsystem promotes salient neural representations of visual objects at its earliest stage by augmenting its
suppression on distractive features in the surround.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: Object vision/fMRI— 134 —

P3-35
Correlations among geometrical illusions dissociate length illusions from size illusions
Takahiro Suzuki1, Daisuke Matsuyoshi1, Katsumi Watanabe1,2
1Faculty of Science and Engineering, Waseda University, 2Art & Design, UNSW Sydney

The majority of studies of geometrical illusions have individually investigated mechanisms underlying
each illusion (but see Axelrod et al., 2017; Grzeczkowski et al., 2017). It would be important to understand common factors in various kinds of visual illusions rather than just focusing on a single illusion.
The present study examined the correlation between five visual illusions (Muller-Lyer, Ebbinghaus,
Delboeuf, vertical-horizontal, and contrast illusions) by using correlation analysis and principal component analysis (PCA). Seventy nine Japanese participants reported the magnitudes of the 5 illusions were
measured by using the adjustment method. We found a significant positive correlation between Ebbinghaus and Delboeuf illusions. The PCA showed that the first two principal components (PC) accounted
for 57% of the variance. The Delboeuf and Ebbinghaus illusions have positive loadings on the first PC,
whereas the Muller–Lyer and vertical-horizontal illusions have negative loadings on the second PC.
The first and second PCs can be interpreted as being related to size perception and length perception,
respectively. Although it should also be noted that the remaining 43% of the variance remains to be
explained, these results suggest that the two illusions of size share common underlying mechanisms andthe two illusion of length share other common mechanisms.
Grant: none
Keywords: visual illusions, geometrical illusions, correlations, psychophysics

P3-36
Experiments for Measurement of Peripheral Contrast Sensitivity Function
Shiori Ito1, Suguru Saito2, Keiji Uchikawa3
1Tokyo Institute of Technology, 2Tokyo Institute of Technology, 3Kanagawa Institute of Technology

For a wide view display such as HMD, considering peripheral visual perception characteristics is usefulfor accelerating rendering speed for computer graphics images, designing UI and reducing the image
data transfer from a host device to a display device. Contrast sensitivity function, CSF, which is one ofthe visual perception characteristics, is the perceivable threshold for the contrast of visual stimulus. We
present our experimental environment and method to measure peripheral color CSFs that have not beenmeasured in previous studies. The measurements are performed in the range from the fovea to peripheral up to 90 degrees in steps of 7 degrees. The stimuli are sinusoidal spatially varying Gaussian enveloped gratings, which are achromatic, red-green and blue-yellow chromatic, presented upon a gray background. The diameter of the stimulus is always constant at 10 degrees. All experiments are performed
photopic and monocularly. Staircase-driven two-alternative forced-choice paradigm to measure thresholds is adopted. The distortion of the distribution of the accuracy rate is reduced using the bootstrap
method, fitted to a sigmoid curve, and a value at which the 75% accuracy rate is used as a threshold.
Grant: none
Keywords: contrast sensitivity function, peripheral vision, wide view image application, spatial frequency

P3-37
The visual cognition of inverted Navon figure: a study by psychophysical method
Takashi Murakami
Ritsumeikan University

We investigated the influence of inverted features of Navon figures of different sizes. According as thevisual angle of Navon figure increases, the local feature of it is more focused. Using the task that theparticipants was asked which local or global feature in each figure was perceived more clearly, we could
determine the threshold size at which local feature was more focused than the global one. We used afactorial within-subjects design of the orientation of global feature (upright/inverted) and the orienta— 135 —tion of local feature (upright/inverted), calculated the threshold size in each conditions and comparedwith them.
Grant: none
Keywords: visual cognition, navon figure, psychophysics

P3-38
Dissecting the Origins of Perceptual Biases during Delayed Orientation Estimation
Dong-gyu Yoo, Sungje Kim, Jungwon Ryu, Sang-Hun Lee
Department of Brain and Cognitive Sciences, Seoul National University

Visual events occur stochastically in nature. The imprecision in our sensory apparatus adds further
noises to sensory measurements of those visual events. Thus, a rational agent is expected to resort to any
prior knowledge about world states available at given moments in space and time and utilize that knowledge to infer the world state that has engendered particular sensory measurements. Indeed, people are
well known to exploit spatial and temporal coincidence statistics in the static environment (long-term
prior) for visual perception. Recent work reports that human perception also reflects rather short-term
prior knowledge about recent and nearby events. We reason that these long-term and short-term priors
both contribute to visual perception. However, despite many separate lines of studies on these two typesof priors respectively, concurrent effects of the long-term and short-term priors on visual perception
have been rarely studied. To address this issue, we conducted a delayed orientation estimation experiment. We found that subjects’ target estimates were systematically biased as a function of ‘current target
orientation’, ‘previous target orientation’, and ‘current non-target orientation’. These results confirm
that both the long-term and short-term priors contribute to visual perception in a scene and require theirconcurrent effects to be investigated.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: Delayed Estimation, Perceptual Biases

P3-39
Color-shape associations in kids and parent-kid pairs
Na Chen1, Katsumi Watanabe2
1Waseda University, 2Waseda University

Neurotypical Japanese people systematically associate shapes with colors (e.g., circle-red, triangle-yellow, and square-blue), which might be explained by common semantic dimensions (e.g., warm/cold).
However, the development of color-shape associations has been yet unknown. In the present study, we
examined color-shape associations in Japanese kids (N=60, 24 male, Mage=8.4, SD=1.8) and theirparents (N=60, 18 male, Mage=42, SD=6.4) using an online questionnaire survey during a lab event.
Results showed that kids could systematically associate certain shapes with particular colors (e.g., circle-red, triangle-yellow, and square-blue/green), consistent with the pattern observed in their parents’group (e.g., circle-red and triangle-yellow), and other adults in a previous study (e.g., circle-red, triangle-yellow, and square-blue/green; Chen et al., 2016). Further analysis on the agreement of those color-shape associations within each parent-kid pair showed that there was little agreement on the color
choices for shapes. Those results suggested that kids at the age around eight might have establish somecolor-shape associations, consistent with adults, and the parenting experience might have little influence on those color-shape associations.
Grant: none
Keywords: experimental psychology— 136 —

P3-40
Visual distractor modulates neural representation of objects’ roughness held in visual working
memoryMunendo Fujimichi1,2, Hiroyuki Tsuda1, Hiroki YAMoto1, Jun Saiki1
1Graduate School of Human and Environmental Studies, Kyoto University, 2Japan Society for the Promotion of Science

We previously examined where objects’ roughness is maintained in the human brain. In the prior study,
the use of blank delay allowed participants to concentrate on holding objects’ roughness. However, thefact that we must process visual information while maintaining memory information in everyday life
casts some doubts whether experiments with the blank delay reflect the nature of visual working memory for roughness. In the current study, we conducted an fMRI experiment using a delayed roughness
discrimination task with visual distractor. We also conducted localizer runs to identify brain regions
processing objects, color, faces, and scenes; and phase-encoded retinotopy measurements to define
retinotopic visual areas. The memorized sample’s roughness was decoded from activity patterns during
the delay in which a distractor was presented in an unpredictable fashion. We found that the ventral
visual cortex could decode the roughness when the distractor was presented, while the secondary somatosensory cortex could decode it when no distractor was presented. Furthermore, similar to the secondary somatosensory cortex, intraparietal sulcus supports maintaining roughness only when there isno distractor in the current study. These results suggest that visual distractor affects neural representation of objects’ roughness held in visual working memory.
Grant: Japan Society for the Promotion of Science
Keywords: visual working memory, fMRI, roughness

P3-41
Reverse correlation analysis of visual evoked potentials for natural texture statistics
Taiki Orima, Isamu Motoyoshi
Department of Life Sciences, the University of Tokyo

Recent evidence shows that primate early visual cortex computes the statistical structure of natural
images. To understand the temporal dynamics of neural encoding of such statistical information, weapplied reverse correlation analysis to visual evoked potentials (VEPs) for image statistics present innatural textures. We recorded EEG signals from 14 observers viewing 166 natural texture images presented foveally in random order for 500 ms with a 750 ms blank (24 repetition each). We computed thecorrelation coefficients between occipital VEP amplitudes (O1+O2) and image statistics believed to be
encoded in V1 and V2 (e.g., Freeman & Simoncelli, 2011). The analysis revealed that correlations with
low-level moment statistics (SD and kurtosis) rose up at different latencies for lower (～120 ms) andhigher (～170 ms) spatial frequency bands. Correlations with higher-order statistics (cross-band energy
correlations) were evident over latencies ranging from 150 to 300 ms. We found no correlation to image
features at a specific spatial location (e.g., fovea). Similar patterns of results were obtained for textures
synthesized with the Portilla-Simoncelli algorithm. These results indicate that early visual cortex encodes with systematically different temporal dynamics for different classes and spatial scales of image
statistics.
Grant: Supported by Commissioned Research of NICT (1940101), and by JSPS KAKENHI JP15H05916 and JP18H04935.
Keywords: natural image statistics, spatial vision— 137 —

P3-42
Effects of surface optics on the perceived shape of elliptical objects
Masakazu Ohara1, Juno Kim2, Kowa Koida1,3
1Department of Computer Science and Engineering, Toyohashi University of Technology, 2School of Optometry and Vision Science, University of

New South Wales, 3Electronics-Inspired Interdisciplinary Research Institute, Toyohashi University of Technology

Pictorial cues such as shading are the basis of our three-dimensional (3D) shape perception. However,natural objects have different forms of surface optics (e.g., specular and diffuse reflectance, as well as
refractivity and translucency) that may potentially complicate the inference of 3D shape. How do weuntangle complex image structure to experience the shape and surface quality of 3D objects? We examined the effects of surface optics on shape perception of virtual objects rendered with varying surface
optics (matte, specular, refractive or combined specular and refractive). We also varied the surface’s
relief (smooth or bumpy) and convexity along the viewing axis. Rendering was performed in the twonatural environments. Observers performed a shape matching task to estimate the convexity of theseobjects when presented either statically or dynamically oscillating horizontally in movie sequences. We
found that purely refractive objects without specular reflection were perceived flatter than specular andmatte objects for all convexity levels. These effects were consistently observed for objects of different
sizes and even for statically presented images. Image pixel and sub-band analysis revealed that narrow
band (not lower band) power could account for perceived shape.
Grant: Leading Graduate School Program R03 of MEXT
Keywords: material perception, depth perception, psychophysics, motion

P3-43
Effects of the manipulation of neural activities in the gloss selective region on the gloss discrimination behavior in the macaque monkey
Akiko Nishio1, Mika Baba2, Takeaki Shimokawa3, Hidehiko Komatsu2
1National Institute for Physiological Sciences, 2Brain Science Institute, Tamagawa University, 3Advanced Telecommunications Research InstituteInternational(ATR)

Previously, we have reported that there exist neurons that selectively responded to specific gloss (gloss
selective neuron) and that these gloss selective neurons were concentrated in a restricted region extending 2–3 mm in the lower bank of the superior temporal sulcus in the central part of the inferior temporal(IT) cortex of the monkey (gloss selective region)(Nishio et. al. 2012). In the present study, to examine
the causal relationships between the activities of the gloss selective neurons and gloss perception, we
manipulated neural activities by applying electrical microstimulation or injecting a small amount ofmuscimol (GABA-A agonist) within the gloss selective region or its surrounding region while monkeys
were performing a gloss discrimination task. We found that microstimulation induced bias toward higher gloss judgment at some sites within and at the vicinity of the gloss selective region. For muscimol
injection, the gloss discrimination performance was degraded after the first injection of muscimol into
this region. These results suggest that gloss selective neurons in IT cortex have causal relationships withgloss perception.
Grant: KAKENHI (16K21587), KAKENHI (15H05916)
Keywords: gloss perception, muscimol injection, microstimulation, macaque

P3-44
Effects of optical parameters on perceptual transparency
Mika Baba1, Kei Kanari1, Kei Iwasaki2, Hidehiko Komatsu1
1Brain Science Institute, Tamagawa University, 2Wakayama University

Transparency or translucency are important characteristics for visually estimating material properties ofobjects. It is widely acknowledged that the way lights transmit and scatter inside an object affects theperceptual transparency, although only few studies have systematically examined the relationship be— 138 —tween physical parameters of optical transmission/scattering and perceived transparency or translucency. Recently, it has been reported that parameters related to phase function of light scattering affectperceptual translucency (Gkioulekas et al., 2013). In the present study, we investigated how other parameters related to light transmission/scattering (absorption coefficient and scattering coefficient) affectthe perceived transparency. We asked subjects to evaluate the degree of transparency of computer
graphics images of objects having different combinations of extinction coefficient (sum of absorption
and scattering coefficients) and albedo (ratio between absorption and scattering coefficients), generatedby Mitsuba renderer. We found that perceived transparency mainly depended on extinction coefficient.
However, albedo also had significant effect on perceived transparency and the effect depended on thecomplexity of object shapes.
Grant: KAKENHI 15H05916
Keywords: psychophysics, perceptual transparency, shitsukan

P3-45
Perceived glossiness based on low-luminance specular components can be increased by enhancing
luminance edge contrasts
Hiroaki Kiyokawa1, Tomonori Tashiro1, Yasuki Yamauchi1, Takehiro Nagai2
1Yamagata University, 2Tokyo Institute of Technology

It has been reported that our visual system utilizes low-luminance specular components for glossinessperception even on object surfaces without specular highlights (Fleming et al., 2003; Kim et al., 2012).
Previously, we found that amounts of luminance edges are well correlated with perceived glossiness onsome object images whose highlight dependency (HD) of glossiness perception was weak. Here, we
tested whether manipulation of luminance edge contrasts affects perceived glossiness obtained fromlow-luminance specular components. We manipulated luminance edge contrasts using a Laplacian filteron six object images used in previous our experiment (three object images with high HDs and otherthree images with low HDs). Then, perceived glossiness was measured on these stimuli in a glossinessrating experiment. In the results, perceived glossiness was significantly enhanced by increasing theedge contrast on the low HD images, while it was not strongly enhanced by edge contrast manipulationon the high HD samples. These results suggest that our visual system also utilizes luminance edges for
glossiness perception as a cue, though there should be some constraints in object image characteristics
for luminance edges to act as a cue for glossiness perception.
Grant: none
Keywords: Material perception, Glossiness perception, Psychophysics

P3-46
Perceptual dynamics for diffuse-specular spatial congruence in gloss perception
Ryotaro Maki1, Tomonori Tashiro1, Yasuki Yamauchi1, Takehiro Nagai2
1Yamagata University, 2Tokyo Institute of Technology

Spatial congruence between specular and diffuse reflection components is crucial for glossiness perception. Here, we investigated if modulation of glossiness perception due to the specular/diffuse congruence accompanied with recognition of the congruence by comparing perceptual dynamics of glossinessperception and congruence detection. The stimulus was a pair of computer-graphics images, whichwere briefly presented at the left and right on an LCD monitor. In one of the images, specular and diffuse components were spatially congruent, while in the other, the specular components were rotatedrelative to the diffuse components. Participants performed two tasks: glossiness task and congruencetask. In glossiness task, they judged which image was glossier. In congruence task, they judged which
image had spatially congruent specular/ diffuse components. For these two tasks, the effects of stimulus
duration on the accuracy were investigated. The results showed that the accuracy was better for theglossiness task than for the congruence task, and that the accuracy differences became larger as thestimulus duration got shorter. These results suggest that the spatial incongruence of the specular/diffuse— 139 —

components affects perceived glossiness without recognition of it, that is, the incongruence was automatically detected for glossiness perception in the visual system.
Grant: none
Keywords: material perception, perceptual dynamics, psychophysics

P3-47
Relationship between image statistics and psychophysical dynamics of perception of various surface qualities
Ryoto Seno1, Tomonori Tashiro1, Yasuki Yamauchi1, Takehiro Nagai2
1Yamagata University, 2Tokyo Institute of Technology

Humans can perceive different kinds of surface qualities on object surfaces at a glance. In this study, we
examined how lower-order image statistics relate to surface quality perception on briefly presented
object images. The stimulus was an image pair selected from 131 object images, which was briefly (for33.4–150.2 ms) presented to observers. They responded which of two images gave stronger impression
regarding either glossiness, transparency, warmness, or heaviness. In addition, we optimized a linear
support vector machine (SVM) based on lower-order image statistics to predict observer’s responses.
The SVM performance was used as an index, which describes relationship between image statistics andhuman perception. In the results, the difference in perception accuracies between the surface qualities
enlarged as the stimulus durations got shorter. In addition, the surface quality that can be perceived
stably even for short presentation duration, such as glossiness and transparency, had closer relationshipwith lower-order image statistics than the other qualities. These results suggest that our instantaneous
surface quality perception may depend on lower-order image features.
Grant: none
Keywords: material perception, perceptial dynamics, psychophysics

P3-48
Estimation of difference in Unified Material-Appearance Yielded by Color and Gloss of a Surface
Kenji Kagitani1, Takehiro Nagai2, Tomohisa Matsumoto3, Keiji Uchikawa3
1Ricoh Co., Ltd., 2Tokyo Institute of Technology, 3Kanagawa Institute of Technology

It has been studied how a material appearance of a surface is quantified using image feature values when
it varies in a single attribute, such as gloss, color or texture. However, in our real word, surfaces vary
not in a single attribute but in several attributes, which are unified into a material appearance. In thisstudy, we aimed at quantifying this “unified material-appearance”. We measured differences in material-appearance of surfaces, using CG-faces and plastic corrugated sheets as stimuli. We used colors andglosses in several steps as material attributes, and made all combinations of these colors and glosses. In
experiments two stimuli of different combinations were presented side by side on a display. Observers
estimated the magnitude of difference in unified material-appearance of the stimuli with 2 or 4 scales.
Our prediction model used up-to-third order image statistics (mean, standard deviation and skewness)in a color space, and showed high correlations with the estimations. It consisted of the same explanatory variables with very close standardized partial regression coefficients for both type of stimuli. These
results indicate that our model is not restricted to specific objects but could be possibly used for general objects.
Grant: This work was supported by JSPS KAKENHI Grant Number JP17H01809.
Keywords: color, material perception— 140 —

P3-49Influence of the HDR environment on Shitsukan perception
Gaku Watanabe1,2, Ichiro Kuriki1,2, Yasuhiro Hatori1,2, Chia-huei Tseng1,2, Satoshi Shioiri1,2
1Research Institute of Electrical Communication, Tohoku University, 2Graduate School of Information Sciences, Tohoku University

High dynamic range (HDR) display is a technology to present high and low luminance (over 1 : 10,000
in min-to-max ratio) simultaneously. Recently, HDR displays like organic electroluminescent display(OLED) becomes more accessible, and its luminance contrast is significantly higher than standard dynamic range (SDR) displays like liquid crystal displays (LCDs). If human visual sensitivity changed
with the dynamic range, apparent lightness contrast would be different between SDR and HDR environments, which could affect texture perception of material surfaces. However, this was not intensively
studied. We first examined the lightness perception of various luminance patches under various surround conditions of luminance dynamic range, by using an OLED display in an otherwise dark room.
We found that the lightness perception is significantly affected in darker part by the luminance dynamic range of surround. Next, we presented material sample images (fabric, wood, stone, and leather) on
the SDR (1 : 1,000) and HDR (1 : 100,000) surrounds, and asked participants to choose one in which
the clues for material perception are more clearly recognizable. The choice ratio for samples in the HDR
background was significantly higher than the chance level. This is probably because the perceived contrast, as our lightness matching experiment suggested, was higher in HDR environment.
Grant: none
Keywords: high dynamic range, lightness perception, material perception, psychophysics

P3-50
Metal- and gloss-perceptions and object impression measured by semantic differential method on
gold-, silver- and copper-gradation-colored CG objects
Keizo Shinomori, Takumi Inoue
School of Information, Kochi University of Technology

Recently, various studies on occurrence conditions of the metal- and gloss-perceptions have been conducted in views of material perception. However, the relationship between the metal- and gloss-perceptions and object impression which can be measured by semantic differential method has not been investigated yet. In this research, the magnitude of these perceptions and the object impression were measured
on CG objects when parameters of surface reflection properties were changed. Colors of objects weregold, silver and copper and additionally, we created unrealized object images that had gradational color
changes between two colors of them. Both of metal- and gloss-perception scores increased in objects oflarger specular reflection value and lower surface roughness value. We employed the principal component (PC) analysis to scores of the semantic differential evaluation. Only the first PC score had thesignificant correlation (p＜0.001) with scores of metal- and gloss-perceptions, while the second andfourth PC scores had significant relationship (p＜0.05) with colors of objects. The usage of unrealized
objects (in gradation color) did not show any special effect; the object impression tended to be determined by primary visual information from the object surface rather than the logical understanding or
recognition of the unrealized objects.
Grant: JSPS KAKENHI Grant Number 18H03323
Keywords: metal perception, gloss perception, object impression, semantic differential method

P3-51
Illusory enhancement of brightness contrast of sinusoidal grating by a salient spot
Soyogu Matsushita1, Sakiko Kikunaga2, Junya Aoyama2, Tsuyoshi Nomura2
1Osaka Shoin Women’s University, 2Pias Group Central R&D Laboratory

Perceived brightness is calculated from not only the target stimulus but also from various visual elements in the visual field. In this study, we report a novel phenomenon in which a salient spot illusory— 141 —

increases the perceived contrast of brightness of the adjacent area. The stimulus images were sinusoidal
profiled grayscale gratings with/without a black patch. In the results, the dark area of the grating with ablack patch was perceived as darker and the bright area was perceived as brighter than those without thepatch. These results indicate that a salient spot in certain conditions enhances the apparent brightness
contrast rather than masking it.
Grant: none
Keywords: brightness, contrast, illusion

P3-52
Color adaptation to temporal color modulations along complicated loci in the chromaticity-luminance plane
Kana Kakuta1, Tomonori Tashiro1, Yasuki Yamauchi1, Takehiro Nagai2
1Yamagata University, 2Tokyo Institute of Technology

Color contrast adaptation to temporally color-modulated stimuli, in which chromaticity and luminanceare one-dimensionally correlated, is well known. However, considering complex perceptual phenomena such as color constancy based on physical features of specular highlight colors, there is a possibility
that color contrast adaptation also occurs to stimuli with more complicated relations between chromaticity and luminance. In this study, we examined if there are color mechanisms that adapt to temporalcolor modulations along complicated loci in the chromaticity-luminance plane. The adaptation stimulus
was a uniformly colored circle. Its color temporally changed along the “〈“ or ”〉” shaped locus in thechromaticity (L–M)-luminance plane. After the observer adapted to this stimulus, achromatic points
were measured for several luminance levels. In the results, the achromatic point shifted toward the same
direction as the adapted chromaticity at each luminance level; namely, after adapted to the “＜” stimulus, the achromatic points also formed a “＜” shape, and vice versa. In addition, these achromatic points
were well predicted by the higher-order color representation model with multiple channels. These results suggest that the visual system can adapt to different chromaticity independently at low/high luminance levels.
Grant: none
Keywords: contrast adaptation, color vision, psychophysics

P3-53
Sensitivity to different levels of supra-threshold color difference
Yuken Ito1, Tomoharu Sato2, Tomonori Tashiro1, Yasuki Yamauchi1, Takehiro Nagai3
1Yamagata Univercity, 2Ichinoseki College, 3Tokyo Institute of Technology

Our previous study demonstrated that color discrimination and supra-threshold color difference perception exhibited different sensitivity transition patterns along stimulus chromaticity (Sato et al., 2016). In
this study, we examined whether sensitivity properties of supra-threshold color difference perceptionchange with the stimulus color difference. In the experiments, the stimuli consisted of three squares
with different chromaticity on the LM axis. The left and center squares, and right and center squares
were defined as pairs, respectively. There were several conditions about physical color differences between the pairs. The observers selected which pair exhibited larger perceptual color difference. The
sensitivities for supra-threshold color differences on all the stimulus chromaticity were estimated with
the Maximum Likelihood Difference Scaling (MLDS) method from the observer’s responses for eachcolor difference condition. In the results, for the smallest color difference there was only a sensitivity
peak on the L–M axis near the achromatic point, while for larger color differences several sensitivity
peaks were clearly apparent. These results suggest that the color mechanisms involved in supra-threshold color difference perception may change with the color difference to be judged.
Grant: none
Keywords: supra-threshold color differences, psychophysics, color vision— 142 —

P3-54Magnitude of yellow-blue color aftereffect varied depending on luminance of test stimuli
Yuta Watanabe1, Kowa Koida1,2
1Department of Computer Science and Engineering, Toyohashi University of Technology, 2Electronics-Inspired Interdisciplinary Research Institute,

Toyohashi University of Technology

Color and luminance are thought to be processed independently at early stages of visual processing,
however the interaction between them are poorly understood. Adaptation technique has been widelyused to reveal the coding strategies in the visual system. How does color aftereffect differ when theluminance of test stimuli changed? We measured the aftereffect by using five level of luminance of test
stimuli. Adaptation stimuli were circular patches colored either blue-yellow direction or L–M cone direction on gray background. After adapting to color, observers were asked to null the appearance ofcolor by modulating chromaticity of test stimuli. We found color aftereffect induced by blue-yellow
stimuli enhanced when test stimulus was darker than adapting stimuli. In contrast, those luminancedependency of color aftereffects were not observed for L–M cone color adapter. These luminance dependencies were similarly observed across three types of test stimuli in which uniform screen, circular
patches same to the adapter, and textured pattern. These data indicate that integration of color and luminance signals is different between two cardinal axes.
Grant: none
Keywords: color vision, psychophysics

P3-55
Brightness perception of face in different type of skin color
Suguru Tanaka, Yoko Mizokami
1Department of Imaging Sciences, Graduate School of Engineering, Chiba University

Yoshikawa et al. (2012) showed that a face with reddish skin appeared brighter than that with yellowish
skin, even though the average lightness of both faces was the same. In their experiment, the face and theskin color was the average of Japanese females, and the observers were Japanese. However, the characteristics of skin color depend on ethnicities, environments and other factors. In this study, we investigated whether brightness perception was similar in the skin color of different ethnicities. The average skincolors of Caucasian, Thai, and African were reproduced on a Japanese female face. We prepared reference face stimuli with five hue angles including yellower and redder than the original hue for eachethnicity. A matching stimulus with the average skin color changing only lightness was created for eachethnicity. Observers adjusted the brightness of the matching stimulus to match the brightness of thereference stimulus. We also tested stimuli with different lightness conditions to examine the influenceof hue and lightness on the brightness perception. As a result, reddish skin tended to appear brighter andyellowish skin appeared darker in any skin color. However, this effect decreased as the lightness of thefaces decreased.
Grant: JSPS KAKENHI JP18H04183
Keywords: skin, face, brightness, color

P3-56
Influence of skin color to the brightness perception of facial skin—Comparison of Japanese, Thaiand Chinese
Yuanuan He, Taiga Mikami, Suguru Tanaka, Yoko Mizokami
Chiba University

It was shown that reddish skin appeared brighter than yellowish skin when both had the same lightness(Yoshikawa et al., 2012). However, this effect was confirmed only for Japanese observers, and it is notclear how the brightness perception of facial skin influenced by the diversity of skin colors and observers. Here, we investigate the influence of skin color to the brightness perception of facial skin for Japa— 143 —nese and Thai and Chinese observers. We used a young Japanese female face as an original face. We
prepared test faces with four skin color types that were the average skin colors of Japanese, Thai, Caucasian, and African. A test face image (one of five images with constant lightness and different hue angles) and a scale face image (skin color of each skin color types and different lightness levels) were
presented side by side on a tablet display. Observers adjusted the brightness of a scale face to match thatof a test face. As a result, Japanese showed a trend consistent with the previous study, whereas Thai
showed an opposite trend and Chinese did not show the influence of hue, suggesting diversity in thebrightness perception of facial skin.
Grant: JSPS KAKENHI JP16H01663 and JP18H04183
Keywords: Color perception, Brightness perception, Facial skin, Psychophysics

P3-57
The development of handy measurements for visual dynamic range
Satoshi Nakadomari1,2,3, Eiji Suzuki4, Hiroshi Horiguchi3, Takashi Fujikado5, Muneto Tatsumoto6,
Takeo Fukuchi7, Yasuo Kurimoto2
1Next Vision Public-interest Co., 2Kobe City Eye Hospital, 3The Jikei University School of Medicine, 4Tokai Optical Co., Ltd., 5Osaka University,
6Dokkyo Medical University, 7Niigata University

We developed handy measurements to estimate the abnormality of visual dynamic range (DR) of the
Human eye. Here we defined DR as the range that a subject could promptly distinguish gray gradation.
Twenty-three healthy controls and 31 photophobic patients with eye diseases were participated. A thickbar whose color was gradually changing spatially from white to black was displayed on a tablet PC. A
subject tapped a border between grayish white/black and perfect white/black with three conditions ofbackground brightness. In controls, a range of gray gradation was 77.7±9.7%, 76.8±10.0% and77.7%±9.2% in dark, middle and bright condition, respectively. A gray center point shifted at 1.6±2.3%
from bright to dark background in controls. On the other hand, in patients, the gray range was
67.0±19.5%, 64.5±20.0% and 65.0±20.3%, respectively. The gray center shifted at 3.7±5.8% in patients. The range of gray gradation area was consistent with three different background both in controls
and patients. The range of patients was significantly smaller than controls and the gray center in patients
shifted more than controls, which might result from a disorder of automatic gain control system in patients.
Grant: none
Keywords: contrast sensitivity, eye disease, psychophysics, handy measurements

P3-58
Gender Recognition Biased by Facial Beauty, Likability, and Attractiveness
Kanako Mitsuhiro, Akiyoshi Kitaoka
Ritsumeikan University

It has been found that faces that emphasize feminine traits are evaluated more attractive than the originals whereas those that emphasize masculine traits are not. If gender differences in faces affect evaluations of facial attractiveness, it is suggested that facial attractiveness might affect gender judgement. In
this study, we examined the relationships between three different evaluations (beauty, likability, andattractiveness) and gender judgement. Participants rated the beauty, likability, and attractiveness of 36
illustrated, neutral faces with 6-point scale, and subsequently they judged the gender of each face. As aresult, faces that were evaluated more highly tended to be judged as female in any of three evaluations.
This finding suggests a possibility that aesthetic evaluation of faces might be used as a clue for genderrecognition of faces.
Grant: none
Keywords: face, attractiveness, gender recognition, illustrated face

— 144 —

P3-59Hand-written Chinese calligraphy activated the mirror neuron system
Wei-Li Tu, Shwu-Lih Huang, Guang-Yi Lai, Yun-An Yu
National Chengchi University

As Umilta, Berchio, Sestito, Freedberg, and Gallese (2012) found that mu rhythm suppression was
evoked by the observation of original artworks by Lucio Fontana, the result might suggest that even thestatic artworks could arise the cortical motor activation while there were some motor actions implied.
Following this view, our research assumed that the hand-written words might play the same role whilepeople appreciating the Chinese calligraphy artworks. We used four kinds of typefaces as the stimuli,
including two hand-written styles (regular script and running hand) and two printed fonts (Ming andboldface). EEG data was recorded as the Chinese participants viewing every single-word stimuli one byone. Our result demonstrated that the hand-written words led to higher cortical activation of mirror
neuron system (MNS) as reflected by mu rhythm suppression in C3 C4 channel compared to the printed
words. And the running hand, which is more dynamic, induced more mu rhythm suppression in contrast
to the regular script. The result supported that the implied motor information of artworks might initiate
the beholders’ MNS and reflected in EEG data.
Grant: none
Keywords: Neuroaesthetics, Vision science, Art

P3-60
The Geometric, Not Photometric Structure of Synthetic Images Determines Discrimination Sensitivity, Perceived Similarity and Visual Preferences
Leena Y Duyen Nguyen, Zoey Isherwood, Branka Spehar
School of Psychology, University of New South Wales

Despite the apparent variety and diversity of natural scenes, their statistical structure is non-random andhighly ordered. Photometric (intensity based) analyses of natural scenes show that a majority of signal
amplitude is distributed at low spatial frequencies, with amplitude dropping off towards high spatial frequencies: known as a 1/f α linear function whose slope for natural scenes averages～1.25. Previous work
has demonstrated that discrimination sensitivity and preferences peak in response to stimuli with natural
α. However, recent work has suggested that both neural response and visual preference are better accounted for by geometric (contour based) image properties across a wide range of synthetic images. This study
investigates discrimination sensitivity, perceived similarity and visual preference across three types ofsynthetic images: grayscale (GS); black and white thresholded (TH) and edges only (ED). While the photometric properties vary substantially across different image types, their geometric properties remain
stable. Measured discrimination thresholds and visual preference both peaked at natural α and were very
stable across image type. Additionally, Multidimensional Scaling analysis of perceived similarity between different images types supports these conclusions. This suggests that geometric image properties
predominantly drive the observed sensitivity and preference across a diverse set of synthetic images.
Grant: none
Keywords: Natural scene statistics, Psychophysics, Aesthetics, Similarity

P3-61
Emotion modulates multiple colors for a short duration
Noriyo Shibata1, Ko Sakai2
1Graduate school of Systems and information Engineering, University of Tsukuba, 2Department of computer science, University of Tsukuba

The relationship between color and emotion has been investigated for a long time but not clarified indetail. We examined whether emotional states (happy, angry, and neutral) modulate color perception,
where the emotion was controlled by showing affective face images. Participants were asked to choose
one out of three color test patches that appeared most similar to the reference. Fifteen reference colors— 145 —

were evenly selected in Lab color space with L fixed, and the test colors were 6 or 12 degree away fromthe reference. The results showed that there was no difference in the discrimination accuracy acrossemotion, but there were significant differences in the directions of the chosen colors (bias). We observedthat happy and angry significantly extended the perceptual range of red and shifted green-blue, but
neutral in the opposite directions. The results indicate that happy and angry showed the same tendency,
and that the emotion affected discontinuous multiple colors. We also examined the effective duration of
the modulation by performing a delayed-match-to-sample test. The observed bias disappeared within
the duration of 2s, which might correspond to the time course of emotion.
Grant: none
Keywords: psychophysics, emotion, color

P3-62
Is trypophobia affected by size illusion?
Kanichi Fukumoto, Kenji Yokoi
National Defense Academy of Japan

Aversion to clusters of holes or warts is known as trypophobia. In our previous study, we manipulated
various spatial properties, such as frequency, size, viewing distance, and so on, to clarify the crucial
factor for trypophobia. The results revealed that trypophobic discomfort was depended on the size ofstimuli, not on the frequency that has been thought to be the important feature of trypophobic images.
Concerning the size of stimuli, however, the subjective rating suggested that the apparent size should be
effective, while the pupillary response indicated that the retinal size might affect discomfort. To clarify
the relationship between the size of images and trypophobia furthermore, we adopted the Ebbinghaus
illusion. The images containing holes or warts were presented at the center with surrounding inducers.
The distance and the size of inducers were manipulated to change the apparent size of the central image
while keeping the retinal size constant. Participants were asked to rate both discomfort and arousal
against the images. Their pupillary responses were also recorded. The relationship among the apparent
size, the retinal size, and trypophobia was discussed.
Grant: none
Keywords: Trypophobia, Discomfort, Pupil, Illusion

P3-63
Identifying cortical area for processing of emotional facial expressions in ADHD children measured by near-infrared spectroscopy
Megumi Kobayashi1, Masako Nagashima2, Tatsuya Tokuda3, Takahiro Ikeda2, Yukifumi Monden2,4, So
Kanazawa5, Masami K Yamaguchi6, Ryoichi Sakuta7, Takanori Yamagata2, Ippeita Dan3
1Institute for Developmental Research, Aichi Developmental Disability Center, 2Department of Pediatrics, Jichi Medical University, 3Applied

Cognitive Neuroscience Laboratory, Chuo University, 4Department of Pediatrics, International University of Health and Welfare, 5Department of
Psychology, Japan Women’s University, 6Department of Psychology, Chuo University, 7Child Development and Psychosomatic Medicine Center,
Dokkyo Medical University Saitama Medical Center

Previous studies reported that children with ADHD had impairment in negative emotional facial expressions, especially angry, but not in positive facial expressions (e.g., Pelc et al., 2006), and that they also
showed atypical brain activity to angry expressions (Ichikawa et al., 2014). However, little is known
about neural basis of recognition of facial expressions in ADHD children. We used near-infrared spectroscopy to measure nineteen ADHD children’s hemodynamic responses in the bilateral temporal-occipital areas during presentation of happy and angry facial expressions before and after methylphenidate (MPH) or placebo administration. Because MPH is considered to increase synaptic transmission
and consequently improve cerebral processing and cognitive performance (e.g., Monden et al., 2012),
we predicted that the cortical areas involved in recognition of angry showed increased hemodynamic
responses by MPH administration. We found that for happy expressions, ADHD children showed increased hemodynamic responses in the right inferior occipital gyrus (IOG) regardless of medication. In— 146 —

contrast, for angry expressions, the left IOG significantly activated by MPH administration, but not by
placebo administration. Our results suggest that (1) ADHD children’s processing of facial expressions
would rely on information of physical forms of faces, (2) MPH administration facilitate processing ofphysical form information of angry expressions.
Grant: This work was supported in part by JST-RISTEX to ID, and the Grant-in-Aid for Scientific Research from the Japan Society for Promotionof Science (19K14492) to MK
Keywords: facial expression, attention-deficit/hyperactivity disorder, brain, NIRS

P3-64
The effect of mood state on visual search times under VR environment
Ikuhisa Mitsugami1, Miyu Sakai1, Rina Yonami1, Jun’ichi Murakami1, Noriko Yamagishi2
1Hiroshima City University, 2Ritsumeikan University

It was reported that an individual’s perceived happiness level affects their ability of visual search(Maekawa et al., 2018). In their work, however, the visual search task was performed on a small smartphone display. It is unclear whether this tendency is effective even under more general conditions, likein our daily lives. This work expanded the small search area to all circumferences (canvas size=22.6×360
deg) by introducing Virtual Reality techniques to investigate whether the tendency is effective undersuch conditions. We employed a pop-out and serial visual search paradigm, and implemented a VR
application that allowed search times and self-rated levels of happiness to be recorded. Each participant
performed a session three times a day, for two weeks. From collected data of 23 participants, we confirmed that we were able to replicate the classic visual search findings, whereby pop-out search times
remained largely unaffected by the number of distractors whereas serial search times increased withincreasing number of distractors. While pop-out search times were unaffected by happiness level, serial
search times with the maximum numbers of distractors (n=240) were significantly faster for high happiness levels than low happiness levels (p＜0.05).
Grant: none
Keywords: visual search, VR, emotion, experience samplingP3-65
Convolutional Neural Networks for humanlike Image Assessment
Hassan Matout1,2, Hao Wang2, Yasuhiro Hatori2,3, Yoshiyuki Sato3,4, Kazuya Matsubara5, Yuji Wada6,
Chia-huei Tseng2,3, Ichiro Kuriki2,3, Satoshi Shioiri2,3,4
1Department of Computer Science, TU Dortmund University, 2Graduate School of Information Science, Tohoku University, 3Research Institute ofElectrical Communication, Tohoku University, 4Advanced Institute for Yotta Informatics, Tohoku University, 5BKC Research Organization ofSocial Sciences, Ritsumeikan University, 6College of Gastronomy Management, Ritsumeikan University

One serious problems in an information-intensive society is to face too much information to handle,
which affects working efficiency as well as cost for storing and processing. Obviously, prioritizing anddeleting data is crucial, so we investigated the usage of Convolution Neural Networks as decision support system for high level human judgments such as preference of images. For this purpose, we used alunchbox dataset, containing 760 images and subjective judgments by 2120 subjects (Wada & Matsubara, 2018). Each image of the dataset was rated for 6 qualities (“want to eat”, “made for young/old”,
etc.) on a discrete scale (1 to 6). To compensate the small size of the dataset, we fine-tuned several
layers of a trained CNN for object recognition (AlexNet). The network was tested with one quarter ofthe dataset after training with three quarters. Results have mean absolute error of 0.34 on average, suggesting that high-level human judgments could be estimated with dataset size of less than 1000 with aconsiderable accuracy. Differences in prediction rate are also seen among different judgments. Subjective qualities (such as gender) yield larger errors (0.48) compared to objective qualities (0.28). In conclusion, CNNs are a decent approach for estimating human judgments.
Grant: none
Keywords: image assessment, human preference, convolutional neural networks— 147 —

P3-66
Attitudes to vision science and phenomenology: a survey
David Rose
University of Surrey

There has been much interest recently in the definition of illusions and their implications for the relationship between perception and reality. Several symposia have been organized (at ECVP in 2015, 2017and 2019), special issues of journals have been published, a series of editorials in Perception, chaptersin a major compendium, and an extensive discussion took place on CVNet in early 2016. For example
Koenderink (Perception 43, 1–6, 2014) has claimed that scientists believe in “a silly delusion”—that
there exists an objective reality, which exists even when not observed. Also, we are mistaken if we believe it is the aim of the visual system to construct, to the best of its ability, a veridical representation ormodel of that external reality. Our common understanding of illusions as deviations from the perceptionof physical reality is thus challenged. Informal discussions with my fellow researchers have shown thatmany of them agree with Koenderink, while many others do not. At this poster I will collect data on therelative popularities of these two views, to try to find the roots of this divergence. Is one view held by amajority? Does the difference correlate with whether researchers have been trained in ‘continental’
phenomenology or ‘oriental’ philosophy, as opposed to ‘anglophone’ or ‘scientific’ worldviews?
Grant: none
Keywords: philosophy of perception, illusions

P3-67
Enhanced perceptual sensitivity for negative facial expressions in trait anxiety individuals
Li-Chuan Hsu1,2, Yi-Min Tien3, Chia-Yao Lin1,2, Ya-Ting Wu4
1School of Medicine, China Medical University, 2Graduate Institute of Biomedical Sciences, 3Department of Psychology, Chung Shan Medical

University, 4College of Public Health, China Medical University

Individuals with high trait anxiety often demonstrate attentional bias when they meet threatening stimulus. Furthermore, these people also show higher sensitivity of recognizing fearful faces than low trait
anxiety ones. We aim to examine whether high trait anxiety people would display higher sensitivity inperceiving other types of facial expressions, such as angry faces. Trait anxiety was assessed for participants by using the State-Trait Anxiety Inventory- Trait Scale. In Experiment 1, we manipulated emotion intensity of four facial expressions (happiness, fear, sadness, anger). Participants had to detect any
emotionality of the presented faces. In Experiment 2, by blending two facial expressions with reciprocal
proportions, three sets of morphed faces were created: the happy face gradually morphs and blends with
one of the negative faces (fear, sadness, or anger). For example, a face consists 20% happy and 80%
fearful expression. Participants were asked to discriminate the facial expression as positive or negative.
The results revealed the group with high trait anxiety expressed significantly higher sensitivity to sad,angry and fearful faces compared to the group with low trait anxiety. It suggests that an individual withtrait anxiety showed negative bias for facial expressions.
Grant: MOST 106-2629-H-040-001 & MOST 107-2410-H-039-002
Keywords: facial expression, emotion, psychophysics

P3-68
Differential effects of color on fear and disgust
Hiromi Sato1, Shiori Muranaka2, Wakana Hata2, Isamu Motoyoshi1
1Department of Life Sciences, The University of Tokyo, 2Department of Integrated Sciences, The University of Tokyo

Natural scenes evoke a variety of affective response in humans. In particular, negative emotions such as
fear and disgust are known to prompt immediate avoidance from threat or danger in the environment.
This leads us to a notion that, independently from the recognition of objects and scenes, some negative
emotions can be directly summoned by simple image features rapidly encoded in the visual cortex (e.g.,— 148 —

Motoyoshi & Mori, 2017). The present study examined how manipulation of simple image features
affects the emotional valence of natural scenes and reports that color (and luminance) have asymmetriceffects on fear and disgust. In separate blocks, observers rated the pleasantness-vs.-disgust and the happiness-vs.-fear of 200 natural scenes, their achromatic version, and their RGB-inverted version. We
found that (1) removal of color information strongly reduces disgust, but not fear, and (2) RGB-inversion reduces disgust while increasing fear. The results further demonstrate the impact of image features
on emotion and suggest distinct visual pathways (e.g., Magno/Parvo streams) involved in neural processing of fear and disgust.
Grant: Supported by the Commissioned Research of NICT, and by JSPS KAKENHI JP15H05916 and 18H04186.
Keywords: psychophysics, emotional valence, color

P3-69
The difference in emotions aroused by self- and automatically-controlled facial expressions
Kana Ohashi1, Takao Sato2
1Department of Psychology, Ritsumeikan University, 2College of Comprehensive Psychology, Ritsumeikan University

In self-controlled condition, observer made emotional expressions, smiling or sad faces, and the real-time video image was presented on a display. In automatic-condition, the expressions were automatically generated by a computer by deforming the neutral face of the observer. The observer observed
one of these stimuli for 90 seconds while conducting unrelated distracter tasks, poking a circle presented at a random position within the stimulus field. After the observation period, observers’ emotional
status after the observation was measured by a questionnaire (IPANAT). Observers were also asked
whether they noticed the expression was manipulated in the automatic condition. It was found that
positive impression increases and negative impression decreases for the self-generated condition relative to the automatic condition regardless the type of expressions used. In addition, the score for helplessness was higher when observers noticed the manipulation of expression in the automatic condition.
These results indicate that, when observers observe their own face, the difference in who generates theexpression (observers themselves or computer), affects the emotional status of observers. In addition,
the results suggest the sense of agency is an important factor for arousing emotions.
Grant: none
Keywords: emotion, facial expression, sense of agency

P3-70
Salience: a comparative study of the experience of visual art in the laboratory and the art museum
Vicente Estrada-Gonzalez1, Branka Spehar1, Michael Garbutt2, Scott East2
1University of New South WalesSchool of Psychology, 2University of New South WalesArt & Design Faculty

Since experimental aesthetics have mostly focused on fine arts, visual salience has become a relevant
concept to understand how individuals experience aesthetics. Salience modulates gaze behaviour byattracting eye fixations towards conspicuous elements of the visual field. This characteristic is mainly
determined by low-level visual properties such as colour and spatial frequency content. Nevertheless, it
has also been demonstrated that other factors, such as the context in which artworks are exhibited, cansignificantly influence salience computation and, in doing so, eye gaze is modulated. Additionally, context has been demonstrated to affect aesthetic experience as well. For that reason, the aim of this study
is to demonstrate whether 1) people look at artworks differently depending on the context they arepresented (museum or lab). Secondly, 2) if people´s art experience is correlated to specific eye movements (e.g. Fixation Duration, Number of Fixations) and finally, 3) to explore if salience is modulatedby the context. We conducted a study where artworks were presented in two different conditions (in-museum and on-screen), while participants’ eye movements were recorded by an eye-tracker. The preliminary results show that some components of the gazing behaviour (i.e., Average Fixation Duration) are
different when participants consume art in the museum than when works of art are shown on a screen.
— 149 —

Grant: none
Keywords: empirical aesthetics

P3-71
Emotional facial detection in the foveal and peripheral vision
Wan-Ting Huang, Pi-Chun Huang
Department of Psychology, National Cheng Kung University (NCKU)

The ability to detect emotional facial expressions is an important aspect of social cognition. Processing
facial expressions in central vision has been extensively studied, but processing it in peripheral vision
has rarely been studied. This study compared the emotional facial detection ability of the central andperipheral visual field. Three basic facial expressions, including happy, angry, and sad, were morphedfrom a neutral expression to nine different intensities (10% to 90%), respectively. The faces were presented in either fovea or the peripheral visual field (8 degrees in the left and right visual field), andparticipants were asked to decide whether the presented face showed an emotion. The subjective judgement and the response time were recorded. Our results showed that participants required a similar levelof morphing to detect emotions when the target was presented in the fovea. A happy facial expression
required a higher morphed level, but the other two facial expressions required a lower morphed level
for the participant to decide if the face expressed an emotion. The response times were shortest for angry and sad faces, and longest for happy faces. Our results suggests that facial expression processing isdifferent in the foveal and peripheral vision.
Grant: This work was supported by Minister of Science and Technology in Taiwan (MOST 104-2628-H-006-001-MY3) to PCH.
Keywords: facial expression, morphed task, peripheral vision

P3-72
Symmetry or Beauty at First Sight: Neural Responses to Human Face Symmetry and AttractivenessChih-Chia Hsing, Pi-Chun Huang
Department of Psychology, National Cheng Kung University

Previous studies have shown a positive correlation between facial symmetry and facial attractiveness.
However, few studies have investigated how the brain processes interactions between them. This study
adopts 36 pairs of photographs containing asymmetrical human faces and their symmetrical versions as
our stimuli. Functional magnetic resonance imaging (fMRI) was conducted while the subjects performed the symmetry rating task and the attractiveness rating task. Behavioral results showed that thesymmetrical versions of the stimuli received higher ratings in both tasks. A comparison of fMRI data
between symmetrical and asymmetrical stimuli showed activation at the right superior parietal gyrus in
the symmetry task, whereas no activation was found during the attractiveness task. Another analysis
was conducted according to the difference in ratings between the two versions of the same face. The
analysis revealed greater activity at the reward- and emotion-related brain areas while assessing attractiveness, whereas activity in the right inferior occipital gyrus and the right anterior cingulate gyrus increased in the symmetry task. Our results were in line with previous studies. Nevertheless, while earlier
research describes the assessment of facial attractiveness as automated, our study demonstrated that
evaluation of facial symmetry is not an automated process.
Grant: This work was supported by Minister of Science and Technology in Taiwan (MOST 104-2628-H-006-001-MY3) to PCH.
Keywords: fMRI, facial attractiveness, facial symmetry— 150 —

P3-73
Trial order effect in size preference 2AFC judgment task about natural scene moving images
Masamitsu Harasawa1,2, Yasuhito Sawahata1, Yamato Miyashita1, Kazuteru Komine1, Satoshi Shioiri2
1Japan Broadcasting Corporation, 2Tohoku University

We measured the preferred size of natural scene moving images (5 secs) by method of constant stimuli
where participants reported their preference of size by 2AFC judgment, enlarge / shrink, on 100 moving
images with 7 steps (25-100% to original) of physical size. 255 participants performed 700 trials separated into 6 sessions consisted of 116 or 117 trials where presentation order of stimuli was randomized
for each participant. To investigate the effect of trial order, we calculated the 50% response ratio threshold as a preferred size for each trial number from 1st to 700th by gathering 255 trials from all participants. The preferred size showed shrinking with progress of the experiment and recovers in few minutesof breaks between the sessions. On average, the preferred size shrunk 9.7% for a whole experiment and7.1% for a session, respectively. While these trends seem to be derived from some adaptation to stimulus exposure, it is unclear why the adaptation appeared as shrinking instead of enlarging. In addition,
2AFC responses showed negative correlations between adjacent trials. This effect lasted for six trials
and suggested that participants tried to avoid repeating the same responses.
Grant: none
Keywords: size preference, aesthetic judgment, trial order effect, psychophysics

P3-74
Impaired emotion processing in voice and content is associated with alexithymia, the inability toname and describe feelings
Yutong Lin1,2, Xuanchang Lin1,2, Hong Xu1,2, Kalon Sou1,2, Fun Lau1,2
1Nanyang Technological University, 2Raffles Institution

Alexithymia, the difficulty in interpreting and verbalizing one’s own and others’ feelings, has received
heightening attention due to its potential correlation with various clinical illnesses and social dysfunctioning. Our study specifically examines the integration of emotional information from voice and speech
content and if there exists any correlation with alexithymic traits. Vocal stimulus used in the experiment
comprises of validated and randomized recordings that can be either congruent or incongruent in termsof the emotions conveyed through voices and contents. Two blocks of experiments were carried out for
24 participants to rate the emotion within either voice or sentence content independent of the other.
Participants with varied alexithymia levels as calculated by the Toronto Alexithymia Scale (TAS 20)
display differed abilities to identify content or voice emotions with a different combination of voice andcontent emotions. The results suggest that those with higher alexithymic level have greater difficulty indissociating emotional information in speech, especially from the emotional content when voices arevaried, and the effect is the most pronounced when they are exposed to a material with a sad voice.
Therefore, the existing approach to mitigate the effect of alexithymia may need to be further revised andenhanced.
Grant: none
Keywords: Alexithymia, Emotion processing, Voice, Content

P3-75
Effect of task-irrelevant ugly-beauty faces on involuntary attention: ERP study and individual
differences
Eriko Matsumoto1, Tomoya Kawashima2, Tomoyuki Naito3
1Kobe University, 2NICT (national institute of information and communications technology), 3Osaka University

The aim of this study is to examine how ugly or beauty faces capture attention even they were completely task-irrelevant. Many studies have reported that human face attracts attention powerfully. Especially,
attractive faces or threat-related faces capture more attention. Several neuroimaging studies have re— 151 —ported the emotional brain network for ugly stimuli perception, however, little is known the differenceof the effects on involuntary attention between beauty and ugly. We employed the letter detection task
to measure the distractibility of attention by peripheral images (beauty face, ugly face, and control stimuli) with recording the distractor time-locked ERPs. In this task, participants were asked to detect thetarget letter with ignoring peripheral stimuli. We used artificial ugly/beautiful faces as distractors created by using a psychophysical reverse-correlation technique (Naito et al., 2017). The results showed that
N2pc peak amplitude was modulated by the face presentation compared to control images but there
were no significant difference between face conditions. LPP amplitude was significantly reduced whenugly face was presented. Negative correlation was observed between LPP amplitude and the correct
detection rate with ugly face distractor. The results suggest that ugly faces could have higher distractibility feature than other faces.Thursday, August 1
Grant: none
Keywords: attention, face, ERP— 152 —

Thursday, August 1
Symposium 4-1 9 : 00 AM-11 : 00 AM, Grand hallColor vision in naturalistic objects and environments
Organizer:
Yoko Mizokami(Chiba Univ)
Color perception in real life is adjustable and stable. Color adaptation and color constancy are good
examples of this flexibility of color vision, but recent researches have revealed much more complexity
and the influence of various factors such as color distribution in an environment, naturalistic change inillumination, the property of material, cue integration from different visual dimensions, memory andlearning, the recognition of naturalness of objects and scenes.
This symposium focuses on the property of our color vision for real or realistic objects and environment
and also discuss how we should test those properties, by introducing the latest researches of five researchers working on complex color vision in different viewpoints, but their interests are overlapping
each other.
Dr. Webster will talk about environmental influences on color appearance through his extensive work
related to adaptation to various environments. Dr. Olkkonen will talk about how learning and memory
affect our color perception. Dr. Sarrela will talk about how cue integration from different visual dimensions helps color and material perception. Dr. Nagai will talk about the effects of specular reflection
components on color constancy using the various combination of complex stimuli generated by computer graphics. Dr. Mizokami will talk about color and material perception under different lighting
conditions in a real environment
S4-1-1
Blue and yellow in the world and the brain
Michael A. Webster(University of Nevada)
Blue-yellow variations are a prominent property of the natural environment. For example, different
phases of daylight vary along a blue-yellow axis, and the gamut of colors in many natural scenes varies
from blue sky to predominantly yellowish or brown terrain. These stimulus biases may have shaped
many aspects of human color vision, including chromatic sensitivity and color appearance. Sensitivity
can be weaker along the blue-yellow axis, and this may reflect adaptation to the stronger blue-yellow
contrasts in scenes. This bias is also manifest in the scaling chosen for many perceptually uniform color
spaces. Similarly in color appearance, blue and yellow can seem more pure or “unique,” even thoughthese hues do not clearly reflect special states in the underlying neural code for color. There are also
important differences between blue and yellow percepts which suggest they are not treated as two polesof a common underlying dimension. In particular, bluish tints are more likely to be attributed to the illuminant, while yellowish tints are more likely to be associated with surface color. These asymmetries
are largely restricted to the blue-yellow axis, and may again be shaped by high-level inferences about
the chromatic properties of the world.
S4-1-2
Learning and memory in color perception
Maria Olkkonen(Durham University)
We often have the experience of perceiving the colors and materials of objects in our environment effortlessly. But estimating the material properties of objects is in fact a computationally hard problem forthe visual system, because the light signal that reaches our eyes from surfaces in our environment de— 153 —pends not only on the reflectance of the surface, but also on the illumination impinging on the surface.
Statistical regularities about surfaces and illuminants, learned through interacting with our environment
and through social communication, may contribute to our ability to compensate for changes in illumination when estimating object color. In this talk, I will link human color constancy to a probabilistic
framework of perceptual estimation, and will give an overview of experiments testing predictions fromthis framework. The results so far suggest that human color constancy can be modeled in the probabilistic framework, but more work remains to be done to uncover the computational mechanisms of color
constancy in natural scenes. I will end by discussing ongoing research to push the study of color constancy to more realistic scenes and tasks.
S4-1-3
Cue integration in color and material perception
Toni Saarela(University of Helsinki)
Visual features do not occur in isolation, and surfaces and materials in our visual environment differ
from each other in several respects: in color, lightness, glossiness, and texture, for example. Integrating
information from several such sources, or "cues", is a fundamental property of the visual system andcan enable us to perform better in several visual tasks. Visual cue integration can occur "across space",
as when integrating color information from distinct spatial locations to estimate the body color of an
object. It can also happen "across dimensions", as when integrating different types of spatially overlapping cues, for example color and glossiness when discriminating or identifying materials. I will present
examples of both types of integration. First, as an example of spatial integration, I will discuss resultsfrom experiments characterizing the sampling of hues when estimating the mean hue of an ensemble ofcolors. Color discrimination was measured for a range of stimulus sizes, and stimulus colors where
perturbed by noise. Through modeling, we derived estimates of the observers' ability to sample thestimulus when discriminating mean color. The estimates far exceed those previously reported in theliterature based on a more limited set of experimental conditions. To illustrate spatially local integrationof cues from different visual dimensions, I present results from optimal integration color, texture, andglossiness cues when evaluating surface properties. Finally, I will highlight the importance of manipulating the extrinsic uncertainty in a psychophysical task when measuring integration, and will show how
mandatory integration of visual cues can also have its downsides, as it can in some cases prevent the
selection of individual feature dimensions for further processing.
S4-1-4
Effects of specular reflection components on color constancy
Takehiro Nagai(Tokyo Institute of Technology)
The visual system is considered to employ various heuristics in retinal images which reflect illumination colors in scenes for color constancy. Specular highlight is one of such candidate cues, because they
typically reflect spectral components of illumination directly. Although some previous studies reported
small improvement of color constancy in scenes with glossy objects, the degree of the improvement
largely differed across the studies. We have investigated psychophysically 1) if effectiveness of specular highlights is valid under different stimulus conditions, and 2) which image features explain suchhighlight effects on color constancy.
The stimulus consisted of a test sphere and many background objects, which had different levels ofspecular reflectance (SR) and fixed diffuse reflectance. Observers performed achromatic-setting tasks
on the test sphere under D65, A, or 25000K illuminant.
First, the color constancy index increased by maximum of 30% from minimum to maximum SR
under A. In contrast, SR did not significantly affect color constancy index under 25,000K. These results
suggest that the conditions under which specular components contribute to color constancy are limited;— 154 —

the roles of specular components seem just supportive, not very pronounced. Second, when we performed almost the same experiments except that the images of background objects were phase-randomized while keeping luminance-chromaticity histograms unchanged, the improvement of color constancy was dramatically diminished. Also, by removing high-luminance components in specular reflections
the improvement of color constancy was completely lost. The high-luminance components look likespecular reflections seem to be crucial for the improvement effect in color constancy.
S4-1-5
Color and material perception in real illuminating environment
Yoko Mizokami(Chiba University)
It has been suggested that the specular reflection occurring on a surface of an object would contributeto color and material perception. First, we examined the effect of the surface and specular reflection of
objects on color constancy using real vegetables as familiar objects in real space. Observers evaluatedstimuli with different glossiness under white and reddish color illumination, and we compared thosecolor appearances. As a result, in the real space, specular reflection hardly affected color constancy, but
under the limited view condition, color constancy was a little bit better for the glossy surface than thematte surface. These results suggest that the specular reflection slightly contributes to color constancy
under limited conditions. Second, we examined how the color appearance of object surface was influenced by the diffuseness of lighting in real miniature rooms. We used two miniature rooms illuminatedby a diffused light and a direct light, respectively. We presented a test sample with sine-wave surface.
Both glossy and matte surface materials with five colors were prepared for the samples. Observers
judged the color appearance of samples by selecting their corresponding colors. The correspondingcolor for test samples were similar under both diffused and direct lighting conditions. The color appearance of object surface would be quite stable among the change in material and illumination.

— 155 —

Thursday, August 1
Oral 4-1, Cognition
9 : 00 AM-11 : 00 AM, Colloquium
Moderators: Su-Ling Yeh, Sang-Hun Lee
O4-1-1
9 : 00 AM-9 : 15 AM
Perceived Dominance from Face Images Depends on Interaction Situations: Examinations ofConsistency across Japanese and Taiwanese and the Own-Race Bias
Yoshiyuki Ueda1, Bo-Cheng Huang2, Su-Ling Yeh2, Sakiko Yoshikawa1
1Kokoro Research Center, Kyoto University, 2Department of Psychology, National Taiwan University

Facial features and expressions can be used as important nonverbal cues to infer other’s personality
traits and status such as perceived dominance. Most previous studies used a single face presentation toinvestigate this issue; however, in everyday life our communication is not limited to one-on-one situations. For example, Ueda and Yoshikawa (2018) showed that while faces with angry/disgusted expressions were perceived as more dominant in one-on-one situations, those showing happy expressions
were perceived as more dominant in two-person interaction scenes instead. In this study, using Caucasian and East Asian faces, Japanese and Taiwanese participants judged which person was more dominant in two-person interaction scenes to examine the possibility of idiosyncrasy of Japanese participants
and the own-race bias of face perception. The results showed that i) both Japanese and Taiwanesejudged that people showing happy expressions were dominant in two-person interaction scenes regardless of image races, suggesting that concealing negative expressions against disgusted persons makethemselves more dominant, and ii) people showing happy expressions were perceived as more dominant for Japanese than Taiwanese. These findings indicate both commonality and difference in the signal of facial expressions for perceived dominance.
Grant: none
Keywords: facial expression, face recognition, dominance, own-race bias

O4-1-2
9 : 15 AM-9 : 30 AM
A novel neural mechanism for autistic vision through rose coloured spectacles
David Philip Crewther1, Laila Hugrass2, Eveline Mu1
1Centre for Human Psychopharmacology, Swinburne University of Technology, 2School of Psychology and Public Health, La Trobe University

Autism shows consistent visual abnormalities, particularly in magnocellular processing. Also, saccadic
suppression—loss of visual contrast sensitivity associated with a rapid eye movement appears to be
selective for low spatial frequencies (attributed to magnocellular selection) only in individuals withhigh autistic tendency. Primate studies suggest such suppression arises in superior colliculus (SC) topulvinar (PUL) inhibition, also that early PUL inputs to cortical area MT gradually withdraw, replaced
by inputs from area V1. Thus, we propose that the withdrawal process in autism is not as complete as
in typical development. Altered balance of LGN vs PUL inputs to cortex could be achieved throughinhibition of the Type IV M cells which are suppressed by red light and which project to LGN but not
SC. We tested this hypothesis by looking at the effects on ERP P100 and N170 responses to facial emotion in those high (n=22) and low (n=21) in autistic tendency using red and green backgrounds of equal
luminance. For the low AQ group, red surrounds reduced the effect of fear on P100 amplitude. For thehigh AQ group, red surrounds enhanced low spatial frequency fearful P100 amplitudes, implying adisinhibition of amygdala connected attentional input.
Grant: none
Keywords: EEG, psychophysics, autistic vision, facial emotion— 156 —

O4-1-3
9 : 30 AM-9 : 45 AM
Perceptual learning along the “weaker” principal meridian improves contrast sensitivity function
and visual acuity in patients with astigmatism
Li Gu1, Jinrong Li1, Jing Zhong1, Zhipeng Chen1, Zhong-Lin Lu2, Yuan Jin1
1State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center,

Sun Yat-sen University, 2Department of Psychology, The Ohio State University

Astigmatism before visual development results in abnormal visual development due to principal meridional variations in visual processing. Ten subjects with with-the-rule astigmatism (13.90±1.73 years)
participated in baseline assessments, which consisted of visual acuity and CSFs measured with bothvertical and horizontal sinewave gratings. They were then trained in a luminance grating orientation
identification task (±5°) around the vertical direction at their individual cutoff SF, whichever had relatively poorer CSF. Post-training assessments were the same as the baseline. Results from the baseline
tests showed that the cut-off SF on the horizontal meridian was lower than that on the vertical meridian(t9=1.94, p=0.084), demonstrating differential effects of astigmatism on visual processing in different
meridians. Additionally, training in the weaker meridian near cut-off SF led to significant improvements
in contrast sensitivity at the trained SF measured with vertical gratings (4.50 dB or 67.96%; t9=2.81,
p=0.020). No significant improvement was found in contrast sensitivity at the trained SF measured withhorizontal gratings. Moreover, the training improved visual acuity of the trained eye by 3.70 dB (or53.17%). These findings demonstrate effects of astigmatism on visual processing and provide empiricalevidence for perceptual learning as a potential treatment for astigmatism.
Grant: none
Keywords: psychophysics, astigmatism, perceptual learning

O4-1-4
Short-Term Source Amnesia Does Not Persist in Auditory Modality
Ping Zhu, Mengjiao Xu, Yingtao Fu, Jiahan Yu, Mowei Shen, Hui Chen

9 : 45 AM-10 : 00 AM

Department of Psychology and Behavioral Sciences, Zhejiang University

Failing to remember the source of retrievable information is known as source amnesia. This phenomenon has been extensively investigated in long-term memory but rarely in short-term or working memory, as we share the intuition that source information of an item that we have encountered momently
before is always available. However, a recent study (Chen, Carlson, & Wyble, 2018) challenged thiscommon sense by showing a striking phenomenon of source amnesia for simple visual stimuli in thecontext of working memory when participants did not expect to report source information. The current
study sought to explore the boundaries of short-term source amnesia by testing whether it persists incomplex and meaningful stimuli in the visual modality (Experiment 1), cross-visual-and-auditory modalities (Experiments 2a & 2b), and within-auditory modality (Experiment 3). The results revealed thatshort-term source amnesia was a stable phenomenon in the visual modality, whereas it was absent in the
cross-visual-and-auditory or within-auditory modalities, regardless of reporting expectation. This indicated differences between working memory representations of auditory stimuli and that of visual stimuli, namely, the former was automatically bound to the corresponding original sources, while the latter
was stored independently of its source information.
Grant: National Natural Science Foundation of China (No.31771201), and National Science Foundation for Distinguished Young Scholars ofZhejiang Province, China (No. LR19C090002).
Keywords: working memory, source memory— 157 —

O4-1-5
Memory-driven capture is at the level of features not objects
Edyta Sasin, Daryl Fougnie

10 : 00 AM-10 : 15 AM

New York University of Abu Dhabi

Previous findings have shown that items in memory capture attention (memory-driven capture). Research has also shown that people are able to selectively maintain a subset of the features previously
encoded into working memory. Here, we examined whether memory-driven capture operates at thelevel of the object or at the level of an individual feature. After remembering the color and orientationof a triangle, participants were instructed, via cue, whether the color, the orientation, or both features
had to be remembered for a later continuous report. To measure memory-driven capture we asked participants to execute a subsequent search task and we compared performance in displays that did and did
not contain memory-matching feature. The results showed that color attracted attention only when it
was indicated as task relevant by the cue. The attentional capture by color was reduced when both colorand orientation had to be held in memory and it was eliminated when color was indicated as no longer
relevant. There was no evidence of capture by orientation. Taken together, our results suggest that both
memory selection and memory-driven attentional capture operate on individual features, supporting thenotion that features are stored separately rather than in an integrated form.
Grant: none
Keywords: memory-driven capture, working memory, attentional selection

O4-1-6
The storage of dynamic relations in visual working memory
Jing Chen, Jifan Zhou, Mowei Shen

10 : 15 AM-10 : 30 AM

Department of Psychology and Behavioral Sciences, Zhejiang University

The ability of briefly holding and manipulating object relations provides a foundation stone for interacting with the complex environment around us. As the first step to understand the storage mechanism ofobject relations in visual working memory (VWM), we measured the capacity of holding dynamic relations of objects, by using a modified change-detection paradigm with moving objects as memory
items. Participants were required to memorize the object relations showed by the dynamic display inwhich several pairs of objects moved under each other’s constraint (e.g., two moving balls connectedby a spring). After holding a while, participants reported whether the relation of probe objects was
identical to one of the memorized relations. The results showed that participants were able to hold approximately 2 relations, whether the relation was familiar (e.g., piston motion) or unfamiliar (e.g.,
synchronous vibration). When the complexity of relations increased (i.e., an object simultaneously related to more objects) the memory accuracy decreased. These findings suggested that the VWM capacity of holding dynamic relations depended on the complexity of relation. For the display containing
simple relations, in which each object related to only one object, the capacity is 2; while it was even lessfor more complex relations.
Grant: the National Natural Science Foundation of China (No. 31871096, 31600881)
Keywords: visual working memory, object relation, dynamic relation, memory capacity

O4-1-7
Differential neural activation to explicit and implicit moral processing
Dan Tao1, Yue Leng2

10 : 30 AM-10 : 45 AM

1Southeast University, 2Southeast University

Explicit moral judgement was often accompanied by active attention and explicit response to moral
information in previous studies. However, implicit moral information could also affect other cognitive
processes that have no relation with moral judgment. The present study aimed to investigate the differences of neural temporal dynamics between the implicit and explicit harm/care moral processing. Par— 158 —ticipants were enrolled and the event-related potential (ERP) responses were recorded while viewing
192 images indicating moral behaviors based on harm/care with high/low arousal. Half participants
were instructed whether pictures represented moral or immoral behavior (explicit task) while the otherhalf were instructed whether pictures involved kids or animals, which served as distraction stimulate(implicit task). The results showed that distraction stimulate was more disturbed under the high-arousal
moral condition(indexed by accuracy and reaction time); For both implicit and explicit task, moral information could cause early attention of the subject (indexed by the N1, P1, and N2); Attention of
moral rightness only affect the early period in explicit task, while the implicit task was influenced in thewhole phase (indexed by P300, Parietal-occipital LSW); The difference between two tasks may introduced by the regulatory capacity of inhibitory control to moral cues (indexed by Frontal LSW).
Grant: none
Keywords: implicit moral processing, explicit moral processing, behavioral method, event-related potential

O4-1-8
‘Sociality’ Matters in Emotion Perception of Visual Narratives
Jinyoung Kim, Yeonwha Kim, Sang-Hun Lee

10 : 45 AM-11 : 00 AM

Department of Brain and Cognitive Sciences, Seoul National University

Visual perception is typically conceptualized as inferring external world states from visual sensory
measurements, whereby people are assumed to utilize prior knowledge about the physical environment
to compensate for the imprecision of sensory measurements. By the same token, visual perception canalso be directed toward internal emotional states when people navigate and act in their social environment, whereby certain prior knowledge about the social environment are expected to assist people toread nuanced emotions out of ambiguous visual narratives unfolding in various social contexts. We
reasoned that such prior knowledge required for emotion perception is likely to vary from individual toindividual depending on their personality traits, particularly those associated with ‘sociality’ – the extent to which individuals engage in social activities or transactions. To explore this idea, we characterized the personality traits of human observers with a multitude of psychometric questionnaires and assessed their emotion perception by asking them to assign affective states to a wide range of visual
narratives (short excerpts from movies). Using multivariate analyses, we discovered a tight linkage
between personality traits and emotion perception: individuals characterized with strong sociality traits
tend to assign more intensified affective states to visual narratives, compared to those with weak sociality traits.
Grant: The Brain Research Programs and Basic Research Laboratory Program through the National Research Foundation of Korea (NRF2015M3C7A1031969; NRF-2017M3C7A1047860; NRF-2018R1A4A1025891)
Keywords: Visual cognition, High-level visual perception, Psychophysics, Canonical correlation analysis— 159 —

Thursday, August 1
Symposium 4-2 9 : 00 AM-11 : 00 AM Colloquium
Multi-dimensional approach to understand anatomical basis of visual functions
Organizers:
Hiromasa Takemura1, Toru Takahata2(1CiNet, NICT,2Zhejiang University)
Although visual system has been widely studied over several last decades, there is one major question
remains largely unanswered: how functions of visual system are related to underlying anatomical properties. This symposium features investigators working with cutting edge approach for addressing thisquestion, by using a various type of methods spanning from molecular, microscale to macro-scale level.
The symposium will address how anatomical measurements will help to understand disorders, organization, plasticity and evolution of the visual system.
S4-2-1
Understanding major white matter pathways in visual system: from neuroimaging to neuroanatomy
Hiromasa Takemura1,2(1Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, 2Osaka University)
Human and non-human primate visual system is composed of a number of geniculo-cortical and cortico-cortical white matter pathways, which support communication between distinct visual areas. This
talk describes recent progress in analyzing these pathways to understand disorders, organization andfunction of the visual system. First, I will demonstrate the evidence showing retinal ganglion cell disease, Leber’s Hereditary Optic Neuropathy, caused different types of neurobiological change among
different part of visual pathways (optic tract and optic radiation) by combining two types of neuroimaging measurements, diffusion MRI (dMRI) and quantitative MRI (qMRI; Mezer et al., 2013). Second,
I will describe recent progress in analyzing the vertical occipital fasciculus (VOF; Yeatman et al., 2014)
by combining dMRI and anatomical measurements. The VOF is an important white matter tract to understand visual processing streams because it connects dorsal and ventral streams (Takemura et al.,2016). To improve our understanding of this pathway, we first analyzed high-resolution dMRI dataobtained from non-human primate brains. The analysis of dMRI data reveals that inter-species similarities of VOF across primate species, but also provides consistency of VOF cortical endpoints among
dMRI and previous invasive studies. Furthermore, I will also describe an analysis of data obtained byusing polarized light imaging (PLI; Axer et al., 2011), which provide fiber orientation at micrometer
resolution. PLI data not only supports the existence of the VOF, but also disentangles current controversies in the visual white matter pathways, such that how much the VOF is distinct from a pathway connecting occipital and inferotemporal cortex. Finally, I will discuss how accurate understanding of whitematter pathways help us to understand the organization of extrastriate cortex.

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S4-2-2
Across the V1 orientation map long-range lateral inputs onto local inhibitory neurons sharpen
orientation tuning of principal neurons
David C. Lyon
(University of California, Irvine)
Specific cell types and their connectivity are a key determinant in neural function and selectivity. Visualcortex is among the most complex and detailed brain structures and several recent technological advances have enabled more detailed probing of cell type specific relationships to connectivity and function.
Yet, such studies leave many questions unresolved and are largely limited to transgenic mice which lack
more complex organization found in higher visual species such as cat and monkey. Of particular interest,is the role of inhibitory neurons in modulating orientation selectivity. Orientation tuning has been shown
to improve dramatically when visual stimuli expand beyond the classical receptive field (CRF) into theextraclassical surround (ECS). Moreover, in addition to sharper orientation tuning, firing rate is also reduced, suggesting a role of inhibition. Long-range horizontal projections, which allow for integration
across the visual field within V1 and represent visual space corresponding to parts of the ECS, preferentially connect regions, or domains, of neurons with like-orientation preference. Using a novel cell-type
specific rabies virus tracing strategy we have shown that a major target of these orientation tuned inputs
is local inhibitory neurons (Liu et al., 2013, Curr Biol). We hypothesize that these inputs play a key rolein the orientation selectivity of the suppressive effects attributed to the ECS. To test this, we retrogradely delivered light gated opsin, ChR2 or ArchT, to these long-range inputs through our rabies virus technique. We then measured the effects of their light mediated activation or blockade, respectively, on single
unit responses to various center-surround visual stimulus conditions. When only a CRF sized stimulus
was shown, ChR2 activation simulated surround suppression, reducing firing rate and sharpening orientation tuning. Conversely, ArchT mediated suppression of long range inputs under conditions including
the ECS, blocked the effects of suppression and orientation tuning broadened. Because the labeled longrange inputs are largely excitatory neurons synapsing onto local inhibitory neurons these results showthat interconnectivity between orientation domains play a major role in modulating orientation tuning.
S4-2-3
Possible parallel visual pathways between the lateral pulvinar and V2 thick/thin stripes in macaques
Toru Takahata(Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Zhejiang University)
It has been known that primate V2 is subdivided into at least three sub-compartments: thick stripes, thin
stripes, and pale stripes, according to their reactivity to cytochrome oxidase (CO) histochemistry. Later, it
has been revealed that these histochemical sub-compartments are associated with functional reactivity to
distinct types of visual stimuli, such that thick stripes are more responsive to directional movement anddepth coding, thin stripes are more responsive to color stimuli, and pale stripes are more responsive toform and orientation of the visual stimuli. Furthermore, these physiological properties are reasonably
associated with connectivity from V1, as color-coding neurons in CO blobs preferentially project to thin
stripes and neurons in interblobs preferentially project to thick and pale stripes. They are recognized as“parallel visual pathways”: The “P” pathway that goes through geniculate parvocellular layers/V1 CO
blobs/V2 thin stripes and the “M” pathway that goes through geniculate magnocellular layers/V1 interblobs/V2 thick stripes. On the other hand, it was previously revealed that thick and thin stripes receive
direct projections from the pulvinar complex of the thalamus, but pale stripes do not. Furthermore, previous electrophysiological studies also revealed that there are two distinct visuotopic maps within the lateral pulvinar. Thus, we hypothesized that there is another set of parallel pathways between the pulvinar andV2. To address this possibility, we injected different kinds tracers, BDA, CTB-Alexa-488 and CTB-Alexa-555, into three consecutive thick/thin stripes in V2 after identifying V2 stripe maps by intrinsic signal
optical imaging and examined retrograde labeling in the pulvinar of macaques. As a result, we found that
there are a few patchy distinct labeling for each retrograde tracer, and that thick stripe-projecting compart— 161 —ments and thin stripe-projecting compartments are segregated, although they are located next to eachother within the lateral pulvinar. Our study indicates a possibility that there are several parallel pathways
within the pulvinar-V2 projection, similar to the manner of geniculo-striate projections.
S4-2-4Development of pulvino-cortical circuits: implications for visual behaviours and disorders
James Bourne(Australian Regenerative Medicine Institute, Monash University)
The pulvinar is the largest collection of nuclei of the thalamus in primates, including humans, comprising 3 nuclei and further subdivisions. Even though it has been demonstrated to be embedded withinsensory systems and connect with the majority of the neocortex, its function remains unclear. Over the
past decade, my group have been instrumental in demonstrating in the marmoset monkey the role of themedial subdivision of the inferior pulvinar in the development of the dorsal stream visual cortex and the
manifestations of a lesion to this region of the brain in early life. To this end, we now know that this area
plays an implicit role in the development of the visual cortex and establishment of visuomotor behaviours, such as reaching and grasping. Furthermore, we have evidence that the pulvinar can routevisual information to the visual cortex following a lesion of the geniculostriate pathway in early life inboth monkeys and humans. Collectively, these data demonstrate an essential role for the inferior
pulvinar thalamic nuclei in early life. Furthermore, up to this point, it was suggested that the thalamocortical circuits were ‘hardwired’ by birth yet we now have evidence and an example of their inherent
plastic nature early in life and ability to reroute sensory information.

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