julilili42/papers huggingface dataset:
Mutual influence between language and perception in multi-agent communication games
2022-10-31

Language interfaces with many other cognitive domains. This paper explores how interactions at these interfaces can be studied with deep learning methods, focusing on the relation between language emergence and visual perception. To model the emergence of language, a sender and a receiver agent are trained on a reference game. The agents are implemented as deep neural networks, with dedicated vision and language modules. Motivated by the mutual influence between language and perception in cognition, we apply systematic manipulations to the agents’ (i) visual representations, to analyze the effects on emergent communication, and (ii) communication protocols, to analyze the effects on visual representations. Our analyses show that perceptual biases shape semantic categorization and communicative content. Conversely, if the communication protocol partitions object space along certain attributes, agents learn to represent visual information about these attributes more accurately, and the representations of communication partners align. Finally, an evolutionary analysis suggests that visual representations may be shaped in part to facilitate the communication of environmentally relevant distinctions. Aside from accounting for co-adaptation effects between language and perception, our results point out ways to modulate and improve visual representation learning and emergent communication in artificial agents.
Vigilance, arousal, and acetylcholine: Optimal control of attention in a simple detection task
2022-10-31

Paying attention to particular aspects of the world or being more vigilant in general can be interpreted as forms of ‘internal’ action. Such arousal-related choices come with the benefit of increasing the quality and situational appropriateness of information acquisition and processing, but incur potentially expensive energetic and opportunity costs. One implementational route for these choices is widespread ascending neuromodulation, including by acetylcholine (ACh). The key computational question that elective attention poses for sensory processing is when it is worthwhile paying these costs, and this includes consideration of whether sufficient information has yet been collected to justify the higher signal-to-noise ratio afforded by greater attention and, particularly if a change in attentional state is more expensive than its maintenance, when states of heightened attention ought to persist. We offer a partially observable Markov decision-process treatment of optional attention in a detection task, and use it to provide a qualitative model of the results of studies using modern techniques to measure and manipulate ACh in rodents performing a similar task.
More linear than log? Non-symbolic number-line estimation in 3- to 5-year-old children
2022-10-31

The number-line estimation task has become one of the most important methods in numerical cognition research. Originally applied as a direct measure of spatial number representation, it became also informative regarding various other aspects of number processing and associated strategies. However, most of this work and associated conclusions concerns processing numbers in a symbolic format, by school children and older subjects. Symbolic number system is formally taught and trained at school, and its basic mathematical properties (e.g., equidistance, ordinality) can easily be transferred into a spatial format of an oriented number line. This triggers the question on basic characteristics of number line estimation before children get fully familiar with the symbolic number system, i.e., when they mostly rely on approximate system for non-symbolic quantities. In our three studies, we examine therefore how preschool children (3–5-years old) estimate position of non-symbolic quantities on a line, and how this estimation is related to the developing symbolic number knowledge and cultural (left-to-right) directionality. The children were tested with the Give-a-number task, then they performed a computerized number-line task. In Experiment 1, lines bounded with sets of 1 and 20 elements going left-to-right or right-to-left were used. Even in the least numerically competent group, the linear model better fit the estimates than the logarithmic or cyclic power models. The line direction was irrelevant. In Experiment 2, a 1–9 left-to-right oriented line was used. Advantage of linear model was found at group level, and variance of estimates correlated with tested numerosities. In Experiment 3, a position-to-number procedure again revealed the advantage of the linear model, although the strategy of selecting an option more similar to the closer end of the line was prevalent. The precision of estimation increased with the mastery of counting principles in all three experiments. These results contradict the hypothesis of the log-to-linear shift in development of basic numerical representation, rather supporting the linear model with scalar variance. However, the important question remains whether the number-line task captures the nature of the basic numerical representation, or rather the strategies of mapping that representation to an external space.
Improved order and transport in C60 thin films grown on SiO2 via use of transient templates
2022-10-31

The performance of C60 semiconducting films is linked to the degree of crystallinity and ordering, properties that strongly depend on the substrate, and growth conditions. Substrate–molecule interactions can be specifically tailored by employing growth templates to achieve a desired thin film structure. However, the presence of a growth template after the film deposition is usually not desirable as it may change the properties of the layer of interest. The ability to remove a growth template without any disruption to the active layer would be highly beneficial. A simple method of template removal by annealing is presented here. A variety of small organic molecules (perfluoropentacene, [6]phenacene, and α-sexithiophene) were used as a growth template to obtain a high-quality well-ordered C60 thin film. In situ grazing-incidence wide-angle x-ray scattering was employed to study the structural changes of C60 thin films during template removal. While a slight disturbance of the thin film structure was observed during template removal caused by evaporated molecules from the growth template escaping through the C60 layer, the disruption is only temporary. When the annealing process is concluded, only the well-ordered C60 thin film directly on top of SiO2 is left, which is not achievable without the use of a growth template. Improved crystallinity and grain size of such a thin film, when compared to preparation without a growth template, lead to a significant improvement of the charge carrier mobility. Importantly, template removal prevents the formation of undesired ambipolar transistor characteristics.
Political Obfuscation and Literary Ambiguity
2022-10-31

Abstract In this paper, we are addressing the relationship between ambiguity and obscurity by comparing political with literary use of language. In particular, we are considering contexts in which ambiguity, deriving from underspecification, is strategically used as a device to establish a certain degree of obscurity. We suggest that this strategy is based on an undeclared identification of meanings that are in fact distinct, thus creating false or at least misleading impressions. By contrast, we present literary strategies of ambiguity which also work with combinations of meanings. While the strategies share this combination, they differ vastly in purpose and effect. Our examples are taken from Boris Johnson’s 2021 »Levelling Up«-Speech as well as from poetry and plays by William Shakespeare. Their comparison proves to be particularly fruitful when it comes to conceptualising the ambiguities of »levelling (up)« and their uses in context.
Exploring neural question generation for formal pragmatics: Data set and model evaluation
2022-10-31

We provide the first openly-available German QUestion-Answer Congruence Corpus (QUACC), designed for the task of sentence-based question generation with question-answer congruence. Based on this corpus, we establish suitable baselines for question generation, comparing systems of very different nature. Question generation is an interesting challenge in particular for current neural network architectures given that it combines aspects of language meaning and forms in complex ways. The systems have to generate question phrases appropriately linking to the meaning of the envisaged answer phrases, and they have to learn to generate well-formed questions using the source. We show that our QUACC corpus is well-suited to investigate the performance of various neural models and gain insights about the specific error sources.
Durable spike-specific T cell responses after different COVID-19 vaccination regimens are not further enhanced by booster vaccination
2022-11-01

Several COVID-19 vaccines are approved to prevent severe disease outcome after SARS-CoV-2 infection. Whereas induction and functionality of antiviral antibody response are largely studied, the induction of T cells upon vaccination with the different approved COVID-19 vaccines is less studied. Here, we report on T cell immunity 4 weeks and 6 months after different vaccination regimens and 4 weeks after an additional booster vaccination in comparison with SARS-CoV-2 T cell responses in convalescents and prepandemic donors using interferon-gamma ELISpot assays and flow cytometry. Increased T cell responses and cross-recognition of B.1.1.529 Omicron variant–specific mutations were observed ex vivo in mRNA- and heterologous-vaccinated donors compared with vector-vaccinated donors. Nevertheless, potent expandability of T cells targeting the spike protein was observed for all vaccination regimens, with frequency, diversity, and the ability to produce several cytokines of vaccine-induced T cell responses comparable with those in convalescent donors. T cell responses for all vaccinated donors significantly exceeded preexisting cross-reactive T cell responses in prepandemic donors. Booster vaccination led to a significant increase in anti-spike IgG responses, which showed a marked decline 6 months after complete vaccination. In contrast, T cell responses remained stable over time after complete vaccination with no significant effect of booster vaccination on T cell responses and cross-recognition of Omicron BA.1 and BA.2 mutations. This suggested that booster vaccination is of particular relevance for the amelioration of antibody response. Together, our work shows that different vaccination regimens induce broad and long-lasting spike-specific CD4 + and CD8 + T cell immunity to SARS-CoV-2.
Effects of Impact and Target Parameters on the Results of a Kinetic Impactor: Predictions for the Double Asteroid Redirection Test (DART) Mission
2022-11-01

Abstract The Double Asteroid Redirection Test (DART) spacecraft will impact into the asteroid Dimorphos on 2022 September 26 as a test of the kinetic impactor technique for planetary defense. The efficiency of the deflection following a kinetic impactor can be represented using the momentum enhancement factor, β , which is dependent on factors such as impact geometry and the specific target material properties. Currently, very little is known about Dimorphos and its material properties, which introduces uncertainty in the results of the deflection efficiency observables, including crater formation, ejecta distribution, and β . The DART Impact Modeling Working Group (IWG) is responsible for using impact simulations to better understand the results of the DART impact. Pre-impact simulation studies also provide considerable insight into how different properties and impact scenarios affect momentum enhancement following a kinetic impact. This insight provides a basis for predicting the effects of the DART impact and the first understanding of how to interpret results following the encounter. Following the DART impact, the knowledge gained from these studies will inform the initial simulations that will recreate the impact conditions, including providing estimates for potential material properties of Dimorphos and β resulting from DART’s impact. This paper summarizes, at a high level, what has been learned from the IWG simulations and experiments in preparation for the DART impact. While unknown, estimates for reasonable potential material properties of Dimorphos provide predictions for β of 1–5, depending on end-member cases in the strength regime.
A review of natural hydrofractures in rocks
2022-11-01

Abstract Hydrofractures, or hydraulic fractures, are fractures where a significantly elevated fluid pressure played a role in their formation. Natural hydrofractures are abundant in rocks and are often preserved as magmatic dykes or sills, and mineral-filled fractures or mineral veins. However, we focus on the formation and evolution of non-igneous hydrofractures. Here we review the basic theory of the role of fluid pressure in rock failure, showing that both Terzaghi’s and Biot’s theories can be reconciled if the appropriate boundary conditions are considered. We next discuss the propagation of hydrofractures after initial failure, where networks of hydrofractures may form or hydrofractures may ascend through the crust as mobile hydrofractures. As fractures can form as a result of both tectonic stresses and an elevated fluid pressure, we address the question of how to ascertain whether a fracture is a hydrofracture. We argue that extensional or dilational fractures that formed below c. 2–3 km depth are, under normal circumstances, hydrofractures, but at shallower depth they may, but must not be hydrofractures. Since veins and breccias are often the products of hydrofractures that are left in the geological record, we discuss these and critically assess which vein structures can, and which do not necessarily, indicate hydrofracturing. Hydrofracturing can suddenly and locally change the permeability in a rock by providing new fluid pathways. This can lead to highly dynamic self-organization of crustal-scale fluid flow.
Observations of 4U 1626–67 with the Imaging X-Ray Polarimetry Explorer
2022-11-01

Abstract We present measurements of the polarization of X-rays in the 2–8 keV band from the pulsar in the ultracompact low-mass X-ray binary 4U 1626–67 using data from the Imaging X-Ray Polarimetry Explorer (IXPE). The 7.66 s pulsations were clearly detected throughout the IXPE observations as well as in the NICER soft X-ray observations, which we used as the basis for our timing analysis and to constrain the spectral shape over the 0.4–10 keV energy band. Chandra HETGS high-resolution X-ray spectra were also obtained near the times of the IXPE observations for firm spectral modeling. We found an upper limit on the pulse-averaged linear polarization of &lt;4% (at 95% confidence). Similarly, there was no significant detection of polarized flux in pulse phase intervals when subdividing the bandpass by energy. However, spectropolarimetric modeling over the full bandpass in pulse phase intervals provided a marginal detection of polarization of the power-law spectral component at the 4.8% ± 2.3% level (90% confidence). We discuss the implications concerning the accretion geometry onto the pulsar, favoring two-component models of the pulsed emission.
A Simulation Study on Latent Transition Analysis for Examining Profiles and Trajectories in Education: Recommendations for Fit Statistics
2022-11-01

Latent transition analysis is an informative statistical tool for depicting heterogeneity in learning as latent profiles. We present a Monte Carlo simulation study to guide researchers in selecting fit indices for identifying the correct number of profiles. We simulated data representing profiles of learners within a typical pre- post- follow up-design with continuous indicators, varying sample size (N from 50 to 1,000), attrition rate (none/10% per wave), and profile separation (entropy; from .73 to .87). Results indicate that the most commonly used fit index, the Bayesian information criterion (BIC), and the consistent Akaike information criterion (CAIC) consistently underestimate the real number of profiles. A combination of the AIC or the AIC3 with the adjusted Bayesian Information Criterion (aBIC) provides the most precise choice for selecting the number of profiles and is accurate with sample sizes of at least N = 200. The AIC3 excels starting from N = 500. Results were mostly robust toward differing numbers of time points, profiles, indicator variables, and alternative profiles. We provide an online tool for computing these fit indices and discuss implications for research.
Faster Detection of “Darks” than “Brights” by Monkey Superior Colliculus Neurons
2022-11-01

Visual processing is segregated into ON and OFF channels as early as in the retina, and the superficial (output) layers of the primary visual cortex (V1) are dominated by neurons preferring dark stimuli. However, it is not clear how the timing of neural processing differs between “darks” and “brights” in general, especially in light of psychophysical evidence; it is also equally not clear how subcortical visual pathways that are critical for active orienting represent stimuli of positive (luminance increments) and negative (luminance decrements) contrast polarity. Here, we recorded from all visually-responsive neuron types in the superior colliculus (SC) of two male rhesus macaque monkeys. We presented a disk (0.51° radius) within the response fields (RFs) of neurons, and we varied, across trials, stimulus Weber contrast relative to a gray background. We also varied contrast polarity. There was a large diversity of preferences for darks and brights across the population. However, regardless of individual neural sensitivity, most neurons responded significantly earlier to dark than bright stimuli. This resulted in a dissociation between neural preference and visual response onset latency: a neuron could exhibit a weaker response to a dark stimulus than to a bright stimulus of the same contrast, but it would still have an earlier response to the dark stimulus. Our results highlight an additional candidate visual neural pathway for explaining behavioral differences between the processing of darks and brights, and they demonstrate the importance of temporal aspects in the visual neural code for orienting eye movements. SIGNIFICANCE STATEMENT Objects in our environment, such as birds flying across a bright sky, often project shadows (or images darker than the surround) on our retina. We studied how primate superior colliculus (SC) neurons visually process such dark stimuli. We found that the overall population of SC neurons represented both dark and bright stimuli equally well, as evidenced by a relatively equal distribution of neurons that were either more or less sensitive to darks. However, independent of sensitivity, the great majority of neurons detected dark stimuli earlier than bright stimuli, evidenced by a smaller response latency for the dark stimuli. Thus, SC neural response latency can be dissociated from response sensitivity, and it favors the faster detection of dark image contrasts.
Balancing novelty and appropriateness leads to creative associations in children
2022-11-01

Abstract Creative problem solving is a fundamental skill of human cognition and is conceived as a search process whereby a novel and appropriate solution is generated. However, it is unclear whether children are able to balance novelty and appropriateness to generate creative solutions and what are the underlying computational mechanisms. Here, we asked children, ranging from 10 to 11 years old, to perform a word association task according to three instructions, which triggered a more appropriate (ordinary), novel (random), or balanced (creative) response. Results revealed that children exhibited greater cognitive flexibility in the creative condition compared to the control conditions, as revealed by the structure and resiliency of the semantic networks. Moreover, responses’ word embeddings extracted from pretrained deep neural networks showed that semantic distance and category switching index increased in the creative condition with respect to the ordinary condition and decreased compared to the random condition. Critically, we showed how children efficiently solved the exploration/exploitation trade-off to generate creative associations by fitting a computational reinforcement learning (RL) model that simulates semantic search strategies. Our findings provide compelling evidence that children balance novelty and appropriateness to generate creative associations by optimally regulating the level of exploration in the semantic search. This corroborates previous findings on the adult population and highlights the crucial contribution of both components to the overall creative process. In conclusion, these results shed light on the connections between theoretical concepts such as bottom-up/top-down modes of thinking in creativity research and the exploration/exploitation trade-off in human RL research.
Posts About Students on Facebook: A Data Ethics Perspective
2022-11-01

Public schools and districts use social media to share announcements and communicate with parents and the community, but alongside such uses run risks to students’ privacy. Using a novel data set of 18 million posts on Facebook by schools and school districts in the United States, we sought to establish how frequently photos of students were shared. Through sequential mixed-methods, we estimated that around 4.9 million posts included identifiable images of students and that approximately 726,000 of these posts also included students’ first and last names and their approximate location. We discuss these findings’ implications from a data ethics perspective.
It's better when I see it: Students benefit more from open‐book than closed‐book teaching
2022-11-01

Abstract Teaching previously learned contents to (fictitious) peers is regarded as a beneficial activity that aids learning. However, it is still an open question which cognitive mechanism (generating versus retrieving information) account for this learning‐by‐teaching effect. To examine the role of retrieval during generative processing while learning‐by‐teaching, we conducted an experiment. After a learning phase about the human respiratory system, university students ( N = 108) either taught the learned contents with (open‐book teaching) or without (closed‐book teaching) access to the learning material. Students in the control group restudied the contents. Results indicated that teaching was not more beneficial than restudying regarding students' learning outcome (i.e., retention, drawing knowledge, transfer knowledge). However, open‐book teaching was more effective than closed‐book teaching regarding students' retention. This effect was mediated by the richness (i.e., number of concepts) and completeness of students' explanations. The findings suggest that retrieval failure may constrain potential effects of closed‐book explaining.