bluuebunny/crossref_metadata_2025 huggingface dataset:
The State of Biological Anthropology in 2008: Is Our Discipline Strong and Our Cause Just?
Authors: Malone Nicholas
Published: May 2009

ABSTRACT Biological anthropologists inform a largely professional discourse on the evolutionary history of our species. In addition, aspects of our biology, the ways in which we vary, and certain patterns of behavior are the subjects of a more public and popular conversation. The social contexts in which we work not only define our times but also produce the anthropologists that in turn construct an emergent understanding of our species’ (and our societies’) inner workings. In this review of scholarly production, I focus on developments within a selection of “sub‐subdisciplines” that were particularly influential in bending the arc of biological anthropology in 2008, namely: evolutionary medical anthropology, anthropological neuroscience, forensic anthropology, primatology, and paleoanthropology. Ultimately, this review demonstrates, yet again, anthropology's great contribution: the ability to incorporate new technologies and research methodologies into a synthetic and integrative interdisciplinary approach toward the elucidation of human behavior, evolution, and biocultural engagements with the environment. [Keywords: biological anthropology, year in review, 2008, science and society]
On Neoliberalism and Other Social Diseases: The 2008 Sociocultural Anthropology Year in Review
Authors: Richland Justin B.
Published: May 2009

ABSTRACT  In this article, I consider a selection of the 129 articles of new research published in five of the leading Anglo‐American peer‐reviewed outlets for sociocultural anthropology in 2008, discerning two general, but related, trends. The first suggests an ongoing interest among sociocultural anthropologists in new forms and contexts of market capitalism and a deepening concern for the multiple, complex, and even contradictory orientations to those forms by social actors caught up in them. The second reveals a concern with the imbrications of political and scientific epistemologies, particularly as they emerge in state policies and actions around issues of public health, the environment, and agriculture. Where they come together is in the number of studies whose objects of inquiry reside at the nexus where science, politics, and markets meet in what they see as the creeping expansion of neoliberal logics and their implications for the state as a political formation. [Keywords: sociocultural anthropology, neoliberalism, science studies, public health, capitalism]
Understanding the Rise of Consumer Ethnography: Branding Technomethodologies in the New Economy
Authors: Malefyt Timothy de Waal
Published: May 2009

ABSTRACT  In this article, I aim to contribute to the ongoing discussion on the changing public role of anthropology by exploring the rise of branded ethnographic practices in consumer research. I argue that a juncture in the “New Economy”—the conjoining of corporate interest in branding, technology, and consumers, with vast social changes—may explain the rapid growth of ethnography for consumer research and predict its future direction. An analysis of branded propaganda from ethnographic vendors that claim their technology‐enhanced methods innovate “classic” anthropological practices discloses the way corporations employ technologically mediated means to focus on the reflexive self in consumer research. In this analysis, I reveal that technological methodologies are central to the production of branded ethnographic practices, as forms of branding and technology legitimate consumer–corporate flows of interaction. The conclusion raises awareness to the ways in which modern branding practices reconstruct anthropology in public discourse. [Keywords: branding, consumer research, ethnography, reflexivity, technology]
Resolving the Anti‐Antievolutionism Dilemma: A Brief for Relational Evolutionary Thinking in Anthropology
Authors: Schultz Emily
Published: May 2009

ABSTRACT Anthropologists often disagree about whether, or in what ways, anthropology is “evolutionary.” Anthropologists defending accounts of primate or human biological development and evolution that conflict with mainstream “neo‐Darwinian” thinking have sometimes been called “creationists” or have been accused of being “antiscience.” As a result, many cultural anthropologists struggle with an “anti‐antievolutionism” dilemma: they are more comfortable opposing the critics of evolutionary biology, broadly conceived, than they are defending mainstream evolutionary views with which they disagree. Evolutionary theory, however, comes in many forms. Relational evolutionary approaches such as Developmental Systems Theory, niche construction, and autopoiesis–natural drift augment mainstream evolutionary thinking in ways that should prove attractive to many anthropologists who wish to affirm evolution but are dissatisfied with current “neo‐Darwinian” hegemony. Relational evolutionary thinking moves evolutionary discussion away from reductionism and sterile nature–nurture debates and promises to enable fresh approaches to a range of problems across the subfields of anthropology. [Keywords: evolutionary anthropology, Developmental Systems Theory, niche construction, autopoeisis, natural drift]
Spread of a Terrestrial Tradition in an Arboreal Primate
Authors: Tabacow Fernanda P. , Mendes Sérgio L. , Strier Karen B.
Published: May 2009

ABSTRACT We present data on the spread of terrestrial activities in one group of wild northern muriqui monkeys(Brachyteles hypoxanthus).Both males and females consumed fruit, drank, rested, traveled, and socialized terrestrially, but proportionately more males spent significantly more of their time on the ground than females, and females were more likely to engage in terrestrial activities when accompanied by males than when by themselves. Terrestrial activities occurred in both open and closed habitats where arboreal substrates were available and utilized by other individuals engaged in similar activities. Ecological and demographic factors may have stimulated the muriquis’ vertical niche expansion, but increases in the frequency and diversity of terrestrial activities, the high proportion of group members that engage in terrestriality, and its diffusion along male‐biased social bonds are consistent with the development of a local terrestrial tradition similar to other types of traditions described in other primates. [Key words: terrestriality, ecology, predation, tradition]
Linking Leader-Member Exchange and Employee Work Outcomes: The Mediating Role of Organizational Social and Economic Exchange
Authors: Loi Raymond , Mao Yina , Ngo Hang-yue
Published: May 2009

This study presents and tests a framework that links leader—member exchange (LMX) with two different forms of employee–organization exchange: organizational social exchange and organizational economic exchange. We propose that these two forms of employee exchange with the organization would be the main mechanisms through which LMX affects employees’ affective commitment and intention to leave. We used structural equation modelling to analyze the data collected from 239 employees in a foreign-invested enterprise in China. Results showed that both organizational social exchange and organizational economic exchange acted as full mediators in the relationships between LMX and the two outcome variables but in different directions. Theoretical and practical implications are discussed.
OFFENDER–VICTIM INTERACTION AND CRIME EVENT OUTCOMES: MODUS OPERANDI AND VICTIM EFFECTS ON THE RISK OF INTRUSIVE SEXUAL OFFENSES AGAINST CHILDREN*
Authors: LECLERC BENOIT , PROULX JEAN , LUSSIER PATRICK , ALLAIRE JEAN‐FRANCOIS
Published: May 2009

Criminological research has shown the relevance of examining offender–victim interaction and related factors to understand crime event outcomes. In sexual offenses against children, an obvious lack of knowledge exists regarding this issue. From a criminological perspective, we seek to improve our understanding of the offender–victim interaction in sexual offenses against children and, in particular, what factors might increase the risk of a more intrusive offense. We argue that modus operandi strategies play a central role in crime event outcomes and examine this hypothesis with data obtained from a semistructured interview conducted with offenders. As expected, modus operandi was found to have a strong effect on crime event outcomes, especially victim participation during sexual episodes. Victim effects also emerged from the analyses. Specifically, a strong interaction effect between age and gender of the victim was found for victim participation, which suggests that as the victim gets older, offenders are more likely to make their victim participate in sexual episodes when abusing a male victim but are less likely to do so when abusing a female victim.
THE APPLE DOESN'T FALL FAR FROM THE TREE (OR DOES IT?): INTERGENERATIONAL PATTERNS OF ANTISOCIAL BEHAVIOR—THE AMERICAN SOCIETY OF CRIMINOLOGY 2008 SUTHERLAND ADDRESS*
Authors: THORNBERRY TERENCE P.
Published: May 2009

There is a growing literature on intergenerational studies of antisocial behavior and a growing understanding of the unique contributions they are likely to make. At the same time, the field has yet to agree on core design features for intergenerational study. In this article, I propose a set of defining design elements that all intergenerational studies should meet and I discuss the advantages of these studies for enhancing our understanding of the onset and course of delinquent careers. I then use data from the ongoing Rochester Intergenerational Study to illustrate these points and the potential yield of intergenerational studies. In particular, I examine intergenerational continuities in antisocial behavior and school disengagement, test the cycle of violence hypothesis to see whether a history of maltreatment increases the likelihood of perpetration of maltreatment, and estimate a structural equation model to help identify mediating pathways that link parents and children with respect to antisocial behavior.
Root canal re‐treatment of a mandibular second premolar with three root canals: a case report
Authors: Shokouhinejad Noushin
Published: May 2009

Accurate diagnosis of root canal morphology and anatomy is essential for thorough shaping and cleaning of the entire root canal system and consequent successful root canal treatment. Mandibular premolars show a wide variety of root canal anatomy. This paper describes a case of mandibular second premolar with three root canals that has previously received an incomplete root canal treatment.
Effect of sodium ascorbate on bond strength of different adhesive systems to NaOCl‐treated dentin
Authors: Celik Cigdem , Erkut Selim , Gulsahi Kamran , Yamanel Kivanc , Kucukesmen Cigdem
Published: May 2009

The aim of this study was to evaluate the effects of sodium ascorbate on bond strength of different adhesive systems to NaOCl‐treated dentin. Eighty extracted molar teeth were used in the study. The buccal enamel surfaces were removed to obtain a flat dentin surface. The teeth were mounted in self‐curing resin and dentin surfaces were irrigated with NaOCl for 10 min. Half of the specimens were treated with sodium ascorbate for 10 min. The teeth were randomly assigned to four subgroups according to the adhesive systems used (Clearfil SE Bond, Clearfil Tri‐S Bond, Adper Prompt‐L‐Pop, Adper Single Bond 2). Bond strengths were determined with a Universal Testing Machine, at a crosshead speed of 0.5 mm/min. Data were statistically analysed using anova at a significance level of 0.05. Two‐way anova revealed that the effect of sodium ascorbate application on bond strength of adhesive systems to NaOCl‐treated dentin was statistically significant (P < 0.05). The bond strength results were significantly influenced by the application of sodium ascorbate (P < 0.05) and there was a significant difference between the adhesive systems (P < 0.05). Although statistically significant differences were not demonstrated in all adhesive resin groups, sodium ascorbate application after NaOCl treatment improved the bond strength values.
Vibrotactile Biofeedback Improves Tandem Gait in Patients with Unilateral Vestibular Loss
Authors: Horak Fay B. , Dozza Marco , Peterka Robert , Chiari Lorenzo , Wall III Conrad
Published: May 2009

In a crossover design, subjects with unilateral vestibular loss (UVL) practiced tandem gait with eyes closed on two days, two weeks apart, with and without vibrotactile biofeedback (BF) applied to the lateral trunk. Results showed an immediate improvement in postural stability (reduction of lateral center‐of‐mass displacement, trunk tilt, and medial–lateral step width) that was significantly larger than effects of practice alone. However, BF did not increase the rate of improvement or retention of improved stability during gait.
Postural Compensation for Vestibular Loss
Authors: Horak Fay B.
Published: May 2009

To what extent can remaining sensory information and/or sensory biofeedback (BF) compensate for loss of vestibular information in controlling postural equilibrium? The primary role of the vestibulospinal system is as a vertical reference for control of the trunk in space, with increasing importance as the surface becomes increasingly unstable. Our studies with patients with bilateral loss of vestibular function show that vision or light touch from a fingertip can substitute as a reference for earth vertical to decrease variability of trunk sway when standing on an unstable surface. However, some patients with bilateral loss compensate better than others, and found that those with more complete loss of bilateral vestibular function compensate better than those with measurable vestibulo‐ocular reflexes. In contrast, patients with unilateral vestibular loss (UVL) who reweight sensory dependence to rely on their remaining unilateral vestibular function show better functional performance than those who do not increase vestibular weighting on an unstable surface. Light touch of <100 grams or auditory biofeedback can be added as a vestibular vertical reference to stabilize trunk sway during stance. Postural ataxia during tandem gait in patients with UVL is also significantly improved with vibrotactile BF to the trunk, beyond improvements due to practice. Vestibular rehabilitation should focus on decreasing hypermetria, decreasing an overdependence on surface somatosensory inputs, increasing use of any remaining vestibular function, substituting or adding alternative sensory feedback related to trunk sway, and practicing challenging balance tasks on unstable surfaces.
Human Bipeds Use Quadrupedal Coordination during Locomotion
Authors: Dietz Volker , Michel Jan
Published: May 2009

During evolution, the increased influence of a direct cortical–motoneuronal system in parallel with a more specialized hand function might have replaced phylogenetically older systems that organized locomotor movements. However, recent research indicates that interlimb coordination during human locomotion is organized in a way similar to that in the cat. During locomotion, corticospinal excitation of upper‐limb motoneurons is mediated indirectly, via propriospinal neurons in the cervical spinal cord. This allows a task‐dependent neuronal linkage of cervical and thoracolumbar propriospinal circuits controlling leg and arm movements during human locomotor activities. During obstacle avoidance steps, an anticipatory quadrupedal limb coordination is up‐regulated, with an involvement of proximal arm muscles during the acquisition and performance of this precision locomotor task.
The Human Vertical Translational Vestibulo‐ocular Reflex
Authors: Liao Ke , Walker Mark F. , Joshi Anand , Reschke Millard , Strupp Michael , Leigh R. John
Published: May 2009

Geometric considerations indicate that the human translational vestibulo‐ocular reflex (tVOR) should have substantially different properties than the angular vestibulo‐ocular reflex (aVOR). Specifically, tVOR cannot simultaneously stabilize images of distant and near objects on the retina. Most studies make the tacit assumption that tVOR acts to stabilize foveal images even though, in humans, tVOR is reported to compensate for less than 60% of foveal image motion. We have determined that the compensation gain (eye rotational velocity/required eye rotational velocity to maintain foveal target fixation) of tVOR is held steady at ∼0.6 during viewing of either near or distant targets during vertical (bob) translations in ambient illumination. We postulate that tVOR evolved not to stabilize the image of the target on the fovea, but rather to minimize retinal image motion between objects lying in different depth planes, in order to optimize motion parallax information. Such behavior is optimized when binocular visual cues of both near and distant targets are available in ambient light. Patients with progressive supranuclear palsy or cerebellar ataxia show impaired ability to increase tVOR responses appropriately when they view near targets. In cerebellar patients, impaired ability to adjust tVOR responses to viewing conditions occurs despite intact ability to converge at near. Loss of the ability to adjust tVOR according to viewing conditions appears to represent a distinct disorder of vestibular function.
Testing Human Otolith Function Using Bone‐Conducted Vibration
Authors: Curthoys I.S. , Burgess A.M. , MacDougall H.G. , McGarvie L.A. , Halmagyi G.M. , Smulders Y.E. , Iwasaki S.
Published: May 2009

Bone‐conducted vibration of the forehead, in the midline at the hairline (Fz) causes linear acceleration stimulation of both mastoids and results in an ocular vestibular‐evoked myogenic potential (oVEMP), recorded by surface electromyogram (EMG) electrodes just beneath the eyes. The early n10 component of the oVEMP is symmetrical in healthy subjects, absent in patients with bilateral vestibular loss, and in patients after unilateral vestibular loss (uVL) n10 is small or absent on the side contralateral to the uVL, but of normal amplitude on the side contralateral to the healthy ear. The n10 component probably reflects mainly otolithic function, since in the guinea pig, primary otolith irregular neurons are selectively activated by bone‐conducted vibration (BCV) at low intensities (0.1 g), whereas semicircular canal primary afferents are not activated even at high intensities (10 g).
Temporary Lesions of the Caudal Deep Cerebellar Nucleus in Nonhuman Primates
Authors: Straube Andreas , Scheuerer Werner , Robinson Farrel R. , Eggert Thomas
Published: May 2009

The caudal fastigial nucleus (cFN) is one of the main cerebellar areas involved in the control of eye movements. Lesions of this area cause hypermetria of ipsilateral saccades and hypometria of contralateral saccades, as well as cogwheel smooth pursuit. Most studies with nonhuman primates described this dysmetria with a change of the ratio target amplitude to saccade amplitude, whereas in cats this dysmetria was attributed to a static fixation error. The targeting of visually‐guided saccades before and after 11 unilateral injections of the inhibitory transmitter muscimol into the caudal fastigial nucleus in 5 monkeys was analyzed. In one monkey, who had eye coils implanted in both eyes, the postsaccadic interocular alignment was also analyzed. The main result is that the dysmetria observed in nonhuman primates can be explained as a combination of (1) hypermetria of the ipsilateral horizontal saccade component, and (2) a horizontal static fixation error of about 1.2 deg toward the side of the lesion. The static postsaccadic alignment of both eyes was only slightly disturbed after unilateral injection. The results suggest that the dysmetria seen after muscimol inactivation of the cFN is due to two distinct processes: one causes a gain change, and the other causes the static fixation error. Unilateral lesions have only a slight influence on binocular postsaccadic alignment.
Head‐Shaking Nystagmus in Central Vestibulopathies
Authors: Choi Kwang‐Dong , Kim Ji Soo
Published: May 2009

Mechanisms of head‐shaking nystagmus (HSN) require further exploration in central vestibular disorders. To determine whether impaired uvulonodular inhibition over the velocity storage of the vestibulo‐ocular reflex (VOR) is the mechanism of ipsilesional HSN in lateral medullary infarction (LMI), 17 patients with ipsilesional HSN and LMI underwent measurements of the VOR gains during low‐frequency sinusoidal harmonic accelerations, and the time constants (TC) of the VOR and tilt suppression of the post‐otatory nystagmus during step‐velocity rotation. Compared with normal controls, the patients showed increased VOR gains without difference between ipsi‐ and contralesional rotations, while the VOR TCs were decreased without directional asymmetry during step‐velocity rotation. In contrast, the patients showed impaired tilt suppression of the postrotatory nystagmus, and the impairment of tilt suppression was more severe after contralesional than ipsilesional rotation. The asymmetric tilt suppression may generate ipsilesional HSN by increasing contralesional velocity storage during head shaking, and may be ascribed to disruption of ipsilesional nodulo‐uvular inhibition of the velocity storage mechanism.
Vestibulo‐ocular Signal Transformation in Frequency‐Tuned Channels
Authors: Straka Hans , Lambert François M. , Pfanzelt Sandra , Beraneck Mathieu
Published: May 2009

Self‐generated locomotor activity is accompanied by head movements that cause retinal image displacements with a resultant degradation of visual information processing. To maintain visual acuity, retinal image drift must be counteracted by dynamic compensatory gaze adjustments that derive to a large extent from vestibulo‐ocular reflexes (VOR). During head motion, vestibular signals code a wide frequency range from static head position to high acceleration profiles during rapid head turns. This large dynamic range suggests that the sensory–motor transformation occurs in parallel, yet complementary frequency‐tuned pathways. In fact, the classic “three‐neuronal” VOR pathway is composed of distinct functional subgroups of cells with different intrinsic properties and response dynamics at each synaptic level. This generates sets of neuronal filters that are ideal for particular frequency ranges and signaling patterns, respectively. In second‐order vestibular subgroups, different filter functions, and hence a different synaptic processing is facilitated by a coadaptation of intrinsic membrane and emerging network properties. The consecutive assembly and sequential connectivity of pre‐ and postsynaptic neuronal elements with corresponding physiological properties, generates parallel pathways that allow for separate coding of different dynamic head‐motion components during locomotor activity.
Visual‐Motion Suppression in Congenital Pendular Nystagmus
Authors: Schlindwein P. , Schreckenberger M. , Dieterich M.
Published: May 2009

Patients with a congenital pendular nystagmus are known not to experience oscillopsia in a normal visual environment. The data of a 31‐year‐old female patient suffering from a congenital pendular nystagmus are presented. The aim of the fluorodeoxyglucose positron emission tomography (FDG‐PET) experiment was to analyze the regional cerebral glucose metabolism (rCGM) during minimal as well as maximal nystagmus. Video‐oculography showed a maximum in frequency of the horizontal pendular nystagmus during gaze to the left, whereas the zone of minimal nystagmus was 10° to the right. Two sessions with an 18F‐fluorodeoxyglucose tracer were performed to analyze cerebral blood‐glucose utilization when fixating an object in the areas of maximal and of minimal nystagmus. A structural MRI in a clinicial 1.5‐T scanner was acquired to superimpose the PET results onto the unique anatomy of the patient. By statistical analysis a significant increase in the rCGM in the cerebellar nodulus and a relative decrease in the area of MT/V5 bilaterally during maximal nystagmus were found. When the patient was looking in her null zone, rCGM was increased in V1 and MT/V5 bilaterally. To the best of the authors’ knowledge, this is the first proof by means of functional imaging of a suppression of oscillopsia in higher‐order visual cortex areas in a patient with a congenital nystagmus.
Impact of Vertigo and Spatial Disorientation on Concurrent Cognitive Tasks
Authors: Gresty Michael Andrew , Golding John Foster
Published: May 2009

Disorientation may draw attention from other activities and its impact on cognition may cause pilot error and problems of concentration in dizzy patients. Tasks used to study the impact of disorientation include number processing, intelligence scales and Brookes matrices (reproduction of 2xD patterns of numbers vs. nonsensical sentences), and Stroop tasks to probe selective effects on spatial versus verbally‐loaded tasks. This variety of tasks has been used to evaluate cognitive performance in numerous scenarios, including visual‐vestibular mismatch, vection, spinning, coriolis, balancing, and flight maneuvers. A meta‐analysis provides an overview of how spatial disorientation may affect cognition: Substantial individual differences in managing disorientation are to be expected; errors on cognitive tasks occur during the first few experiences of a disorienting situation and subjects rapidly learn to “quarantine” this “novelty effect”; familiarity with and practice on a test gives protection against disorientation; task performance continues to suffer if the protagonist is unaware of disorientation; with disorientation that demands external resolution (e.g., interpretation of instruments) the subject must learn to switch priority to the cognitive task; there is a moderate preferential impact of disorientation on spatial tasks; anxiety of real situations probably exacerbates the impact of disorientation.
The Perception of Translational Motion
Authors: Seidman Scott H. , Yong Nicholas Au , Paige Gary D.
Published: May 2009

In response to translations of the head, the linear vestibulo‐ocular reflex (LVOR) produces compensatory eye movements that are high‐pass in nature, with a declining response magnitude and an increasing phase lead with declining stimulus frequency. Perception of head translation, however, is reported to be robust at much lower frequency than predicted by the LVOR, causing speculation that the vestibular processing underlying reflex and perceptual responses are different. Direct comparison of these two responses across a large frequency range proves problematic, in part because of difficulties encountered in the assessment of perception at high frequency, and confounding variables at low frequency. We used innovative techniques to measure psychophysical responses to translation, and find strong similarity to the LVOR. These include experiments in which motion cues were limited to those of an inertial nature, and conclude that the vestibular system comprises only one input to perceptual mechanisms related to linear motion, and this is supplemented (particularly at low frequency) by somatic and cognitive cues.
Head‐Free Gaze Control in Humans with Chronic Loss of Vestibular Function
Authors: Lehnen Nadine , Büttner Ulrich , Glasauer Stefan
Published: May 2009

Healthy subjects use the vestibulo‐ocular reflex (VOR) to stabilize gaze. Labyrinthine‐defective humans without VOR still are, to some extent, able to maintain gaze stability during active eye–head movements. Here it is investigated whether this stabilization is due to anticipatory mechanisms or proprioceptive feedback. The head inertia was increased in humans who have undergone bilateral vestibulectomy (vestibular subjects) and in healthy controls during large gaze shifts. This leads to head oscillations in both groups. Whereas controls compensate for head oscillations and maintain gaze stability, vestibular subjects display gaze oscillations along with head oscillations. This indicates that vestibular subjects mainly use learned, anticipatory mechanisms, and not proprioception, to stabilize gaze.
Modification of the Cervico‐ocular Reflex by Canal Plugging
Authors: Yakushin Sergei B. , Tarasenko Yelena , Raphan Theodore , Suzuki Jun‐Ichi , Della Santina Charles C. , Minor Lloyd B. , Cohen Bernard
Published: May 2009

The cervico‐ocular reflex (COR) has a low gain in normal animals. In this study, we determined whether COR gain increases were specific to the low/midband frequency range, which is the range over which the angular vestibulo‐ocular reflex (aVOR) is compromised by plugging. The gain and phase of the yaw and pitch COR and aVOR were compared in normal monkeys and those with all six semicircular canals or only the lateral canal plugged. During experiments animals sat with the body fixed to a chair and the head fixed in space. The body was oscillated about body‐yaw and body‐pitch axes over a frequency range of 0.05–6 Hz, with amplitude <10°. For normal animals, both yaw and pitch eye velocities were compensatory to the relative velocity of the head with respect to the body. The gains were 0.1–0.2 at frequencies below 1 Hz and decreased to zero as stimulus frequency increased above 1 Hz. Canal‐plugged animals had COR gains close to 1.0 at low frequencies, decreasing to ≈0.6 at 0.5 Hz and to 0.2 for stimulus frequencies above 3 Hz. The phase of eye velocity was 180° relative to head‐re‐body velocity at frequencies below 0.5 Hz and shifted toward 270° as frequencies were increased to 4 Hz. This study demonstrates that adaptation of COR gain is tuned to a frequency range at which the aVOR is compromised by the canal plugging.
On‐Line Classification and Prediction of Eye Movements by Multiple‐Model Kalman Filtering
Authors: Kohlbecher Stefan , Schneider Erich
Published: May 2009

An extensible multiple‐model Kalman filter framework for eye tracking and video‐oculography (VOG) applications is proposed. The Kalman filter predicts future states of a system on the basis of a mathematical model and previous measurements. The predicted values are then compared against the current measurements. In a correcting step, the predicted state is enhanced by the measurements. In this work, the Kalman filter is used for smoothing the VOG data, for on‐line classification of eye movements, as well as for predictive real‐time control of a gaze‐driven head‐mounted camera (EyeSeeCam). With multiple models running in parallel, it was possible to distinguish between fixations, slow‐phase eye movements, and saccades. Under the assumption that each class of eye movement follows a distinct model, one can decide which types of eye movement occurred by evaluating the probability for each model.
Effects of the Linear Vestibulo‐ocular Reflex on Accommodative Vergence Eye Movements
Authors: Yakushin Sergei B. , Kunin Mikhail , Ogorodnikov Dmitri , Cohen Bernard , Raphan Theodore
Published: May 2009

The aim of the study was to determine whether accommodation to the relative motion of a target along the visual axis of one eye during fore–aft movement of the head could induce accurate vergence over a wide range of viewing distances and frequencies of oscillation, despite lack of vision in the second eye. This was compared to the vergence when both eyes viewed the target. Two rhesus monkeys were trained to fixate a visual target located 216–336 mm in front and along the visual axis of one eye, while being sinusoidally translated in the fore–aft direction. There was no movement of the seeing eye while the other eye converged, regardless of whether there was vision in the converged eye. Gain and phase of the convergence were determined based on the ratio of actual versus expected eye position if the target was accurately fixated. During translation at frequencies from 0.05 to 2 Hz, the eye converged on the target with an eye position gain of ≈1, and a phase close to zero. When vision was occluded in the converging eye, gains of convergence were 0.6–0.8 Hz up to 2 Hz, and the phases remained close to zero. At low frequencies of fore–aft movement, when the acceleration was negligible, convergence was driven by accommodation in the seeing eye. At higher frequencies, vergence could also be driven by the linear vestibulo‐ocular reflex (lVOR). Thus, vision in one nonmoving eye and the lVOR combine to generate convergence over a wide range of frequencies and viewing distances.
Gait Deviations Induced by Visual Motion Stimulation in Roll Depend on Head Orientation
Authors: Bardins Stanislavs , Schneider Erich
Published: May 2009

Locomotion control uses proprioceptive, visual, and vestibular signals. Previously, we analyzed the visual contribution with visual motion stimulation in roll while participants kept their heads in a normal upright orientation. In this study we applied the same visual disturbance in a head‐upright and a nose‐down condition. Random dot patterns were constantly rotated in roll at ±15°/sec on a computer‐driven binocular head‐mounted display, while the participants walked a distance of 6 m. The stimulation effect was more pronounced in the nose‐down condition. These results are similar to the results of previous galvanic vestibular stimulation (GVS) studies, suggesting that in terms of the direction of action visual motion stimulation in the roll plane is similar to GVS.
Influence of Uninformative Visual Cues on Gravity Perception
Authors: Kupferberg Aleksandra , Glasauer Stefan , Stein Alexandra , Brandt Thomas
Published: May 2009

The perception of the subjective direction of up (subjective visual zenith, SVZ) is influenced by various sensory cues, such as, vestibular and visual input, and by the idiotropic vector, which acts as prior information about self‐orientation with respect to gravity. Here, we tested the influence of a subject‐fixed visual cue, which was uninformative with respect to the direction of gravity, on SVZ settings in different pitch angles. Our results show that in most subjects the SVZ was influenced by the gravity‐unrelated visual cue in a way suggesting that the cue's orientation was memorized in the first trial and used thereafter as reference.
Vertigo as a Symptom of Migraine
Authors: Lempert Thomas , Neuhauser Hannelore , Daroff Robert B.
Published: May 2009

Migraine and vertigo are common disorders, affecting about 14% and 10%, respectively, of the general population. If migraine and vertigo were unrelated, the expected comorbidity would be 1%, whereas recent epidemiological studies indicate that 3.2% of the population have both migraine and vertigo. The excess comorbidity may be attributed to two factors: 1) vertigo syndromes (including Menière's disease, benign paroxysmal positional vertigo, and anxiety‐related dizziness) that are more common in migraineurs than in controls and 2) vestibular migraine (VM) (vertigo as a symptom of migraine.) VM presents with attacks of spontaneous or positional vertigo lasting seconds to days. Headaches are often absent during acute attacks, but other migrainous features such as photophobia or auras, may be present. Like migraine headaches, VM triggers include stress, sleep deprivation, and hormonal changes. During acute attacks, there may be central spontaneous or positional nystagmus and, less commonly, unilateral vestibular hypofunction. In the symptom‐free interval, vestibular testing shows mostly minor and nonspecific findings. The pathogenesis of VM is uncertain, but migraine mechanisms may interfere with the vestibular system at the labyrinth, brainstem, and cerebral cortex. Treatment includes vestibular suppressants for acute attacks and migraine prophylaxis for patients with frequent recurrences. However, treatment efficacy has not been validated by properly controlled clinical trials. VM does not fit into the 2004 International Headache Society Classification, in which “basilar‐type migraine” must have at least two posterior circulation manifestations; isolated vertigo would not satisfy this criterion.
Comparative Neurobiology of the Optokinetic Reflex
Authors: Masseck Olivia Andrea , Hoffmann Klaus‐Peter
Published: May 2009

A comprehensive overview of the optokinetic reflex (OKR) in vertebrates is given. The main objective is to compare the asymmetry in optokinetic reactions when patterns presented to one eye move horizontally in temporo‐nasal or naso‐temporal directions. Different hypotheses concerning the evolution of this asymmetry or symmetry in monocular horizontal OKR are discussed.
Signal Processing and Distribution in Cortical‐Brainstem Pathways for Smooth Pursuit Eye Movements
Authors: Mustari Michael J. , Ono Seiji , Das Vallabh E.
Published: May 2009

Smooth pursuit (SP) eye movements are used to maintain the image of a moving object relatively stable on the fovea. Even when tracking a single target over a dark background, multiple areas including frontal eye fields (FEF) and middle temporal (MT) and medial superior temporal (MST) cortex contribute to converting visual signals into initial commands for SP. Signals in the cortical pursuit system reach the oculomotor cerebellum through brainstem centers including the dorsolateral pontine nucleus (DLPN), nucleus reticularis tegmenti pontis (NRTP), and pretectal nucleus of the optic tract (NOT). The relative information carried in these parallel pathways remains to be fully defined. We used multiple linear‐regression modeling to estimate the relative sensitivities of cortical (MST, FEF), pontine (NRTP, DLPN), and NOT neurons to eye‐ and retinal‐error parameters (position, velocity, and acceleration) during step‐ramp SP of macaques (Macaca mulatta). We found that a large proportion of pursuit‐related MST and DLPN neurons were most sensitive to eye‐velocity or retinal error velocity. In contrast, a large proportion of FEF and rostral NRTP neurons were most sensitive to eye acceleration. Visual neurons in MST, DLPN, and NOT were most sensitive to retinal image velocity.
Vestibular–Neck Interaction in Cerebellar Patients
Authors: Kammermeier Stefan , Kleine Justus , Büttner Ulrich
Published: May 2009

Vestibulospinal reflexes are important for upright stance and locomotor control. Information from both the vestibular and the proprioceptive system must be combined centrally to guarantee appropriate compensation for a physical disturbance. Recent single‐unit recordings from the monkey demonstrated vestibulo‐proprioceptive interaction in the fastigial nucleus (deep cerebellar nucleus). The present study investigated whether integration of vestibular and proprioceptive signals is compromised in humans with cerebellar degeneration. Control subjects and patients were exposed to binaural, sinusoidal galvanic vestibular stimulation at 0.16 Hz, while their static head‐on‐trunk position was systematically altered in the head‐horizontal plane from 60° left to 60° right. Controls responded to different head‐on‐trunk positions with fully compensatory changes in the direction of galvanically induced body sway, keeping it aligned with the head‐frontal plane. In patients, this compensatory change was lacking. Findings support the assumption that the cerebellum plays a central role in the integration of vestibular and proprioceptive signals in humans. This form of impaired sensory interaction is probably a clinically important component of cerebellar stance and gait ataxia.
Vestibular Cortex Activation during Locomotor Imagery in the Blind
Authors: Deutschländer Angela , Stephan Thomas , Hüfner Katharina , Wagner Judith , Wiesmann Martin , Strupp Michael , Brandt Thomas , Jahn Klaus
Published: May 2009

A previous functional magnetic resonance imaging (fMRI) study in sighted individuals showed deactivations of multisensory vestibular cortex areas in the posterior insula and adjacent temporal sites during locomotor imagery. These vestibular deactivations were suggested to reflect the suppression of vestibular signals during locomotion in order to prevent potentially adverse interactions of these inputs with the optimized automated locomotion pattern. In this fMRI experiment, 10 totally blind subjects and 10 age‐ and gender‐matched sighted controls imagined several locomotor tasks in a first‐person perspective (kinesthetic imagery of standing, walking, and running). As opposed to their sighted controls, totally blind individuals activated multisensory vestibular areas in the posterior insula and superior temporal gyrus, with right‐sided preponderance during locomotor imagery. These results plausibly suggest that blind subjects rely more on vestibular feedback for locomotor control than do sighted subjects. Thus, this fMRI study provides neuroimaging evidence for distinct cortical processing in the multisensory vestibular system in the blind during locomotor control.
Effect of Gravity on Vertical Eye Position
Authors: Pierrot‐Deseilligny C.
Published: May 2009

There is growing evidence that gravity markedly influences vertical eye position and movements. A new model for the organization of brainstem upgaze pathways is presented in this review. The crossing ventral tegmental tract (CVTT) could be the efferent tract of an “antigravitational” pathway terminating at the elevator muscle motoneurons in the third nerve nuclei and comprising, upstream, the superior vestibular nucleus and y‐group, the flocculus, and the otoliths. This pathway functions in parallel to the medial longitudinal fasciculus pathways, which control vertical eye movements made to compensate for all vertical head movements and may also comprise the “gravitational” vestibular pathways, involved in the central reflection of the gravity effect. The CVTT could provide the upgaze system with the supplement of tonic activity required to counteract the gravity effect expressed in the gravitational pathway, being permanently modulated according to the static positions of the head (i.e., the instantaneous gravity vector) between a maximal activity in the upright position and a minimal activity in horizontal positions. Different types of arguments support this new model. The permanent influence of gravity on vertical eye position is strongly suggested by the vertical slow phases and nystagmus observed after rapid changes in hypo‐ or hypergravity. The chin‐beating nystagmus, existing in normal subjects with their head in the upside‐down position, suggests that gravity is not compensated for in the downgaze system. Upbeat nystagmus due to brainstem lesions, most likely affecting the CVTT circuitry, is improved when the head is in the horizontal position, suggesting that this circuitry is involved in the counteraction of gravity between the upright and horizontal positions of the head. In downbeat nystagmus due to floccular damage, in which a permanent hyperexcitation of the CVTT could exist, a marked influence of static positions of the head is also observed. Finally, the strongest argument supporting a marked role of gravity in vertical eye position is that the eye movement alterations observed in the main, typical physiological and pathological conditions are precisely those that would be expected from a direct effect of gravity on the eyeballs, with, moreover, no single alternative interpretation existing so far that could account for all these different types of findings.
Vertigo and Cerebral Hemoglobin Changes during Unilateral Caloric Stimulation
Authors: Iida Masahiro , Haida Munetaka , Igarashi Makoto
Published: May 2009

The aim of the present study using near‐infrared spectroscopy (NIRS) is to evaluate the correlation of cerebral (parieto‐temporal lobe) hemoglobin changes and vertiginous sensation during unilateral caloric stimulation. During the hot water (44° C) stimulus, cerebral hemoglobin was increased bilaterally, but it was dominant ipsilaterally. During the unilateral cold water (30° C) stimulus, cerebral hemoglobin was decreased on both sides, especially on the ipsilateral side. Vertigious sensation was strong in cases with marked left‐right difference of cerebral hemoglobin changes. The usefulness of NIRS to investigate the relationship between peripheral vestibular organ and vestibular cortex was verified.
The Presence of Lytic HSV‐1 Transcripts and Clonally Expanded T Cells with a Memory Effector Phenotype in Human Sensory Ganglia
Authors: Derfuss Tobias , Arbusow Viktor , Strupp Michael , Brandt Thomas , Theil Diethilde
Published: May 2009

Herpes simplex virus type 1 (HSV‐1) latent persistence in human trigeminal ganglia (TG) is accompanied by a chronic CD8 T‐cell infiltration. Thus far, during HSV‐1 latency only a single transcript, namely the latency‐associated transcript (LAT), has been identified to be synthesized but not translated into a protein. In contrast, the chronic CD8 T‐cell infiltration suggests that an antigen trigger must be present. The focus of the current work was to look for HSV‐1 transcription activity as a potential trigger of the immune response and to demonstrate whether the immune cells are clonally expanded and have a phenotype that suggests that they have been triggered by viral antigen. By combining in situ hybridization, laser cutting microscopy, and single‐cell real time RT‐PCR, we demonstrated expression of the HSV‐1 immediate early (IE) genes ICP0 and ICP4 in human trigeminal neurons. Using CDR3 spectratyping, we showed that the infiltrating T cells are clonally expanded, indicating an antigen‐driven immune response. Moreover, the persisting CD8+ T cells had prominent features of the memory effector phenotype. Chemokines CCL5 and CXCL10 were expressed by a subpopulation of infiltrating cells and the corresponding chemokine receptors CCR5 and CXCR3 were co‐expressed on virtually all T cells bearing the CD8 phenotype. Thus, HSV‐1 IE genes are expressed in human TG, and the infiltrating T cells bear several characteristics that suggest viral antigenic stimulation.
Vestibular and Proprioceptive Contributions to Human Balance Corrections
Authors: Horlings C.G.C. , Carpenter M.G. , Honegger F. , Allum J.H.J.
Published: May 2009

Movement strategies controlling quiet stance and rapid balance corrections may have common characteristics. We investigated this assumption for lower leg proprioceptive loss (PL), peripheral vestibular loss (VL), and healthy controls. Our underlying hypothesis was that changes in movement‐strategy modulation following sensory loss would improve with prosthetic biofeedback. Quiet stance was measured under different sensory conditions and compared to corrections induced by multidirection support‐surface tilts. Response synergies were assessed using electromyography recordings from several muscles. Biofeedback of trunk sway during gait and stance tasks used lower trunk rotations to drive head‐band‐mounted vibro‐tactile and auditory actuators. Strategies of quiet stance were different for roll and pitch, depending on sensory conditions. Simultaneously acting strategies were observed for low‐ and high‐frequency sway. PL induced strategies different from those of VL and controls. VL strategies were identical to those of controls but with greater amplitudes. Tilt perturbation movement strategies were similar to high‐frequency strategies of quiet stance—multisegmental. VL induced increased trunk pitch and roll responses with hypermetric trunk muscle responses and hypometric knee responses but unchanged synergies. Increasing PL up the legs caused changed synergies. Biofeedback reduced stance body sway in VL and elderly subjects. In conclusion, several movement strategies underlie quiet stance with high‐frequency strategies being common to those of perturbed stance. PL changes both movement strategies and synergies, whereas VL only causes pathological changes to the modulation depth. Thus, VL is more easily rectified using trunk sway positional biofeedback.