Visual Pursuit Research Articles

Effects of preference and sensory modality on behavioural reaction in patients with disorders of consciousness

ABSTRACTBackground: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of residual cerebral function could be improved by allowing patients to listen to their favourite music. However, the potential effect of music on behavioural responsiveness, as well as the effect of preferred stimuli in other sensory modalities (e.g. olfaction), remain poorly understood. Objective: The aim of our study was to investigate the effect of sensory modality (auditory versus olfactory) and preference (preferred versus neutral) of the test stimuli on patients’ subsequent performance on the Coma Recovery Scale-Revised (CRS-R). Research design: Within-subject design because of inter-individual differences between patients. Methods and procedures: We studied four items from the CRS-R (visual pursuit using a mirror, auditory localization of the own name and two movements to command) in 13 patients (7 MCS; 6 UWS). Main outcomes and results: Auditory stimuli triggered higher responsiveness compared to olfactory stimuli, and preferred stimuli were followed by higher scores than did neutral stimuli. Conclusions: Findings suggest that preferred auditory stimuli at the bedside contribute to the expression of residual function and could improve the diagnostic assessment.

Prevalence of coma-recovery scale-revised signs of consciousness in patients in minimally conscious state

ABSTRACTDifferent behavioural signs of consciousness can distinguish patients with an unresponsive wakefulness syndrome from patients in minimally conscious state (MCS). The Coma Recovery Scale-Revised (CRS-R) is the most sensitive scale to differentiate the different altered states of consciousness and eleven items detect the MCS. The aim of this study is to document the prevalence of these items. We analysed behavioural assessments of 282 patients diagnosed in MCS based on the CRS-R. Results showed that some items are particularly frequent among patients in MCS, namely fixation, visual pursuit, and reproducible movement to command, which were observed in more than 50% of patients. These responses were also the most probably observed items when the patients only showed one sign of consciousness. On the other hand, some items were rarely or never observed alone, e.g., object localisation (reaching), object manipulation, intelligible verbalisation, and object recognition. The results also showed that limiting the CRS-R assessment to the five most frequently observed items (i.e., fixation, visual pursuit, reproducible movement to command, automatic motor response and localisation to noxious stimulation) detected 99% of the patients in MCS. If clinicians have only limited time to assess patients with disorders of consciousness, we suggest to evaluate at least these five items of the CRS-R.

Objective assessment of visual pursuit in patients with disorders of consciousness: an exploratory study.

Visual pursuit is a key marker of residual consciousness in patients with disorders of consciousness (DOC). Currently, its assessment relies on subjective clinical decisions. In this study, we explore the variability of such clinical assessments, and present an easy-to-use device composed of cameras and video processing algorithms that could help the clinician to improve the detection of visual pursuit in a clinical context. Visual pursuit was assessed by an experienced research neuropsychologist on 31 patients with DOC and on 23 healthy subjects, while the device was used to simultaneously record videos of both one eye and the mirror. These videos were then scored by three researchers: the experienced research neuropsychologist who did the clinical assessment, another experienced research neuropsychologist, and a neurologist. For each video, a consensus was decided between the three persons, and used as the gold standard of the presence or absence of visual pursuit. Almost 10% of the patients were misclassified at the bedside according to their consensus. An automatic classifier analyzed eye and mirror trajectories, and was able to identify patients and healthy subjects with visual pursuit, in total agreement with the consensus on video. In conclusion, our device can be used easily in patients with DOC while respecting the current guidelines of visual pursuit assessment. Our results suggest that our material and our classification method can identify patients with visual pursuit, as well as the three researchers based on video recordings can.

Why use a mirror to assess visual pursuit in prolonged disorders of consciousness? Evidence from healthy control participants

BackgroundEvidence of reliable smooth visual pursuit is crucial for both diagnosis and prognosis in prolonged disorders of consciousness (PDOC). However, a mirror is more likely than an object to elicit evidence of smooth pursuit. Our objective was to identify the physiological and/or cognitive mechanism underlying the mirror benefit.MethodsWe recorded eye-movements while healthy participants simultaneously completed a visual pursuit task and a cognitively demanding two-back task. We manipulated the stimulus to be pursued (two levels: mirror, ball) and the simultaneous cognitive load (pursuit only, pursuit plus two-back task) within subjects.ResultsPursuit of the reflected-own-face in the mirror was associated with briefer fixations that occurred less uniformly across the horizontal plane relative to object pursuit. Secondary task performance did not differ between pursuit stimuli. The secondary task also did not affect eye movement measures, nor did it interact with pursuit stimulus.ConclusionsReflected-own-face pursuit is no less cognitively demanding than object pursuit, but it naturally elicits smoother eye movements (i.e. briefer pauses to fixate). A mirror therefore provides greater sensitivity to detect smooth visual pursuit in PDOC because the naturally smoother eye movements may be identified more confidently by the assessor.

Effects of an 8-week yoga program on sustained attention and discrimination function in children with attention deficit hyperactivity disorder.

This study investigated whether a yoga exercise intervention influenced the sustained attention and discrimination function in children with ADHD. Forty-nine participants (mean age = 10.50 years) were assigned to either a yoga exercise or a control group. Participants were given the Visual Pursuit Test and Determination Test prior to and after an eight-week exercise intervention (twice per week, 40 min per session) or a control intervention. Significant improvements in accuracy rate and reaction time of the two tests were observed over time in the exercise group compared with the control group. These findings suggest that alternative therapies such as yoga exercises can be complementary to behavioral interventions for children with attention and inhibition problems. Schools and parents of children with ADHD should consider alternatives for maximizing the opportunities that children with ADHD can engage in structured yoga exercises.

Visual Dysfunction in Parkinson's Disease.

This chapter describes the visual problems likely to be encountered in Parkinson's disease (PD) and whether such signs are useful in differentiating the parkinsonian syndromes. Visual dysfunction in PD may involve visual acuity, contrast sensitivity, color discrimination, pupil reactivity, saccadic and pursuit eye movements, motion perception, visual fields, and visual processing speeds. In addition, disturbance of visuospatial orientation, facial recognition problems, rapid eye movement (REM) sleep behavior disorder, and chronic visual hallucinations may be present. Problems affecting pupil reactivity, stereopsis, pursuit eye movement, and visuomotor adaptation, when accompanied by REM sleep behavior disorder, could be early features of PD. Dementia associated with PD is associated with enhanced eye movement problems, visuospatial deficits, and visual hallucinations. Visual dysfunction may be a useful diagnostic feature in differentiating PD from other parkinsonian symptoms, visual hallucinations, visuospatial dysfunction, and variation in saccadic eye movement problems being particularly useful discriminating features.

The effect of balance exercises and computerized cognitive training on psychomotor performance in elderly.

[Purpose] The purpose of this study was to investigate the effect of balance and computerized cognitive training on psychomotor performance in elderly females. [Subjects and Methods] Twentynine elderly females with the mean age of 63–71 years old were applied voluntarily and randomly allocated to four groups: balance training (3 d/wk for 12 wk), balance training with computerized cognitive training (3 d/wk for 12 wk), computerized cognitive training group and control group. Psychomotor performance of all subjects was measured by Vienna Test System which was a computerized psychological assessment tool. Determination test (DT) and Visual Pursuit Test (VPT) were used as indexes of psychomotor performance. [Results] The results suggested that DT and VPT were significantly improved in all experimental groups with greater improvement in the balance supplemented with computerized cognitive training group. [Conclusion] Balance training and computerized cognitive are highly recommended in elderly with the aim of increasing cognitive performance.

Disentangling disorders of consciousness: Insights from diffusion tensor imaging and machine learning.

Previous studies have suggested that disorders of consciousness (DOC) after severe brain injury may result from disconnections of the thalamo-cortical system. However, thalamo-cortical connectivity differences between vegetative state (VS), minimally conscious state minus (MCS-, i.e., low-level behavior such as visual pursuit), and minimally conscious state plus (MCS+, i.e., high-level behavior such as language processing) remain unclear. Probabilistic tractography in a sample of 25 DOC patients was employed to assess whether structural connectivity in various thalamo-cortical circuits could differentiate between VS, MCS-, and MCS+ patients. First, the thalamus was individually segmented into seven clusters based on patterns of cortical connectivity and tested for univariate differences across groups. Second, reconstructed whole-brain thalamic tracks were used as features in a multivariate searchlight analysis to identify regions along the tracks that were most informative in distinguishing among groups. At the univariate level, it was found that VS patients displayed reduced connectivity in most thalamo-cortical circuits of interest, including frontal, temporal, and sensorimotor connections, as compared with MCS+, but showed more pulvinar-occipital connections when compared with MCS-. Moreover, MCS- exhibited significantly less thalamo-premotor and thalamo-temporal connectivity than MCS+. At the multivariate level, it was found that thalamic tracks reaching frontal, parietal, and sensorimotor regions, could discriminate, up to 100% accuracy, across each pairwise group comparison. Together, these findings highlight the role of thalamo-cortical connections in patients' behavioral profile and level of consciousness. Diffusion tensor imaging combined with machine learning algorithms could thus potentially facilitate diagnostic distinctions in DOC and shed light on the neural correlates of consciousness. Hum Brain Mapp 38:431-443, 2017. © 2016 Wiley Periodicals, Inc.

Involuntary saccades and binocular coordination during visual pursuit in Parkinson's disease

Involuntary saccades and binocular coordination during visual pursuit in Parkinson's disease

Response properties of MST parafoveal neurons during smooth pursuit adaptation.

Visual motion neurons in the posterior parietal cortex play a critical role in the guidance of smooth pursuit eye movements. Initial pursuit (open-loop period) is driven, in part, by visual motion signals from cortical areas, such as the medial superior temporal area (MST). The purpose of this study was to determine whether adaptation of initial pursuit gain arises because of altered visual sensitivity of neurons at the cortical level. It is well known that the visual motion response in MST is suppressed after exposure to a large-field visual motion stimulus, showing visual motion adaptation. One hypothesis is that foveal motion responses in MST are associated with smooth pursuit adaptation using a small target spot. We used a step-ramp tracking task with two steps of target velocity (double-step paradigm), which induces gain-down or gain-up adaptation. We found that after gain-down adaptation 58% of our MST visual neurons showed a significant decrease in firing rate. This was the case even though visual motion input (before the pursuit onset) from target motion was constant. Therefore, repetitive visual stimulation during the gain-down paradigm could lead to adaptive changes in the visual response. However, the time course of adaptation did not show a correlation between the visual response and pursuit behavior. These results indicate that the visual response in MST may not directly contribute to the adaptive change in pursuit initiation.

Anticipation of physical causality guides eye movements

Causality is a unique feature of human perception. We present here a behavioral investigation of the influence of physical causality during visual pursuit of object collisions. Pursuit and saccadic eye movements of human subjects were recorded during ocular pursuit of two concurrently launched targets, one that moved according to the laws of Newtonian mechanics (the causal target) and the other one that moved in a physically implausible direction (the non-causal target). We found that anticipation of collision evoked early smooth pursuit decelerations. Saccades to non-causal targets were hypermetric and had latencies longer than saccades to causal targets. In conclusion, before and after a collision of two moving objects the oculomotor system implicitly predicts upcoming physically plausible target trajectories.

The Effects of Hearing Aid Directional Microphone and Noise Reduction Processing on Listening Effort in Older Adults with Hearing Loss.

Older listeners with hearing loss may exert more cognitive resources to maintain a level of listening performance similar to that of younger listeners with normal hearing. Unfortunately, this increase in cognitive load, which is often conceptualized as increased listening effort, may come at the cost of cognitive processing resources that might otherwise be available for other tasks. The purpose of this study was to evaluate the independent and combined effects of a hearing aid directional microphone and a noise reduction (NR) algorithm on reducing the listening effort older listeners with hearing loss expend on a speech-in-noise task. Participants were fitted with study worn commercially available behind-the-ear hearing aids. Listening effort on a sentence recognition in noise task was measured using an objective auditory-visual dual-task paradigm. The primary task required participants to repeat sentences presented in quiet and in a four-talker babble. The secondary task was a digital visual pursuit rotor-tracking test, for which participants were instructed to use a computer mouse to track a moving target around an ellipse that was displayed on a computer screen. Each of the two tasks was presented separately and concurrently at a fixed overall speech recognition performance level of 50% correct with and without the directional microphone and/or the NR algorithm activated in the hearing aids. In addition, participants reported how effortful it was to listen to the sentences in quiet and in background noise in the different hearing aid listening conditions. Fifteen older listeners with mild sloping to severe sensorineural hearing loss participated in this study. Listening effort in background noise was significantly reduced with the directional microphones activated in the hearing aids. However, there was no significant change in listening effort with the hearing aid NR algorithm compared to no noise processing. Correlation analysis between objective and self-reported ratings of listening effort showed no significant relation. Directional microphone processing effectively reduced the cognitive load of listening to speech in background noise. This is significant because it is likely that listeners with hearing impairment will frequently encounter noisy speech in their everyday communications.

Selected Cognitive Abilities in Elite Youth Soccer Players.

The identification of talent in soccer is critical to various programs. Although many research findings have been presented, there have been only a few attempts to assess their validity. The aim of this study was to determine the relationship between talent and achievement variables in the Vienna Test System. The participants were 91 Czech soccer players, representing four youth soccer teams, who were born in the year 2000. These boys were divided into two groups according to their coaches’ assessments using a TALENT questionnaire. A two-factor model (component 1: “kinetic finesse”; component 2: “mental strength”) was designed to interpret the responses of the coaches on the questionnaire. The Vienna Test System was used to determine the level of players’ cognitive abilities. In total, the subjects performed seven tests in the following order: Raven’s Standard Progressive Matrices (SPM), a reaction test (RT), a determination test (DT), a visual pursuit test (LVT), a Corsi Block-Tapping Test (CORSI), a time/movement anticipation test (ZBA), and a peripheral perception test (PP). To analyze the relationship between talent and achievement variables within the Vienna Test System, correlation analyses were performed. The results revealed that the talented group attained significantly better results on only 1 of the 16 variables, which was ZBA2: movement anticipation - deviation of movement median (r = .217, p = .019). A comparison of the two talent components showed that component 1 (“kinetic finesse”) was a more significant factor than component 2 (“mental strength”). Although we observed statistically significant correlations, their actual significance remains questionable; thus, further research is required.

Pesticide poisoning and neurobehavioral function among farm workers in Jiangsu, People's Republic of China

Pesticides remain an integral part of agricultural activities worldwide. Although there have been a number of studies over the last two decades concerning the adverse effects of pesticide poisoning and chronic long term exposures on neurobehavioral function, the impact of recent pesticide poisoning and long term pesticide exposure on neurobehavioral function in Chinese farm workers has not been reported. China is the largest user of pesticides worldwide and figures suggest 53,300–123,000 Chinese people are poisoned every year. A case control study was conducted to examine the impact of recent pesticide poisoning on neurobehavioral function and the relationship between years worked in agriculture and lower performance on neurobehavioral tests. A total of 121 farm workers who self-reported recent pesticide poisonings within the previous 12 months (case group) and 80 farm workers who reported no pesticide poisoning in the previous 12 months (control group) were recruited from three areas of Jiangsu Province, China. The World Health Organization (WHO) recommended neurobehavioral core test battery (NCTB) was used to assess neurobehavioral functioning among cases and controls. Student's t tests and two-way covariance analysis (ANCOVA) were used to test for significant differences in the neurobehavioral test results between the groups. Scores on the Profile of Mood States (POMS) in the recently poisoned group were significantly higher for anger-hostility, depression-dejection, tension-anxiety and lower for vigor-activity compared to controls (p < .05). Digit span, digit symbol, Benton visual retention and pursuit aiming scores were all significantly lower among the recently poisoned group compared to the controls (p < .05). Two-way ANCOVA indicated significantly lower performance in correct pursuit aiming and higher error pursuit aiming amongst the recently poisoned group and those who had worked for more than 30 years in agriculture (p < .05). These findings provide important preliminary epidemiological evidence regarding the association between occupational pesticide exposure and neurobehavioral functioning in Chinese farm workers.

OP23 – 2759: Pharmacological treatment of Rett syndrome with glatiramer acetate (Copaxone)

Background Glatiramer Acetate (GA) represents a collection of synthetic polypeptides approved for the treatment of relapsing–remitting multiple sclerosis, for patients who are 18 years or older. Its high safety profile has been documented in large cohorts of patients 10 or older. Quantitative immunofluorescence assays showed about twofold increase in neuronal expression of BDNF following GA treatment. It causes elevation of BDNF expression up to the level in naive control mice in several cortical areas in the Mecp2 mutated mouse brain. The disease progression of Mecp2 mutant mice is affected by the level of BDNF expression (Chang et al. 2006). Objective Increase in BDNF levels, caused by GA administration will lead to amelioration of RTT related symptoms. Hypothesis: The experimental treatment will be well tolerated and result in at least 20% improvement in at least one of the Rett syndrome related symptoms. Methods Study design: Phase II, dose-escalating trial. Inclusion criteria Female, ambulatory patients with genetically confirmed RTT who are 10 or more years old. Outcome measures: Gait, respiratory function, attention and memory, EEG. Objectives • Primary: To assess primary efficacy of GA in improving gait speed in patients with RTT. • Secondary: a. To evaluate secondary efficacy of GA in improving cognition (visual attention, memory and visual pursuit), autonomic (respiratory) function, encephalopathy (EEG), and quality of life. b. To assess safety and maximally tolerated dosage. Results Treatment with GA lead to significant improvement in gait speed, breath hold index and recognition memory. Seven of 10 treated girls exhibited the improvement. There was no difference in age, genetic status or Rett syndrome severity scores between those who did and who did not improve. Conclusion Treatment with GA was well-tolerated and lead to significant improvements in girls with RTT.

Broad thorny ganglion cells: a candidate for visual pursuit error signaling in the primate retina.

Functional analyses exist only for a few of the morphologically described primate ganglion cell types, and their correlates in other mammalian species remain elusive. Here, we recorded light responses of broad thorny cells in the whole-mounted macaque retina. They showed ON-OFF-center light responses that were strongly suppressed by stimulation of the receptive field surround. Spike responses were delayed compared with parasol ganglion cells and other ON-OFF cells, including recursive bistratified ganglion cells and A1 amacrine cells. The receptive field structure was shaped by direct excitatory synaptic input and strong presynaptic and postsynaptic inhibition in both ON and OFF pathways. The cells responded strongly to dark or bright stimuli moving either in or out of the receptive field, independent of the direction of motion. However, they did not show a maintained spike response either to a uniform background or to a drifting plaid pattern. These properties could be ideally suited for guiding movements involved in visual pursuit. The functional characteristics reported here permit the first direct cross-species comparison of putative homologous ganglion cell types. Based on morphological similarities, broad thorny ganglion cells have been proposed to be homologs of rabbit local edge detector ganglion cells, but we now show that the two cells have quite distinct physiological properties. Thus, our data argue against broad thorny cells as the homologs of local edge detector cells.

Smooth pursuit eye and gaze movements to moving auditory targets: Evidence for velocity-specific processing in the auditory system

Auditory motion perception remains poorly understood, in contrast with its well-established visual counterpart. Visual smooth pursuit (SP), a velocity-specific behavior, has been well-quantified during both head-fixed (ocular SP) and head-free (eye + head, or gaze SP) conditions. In contrast, auditory SP tracking has received little attention, despite its potential for demonstrating a motion-specific process in audition. We presented constant-velocity (10–40°/s), free-field auditory (0.2–20 kHz white noise), and visual (LED) targets to head-fixed or head-free subjects while recording ocular and gaze SP responses, respectively. To control for possible SP in the absence of a target, subjects were asked to recreate auditory trajectories after priming with a set of auditory ramps (practiced SP). We found that ocular auditory SP is consistently higher in gain than practiced SP, but variable and lower than visual SP. Further, the gain of auditory gaze SP exceeds ocular auditory SP. Finally, SP of periodic (triangular) motion trajectories revealed that auditory, like visual, SP improves rapidly over time, indicating predictive behavior. In sum, auditory SP closely mimics visual SP but with reduced gain. We propose that auditory motion processing exists, is robust, and recruits a velocity-dependent neural process shared with vision.

Neurobehavioral effects of arsenic exposure among secondary school children in the Kandal Province, Cambodia

The research was carried out at 3 study sites with varying groundwater arsenic (As) levels in the Kandal Province of Cambodia. Kampong Kong Commune was chosen as a highly contaminated site (300–500μg/L), Svay Romiet Commune was chosen as a moderately contaminated site (50–300μg/L) and Anlong Romiet Commune was chosen as a control site. Neurobehavioral tests on the 3 exposure groups were conducted using a modified WHO neurobehavioral core test battery. Seven neurobehavioral tests including digit symbol, digit span, Santa Ana manual dexterity, Benton visual retention, pursuit aiming, trail making and simple reaction time were applied. Children's hair samples were also collected to investigate the influence of hair As levels on the neurobehavioral test scores. The results from the inductively coupled plasma-mass spectrometry (ICP-MS) analyses of hair samples showed that hair As levels at the 3 study sites were significantly different (p<0.001), whereby hair samples from the highly contaminated site (n=157) had a median hair As level of 0.93μg/g, while the moderately contaminated site (n=151) had a median hair As level of 0.22μg/g, and the control site (n=214) had a median hair As level of 0.08μg/g. There were significant differences among the 3 study sites for all the neurobehavioral tests scores, except for digit span (backward) test. Multiple linear regression clearly shows a positive significant influence of hair As levels on all the neurobehavioral test scores, except for digit span (backward) test, after controlling for hair lead (Pb), manganese (Mn) and cadmium (Cd). Children with high hair As levels experienced 1.57–4.67 times greater risk of having lower neurobehavioral test scores compared to those with low hair As levels, after adjusting for hair Pb, Mn and Cd levels and BMI status. In conclusion, arsenic-exposed school children from the Kandal Province of Cambodia with a median hair As level of 0.93µg/g among those from the highly contaminated study site, showed clear evidence of neurobehavioral effects.

Acknowledgments

Acknowledgments Felicity Henderson (bio), Sachiko Kusukawa (bio), and Alexander Marr (bio) these essays arise from a conference, “Curiously Drawn,” held at the Royal Society on June 21–22, 2012. The meeting was part of the activities of a research network, “Origins of Science as a Visual Pursuit,” that sought to bring together historians of science and historians of art to examine the historical role of images in the early Royal Society (see picturingscience.wordpress.com). This project, including the publication of this volume, was supported by the Arts and Humanities Research Council of the United Kingdom. We are grateful to the speakers and participants for their enthusiasm, and in particular to Professor Michael Hunter for acting as commentator-at-large to bring together the various themes that emerged from the meeting. We would like to record our special thanks to Keith Moore, Joanna McManus, Rupert Baker, and Joanna Corden at the Royal Society for their generous help, and to Susannah Gibson, Department of History and Philosophy of Science, University of Cambridge, for assisting with the activities of the network. We are grateful for the patience, support, and enthusiasm of Susan Green, the Director of the Huntington Library Press, in seeing through the publication of this volume. [End Page vii] Felicity Henderson felicity henderson is Lecturer in Archives and Material Culture at Exeter University. Her research focuses on the early history of the Royal Society, and she is currently preparing a scholarly edition of Robert Hooke’s diary for Oxford University Press. Sachiko Kusukawa sachiko kusukawa is Fellow in the History and Philosophy of Science, Trinity College, Cambridge. The author of Picturing the Book of Nature: Image, Text, and Argument in Sixteenth-Century Human Anatomy and Medical Botany (2012), she is now working on the graphic practices of the early Royal Society, for which she has been awarded a grant from the Arts and Humanities Research Council, U.K. Alexander Marr alexander marr is University Lecturer in the History of Art, 1400–1700, at the University of Cambridge and a Fellow of Trinity Hall. He specializes in early modern art and architecture, particularly their intellectual and scientific aspects. He is the Director of the research project “Genius before Romanticism: Ingenuity in Early Modern Art & Science,” funded by the European Research Council. Copyright © 2016 The Johns Hopkins University Press

Peripheral viewing during exposure to a 2D/3D video clip: effects on the human body.

Symptoms of three-dimensional (3D) sickness, such as intoxication and eye fatigue, have been observed in subjects viewing 3D films and vary according to the image quality and visual environment. In addition, the influence of stereoscopic vision on the incidence of 3D sickness has not been explored sufficiently. Therefore, it is important to examine the safety of viewing virtual 3D content. The present study examines the effects of peripheral vision on reported motion sickness during exposure to 2D/3D video clips for 1 min and for 1 min afterwards in human subjects. Stabilograms were recorded during exposure to video clips with or without visual pursuit of a 3D object and compared, and subjects were administered the simulator sickness questionnaire after stabilometry. There were no significant main effects of solidity of the visual stimulous (2D/3D) and the vision method (visual pursuit/peripheral viewing) in accordance with the two-way analysis of variance of the sway values, although the sway values during the 2D/3D video clips were higher than in control subjects. A consistent trend in the main effect of stability was observed. Further, the sway values changed remarkably after the 3D video clip was viewed peripherally and produced a persistent instability in equilibrium function. The questionnaire findings also significantly changed after the subjects viewed the video clips peripherally. Subjective exacerbation and deterioration of equilibrium function were observed after peripheral viewing of 3D video clips. This persistent influence may result when subjects view a poorly depicted background element peripherally, which generates depth perception that contradicts daily experience.