Visual Motion Perception Research Articles

Neural patterns of conscious visual awareness in the Riddoch syndrome

The Riddoch syndrome is one in which patients blinded by lesions to their primary visual cortex can consciously perceive visual motion in their blind field, an ability that correlates with activity in motion area V5. Our assessment of the characteristics of this syndrome in patient ST, using multimodal MRI, showed that: 1. ST’s V5 is intact, receives direct subcortical input, and decodable neural patterns emerge in it only during the conscious perception of visual motion; 2. moving stimuli activate medial visual areas but, unless associated with decodable V5 activity, they remain unperceived; 3. ST’s high confidence ratings when discriminating motion at chance levels, is associated with inferior frontal gyrus activity. Finally, we report that ST’s Riddoch Syndrome results in hallucinatory motion with hippocampal activity as a correlate. Our results shed new light on perceptual experiences associated with this syndrome and on the neural determinants of conscious visual experience.

The relationship between central and mid-peripheral motion perception and the hazard perception test in younger and older adults.

Vision standards for driving are typically based on visual acuity, despite evidence that it is a poor predictor of driving safety and performance. However, visual motion perception is potentially relevant for driving, as the vehicle and surroundings are in motion. This study explored whether tests of central and mid-peripheral motion perception better predict performance on a hazard perception test (HPT), which is related to driving performance and crash risk, than visual acuity. Additionally, we explored whether age influences these associations, as healthy ageing impairs performance on some motion sensitivity tests. Sixty-five visually healthy drivers (35 younger, mean age: 25.5; SD 4.3 years; 30 older adults, mean age: 71.0; SD 5.4 years) underwent a computer-based HPT, plus four different motion sensitivity tests both centrally and at 15° eccentricity. Motion tests included minimum displacement to identify motion direction (Dmin ), contrast detection threshold for a drifting Gabor (motion contrast), coherence threshold for a translational global motion stimulus and direction discrimination for a biological motion stimulus in the presence of noise. Overall, HPT reaction times were not significantly different between age groups (p = 0.40) nor were maximum HPT reaction times (p = 0.34). HPT response time was associated with motion contrast and Dmin centrally (r = 0.30, p = 0.02 and r = 0.28, p = 0.02, respectively) and with Dmin peripherally (r = 0.34, p = 0.005); these associations were not affected by age group. There was no significant association between binocular visual acuity and HPT response times (r = 0.02, p = 0.29). Some measures of motion sensitivity in central and mid-peripheral vision were associated with HPT response times, whereas binocular visual acuity was not. Peripheral testing did not show an advantage over central testing for visually healthy older drivers. Our findings add to the growing body of evidence that the ability to detect small motion changes may have potential to identify unsafe road users.

Backward illusory line motion: Visual motion perception can be influenced by retrospective stimulation.

When a visual cue appears beside a horizontal line segment before the line appears, the illusory motion is perceived as a line extending from the side closest to the side farthest from the cue. This is known as illusory line motion (ILM). In Experiment 1, we presented the cue after the line onset and found that the line seemed to extend toward the side of the cue (backward ILM). In Experiment 2, we confirmed the robustness and replicability of the backward ILM. In Experiments 3 to 5, we investigated the role of endogenous and exogenous attention in the generation of backward ILM and found effects of attention, but not large enough to explain the backward ILM in Experiments 1 and 2. The current findings suggest that the direction of ILM depended on the temporal relation of whether the cue precedes or follows the stimulus appearance, and that attentional shift played a role in the perception of backward ILM.

Effect of metabolic control on cognitive functions in children and adolescents with type 1 diabetes mellitus.

Neurocognitive functions of children with type 1 diabetes mellitus (T1D) are reported to be poorer than those of healthy peers. The aim was to investigate the effects of age of onset of diabetes, metabolic control, and type of insulin regimen on neurocognitive functions in children and adolescents with T1D. Forty-seven children aged 6-18 years, with T1D for at least five years, were included. Children with a known psychiatric disorder or chronic diseases other than T1D were excluded. Intelligence via the Wechsler children's intelligence scale (WISC-R), short-term memory via the audio-auditory digits form B (GISD-B) test, visual motor perception via the Bender Gestalt test, and attention via the Moxo continuous attention and performance test, timing, hyperactivity, and impulsivity (Moxo-dCPT) were assessed. Compared with the T1D group, healthy controls had higher scores in terms of verbal intelligence quotient (IQ), performance IQ, and total IQ mean scores on WISC-R (p=0.01, p=0.05 and p=0.01, respectively). On the MOXO-dCPT test, the T1D group had higher impulsivity compared to the control group (p=0.04). Verbal IQ was better in the moderate control group than in the poorer metabolic control (p=0.01). Patients with no history of diabetic ketoacidosis (DKA) had higher performance, verbal and total intelligence scores than the group with history of DKA. Poor metabolic control and a history of DKA in children with T1D adversely affected neurocognitive functions. It would be beneficial to consider the assessment of neurocognitive functions in T1D and to take the necessary precautions in follow-up.

Starburst amacrine cells, involved in visual motion perception, lose their synaptic input from dopaminergic amacrine cells and degenerate in Parkinson’s disease patients

BackgroundThe main clinical symptoms characteristic of Parkinson’s disease (PD) are bradykinesia, tremor, and other motor deficits. However, non-motor symptoms, such as visual disturbances, can be identified at early stages of the disease. One of these symptoms is the impairment of visual motion perception. Hence, we sought to determine if the starburst amacrine cells, which are the main cellular type involved in motion direction selectivity, are degenerated in PD and if the dopaminergic system is related to this degeneration.MethodsHuman eyes from control (n = 10) and PD (n = 9) donors were available for this study. Using immunohistochemistry and confocal microscopy, we quantified starburst amacrine cell density (choline acetyltransferase [ChAT]-positive cells) and the relationship between these cells and dopaminergic amacrine cells (tyrosine hydroxylase-positive cells and vesicular monoamine transporter-2-positive presynapses) in cross-sections and wholemount retinas.ResultsFirst, we found two different ChAT amacrine populations in the human retina that presented different ChAT immunoreactivity intensity and different expression of calcium-binding proteins. Both populations are affected in PD and their density is reduced compared to controls. Also, we report, for the first time, synaptic contacts between dopaminergic amacrine cells and ChAT-positive cells in the human retina. We found that, in PD retinas, there is a reduction of the dopaminergic synaptic contacts into ChAT cells.ConclusionsTaken together, this work indicates degeneration of starburst amacrine cells in PD related to dopaminergic degeneration and that dopaminergic amacrine cells could modulate the function of starburst amacrine cells. Since motion perception circuitries are affected in PD, their assessment using visual tests could provide new insights into the diagnosis of PD.

Making night-time pedestrians safer using innovative clothing designs

Night-time pedestrians, including recreational walkers and runners, remain at significant risk of being killed or seriously injured, because drivers often fail to see them in time to avoid a collision. Clothing incorporating retro-reflective markers on the moveable joints creates a visual perception of biological motion or “biomotion” which has been shown to improve night-time pedestrian conspicuity. This study investigated whether clothing with markings in the biomotion configuration retains its conspicuity if adapted to include thinner or patterned retro-reflective strips making it more acceptable to wear for recreational pedestrians. In a night-time closed road study, the relative conspicuity of pedestrians to 14 young drivers with normal vision (mean age 24.3 ± 3.1 years) was assessed for pedestrians wearing different thicknesses and patterns of biomotion strips and compared with typical clothing worn by night-time pedestrians, including commercially available sports clothing with retro-reflective elements, a fluorescent yellow top, and black clothing. Results showed that all the biomotion configurations resulted in significantly longer recognition distances: around 2 times longer than the sports clothing, 2.5 times longer than the fluorescent top and 4 times longer than the black clothing. Similar trends were found for the distance at which drivers correctly identified pedestrian orientation (towards or sideways to the vehicle), with significantly longer distances for all the biomotion configurations, when compared to the sports, fluorescent top and black clothing. These findings highlight the effectiveness of biomotion clothing, even when using retro-reflective strips as thin as 0.75 cm and have implications for clothing designs for recreational walkers and runners to enhance their night-time safety.

Can visual cortex non-invasive brain stimulation improve normal visual function? A systematic review and meta-analysis.

Multiple studies have explored the use of visual cortex non-invasive brain stimulation (NIBS) to enhance visual function. These studies vary in sample size, outcome measures, and methodology. We conducted a systematic review and meta-analyses to assess the effects of NIBS on visual functions in human participants with normal vision. We followed the PRISMA guidelines, and a review protocol was registered with PROSPERO before study commencement (CRD42021255882). We searched Embase, Medline, PsychInfo, PubMed, OpenGrey and Web of Science using relevant keywords. The search covered the period from 1st January 2000 until 1st September 2021. Comprehensive meta-analysis (CMA) software was used for quantitative analysis. Fifty studies were included in the systematic review. Only five studies utilized transcranial magnetic stimulation (TMS) and no TMS studies met our pre-specified criteria for meta-analysis. Nineteen transcranial electrical stimulation studies (tES, 38%) met the criteria for meta-analysis and were the focus of our review. Meta-analysis indicated acute effects (Hedges's g = 0.232, 95% CI: 0.023-0.442, p = 0.029) and aftereffects (0.590, 95% CI: 0.182-0.998, p = 0.005) of tES on contrast sensitivity. Visual evoked potential (VEP) amplitudes were significantly enhanced immediately after tES (0.383, 95% CI: 0.110-0.665, p = 0.006). Both tES (0.563, 95% CI: 0.230-0.896, p = 0.001) and anodal-transcranial direct current stimulation (a-tDCS) alone (0.655, 95% CI: 0.273-1.038, p = 0.001) reduced crowding in peripheral vision. The effects of tES on visual acuity, motion perception and reaction time were not statistically significant. There are significant effects of visual cortex tES on contrast sensitivity, VEP amplitude, an index of cortical excitability, and crowding among normally sighted individuals. Additional studies are required to enable a comparable meta-analysis of TMS effects. Future studies with robust experimental designs are needed to extend these findings to populations with vision loss. ClinicalTrials.gov/, identifier CRD42021255882.

An interactive motion perception tool for kindergarteners (and vision scientists).

We implement Adelson and Bergen's spatiotemporal energy model with extension to three-dimensional (x-y-t) in an interactive tool. It helps gain an easy understanding of early (first-order) visual motion perception. We demonstrate its usefulness in explaining an assortment of phenomena, including some that are typically not associated with the spatiotemporal energy model.

Form Properties of Moving Targets Bias Smooth Pursuit Target Selection in Monkeys.

During natural viewing, we often recognize multiple objects, detect their motion, and select one object as the target to track. It remains to be determined how such behavior is guided by the integration of visual form and motion perception. To address this, we studied how monkeys made a choice to track moving targets with different forms by smooth pursuit eye movements in a two-target task. We found that pursuit responses were biased toward the motion direction of a target with a hole. By computing the relative weighting, we found that the target with a hole exhibited a larger weight for vector computation. The global hole feature dominated other form properties. This dominance failed to account for changes in pursuit responses to a target with different forms moving singly. These findings suggest that the integration of visual form and motion perception can reshape the competition in sensorimotor networks to guide behavioral selection.

Visual motion perception before and after sight recovery from early-onset and prolonged near-blindness

Visual motion perception before and after sight recovery from early-onset and prolonged near-blindness

Exercise-induced arousal does not impact center surround suppression of visual motion perception, but chronic stress is correlated to it.

Exercise-induced arousal does not impact center surround suppression of visual motion perception, but chronic stress is correlated to it.

Visual motion perception as online hierarchical inference

Identifying the structure of motion relations in the environment is critical for navigation, tracking, prediction, and pursuit. Yet, little is known about the mental and neural computations that allow the visual system to infer this structure online from a volatile stream of visual information. We propose online hierarchical Bayesian inference as a principled solution for how the brain might solve this complex perceptual task. We derive an online Expectation-Maximization algorithm that explains human percepts qualitatively and quantitatively for a diverse set of stimuli, covering classical psychophysics experiments, ambiguous motion scenes, and illusory motion displays. We thereby identify normative explanations for the origin of human motion structure perception and make testable predictions for future psychophysics experiments. The proposed online hierarchical inference model furthermore affords a neural network implementation which shares properties with motion-sensitive cortical areas and motivates targeted experiments to reveal the neural representations of latent structure.

Особенности сенсомоторных и перцептивных процессов у детей младшего школьного возраста с тяжелыми множественными нарушениями развития

The article focuses on sensorimotor and perceptual processes in primary school children with multiple developmental disorders. The study involved 40 children aged 9–11 with multiple developmental issues. All the participants studied at the Secondary School of Psychological and Pedagogical Support No. 101 (Kemerovo, Russia). The experiment relied on the method developed by N. I. Ozeretskiy and M. O. Gurevich as the main diagnostic tool. The method combines a set of diagnostic tasks aimed at measuring the level of motor and perceptual development in children. The experimental study also included elements of the neuropsychological approach. The authors designed and conducted a series of practice sessions on the development of sensorimotor and perceptual processes. The neuropsychological exercises developed purposeful voluntary actions with objects and materials, improved available sensory experience, increased visual-motor coordination, sharpened the ability to navigate in various physical environments, and improved body control. They facilitated the compensation of residual reflexes, as well as the development of speech and general motor rhythmization. The exercises involved orthopedic mats, massage balls, tasks on visual-motor perception and integration, Balametrics cerebellar stimulation, etc. Statistic results showed a positive trend in the sensorimotor and perceptual processes, except for complex forms of space and time perception.

Stroboscopic vision prolongs visual motion perception in the central nervous system.

Stroboscopic training has repeatedly been shown to improve visual and visuomotor performance in sports. Although recent research suggests that stroboscopic vision puts a training stimulus to the central nervous system, the underlying mechanism how it affects motion perception and processing in the brain is still unknown. Twenty-six participants performed a computer-based simple reaction test in response to a visual motion stimulus under normal (baseline) and stroboscopic conditions (5Hz frequency, 40% duty cycle) (stroboscopic). A third condition under normal vision intermittently stopped the motion stimulus at the same frequency and duty cycle as in the stroboscopic condition. This condition controlled for the amount of visual motion information independent of the shutter glasses (screen shutter) and provided information about the effect of luminance changes induced by the stroboscopic eyewear. A 64-channel EEG was recorded to determine the amplitude and latency of the N2 component as a correlate of visual motion perception in the motion-sensitive visual area MT. Reaction time under stroboscopic conditions was significantly delayed when compared to both the baseline (p < 0.001) and screen shutter (p < 0.001) conditions. This was accompanied by a significantly prolonged N2 latency (p < 0.001) and lower N2 amplitude (p < 0.001) with the shutter glasses. There was no difference in reaction time or N2 amplitude/latency between the baseline and screen shutter condition (p ≥ 0.176). Stroboscopic eyewear delays the speed of visual motion perception and processing in the central nervous system and reduces the visuomotor reaction speed. This may form the neurophysiological basis for performance gains following stroboscopic training.

The Effects of Glare on the Perception of Visual Motion as a Function of Age.

PurposeThe purpose of this study was to determine the impact of glare, that simulated the effects of oncoming vehicle headlights, and age on different aspects of motion perception in central and peripheral vision.MethodsTwenty younger (mean age = 25 years, range = 20–32 years) and 20 older (mean age = 70 years, range = 60–79 years) visually healthy adults completed four visual motion tasks. Stimuli were presented centrally and at 15 degrees horizontal eccentricity for 2 viewing conditions: glare (continuous, off-axis) versus no glare. Motion tasks included minimum Gabor contrast required to discriminate direction of motion, translational global motion coherence, minimum duration of a Gabor to determine direction of motion (2 different size Gabors to determine spatial surround suppression), and biological motion detection in noise. Intraocular straylight was also measured (C-Quant).ResultsOlder adults had increased intraocular straylight compared with younger adults (P < 0.001). There was no significant effect of glare on motion thresholds in either group for motion contrast (P = 0.47), translational global motion (P = 0.13), biological motion (P = 0.18), or spatial surround suppression of motion (P = 0.29). Older adults had elevated thresholds for motion contrast (P < 0.001), biological motion (P < 0.001), and differences in surround suppression of motion (P = 0.04), relative to the younger group, for both the glare and no-glare conditions.ConclusionsAlthough older adults had elevated thresholds for some motion perception tasks, glare from a continuous off-axis light source did not further elevate these thresholds either in central or peripheral vision.Translational RelevanceA glare source that simulated the effect of oncoming headlights, did not impact motion perception measures relevant to driving.

High-definition transcranial direct current stimulation of the left middle temporal complex does not affect visual motion perception learning.

Visual perceptual learning (VPL) refers to the improvement in visual perceptual abilities through training and has potential implications for clinical populations. However, improvements in perceptual learning often require hundreds or thousands of trials over weeks to months to attain, limiting its practical application. Transcranial direct current stimulation (tDCS) could potentially facilitate perceptual learning, but the results are inconsistent thus far. Thus, this research investigated the effect of tDCS over the left human middle temporal complex (hMT+) on learning to discriminate visual motion direction. Twenty-seven participants were randomly assigned to the anodal, cathodal and sham tDCS groups. Before and after training, the thresholds of motion direction discrimination were assessed in one trained condition and three untrained conditions. Participants were trained over 5 consecutive days while receiving 4 × 1 ring high-definition tDCS (HD-tDCS) over the left hMT+. The results showed that the threshold of motion direction discrimination significantly decreased after training. However, no obvious differences in the indicators of perceptual learning, such as the magnitude of improvement, transfer indexes, and learning curves, were noted among the three groups. The current study did not provide evidence of a beneficial effect of tDCS on VPL. Further research should explore the impact of the learning task characteristics, number of training sessions and the sequence of stimulation.

Visual Predictors of Postural Sway in Older Adults.

PurposeAccurate perception of body position relative to the environment through visual cues provides sensory input to the control of postural stability. This study explored which vision measures are most important for control of postural sway in older adults with a range of visual characteristics.MethodsParticipants included 421 older adults (mean age = 72.6 ± 6.1), 220 with vision impairment associated with a range of eye diseases and 201 with normal vision. Participants completed a series of vision, cognitive, and physical function tests. Postural sway was measured using an electronic forceplate (HUR Labs) on a foam surface with eyes open. Linear regression analysis identified the strongest visual predictors of postural sway, controlling for potential confounding factors, including cognitive and physical function.ResultsIn univariate regression models, unadjusted and adjusted for age, all of the vision tests were significantly associated with postural sway (P < 0.05), with the strongest predictor being visual motion sensitivity (standardized regression coefficient, β = 0.340; age-adjusted β = 0.253). In multiple regression models, motion sensitivity (β = 0.187), integrated binocular visual fields (β = −0.109), and age (β = 0.234) were the only significant visual predictors of sway, adjusted for confounding factors, explaining 23% of the variance in postural sway.ConclusionsOf the vision tests, visual motion perception and binocular visual fields were most strongly associated with postural stability in older adults with and without vision impairment.Translational RelevanceFindings provide insight into the visual contributions to postural stability in older adults and have implications for falls risk assessment.

Selective Enhancement of Post-Sleep Visual Motion Perception by Repetitive Tactile Stimulation during Sleep.

Tactile sensations can bias visual perception in the awake state while visual sensitivity is known to be facilitated by sleep. It remains unknown, however, whether the tactile sensation during sleep can bias the visual improvement after sleep. Here, we performed nap experiments in human participants (n = 56, 18 males, 38 females) to demonstrate that repetitive tactile motion stimulation on the fingertip during slow wave sleep selectively enhanced subsequent visual motion detection. The visual improvement was associated with slow wave activity. The high activation at the high beta frequency was found in the occipital electrodes after the tactile motion stimulation during sleep, indicating a visual-tactile cross-modal interaction during sleep. Furthermore, a second experiment (n = 14, 14 females) to examine whether a hand- or head-centered coordination is dominant for the interpretation of tactile motion direction showed that the biasing effect on visual improvement occurs according to the hand-centered coordination. These results suggest that tactile information can be interpreted during sleep, and can induce the selective improvement of post-sleep visual motion detection.SIGNIFICANCE STATEMENT Tactile sensations can bias our visual perception as a form of cross-modal interaction. However, it was reported only in the awake state. Here we show that repetitive directional tactile motion stimulation on the fingertip during slow wave sleep selectively enhanced subsequent visual motion perception. Moreover, the visual improvement was positively associated with sleep slow wave activity. The tactile motion stimulation during slow wave activity increased the activation at the high beta frequency over the occipital electrodes. The visual improvement occurred in agreement with a hand-centered reference frame. These results suggest that our sleeping brain can interpret tactile information based on a hand-centered reference frame, which can cause the sleep-dependent improvement of visual motion detection.

Enhanced vection in older adults: Evidence for age-related effects in multisensory vection experiences.

The illusion of self-motion (vection) is a multisensory phenomenon elicited by visual, auditory, tactile, or other sensory cues. Aging is often associated with changes in sensory acuity, visual motion perception, and multisensory integration, processes which may influence vection perception. However, age-related differences in vection have received little study to date. Thus, the objective of the present study was to investigate age-related differences in vection during multisensory stimulation. Nineteen younger adults and 19 older adults were exposed to rotating visual, auditory, and tactile stimuli (separately or in combination) at a speed of 45°/s inside a VR laboratory inducing circular vection. The size of the field-of-view (FOV) was large (240°), medium (75°), small (30°), or contained no visuals. Vection intensity and duration were reported verbally after each trial. Overall, older adults experienced significantly stronger and longer vection compared to younger adults. Additionally, there were main effects of FOV and sensory cues, such that larger FOVs and the presence of auditory and tactile stimulation increased vection ratings for both age groups. These findings support the idea that vection is a multisensory experience that can be elicited by visual, auditory, and tactile stimuli and demonstrates these effects for the first time in older adults.

Sensory and Motor Visual Functions in Parkinson’s Disease with Respect to Freezing of Gait Symptoms

Freezing of gait (FOG) is considered to be a motor disorder symptom that affects some Parkinson Disease (PD) patients; however, it is hypothesized that sensory systems may also be involved in FOG. This review article summarizes the results from previous studies focusing on visual functions in PD patients. More emphasize will be focused on freezing of gait PD patients and whether visual functions are affected to greater amount among them than non-freezing of gait PD patients. Visual functions include high contrast visual acuity, low contrast visual acuity, contrast sensitivity, Vernier acuity, mesopic vision, stereopsis, motion perception, and vergence eye movements are all affected in PD patients, with FOG patients having more deficits in some of these functions. FOG patients also had larger impairments in non-dopaminergic mediated functions such as pupil light reflex and visual processing speed test, which suggests that FOG patients have greater impairment in two functions that involve cholinergic neurotransmitters. Whether these impairments are contributing to the FOG or just associated with FOG is uncertain.