A Chimeric Point-Light Walker

Perception ◽  
10.1068/p5010 ◽  
2003 ◽  
Vol 32 (3) ◽  
pp. 377-383 ◽  
Author(s):  
Ian M Thornton ◽  
Quoc C Vuong ◽  
Heinrich H Bülthoff
Keyword(s):  
Visual Processing ◽  
Biological Motion ◽  
Ambiguous Figure ◽  
Motion Processing ◽  
The Novel ◽  
Motion Pattern ◽  
Initial Report ◽  
Constant Direction ◽  
Point Light ◽  
The Right

Ambiguity has long been used as a probe into visual processing. Here, we describe a new dynamic ambiguous figure—the chimeric point-light walker—which we hope will prove to be a useful tool for exploring biological motion. We begin by describing the construction of the stimulus and discussing the compelling finding that, when presented in a mask, observers consistently fail to notice anything odd about the walker, reporting instead that they are watching an unambiguous figure moving either to the left or right. Some observers report that the initial percept fluctuates, moving first to the left, then to the right, or vice versa; others always perceive a constant direction. All observers, when briefly shown the unmasked ambiguous figure, have no difficulty in perceiving the novel motion pattern once the mask is returned. These two findings—the initial report of unambiguous motion and the subsequent ‘primed’ perception of the ambiguity—are both consistent with an important role for top–down processing in biological motion. We conclude by suggesting several domains within the realm of biological-motion processing where this simple stimulus may prove to be useful.

Biological motion processing: The left cerebellum communicates with the right superior temporal sulcus

NeuroImage ◽  
2012 ◽  
Vol 59 (3) ◽  
pp. 2824-2830 ◽  
Author(s):  
Arseny A. Sokolov ◽  
Michael Erb ◽  
Alireza Gharabaghi ◽  
Wolfgang Grodd ◽  
Marcos S. Tatagiba ◽  
...  
Keyword(s):  
Biological Motion ◽  
Superior Temporal Sulcus ◽  
Motion Processing ◽  
The Right

Effects of TMS over Premotor and Superior Temporal Cortices on Biological Motion Perception

2012 ◽  
Vol 24 (4) ◽  
pp. 896-904 ◽  
Author(s):  
Bianca Michelle van Kemenade ◽  
Neil Muggleton ◽  
Vincent Walsh ◽  
Ayse Pinar Saygin
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Premotor Cortex ◽  
Control Site ◽  
Object Motion ◽  
Motion Processing ◽  
False Alarms ◽  
Control Task ◽  
Biological Motion Perception ◽  
Point Light

Using MRI-guided off-line TMS, we targeted two areas implicated in biological motion processing: ventral premotor cortex (PMC) and posterior STS (pSTS), plus a control site (vertex). Participants performed a detection task on noise-masked point-light displays of human animations and scrambled versions of the same stimuli. Perceptual thresholds were determined individually. Performance was measured before and after 20 sec of continuous theta burst stimulation of PMC, pSTS, and control (each tested on different days). A matched nonbiological object motion task (detecting point-light displays of translating polygons) served as a further control. Data were analyzed within the signal detection framework. Sensitivity (d′) significantly decreased after TMS of PMC. There was a marginally significant decline in d′ after TMS of pSTS but not of control site. Criterion (response bias) was also significantly affected by TMS over PMC. Specifically, subjects made significantly more false alarms post-TMS of PMC. These effects were specific to biological motion and not found for the nonbiological control task. To summarize, we report that TMS over PMC reduces sensitivity to biological motion perception. Furthermore, pSTS and PMC may have distinct roles in biological motion processing as behavioral performance differs following TMS in each area. Only TMS over PMC led to a significant increase in false alarms, which was not found for other brain areas or for the control task. TMS of PMC may have interfered with refining judgments about biological motion perception, possibly because access to the perceiver's own motor representations was compromised.

scholarly journals Brain function distinguishes female carriers and non-carriers of familial risk for autism

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam T. Eggebrecht ◽  
Ally Dworetsky ◽  
Zoë Hawks ◽  
Rebecca Coalson ◽  
Babatunde Adeyemo ◽  
...  
Keyword(s):  
Biological Motion ◽  
Familial Risk ◽  
Autism Spectrum ◽  
Motion Processing ◽  
Female Ratio ◽  
Brain Responses ◽  
Passive Viewing ◽  
Point Light ◽  
Genetic Loading ◽  
Neural Signatures

Abstract Background Autism spectrum disorder (ASD) is characterized by high population-level heritability and a three-to-one male-to-female ratio that occurs independent of sex linkage. Prior research in a mixed-sex pediatric sample identified neural signatures of familial risk elicited by passive viewing of point light motion displays, suggesting the possibility that both resilience and risk of autism might be associated with brain responses to biological motion. To confirm a relationship between these signatures and inherited risk of autism, we tested them in families enriched for genetic loading through undiagnosed (“carrier”) females. Methods Using functional magnetic resonance imaging, we examined brain responses to passive viewing of point light displays—depicting biological versus non-biological motion—in a sample of undiagnosed adult females enriched for inherited susceptibility to ASD on the basis of affectation in their respective family pedigrees. Brain responses in carrier females were compared to responses in age-, SRS-, and IQ-matched non-carrier-females—i.e., females unrelated to individuals with ASD. We conducted a hypothesis-driven analysis focused on previously published regions of interest as well as exploratory, brain-wide analyses designed to characterize more fully the rich responses to this paradigm. Results We observed robust responses to biological motion. Notwithstanding, the 12 regions implicated by prior research did not exhibit the hypothesized interaction between group (carriers vs. controls) and point light displays (biological vs. non-biological motion). Exploratory, brain-wide analyses identified this interaction in three novel regions. Post hoc analyses additionally revealed significant variations in the time course of brain activation in 20 regions spanning occipital and temporal cortex, indicating group differences in response to point light displays (irrespective of the nature of motion) for exploration in future studies. Limitations We were unable to successfully eye-track all participants, which prevented us from being able to control for potential differences in eye gaze position. Conclusions These methods confirmed pronounced neural signatures that differentiate brain responses to biological and scrambled motion. Our sample of undiagnosed females enriched for family genetic loading enabled discovery of numerous contrasts between carriers and non-carriers of risk of ASD that may index variations in visual attention and motion processing related to genetic susceptibility and inform our understanding of mechanisms incurred by inherited liability for ASD.

scholarly journals Ventral aspect of the visual form pathway is not critical for the perception of biological motion

2015 ◽  
Vol 112 (4) ◽  
pp. E361-E370 ◽  
Author(s):  
Sharon Gilaie-Dotan ◽  
Ayse Pinar Saygin ◽  
Lauren J. Lorenzi ◽  
Geraint Rees ◽  
Marlene Behrmann
Keyword(s):  
Visual Cortex ◽  
Motion Perception ◽  
Biological Motion ◽  
Form Perception ◽  
Motion Processing ◽  
Extrastriate Body Area ◽  
Biological Motion Perception ◽  
Neurobiological Substrates ◽  
Cortical Regions ◽  
Point Light

Identifying the movements of those around us is fundamental for many daily activities, such as recognizing actions, detecting predators, and interacting with others socially. A key question concerns the neurobiological substrates underlying biological motion perception. Although the ventral “form” visual cortex is standardly activated by biologically moving stimuli, whether these activations are functionally critical for biological motion perception or are epiphenomenal remains unknown. To address this question, we examined whether focal damage to regions of the ventral visual cortex, resulting in significant deficits in form perception, adversely affects biological motion perception. Six patients with damage to the ventral cortex were tested with sensitive point-light display paradigms. All patients were able to recognize unmasked point-light displays and their perceptual thresholds were not significantly different from those of three different control groups, one of which comprised brain-damaged patients with spared ventral cortex (n > 50). Importantly, these six patients performed significantly better than patients with damage to regions critical for biological motion perception. To assess the necessary contribution of different regions in the ventral pathway to biological motion perception, we complement the behavioral findings with a fine-grained comparison between the lesion location and extent, and the cortical regions standardly implicated in biological motion processing. This analysis revealed that the ventral aspects of the form pathway (e.g., fusiform regions, ventral extrastriate body area) are not critical for biological motion perception. We hypothesize that the role of these ventral regions is to provide enhanced multiview/posture representations of the moving person rather than to represent biological motion perception per se.

scholarly journals Attentional networks and biological motion

Psihologija ◽  
2010 ◽  
Vol 43 (1) ◽  
pp. 5-20 ◽  
Author(s):  
Chandramouli Chandrasekaran ◽  
Lucy Turner ◽  
Heinrich Bülthoff ◽  
Ian Thornton
Keyword(s):  
Biological Motion ◽  
Human Movement ◽  
Motion Processing ◽  
Light Stimuli ◽  
And Performance ◽  
Highly Correlated ◽  
Point Light ◽  
Perception Of Biological Motion ◽  
The Relationship ◽  
Speed And Accuracy

Our ability to see meaningful actions when presented with point-light traces of human movement is commonly referred to as the perception of biological motion. While traditional explanations have emphasized the spontaneous and automatic nature of this ability, more recent findings suggest that attention may play a larger role than is typically assumed. In two studies we show that the speed and accuracy of responding to point-light stimuli is highly correlated with the ability to control selective attention. In our first experiment we measured thresholds for determining the walking direction of a masked point-light figure, and performance on a range of attention-related tasks in the same set of observers. Mask-density thresholds for the direction discrimination task varied quite considerably from observer to observer and this variation was highly correlated with performance on both Stroop and flanker interference tasks. Other components of attention, such as orienting, alerting and visual search efficiency, showed no such relationship. In a second experiment, we examined the relationship between the ability to determine the orientation of unmasked point-light actions and Stroop interference, again finding a strong correlation. Our results are consistent with previous research suggesting that biological motion processing may requite attention, and specifically implicate networks of attention related to executive control and selection.

scholarly journals Perception of Biological Motion and Emotion in Mild Cognitive Impairment and Dementia

2012 ◽  
Vol 18 (5) ◽  
pp. 866-873 ◽  
Author(s):  
Julie D. Henry ◽  
Claire Thompson ◽  
Peter G. Rendell ◽  
Louise H. Phillips ◽  
Jessica Carbert ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Biological Motion ◽  
Visual Motion ◽  
Facial Affect ◽  
Motion Processing ◽  
Affect Recognition ◽  
Facial Affect Recognition ◽  
Visual Motion Processing ◽  
Point Light

AbstractParticipants diagnosed with mild cognitive impairment (MCI), dementia and controls completed measures that required decoding emotions from point-light displays of bodily motion, and static images of facial affect. Both of these measures tap social cognitive processes that are considered critical for social competency. Consistent with prior literature, both clinical groups were impaired on the static measure of facial affect recognition. The dementia (but not the MCI) group additionally showed difficulties interpreting biological motion cues. However, this did not reflect a specific deficit in decoding emotions, but instead a more generalized difficulty in processing visual motion (both to action and to emotion). These results align with earlier studies showing that visual motion processing is disrupted in dementia, but additionally show for the first time that this extends to the recognition of socially relevant biological motion. The absence of any MCI related impairment on the point-light biological emotion measure (coupled with deficits on the measure of facial affect recognition) also point to a potential disconnect between the processes implicated in the perception of emotion cues from static versus dynamic stimuli. For clinical (but not control) participants, performance on all recognition measures was inversely correlated with level of semantic memory impairment. (JINS, 2012, 18, 1–8)

Neuromagnetic Response to Body Motion and Brain Connectivity

2009 ◽  
Vol 21 (5) ◽  
pp. 837-846 ◽  
Author(s):  
Marina Pavlova ◽  
Christel Bidet-Ildei ◽  
Alexander N. Sokolov ◽  
Christoph Braun ◽  
Ingeborg Krägeloh-Mann
Keyword(s):  
Frontal Cortex ◽  
Visual Processing ◽  
Brain Connectivity ◽  
Temporal Cortex ◽  
Human Locomotion ◽  
Visual Sensitivity ◽  
Body Motion ◽  
Point Light ◽  
The Right ◽  
Rms Amplitude

Visual detection of body motion is of immense importance for daily-life activities and social nonverbal interaction. Although neurobiological mechanisms underlying visual processing of human locomotion are being explored extensively by brain imaging, the role of structural brain connectivity is not well understood. Here we investigate cortical evoked neuromagnetic response to point-light body motion in healthy adolescents and in patients with early periventricular lesions, periventricular leukomalacia (PVL), that disrupt brain connectivity. In a simultaneous masking paradigm, participants detected the presence of a point-light walker embedded in a few sets of spatially scrambled dots on the joints of a walker. The visual sensitivity to camouflaged human locomotion was lower in PVL patients. In accord with behavioral data, root-mean-square (RMS) amplitude of neuromagnetic trace in response to human locomotion was lower in PVL patients at latencies of 180–244 msec over the right temporal cortex. In this time window, the visual sensitivity to body motion in controls, but not in PVL patients, was inversely linked to the right temporal activation. At later latencies of 276–340 msec, we found reduction in RMS amplitude in PVL patients for body motion stimuli over the right frontal cortex. The findings indicate that disturbances in brain connectivity with the right temporal cortex, a key node of the social brain, and with the right frontal cortex lead to disintegration of the neural network engaged in visual processing of body motion. We suspect that reduced cortical response to body motion over the right temporal and frontal cortices might underlie deficits in visual social cognition.

scholarly journals Brain Areas Involved in Perception of Biological Motion

2000 ◽  
Vol 12 (5) ◽  
pp. 711-720 ◽  
Author(s):  
E. Grossman ◽  
M. Donnelly ◽  
R. Price ◽  
D. Pickens ◽  
V. Morgan ◽  
...  
Keyword(s):  
Biological Motion ◽  
Right Hemisphere ◽  
Small Region ◽  
Coherent Motion ◽  
Brain Areas ◽  
Region Matching ◽  
Kinetic Boundary ◽  
Point Light ◽  
The Right ◽  
Perception Of Biological Motion

These experiments use functional magnetic resonance imaging (fMRI) to reveal neural activity uniquely associated with perception of biological motion. We isolated brain areas activated during the viewing of point-light figures, then compared those areas to regions known to be involved in coherent-motion perception and kinetic-boundary perception. Coherent motion activated a region matching previous reports of human MT/MST complex located on the temporo-parieto-occipital junction. Kinetic boundaries activated a region posterior and adjacent to human MT previously identified as the kinetic-occipital (KO) region or the lateral-occipital (LO) complex. The pattern of activation during viewing of biological motion was located within a small region on the ventral bank of the occipital extent of the superior-temporal sulcus (STS). This region is located lateral and anterior to human MT/MST, and anterior to KO. Among our observers, we localized this region more frequently in the right hemisphere than in the left. This was true regardless of whether the point-light figures were presented in the right or left hemifield. A small region in the medial cerebellum was also active when observers viewed biological-motion sequences. Consistent with earlier neuroimaging and single-unit studies, this pattern of results points to the existence of neural mechanisms specialized for analysis of the kinematics defining biological motion.

scholarly journals Perception of biological motion by jumping spiders

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001172
Author(s):  
Massimo De Agrò ◽  
Daniela C. Rößler ◽  
Kris Kim ◽  
Paul S. Shamble
Keyword(s):  
Visual Processing ◽  
Biological Motion ◽  
Spatial Location ◽  
The Body ◽  
Jumping Spiders ◽  
Biological Motion Perception ◽  
History Of ◽  
Point Light ◽  
Perception Of Biological Motion ◽  
Point Light Display

The body of most creatures is composed of interconnected joints. During motion, the spatial location of these joints changes, but they must maintain their distances to one another, effectively moving semirigidly. This pattern, termed “biological motion” in the literature, can be used as a visual cue, enabling many animals (including humans) to distinguish animate from inanimate objects. Crucially, even artificially created scrambled stimuli, with no recognizable structure but that maintains semirigid movement patterns, are perceived as animated. However, to date, biological motion perception has only been reported in vertebrates. Due to their highly developed visual system and complex visual behaviors, we investigated the capability of jumping spiders to discriminate biological from nonbiological motion using point-light display stimuli. These kinds of stimuli maintain motion information while being devoid of structure. By constraining spiders on a spherical treadmill, we simultaneously presented 2 point-light displays with specific dynamic traits and registered their preference by observing which pattern they turned toward. Spiders clearly demonstrated the ability to discriminate between biological motion and random stimuli, but curiously turned preferentially toward the latter. However, they showed no preference between biological and scrambled displays, results that match responses produced by vertebrates. Crucially, spiders turned toward the stimuli when these were only visible by the lateral eyes, evidence that this task may be eye specific. This represents the first demonstration of biological motion recognition in an invertebrate, posing crucial questions about the evolutionary history of this ability and complex visual processing in nonvertebrate systems.

scholarly journals Perception of biological motion in point-light displays by jumping spiders

2021 ◽  
Author(s):  
Massimo De Agrò ◽  
Daniela C. Rößler ◽  
Kris Kim ◽  
Paul S. Shamble
Keyword(s):  
Visual Processing ◽  
Evolutionary History ◽  
Biological Motion ◽  
Jumping Spiders ◽  
Visual Behaviors ◽  
History Of ◽  
Point Light ◽  
Perception Of Biological Motion ◽  
Point Light Display ◽  
Dynamic Traits

AbstractOver the last 50 years, point-light displays have been successfully used to explore how animals respond to dynamic visual stimuli—specifically, differentiation of the biological from the non-biological. These stimuli are designed to preserve movement patterns while minimizing static detail, with single dots representing each of the main joints of a moving animal. Imposed by their internal skeleton, vertebrate movements follow a specific semi-rigid dynamic pattern, termed “biological-motion”, which can be used to distinguish animate from inanimate objects. Although biological motion detection has not been studied in invertebrates, rigid exoskeletons force many species to also follow semi-rigid movement principles. Due to their highly developed visual system and complex visual behaviors, we investigated the capability of jumping spiders to discriminate biological from non-biological motion using point-light display stimuli. By constraining spiders so that they could rotate but not move directionally, we simultaneously presented two point-light display stimuli with specific dynamic traits and registered their preference by observing which pattern they turned towards. Jumping spiders clearly demonstrated the ability to discriminate between stimuli. However, spiders showed no preference when both stimuli presented patterns with semi-rigid movements, results that are directly comparable to responses in vertebrate systems. This represents the first demonstration of biological motion recognition in an invertebrate, posing crucial questions about the evolutionary history of this ability and complex visual processing in non-vertebrate systems.

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