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

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.

2020 ◽  
Vol 3 (1) ◽  
pp. 10402-1-10402-11
Author(s):  
Viswadeep Sarangi ◽  
Adar Pelah ◽  
William Edward Hahn ◽  
Elan Barenholtz

Abstract Humans are adept at perceiving biological motion for purposes such as the discrimination of gender. Observers classify the gender of a walker at significantly above chance levels from a point-light distribution of joint trajectories. However, performance drops to chance level or below for vertically inverted stimuli, a phenomenon known as the inversion effect. This lack of robustness may reflect either a generic learning mechanism that has been exposed to insufficient instances of inverted stimuli or the activation of specialized mechanisms that are pre-tuned to upright stimuli. To address this issue, the authors compare the psychophysical performance of humans with the computational performance of neuromimetic machine-learning models in the classification of gender from gait by using the same biological motion stimulus set. Experimental results demonstrate significant similarities, which include those in the predominance of kinematic motion cues over structural cues in classification accuracy. Second, learning is expressed in the presence of the inversion effect in the models as in humans, suggesting that humans may use generic learning systems in the perception of biological motion in this task. Finally, modifications are applied to the model based on human perception, which mitigates the inversion effect and improves performance accuracy. The study proposes a paradigm for the investigation of human gender perception from gait and makes use of perceptual characteristics to develop a robust artificial gait classifier for potential applications such as clinical movement analysis.


Perception ◽  
10.1068/p3262 ◽  
2002 ◽  
Vol 31 (4) ◽  
pp. 435-443 ◽  
Author(s):  
Marina Pavlova ◽  
Ingeborg Krägeloh-Mann ◽  
Niels Birbaumer ◽  
Alexander Sokolov

We examined how showing a film backwards (reverse transformation) affects the visual perception of biological motion. Adults and 6-year-old children saw first a point-light quadruped moving normally as if on a treadmill, and then saw the same display in reverse transformation. For other groups the order of presentation was the opposite. Irrespective of the presentation mode (normal or reverse) and of the facing of the point-light figure (rightward or leftward), a pronounced apparent-facing effect was observed: the perceptual identification of a display was mainly determined by the apparent direction of locomotion. The findings suggest that in interpreting impoverished point-light biological-motion stimuli the visual system may neglect distortions caused by showing a film backwards. This property appears to be robust across perceptual development. Possible explanations of the apparent-facing effect are discussed.


2012 ◽  
Vol 24 (4) ◽  
pp. 896-904 ◽  
Author(s):  
Bianca Michelle van Kemenade ◽  
Neil Muggleton ◽  
Vincent Walsh ◽  
Ayse Pinar Saygin

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.


Perception ◽  
10.1068/p5010 ◽  
2003 ◽  
Vol 32 (3) ◽  
pp. 377-383 ◽  
Author(s):  
Ian M Thornton ◽  
Quoc C Vuong ◽  
Heinrich H Bülthoff

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam T. Eggebrecht ◽  
Ally Dworetsky ◽  
Zoë Hawks ◽  
Rebecca Coalson ◽  
Babatunde Adeyemo ◽  
...  

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.


2015 ◽  
Vol 112 (4) ◽  
pp. E361-E370 ◽  
Author(s):  
Sharon Gilaie-Dotan ◽  
Ayse Pinar Saygin ◽  
Lauren J. Lorenzi ◽  
Geraint Rees ◽  
Marlene Behrmann

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.


2002 ◽  
Vol 13 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Heather Jordan ◽  
Jason E. Reiss ◽  
James E. Hoffman ◽  
Barbara Landau

Williams syndrome (WS) is a rare genetic disorder that results in profound spatial cognitive deficits. We examined whether individuals with WS have intact perception of biological motion, which requires global spatial integration of local motion signals into a unitary percept of a human form. Children with WS, normal mental-age-matched children, and normal adults viewed point-light-walker (PLW) displays portraying a human figure walking to the left or right. Children with WS were as good as or better than control children in their ability to judge the walker's direction, even when it was masked with dynamic noise that mimicked the local motion of the PLW lights. These results show that mechanisms underlying the perception of at least some kinds of biological motion are unimpaired in children with WS. They provide the first evidence of selective sparing of a specialized spatial system in individuals with a known genetic impairment.


2013 ◽  
Vol 44 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Kaivo Thomson ◽  
Anthony Watt

Abstract The purpose of the study was to compare the visuospatial decision-making error scores related to the perception of biological motion of individuals categorized as field dependent or field independent. A sample of 69 participants aged 18-27 years (M = 21.91, SD = 2.39) that included 33 males and 36 females completed the experiment. Cognitive style was assessed using the Group Embedded Figure Test. Perception of biological motion was evaluated using two different point-light stimuli developed from video images of a ballet dancer’s performance of a correct and incorrect turn in the fifth position. The results showed that individuals classified as field independent made significantly fewer visuospatial processing errors. The findings are considered and discussed in relation to theoretical perspectives associated with both cognitive processing and cognitive style.


Perception ◽  
1997 ◽  
Vol 26 (12) ◽  
pp. 1539-1548 ◽  
Author(s):  
Vicki Ahlström ◽  
Randolph Blake ◽  
Ulf Ahlström

Boundary conditions for perception of biological motion were explored with the use of computer-generated point-light animation sequences. Perception of this unique form of structure from motion is immune to variations in dot contrast polarity, dot disparity, and spatial-frequency filtering. Biological motion is perceived in texture-defined animation sequences that presumably stimulate only second-order motion pathways, and it is undisturbed by dichoptic presentation of portions of the animation tokens separately to the two eyes.


2012 ◽  
Vol 18 (5) ◽  
pp. 866-873 ◽  
Author(s):  
Julie D. Henry ◽  
Claire Thompson ◽  
Peter G. Rendell ◽  
Louise H. Phillips ◽  
Jessica Carbert ◽  
...  

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)


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