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.

The expressivity dimension of speech is the basis of the expression dimension. Evidence from behavioural and neuroimaging studies

2020 ◽  
Author(s):  
Isabelle Hesling
Keyword(s):  
Language Acquisition ◽  
Experimental Psychology ◽  
Right Hemisphere ◽  
Word List ◽  
Behavioral Experiments ◽  
Brain Areas ◽  
Language Communication ◽  
Neuroimaging Data ◽  
List Processing ◽  
The Right

The modalities of communication are the sum of the expression dimension (linguistics) and the expressivity dimension (prosody), both being equally important in language communication. The expressivity dimension which comes first in the act of speech, is the basis on which phonemes, syllables, words, grammar and morphosyntax, i.e., the expression dimension of speech is superimposed. We will review evidence (1) revealing the importance of prosody in language acquisition and (2) showing that prosody triggers the involvement of specific brain areas dedicated to sentences and word-list processing. To support the first point, we will not only rely on experimental psychology studies conducted in newborns and young children but also on neuroimaging studies that have helped to validate these behavioral experiments. Then, neuroimaging data on adults will allow for concluding that the expressivity dimension of speech modulates both the right hemisphere prosodic areas and the left hemisphere network in charge of the expression dimension

scholarly journals Neural and Neuromimetic Perception: A Comparative Study of Gender Classification from Human Gait

2020 ◽  
Vol 3 (1) ◽  
pp. 10402-1-10402-11
Author(s):  
Viswadeep Sarangi ◽  
Adar Pelah ◽  
William Edward Hahn ◽  
Elan Barenholtz
Keyword(s):  
Biological Motion ◽  
Human Perception ◽  
Movement Analysis ◽  
Inversion Effect ◽  
Human Gait ◽  
Computational Performance ◽  
Potential Applications ◽  
Perceptual Characteristics ◽  
Point Light ◽  
Perception Of Biological Motion

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.

Biological Motion Shown Backwards: The Apparent-Facing Effect

Perception ◽  
10.1068/p3262 ◽  
2002 ◽  
Vol 31 (4) ◽  
pp. 435-443 ◽  
Author(s):  
Marina Pavlova ◽  
Ingeborg Krägeloh-Mann ◽  
Niels Birbaumer ◽  
Alexander Sokolov
Keyword(s):  
Visual Perception ◽  
Biological Motion ◽  
Presentation Mode ◽  
Reverse Transformation ◽  
Perceptual Identification ◽  
Perceptual Development ◽  
Apparent Direction ◽  
Point Light ◽  
Perception Of Biological Motion ◽  
Order Of Presentation

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.

Biological Motion Perception: From Inversion to Upright Display Orientation

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 118-118
Author(s):  
M A Pavlova
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Presentation Rate ◽  
Event Perception ◽  
Veridical Perception ◽  
Invariant Structure ◽  
Upright Orientation ◽  
Biological Motion Perception ◽  
The Right ◽  
Perception Of Biological Motion

How does biological motion perception change with display orientation? As previously shown, display inversion (180°) completely prevents veridical perception of biological motion. However, with upright orientation (0°), observers are able to recover the invariant structure through biological motion despite reverse transformation (showing the film backwards) or changing the presentation rate (Pavlova, 1995 Perception24 Supplement, 112). In the present experiments, observers saw the biological motion pattern at various display deviations, from inverted to upright orientation (180°, 150°, 120°, 90°, 60°, 30°, 0°), in the right or left hemifield, on a circular screen monitor. The display consisted of an array of 11 dots on the main joints of an invisible walker moving as if on a treadmill. While viewing (60 s), observers pressed a key each time their perception changed from one stable percept to another (eg when the direction of apparent rotation of the pattern reversed). The perceived multistability (the number of key-presses) increased as orientation was varied from inverted to 90°, and then decreased between 90° and upright. The recognition of walking figure improved abruptly with changing orientation: at deviations of 60° and 30° most observer reported seeing the walking figure spontaneously, yet the pattern was seen as multistable. The findings imply the relative power of constraints (such as orientation) in perception of biological motion that is discussed in relation to the KSD principle in event perception [Runeson, 1994, in Perceiving Events and Objects Eds Jansson, Epstein, Bergström (Hillsdale, NJ: Erlbaum) pp 383 – 405].

Biological Motion Alters Coherent Motion Perception

Perception ◽  
10.1068/p5933 ◽  
2008 ◽  
Vol 37 (12) ◽  
pp. 1783-1789 ◽  
Author(s):  
Kiyoshi Fujimoto ◽  
Akihiro Yagi
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Coherent Motion ◽  
Choice Procedure ◽  
Motion Coherence ◽  
Forced Choice Procedure ◽  
The Mean ◽  
Point Light ◽  
Direction Opposite ◽  
Method Of Constant Stimuli

When a movie presents a person walking, the background appears to move in the direction opposite to the person's gait. This study verified this backscroll illusion by presenting a point-light walker against a background of a random-dot cinematogram (RDC). The RDC consisted of some signal dots moving coherently either leftward or rightward among other noise dots moving randomly. The method of constant stimuli was used to vary the RDC in motion coherence from trial to trial by manipulating the direction and percentage of the signal dots. Six observers judged the perceived direction of coherent motion in a two-alternative forced-choice procedure. Response rates for coherent motion perception in the direction opposite to walking were evaluated as a function of motion coherence. The results showed that the psychometric function shifted toward the direction determined by a bias in the opposite direction to the walker. The mean threshold was about half as high as that in a control condition in which the positions of the point-lights were scrambled to impair the recognition of the walker. The results demonstrate that biological motion noticeably affects the appearance of motion coherence in the background.

Are Mechanisms for Perception of Biological Motion Different from Mechanisms for Perception of Nonbiological Motion?

2002 ◽  
Vol 95 (3_suppl) ◽  
pp. 1301-1310 ◽  
Author(s):  
Leo Poom ◽  
Henrik Olsson
Keyword(s):  
Biological Motion ◽  
Three Dimensional ◽  
Constant Time ◽  
Coherent Motion ◽  
Two Dimensional ◽  
Dimensional Shape ◽  
Perception Of Biological Motion ◽  
Three Dimensional Shape ◽  
Over Time ◽  
Unidirectional Motion

We compared the integration of information over space and time for perceiving different configurations of moving dots: a walking person (biological motion), rigid three-dimensional shapes, and unidirectional coherent motion of all dots (translation). No performance differences in judging walking direction and coherent translation direction were obtained in conditions with constant presentation times and varying number of target dots (integration over space). Depending on the speed of the two-dimensional configurations judgments were either worse or better than the judgments of walking direction. The results for conditions with different presentation times (integration over time) show that information about biological motion is integrated over time that increases with increasing gait period, while two-dimensional unidirectional motion is integrated over constant time independent of speed. The effect is not due to the oscillatory nature of the biological motion since information about a rigid three-dimensional shape is summed over a constant time independent of the period of the motion cycle. This could be interpreted as different neural mechanisms mediating the temporal summation for walking direction compared to detecting the orientation of rigid structure, or the direction of two-dimensional unidirectional motion. Since biological motion is characterized by nonrigidity, it is possible that the form itself is integrated over time and not the motion pattern.

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.

Intact Perception of Biological Motion in the Face of Profound Spatial Deficits: Williams Syndrome

2002 ◽  
Vol 13 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Heather Jordan ◽  
Jason E. Reiss ◽  
James E. Hoffman ◽  
Barbara Landau
Keyword(s):  
Williams Syndrome ◽  
Biological Motion ◽  
Genetic Disorder ◽  
Spatial Integration ◽  
Local Motion ◽  
Human Form ◽  
The Face ◽  
Spatial System ◽  
Point Light ◽  
Perception Of Biological Motion

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.

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