scholarly journals Local motion versus global shape in biological motion: A reflexive orientation task

2010 ◽  
Vol 10 (7) ◽  
pp. 786-786
Author(s):  
M. Hirai ◽  
D. R. Saunders ◽  
N. F. Troje
Keyword(s):  
Biological Motion ◽  
Local Motion ◽  
Global Shape ◽  
Orientation Task ◽  
Motion Versus

scholarly journals Allocation of attention to biological motion: Local motion dominates global shape

2011 ◽  
Vol 11 (3) ◽  
pp. 4-4 ◽  
Author(s):  
M. Hirai ◽  
D. R. Saunders ◽  
N. F. Troje
Keyword(s):  
Biological Motion ◽  
Local Motion ◽  
Global Shape

Body Configuration Modulates the Usage of Local Cues to Direction in Biological-Motion Perception

2011 ◽  
Vol 22 (12) ◽  
pp. 1543-1549 ◽  
Author(s):  
Masahiro Hirai ◽  
Dorita H. F. Chang ◽  
Daniel R. Saunders ◽  
Nikolaus F. Troje
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Visual Display ◽  
Local Motion ◽  
Direction Discrimination ◽  
Biological Motion Perception ◽  
Vertical Location ◽  
Local Inversion ◽  
Point Light ◽  
Local Cues

The presence of information in a visual display does not guarantee its use by the visual system. Studies of inversion effects in both face recognition and biological-motion perception have shown that the same information may be used by observers when it is presented in an upright display but not used when the display is inverted. In our study, we tested the inversion effect in scrambled biological-motion displays to investigate mechanisms that validate information contained in the local motion of a point-light walker. Using novel biological-motion stimuli that contained no configural cues to the direction in which a walker was facing, we found that manipulating the relative vertical location of the walker’s feet significantly affected observers’ performance on a direction-discrimination task. Our data demonstrate that, by themselves, local cues can almost unambiguously indicate the facing direction of the agent in biological-motion stimuli. Additionally, we document a noteworthy interaction between local and global information and offer a new explanation for the effect of local inversion in biological-motion perception.

Off on the Wrong Foot: Local Features in Biological Motion

Perception ◽  
10.1068/p6140 ◽  
2009 ◽  
Vol 38 (4) ◽  
pp. 522-532 ◽  
Author(s):  
Daniel R Saunders ◽  
Julia Suchan ◽  
Nikolaus F Troje
Keyword(s):  
Motion Perception ◽  
Discrimination Task ◽  
Biological Motion ◽  
Large Body ◽  
Detection Task ◽  
Observer Performance ◽  
Local Motion ◽  
Motion Patterns ◽  
Direction Discrimination ◽  
Biological Motion Perception

Biological-motion perception consists of a number of different phenomena. They include global mechanisms that support the retrieval of the coherent shape of a walker, but also mechanisms which derive information from the local motion of its parts about facing direction and animacy, independent of the particular shape of the display. A large body of the literature on biological-motion perception is based on a synthetic stimulus generated by an algorithm published by James Cutting in 1978 ( Perception7 393–405). Here we show that this particular stimulus lacks a visual invariant inherent to the local motion of the feet of a natural walker, which in more realistic motion patterns indicates the facing direction of a walker independent of its shape. Comparing Cutting's walker to a walker derived from motion-captured data of real human walkers, we find no difference between the two displays in a detection task designed such that observers had to rely on global shape. In a direction discrimination task, however, in which only local motion was accessible to the observer, performance on Cutting's walker was at chance, while direction could still be retrieved from the stimuli derived from the real walker.

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.

scholarly journals Local motion-contrast Interactions Influence Global Shape Perception

2013 ◽  
Vol 13 (9) ◽  
pp. 377-377
Author(s):  
G. Gurariy ◽  
G. Caplovitz
Keyword(s):  
Shape Perception ◽  
Local Motion ◽  
Global Shape ◽  
Motion Contrast

scholarly journals Biological motion versus coherent motion perception: The role of the cerebellum

2005 ◽  
Vol 5 (8) ◽  
pp. 934-934
Author(s):  
D. Jokisch ◽  
I. Daum ◽  
B. Koch ◽  
M. Schwarz ◽  
N. F. Troje
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Coherent Motion ◽  
Motion Versus

Cats Perceive Biological Motion

1993 ◽  
Vol 4 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Randolph Blake
Keyword(s):  
Biological Motion ◽  
Higher Order ◽  
Local Motion ◽  
Motion Vectors ◽  
Global Synchrony ◽  
Behavioral Techniques ◽  
Motion Sequence ◽  
Point Light

With behavioral techniques, cats were trained to discriminate a point-light animation sequence depicting biological motion (i.e., a cat walking) from an animation sequence consisting of equivalent local motion vectors lacking the global synchrony present in the biological-motion sequence (i.e., “foil” displays). Successful discrimination was evidenced for even the most difficult foil display and for different versions of the biological-motion sequence, indicating that cats are able to extract the higher order kinematic invariants embodied in these novel motion displays.

Dichotomy in Biological Motion Perception: Pigeons Use Feet Local Motion to Determine Direction

2017 ◽  
Author(s):  
Michelle Tong ◽  
Priyanka Mensinkai
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
The Body ◽  
The Other ◽  
Local Motion ◽  
Visual Processes ◽  
Biological Motion Perception ◽  
Ecological Implications ◽  
Direction Of Movement ◽  
Point Light

The study examines the visual processes underlying the detection of the motion of land animals, or biological motion. The ability to process the motion of other living beings has profound ecological implications in the wilderness and in our everyday life. Earlier models suggest that there are two distinct ways to process this information. One uses the shape of an entire figure and one uses the motion of one part of the body. In this experiment, we aim to study whether the local motion of the feet or the configuration of the body is used to determine the direction into which a figure is facing. We do this by training pigeons to discriminate facing direction of a stationary walking point‐light figure. Pigeons chose one of two walkers by pecking on a touch screen. Once the task was learned, catch trials of backwards walkers were introduced. This kind of display gives the pigeon opposing information about direction. While the shape of the walker tells them it is walking one way, the feet give the impression that it is moving in the other. Pigeons were successful in learning to discriminate directions and at the introduction of the catch trials, most birds used the local motion cue of the feet to determine direction. The results indicate that pigeons seem to being using the feet, rather than the shape of a figure, to process direction of movement. In conjunction with previous literature, this study suggests that there exists an innate “life detector” specialized for filtering the movement of the feet.

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