Abstract
Recent perceptual experiences can alter visual perception in two distinct ways: priming and adaptation-induced aftereffects. While priming typically leads to facilitation effects, associated with faster and/or more accurate responses to the same stimulus, adaptation results in repulsive aftereffects, revealed by slower and/or less accurate responses to the same stimulus. In the present study, we examined priming and adaptation effects in biological motion perception, and their interactions with part/whole body structure. On each trial, participants first viewed a walking action (S1) presented as either the whole-body motion, or as subparts of body movements (bipedal leg movements, bilateral arm-leg movements with the same motion direction, and unilateral arm-leg movements with the opponent motions). The S1 stimuli were presented in the forms of point-light or skeleton walkers for either a short duration (100 ms) or a long duration (500 ms). After the presentation of S1, a point-light whole-body walker was shown briefly as the second stimulus (S2) for 200 ms. Participants were asked to judge the facing direction of the walker in S2. Results showed that with a short duration of S1 (100 ms), both whole-body and subpart movements in S1 elicited robust priming effects but with different facilitation magnitudes. For subpart movements, bipedal feet movements and bilateral arm-leg movements showed stronger priming effects than did unilateral arm-leg movements, suggesting that some subparts of body movements may be encoded in the hierarchical representation of actions. When the S1 stimulus was presented for a long duration (500 ms), the whole-body skeleton display yielded an adaptation effect, and no other conditions yielded aftereffect, suggesting that biological motion adaptation depends on the global whole-body representation of actions. These findings also indicate that a transition from priming to adaptation depends on the temporal duration of the first stimulus.
Meeting abstract presented at VSS 2017