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Viewpoint and pose in body-form adaptation




Faces and bodies are complex structures, perception of which can play important roles in person identification and inference of emotional state. Face representations have been explored using behavioural adaptation: in particular, studies have shown that face aftereffects show relatively broad tuning for viewpoint, consistent with origin in a high-level structural descriptor far removed from the retinal image. Our goals were to determine first, if body aftereffects also showed a degree of viewpoint invariance, and second if they also showed pose invariance, given that changes in pose create even more dramatic changes in the 2-D retinal image. We used a 3-D model of the human body to generate headless body images, whose parameters could be varied to generate different body forms, viewpoints, and poses. In the first experiment, subjects adapted to varying viewpoints of either slim or heavy bodies in a neutral stance, followed by test stimuli that were all front-facing. In the second experiment, we used the same front-facing bodies in neutral stance as test stimuli, but compared adaptation from bodies in the same neutral stance to adaptation with the same bodies in different poses. We found that body aftereffects were obtained over substantial viewpoint changes, with no significant decline in aftereffect magnitude with increasing viewpoint difference between adapting and test images. Aftereffects also showed transfer across one change in pose but not across another. We conclude that body representations may have more viewpoint invariance than faces, and demonstrate at least some transfer across pose, consistent with a high-level structural description. Keywords: aftereffect, shape, face, representation

Author(s): Alla Sekunova and Michael Black and Laura Parkinson and Jason J S Barton
Journal: Perception
Volume: 42
Number (issue): 2
Pages: 176--186
Year: 2013

Department(s): Perceiving Systems
Research Project(s): Body Perception
Bibtex Type: Article (article)
Paper Type: Journal

URL: http://www.perceptionweb.com/abstract.cgi?id=p7265

Links: pdf from publisher


  title = {Viewpoint and pose in body-form adaptation},
  author = {Sekunova, Alla and Black, Michael and Parkinson, Laura and Barton, Jason J S},
  journal = {Perception},
  volume = {42},
  number = {2},
  pages = {176--186},
  year = {2013},
  url = {http://www.perceptionweb.com/abstract.cgi?id=p7265}