S5-2: Shifting the Perspective on Biological Movement Perception

Abstract

Most efforts for understanding biological movement perception seem to agree in assuming a key role of some version of 2D projective geometry being the basis of either computation or invariant detection somewhere between the stimulus and perception. Recent studies invite considering alternatives. Beintemma and Lappe (2002 PNAS 99 5661–5663) constructed sequential walker displays in which points were assigned along limb segments at random position at each frame and still reported correct responses. In our study, point light displays were prepared from motion-capture data of humans performing everyday activities. Animations were rendered either from a fixed camera position or from a curvilinear trajectory around the target. Same mean response time in the two conditions suggests that information for making correct judgments remained accessible despite the superposition of camera movement induced changes on the projection. An alternative approach is offered, based on Gibson's (1986, Lawrence Erlbaum Associates...