Abstract
Most studies of biological motion perception have used walkers seen in profile from the side. However, recent psychophysical and electrophysiological investigations have found that recognition ability is different for different views (frontal, half-profile or profile), and that body posture sensitive cells in the ventral visual system are tuned to the facing-in-depth of the body. We present a neural model of three-dimensional biological motion perception from two-dimensional views, based on earlier modeling work with profile views. The model consists of posture-sensitive cells that each represent a 2D view of particular body posture. Template matching between the stimulus and the posture cells induces a temporal variation of activity in the body posture representation tuned for a particular view. Temporal filters then create a representation of body motion. The model is tested in comparison to psychophysical and electrophysiological data. It reproduces the dependence of recognition ability on view orientation, and certain ambiguities both in perception and in the neuronal tuning functions for body views in primate STS. Because the model uses primarily body form information, along with its temporal evolution, it is helpful in explaining how much of the specificities of 3D biological motion perception rely on the geometrical properties of the stimulus.
Meeting abstract presented at VSS 2012