Dynamic Form Templates Determine Sensitivity to Biological Motion

Abstract

Visual perception of biological motion shows a remarkable robustness against noise, fundamentally different from sensitivity to other moving stimuli. This is evidence for especialized mechanisms for biological motion perception that are more sensitive to biological motion than to other stimuli. Yet, the specifics of biological motion stimuli or the mechanisms which might explain the qualitative discrepancy between coherent motion and biological motion in terms of sensitivity remain elusive. In a combination of neurocomputational modeling and psychophys-ical experiments we investigated how form and motion signals influence sensitivity to biological motion in noise. With stimuli that vary in the amount of motion signals we tested the ability to detect and discriminate biological motion in human observers and in a dynamic neuro-cognitive model of biological motion perception. These results suggest that the sensitivity to human movements is caused by a specialization to the dynamic and complex pattern of the changing form of the body over time.