Abstract
Determining the contributions of the body form and motion cues to the perception of biological motion is important for understanding how we recognize actions. In this study we examined the effects of contrast on the discrimination of different point-light human actions. Participants (N=11) determined which of four simultaneously presented actions (boxing, leaping, running, or walking) matched a central action. The central action was always intact point-light biological motion and at 100% contrast, while the four choice actions varied in contrast and were either intact point-light biological motion, scrambled biological motion, or static body form. Results showed a similar increase in accuracy with increasing contrast for the intact and scrambled biological motion stimuli. This increase occurred at lower contrast levels for intact and scrambled biological motion relative to the static form stimuli. Even at lower contrast levels, however, accuracy was higher for intact than for scrambled biological motion stimuli, and remained so until the highest contrast level. Accuracy was higher for intact and scrambled biological motion than static form at all contrast levels except the highest. These results support previous findings showing that the perception of biological motion is contrast-dependent. Our results provide new details about the contrast-dependence of form and motion contributions to the discrimination of human actions.
Meeting abstract presented at VSS 2012