题目：Is Biological Motion Special? A Psychophysical and Computational Investigation

报告人：Hongjing Lu ( Departments of Psychology and Statistics, UCLA )

时间：2014年03月11日 星期二 13:00-14:30

地点： 生命科学学院 邓佑才报告厅（101室）

邀请人：方方

摘要：

Many animal species are sensitive to motion patterns generated by other living organisms, presumably due to the ecological importance of biological motion. Human observers show an exquisite ability to accurately identify attributes of an actor, such as identity, emotional state and gender, even when the stimulus lacks a detailed human body form (e.g., a point-light display). However, it remains unclear whether superior perception of biological motion is supported by distinct and specialized mechanisms. In this talk, I will present behavioral and computational evidence showing that both specialized and generic mechanisms are involved in analyzing biological motion. For motion analysis, humans are tuned to two basic characteristics specialized to biological motion: efficient detection of a signature movement, and sensitivity to the congruency between the direction of global body motion and the direction implied by intrinsic limb movements. However, for form analysis, we found no evidence for differences in the visual processing of biological motion versus non-biological object movements. A Bayesian model will be described, which shows that the dynamic form analysis underlying biological motion perception is based on a generic mechanism for integrating probabilistic position and orientation signals in a rational way.