Speaker: A/P Hongjing Lu
Title: Is Biological Motion Special? A Psychophysical and Computational Investigation
Date: 26 March 2014, 12pm
Venue: AS4/02-08 (Psychology Department Meeting Room)
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. At the end, I will also present some recent findings on action adaptation in autism and discuss the implications.
About the Speaker:
Dr. Hongjing Lu received a PhD in Psychology at UCLA in 2005 and postdoctoral training in the Department of Statistic at UCLA in 2006. Prior to joining the faculty at UCLA in 2008, she was an Assistant Professor at the University Hong Kong in 2007. The basic goal of her research is to investigate how humans learn and reason, and how intelligent machines might emulate them. Dr. Lu has a broad background in psychology and statistics, with specific training and expertise in designing psychophysical experiments and developing computational models. Dr. Lu has been the recipient of an NSF CAREER award.