Abstract:
Human and nonhuman primates are capable of recognizing the motion of biological entities in complex visual scenes, even when it is depicted with a handful of point-lights attached to the head and major joints. This inherent ability is quite stable through our life span and very important to both our daily activities and social interactions. The behavioral/psychophysical studies of biological motion recognition has a long history and provide many great insights on the nature of this ability. Using functional brain imaging techniques, researchers have localized a large number of brain areas, which can be activated with PLD (point-light displays) biological motion stimuli. Unfortunately, the neuronal processing of biological information remains unclear. Previous studies have shown that STS may be a key sulcus for biological motion recognition. Both MT and MST area are located in STS, but MST is a higher order brain area in visual motion processing. In order to uncover the neuronal mechanism of biological motion recognition, we record neuronal responses to PLD biological motion stimuli from macaque MT and MST. We found that both MT and MST neurons were activited by PLD stimuli, which is consistent with previous fMRI findings, but only MST neurons were caplable of encoding different features of biological motion. Furthermore, this capability is closely related to the selective response of MST neuron to optic flow pattern. Our results suggest MST is the brain area specifically involved in biological motion recognition, not MT.
Biography
Tao Zhang is a Professor from the State Key Laboratory of Brain and Cognitive Science at the Institute of Psychology at the Chinese Academy of Sciences.