Brain areas involved in perception of biological motion

These experiments use functional magnetic resonance imaging (fMRI) to revea l neural activity uniquely associated with perception of biological motion. We isolated brain areas activated during the viewing of point-light figure s, then compared those areas to regions known to be involved in coherent-mo tion perception and kinetic-boundary perception. Coherent motion activated a region matching previous reports of human MT/MST complex located on the t emporo-parietooccipital junction. Kinetic boundaries activated a region pos terior and adjacent to human MT previously identified as the kinetic-occipi tal (KO) region or the lateral-occipital (LO) complex. The pattern of activ ation during viewing of biological motion was located within a small region on the ventral bank of the occipital extent. of the superior-temporal sulc us (STS). This region is located lateral and anterior to human MT/MST, and anterior to KO. Among our observers, we localized this region more frequent ly in the right hemisphere than in the left. This was true regardless of wh ether the point-light figures were presented in the right or left hemifield . A small region in the medial cerebellum was also active when observers vi ewed biological-motion sequences. Consistent with earlier neuroimaging and single-unit studies, this pattern of results points to the existence of neu ral mechanisms specialized for analysis of the kinematics defining biologic al motion.