Grant: Discovery Grants Program - Individual

) Research on visual motion perception to date may be subdivided into object motion (usually translation) and biological motion, generally studied with point-light displays. However, there remains an unexplored category of motion perception that plays an important role in human perception and learning: perception of closed motion trajectories. Controlling a machine on an assembly line, many movements in sports, and other skilled actions all involve recognizing and learning repetitive patterns of movement. Perception of complex motion trajectories may be regarded as related to biological motion of a type not previously studied. In this proposal I introduce a novel stimulus paradigm for studying discrimination, learning, and categorization of periodic motion trajectories. Proposed experiments will utilize psychophysics and brain imaging (fMRI) to explore this new area. ) Results of psychophysical experiments will provide basic data on discrimination and memory for motion trajectories as a function of speed, moving pattern size, and other variables. This will then permit us to frame several important questions for fMRI studies. First, do motion trajectories activate both human motion areas MT/MST and also areas activated by biological motion? Second, do these trajectories also activate areas such as V4 that are activated by static patterns with the same shape as the trajectory? If so, this could provide a major link between the dorsal and ventral visual pathways in the brain. Third, does learning of motion trajectories activate areas containing mirror neurons, which are believed to be important in learning via imitation? The proposed experiments will provide major insights into this unexplored area of motion perception and motion learning, and the results could well have major consequences for our understanding of learning by imitation. Furthermore, the results should provide new tools for future studies of visual deficits in a variety of conditions, including healthy human aging.