Visual motion and the neural correlates of event perception.

People perceive ongoing activity in terms of discrete temporal events. Distinctive changes in the movement of objects or actors may contribute to the perception that one event has ended and another has begun. However, little is known about the quantitative contribution of movement information to the processing of events. This study investigated how movement features are related to the neural processing of events by performing functional magnetic resonance imaging while participants viewed simple animations of moving objects. After the imaging session, participants watched the animations again and segmented them into meaningful events. Movement features were systematically related to viewers' perceptual segmentation and to cortical activity throughout visual processing areas. Activity in the MT complex, which is known to be specialized for processing motion, increased with increases in the objects' speed. The perception of an event boundary was associated with transient changes in the MT complex and in a nearby region in the superior temporal sulcus associated with processing biological motion. Other movement features were associated with changes in activity in occipital, parietal, and frontal cortex. These results indicate a role for movement features in the perceptual processing of meaningful events, and in the neural basis of that processing.