Some complex aspects of visual stimuli are processed in the primate brain in areas besides the primary visual cortex, in areas known as association cortex. This 'higher-order' processing includes responses by neurons (nerve cells) to stimuli producing the perception of objects in motion. Perception of 'optic flow' occurs when a sensation of forward motion is elicited by a group of objects or even dots radially expanding from a central point, and 'structure from motion' occurs when a shape is perceived from just a pattern of dots moves coherently among other dots. We know that there is some specialization of information flow into 'object' processing and 'motion' processing in the visual cortex, but it is not clear how those information streams are integrated to perceive moving objects. This project begins to explore this integration in areas of the temporal cortex, where responses have been found to motion, to objects, and to motion of objects. Behavioral tests and electrophysiological responses to visual stimuli are used to find out whether neurons in parts of the superior and inferior temporal cortex do encode sensory and cognitive signals. This exploratory work has potentially high impact on clarifying the hierarchical structure of visual processing, as well as providing a basis for further advanced computational studies in motion processing. It also will provide student training that combines neurobiology, psychology and computational neuroscience.
