Frontal cortical control of smooth-pursuit.

To maintain optimal clarity of objects moving slowly in three dimensional space, frontal eyed-primates use both smooth-pursuit and vergence (depth) eye movements to track precisely those objects and maintain their images on the foveae of left and right eyes. The caudal parts of the frontal eye fields contain neurons that discharge during smooth-pursuit. Recent results have provided a new understanding of the roles of the frontal eye field pursuit area and suggest that it may control the gain of pursuit eye movements, code predictive visual signals that drive pursuit, and code commands for smooth eye movements in a three dimensional coordinate frame.