Achievement

Trainees Santos, Ross and Gnang studied how smooth pursuit eye movements are controlled by expectations and predictions. They found that pursuit could be reliably elicited by expectations about the future direction of discrete object motion, as well as global motion (random dots). Expectations derived from visual cues were as effective as expectations derived from internal motor cues that were generated when observers controlled the motion of a moving disc themselves. The patterns of the anticipatory eye movements depended on whether the self-generated motions had smooth or abrupt trajectories. Smooth trajectories tended to produce very close matching of eye and target (zero lags) while abrupt trajectories tended to produce anticipation of the eye. These results show that the oculomotor system and cognitive system operate in close register to minimize overall pursuit error and minimize retinal velocity so as to optimize visual performance.