INITIATION OF DISJUNCTIVE SMOOTH-PURSUIT IN MONKEYS - EVIDENCE THAT HERING LAW OF EQUAL INNERVATION IS NOT OBEYED BY THE SMOOTH-PURSUIT SYSTEM

Monkeys generated disjunctive smooth pursuit eye movements when they t racked visual targets that moved toward or away from them. Eye acceler ation was computed during the initial 100 msec of pursuit (the open-lo op interval) for various target trajectories. The initial acceleration of either eye was a function of the target's motion with respect to t hat eye, regardless of whether or not the pursuit was conjugate or dis junctive, or performed with one eye occluded. Eye movements produced b y fusional vergence could be separated temporally from eye movements p roduced by smooth pursuit using step-ramp paradigms, The separation of the two responses demonstrates that the fusional vergence system oper ates in parallel with the smooth pursuit system, presumably to minimiz e disparity, but not to generate disjunctive components of smooth purs uit eye movements.