NEURAL CIRCUITS INVOLVED IN VISUOMOTOR REACTION TIME IN MONKEYS

Abstract

Monkeys with chronic electrodes implanted in the visual cortex and later algeniculate nucleus (LGN) were trained to release akey following onset of aphotic stimulus. When coupled with differential reinforcement for brief-latency responses, this training procedure gave quite short, stable reaction times. The key release response readily transferred to LGN and cortical stimuli. Thereaction times to photic and central stimulation were inversley related to stimulus intensity. Reactiontimes to cortical stimuli were consistently shorter than those tophotic stimuli. In general LGN stimuli elicited a re-action time which was shorter than that to photic stimuli and longer than that to cortical stimuli. The decrease in reaction time to cortical stimulation is comparable to the latency of the early photically evoked cortical potential recorded from the unanesthetized monkey. The afferent neural circuits involved in such behavioral responses can probably be studied as a "aeries circuit,".