Effects of components of displacement-step stimuli upon latency for saccadic eye movement.

The standard displacement-step stimulus often used to produce lateral saccadic eye movements is considered in terms of the effects of its components: termination of stimulation at an initial fixation point, and onset of stimulation at a new, laterally displaced fixation point. If the termination and onset are simultaneous, saccade latency is about 200 msec. If there is a gap of 200 msec or more between these events, latency decreases to about 150 msec. If the termination follows the onset by 100 msec or more, latency increases to about 250 msec.