Saccadic movements. A computerized study of their velocity and latency.

Abstract

The mean velocity of the eye during the execution of a voluntary saccade can reach levels close to 400 degrees/sec, for amplitudes of 40 degrees. However, during the execution of these saccades, there are moments in which the eye develops velocities superior to 500 degrees/sec. The latency of the saccades diminishes when the stimuli are periodic, though it increases in the measure that the amplitude of the movement to be carried out increases. During the execution of the saccade the eye goes through a phase of rapid acceleration which occupies approximately a third of the total time used in the saccade. The rest of the time is spent in decreasing the velocity of the ocular movement. We feel that the velocities of all fast eye movements are not equal. Rather, the fast phases of nystagmus have a lesser velocity than do the saccades; though this last point is an opinion subject to future statistical confirmation.