Dependence of Saccadic Prediction on Asymmetrical Periodic Stimulus

Abstract

In man, the saccadic response to a visual random unpredictable target is known to have a delay of about 250 msec. When the target motion is a periodic square move in the horizontal plane, this delay gradually decreases as the tracking proceeds, until the eye actually overtakes the target. Thereafter, the eyes continue to move accurately with the target with little or no time lag (Stark et al., 1962; Dallos, Jones, 1963; Fuchs, 1967). This prediction is not an “either-or” property of the prediction system (Michael, Melvill Jones, 1966; Stark, 1968). When a subject is presented with a periodic square wave target, after about 10 cycles a rapid buildup of prediction occurs, changing the periodicity and changing the (mean) prediction depending on the cycle duration.