Applying a model of saccadic prediction to patients' saccadic eye movements.

A mathematical model of eye tracking of periodic square wave target motion has previously been proposed. In this work the model was further studied with regard to saccadic response time to symmetrical square wave target motion in 6 patients with unilateral parietal lesions following cerebrovascular accidents. Three types of saccadic response time were noted. In patients with type I, saccades contralateral to the damaged hemisphere had similar characteristics to those found in ipsilateral direction, but with longer response time. In those with type II, the saccadic response time was about the same on movement in either direction for repetitive target cycle durations of 1.2 or 2.0 s. In patients with type III, the target motion could not be predicted, in either direction.