A modeling approach to the assessment of smooth pursuit eye movement.

We have proposed a quasilinear model of the oculomotor system in the performance of a smooth pursuit tracking task. Model parameters (gain, phase, and spectral purity) have been measured for 21 normal subjects at stimulus frequencies of 0.2, 0.4, 0.8, 1.2, and 1.6 Hz. The normal oculomotor system was found to be quite linear when tracking at the three lowest frequencies, with up to 95% of the output power being linearly correlated with the input stimulus. Data from patients with known pathology are presented to demonstrate model parameter sensitivity to oculomotor dysfunction.