Anticipatory eye movements stabilize gaze during self-generated head movements

Visual acuity and motion perception are degraded during head movements unless the eyes counter-rotate so as to stabilize the line of sight and the retinal image. The vestibulo-ocular reflex (VOR) is assumed to produce this ocular counter-rotation. Consistent with this assumption, oscillopsia is a common complaint of patients with bilateral vestibular weakness. Shanidze et al. recently described compensatory eye movements in normal guinea pigs that appear to anticipate self-generated head movements. These responses effectively stabilize gaze and occur independently of the vestibular system. These new findings suggest that the VOR stabilizes gaze during passive perturbations of the head in space, but anticipatory responses may supplement or even supplant the VOR during actively generated head movements. This report reviews these findings, potential neurophysiological mechanisms, and their potential application to human clinical treatment of patients with vestibular disease.