The functional operation of the vestibulo-ocular reflex

The biophysical properties of the labyrinthine semicircular canals, and the electrophysiological properties of peripheral vestibular afferent neurons over a range of stimulus frequencies, are reviewed. Resting discharge activity and adaptive properties of vestibular neurons are discussed. Central processing of vestibular signals is then examined, including push-pull organization and the velocity storage mechanism. A detailed treatment of the final common neural integrator for oculomotor signals follows with consideration of its neural substrate and how distributed networks of neurons can overcome several problems posed by conventional control-systems models, such as why neural signals, but not background discharge, are integrated. Next, the behavior of the vestibulo-ocular reflex in darkness is compared with how it satisfies visual demands during natural activities. Finally, the reflex's performance at high frequencies of head rotation is discussed.