A Proposed Model of the Vestibulo-Ocular Reflex Manifest by Counterroll.

Abstract : A model of the vestibulo-ocular reflex manifest by counterroll, including otolith organ dynamics, was derived for primates. Six rhesus monkeys were subjected to a profile of dynamic tests, consisting of constant speed rotation, pendular oscillations and gaussian random disturbances, about an axis through their line-of-sight. The resulting counterroll data was obtained by mechanically coupling the eyeball to a linear resolver, and analyzed by use of the fast Fourier transform. The results of this study indicate that the otolith organs are capable of producing low frequency lead, implying that they not only sense acceleration, but also the rate at which acceleration is being applied. The study also shows that there is no significant decrement in the amplitude of counterroll up to 1 Hz, which indicates that the otolith organs are also capable of responding to frequencies up to 1 Hz. (Author)