Dynamic Range of the Frequency Response of the Horizontal Vestibulo-Ocular Reflex of the Alert Rhesus Monkey

Abstract

The vestibulo-ocular reflex (VOR) of the alert rhesus monkey was studied using rotational acceleration in the horizontal plane. Both sinusoidal and pseudorandom binary sequence (PRESS) stimuli were used to perform an input-output analysis and generate gain and phase parameters. Results from sinusoidal studies over the frequency range 0.01 to 1.28 Hz, with stimulus amplitudes ranging from 16 to 256 degrees/second were consistent with a linear model of the VOR. Results from PRBS stimuli whose bandwidths extended from 0.008 to 0.45 Hz with amplitudes of 4 to 256 degrees/second/second corroborated the sinusoidal results. Sinusoidal data obtained at high rotational frequencies indicated that a peak VOR gain occurred at approximately 4 Hz. Close agreement between sinusoidal and PRBS data suggested that the rhesus VOR does not manifest the predictive behavior reported in studies of smooth pursuit eye movements.