Modes of vestibular habituation.

An experiment was designed to investigate the effect of different modes of vestibular habituation. Volunteers were divided into two groups differing only in visual fixation. A theoretical explanation of the observed differences in nystagmus speed and frequency of beats between groups is offered. Secondary experiments designed to support the conclusions were performed using optokinetic stimulation with a stationary line for visual fixation. An increase in conjugate tone potential opposed to the unwanted optokinetic stimulus developed. Post-habituation nystagmus patterns appear to depend in considerable part on learned responses originating in the gray matter of the brain.