ABSTRACT
“Reflexive” eye movement responses are one commonly studied vestibular response to motion stimuli, but perceptual correlates of the stimuli are elicited by motion. Complex motion stimuli provide a unique and powerful method to stretch the limited range of sensory stimulation we normally experience and to decouple those sensory inputs which normally correlate with one another during normal movements. The input during inertial stimulation consists of angular acceleration, detected mainly by the semicircular canals, and linear acceleration, measured by all physiological linear accelerometers, including the otolith organs. One compelling example remains the comparison between the responses to lateral tilt stimulation and eccentric rotation about an earth-vertical axis. The experimental results have shown that the perceived subjective vertical changes rapidly during tilt, but tilts slowly towards alignment with gravito-inertial force during centrifugation. During onset of centrifugation, the change of direction of the gravito-inertial acceleration is only slowly reproduced by the internal estimates, as reflected by the subjective vertical.
