ALTERATION OF EYE-MOVEMENTS AND MOTION PERCEPTION IN MICROGRAVITY

This review article summarizes the results of space research on eye mo vements and subjective perception during Vestibular stimulation. Infli ght and postflight changes in reflex eye movements gain are described for head angular rotation (yaw, pitch, and roll), linear acceleration, off-vertical axis rotation, and optokinetic stimulation. There is evi dence that changes in eye movements in microgravity primarily occur fo r head movements in pitch or roll which normally stimulate the otolith organs on Earth, but the data are not conclusive. The relationship be tween the eye movements gain and self-motion perception remains to be determined. We advocate the use of a human on- and off-axis rotator co mbined with the measurements of both tri-dimensional eye movement and perceptual response as a method to systematically investigate the adap tive changes in vestibular function to microgravity. (C) 1998 Elsevier Science B.V. All rights reserved.