"Torso rotation" experiments; 1: Adaptation to motion sickness does not correlate with changes in VOR gain.
Following a 30-minute exposure to an unusual motor strategy called "Torso Rotation" (TR), the signs and symptoms of motion sickness appear along with perceptual illusions during movement, gaze and postural instability, and a significantly reduced vestibulo-ocular response (VOR) gain. With repeated exposure to TR, the motion sickness disappears and gaze instability seems to be reduced. Is this apparent improvement in gaze stability associated with a reduction of the transient change in VOR gain? Motion sickness (subjective questionnaire) and VOR gain (passive step rotations in darkness) were measured before and repeatedly after TR on 7 consecutive days. Despite a complete loss of symptoms in 3 to 4 days, the transient, daily change in VOR gain remained unaffected. Furthermore, there was no increase in the use of compensatory saccades. It is concluded that adaptation to TR-induced motion sickness is not the result of a change in VOR's sensitivity to TR.
Aerospace Medical Research Unit, McGill University, Montreal, Canada. bouyer@medcor.mcgill.ca
L J
LJ
Bouyer
D G
DG
Watt
D000222:Adaptation, Physiological / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000503:physiopathology*; D009068:Movement; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D014796:Visual Perception / Q000502:physiology