Article

Self-motion perception and vestibulo-ocular reflex (VOR) were studied during
whole body yaw rotation in the dark at different static head positions. Rotations
consisted of four cycles of symmetric sinusoidal and asymmetric oscillations.
Self-motion perception was evaluated by measuring the ability of subjects to
manually track a static remembered target. VOR was recorded separately and the
slow phase eye position (SPEP) was computed. Three different head static yaw
deviations (active and passive) relative to the trunk (0 degrees , 45 degrees to
right and 45 degrees to left) were examined. Active head deviations had a
significant effect during asymmetric oscillation: the movement perception was
enhanced when the head was kept turned toward the side of body rotation and
decreased in the opposite direction. Conversely, passive head deviations had no
effect on movement perception. Further, vibration (100 Hz) of the neck muscles
splenius capitis and sternocleidomastoideus remarkably influenced perceived
rotation during asymmetric oscillation. On the other hand, SPEP of VOR was
modulated by active head deviation, but was not influenced by neck muscle
vibration. Through its effects on motion perception and reflex gain, head
position improved gaze stability and enhanced self-motion perception in the
direction of the head deviation.
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Langue : ANGLAIS