Visuo-vestibular contributions to vertical self-motion perception in healthy adults

The intensity of the visuo-vestibular interaction, i.e., visuo-vestibular conflict, would influence upward self-motion and downward self-motion latencies and cardiovascular activity. In order to test this hypothesis, thirty five healthy adults aged 22 years in average have been immersed to a central visual motion via a HMD. During upward and downward self-motion perception, the engagement of vestibular saccular organs seems to contribute differently to latencies and cardiovascular activation depending on the direction of gravitational acceleration. Downward self-motion latencies (same direction acceleration) are shorter than upward self-motion latencies (opposite direction acceleration). In the same vein, cardiovascular autonomic activation, reflecting by heart rate, is lower for downward self-motion than for upward self-motion. Our results provide evidence that visuo-vestibular interaction would contribute to influence both latencies and cardiovascular variation in vertical self-motion perception.