The influence of gravitoinertial force level on oculomotor and perceptual responses to Coriolis, cross-coupling stimulation

The goal of the present experiment was to determine whether gravitoinertial force magnitude influences oculomotor and perceptual responses to Coriolis cross-coupling stimulation. Blindfolded subjects who were rotating at constant velocity were asked to make standardized head movements during the free-fall and high-force phases of parabolic flight, and the characteristics of their horizontal nystagmus and the magnitude of their experienced self-motion were measured. Both responses were less intense in the free-fall periods than in the high-force periods. These findings suggest that the response to semicircular canal stimulation depends on the background level of gravitoinertial force.