The effects of strobe rate of head-fixed visual targets on suppression of vestibular nystagmus.

The effects of degrading retinal image velocity information on suppression of the vestibulo-ocular reflex have been assessed through tachistoscopic presentation of target sources in man. Subjects were required to fixate a head-fixed display during exposure to a 0.5 Hz sinusoidal angular oscillation of the head at +/- 60 degrees/s. In the first experiment it was found that the degree of suppression was progressively degraded as the interval between successive target presentations was increased from 10 to 3,000 ms. In the second experiment no effect of changing the duration of the target pulse was observed over a range from 20 to 1,000 microseconds. The results appear consistent with a model of visual motion sensitivity in which relative velocity information is obtained by the temporal integration of responses from spatially separated retinal cells.