Abstract
Visual and vestibular information are both informative about self-motion and recent work shows that vestibular signals can influence visual motion perception. Here we ask whether vestibular input can influence the dynamics of binocular rivalry created by opposed visual motions. In 64 s trials, 10 observers in a CKAS 6 degrees-of-freedom motion platform system (Hexapod) underwent sinusoidal yaw rotations that oscillated between ±15 degrees with a full cycle period of 4 seconds while viewing motion rivalry. Observers viewed left- and rightward moving gratings which were dichoptically presented via an Oculus head-mounted display, and continuously tracked their dominant visual motion percept while their head and eye movements were recorded. The rivalry tracking time-series were epoched into 4 s periods to line up with one cycle of self-motion and averaged to show the mean dominance percept for every position of the yaw-rotation cycle. Fitting a sinewave to the epoched data of each participant showed that rivalry dominance tended to correlate with the direction of yaw rotation. The group mean sine period was 3.88 s, indicating that the motion rivalry dynamics were entrained by the self-motion oscillation. Fitted sine amplitudes varied between observers from 0.04 to 0.31, relative to a maximum amplitude of 0.5. The phase of the sine fitted to the rivalry alternations was stable and tightly linked to the phase of yaw rotation. For 7/10 observers it was in-phase (the dominant motion matched the direction of self-motion), and for 3/10 it was in anti-phase (the dominant motion was opposite to the direction of self-motion). Control data showed that the same yaw rotation had no influence on motion rivalry dynamics between upwards and downwards directions. We conclude that vestibular signals from self-motion input to the visual system and can help resolve perceptual ambiguity from motion rivalry.
Meeting abstract presented at VSS 2018