Global-perspective jitter improves vection in central vision

Previous vection research has tended to minimise visual-vestibular conflict by using optic-flow patterns which simulate self-motions of constant veloc ity. Here, experiments are reported on the effect of adding 'global-perspec tive jitter' to these displays-simulating forward motion of the observer on a platform oscillating in horizontal and/or vertical dimensions. Unlike no n-jittering displays, jittering displays produced a situation of sustained visual-vestibular conflict. Contrary to the prevailing notion that visual-v estibular conflict impairs vection, jittering optic flow was found to produ ce shorter vection onsets and longer vection durations than non-jittering o ptic flow for all of jitter magnitudes and temporal frequencies examined. O n the basis of these findings, it would appear that purely radial patterns of optic flow are not the optimal inducing stimuli for vection. Rather, flo w patterns which contain both regular and random-oscillating components app ear to produce the most compelling subjective experiences of self-motion.