Effects of virtual body motion on visually-induced motion sickness.

To reduce possibilities of visually-induced motion sickness caused by animations, video games and movies, we need to develop an evaluation method of visually-induced motion sickness. Our previous results have shown that virtual roll motion had the most effective for producing the sickness. In the present study, we focused on the effectivity of image types, such as random dots and ordinary scene, and also the effectivity of virtual rotation speed on the sickness. In the first experiment, we confirmed our former results that virtual roll motion produced the highest score relating motion sickness, regardless of image types. In the second experiment, virtual rotation speed of 30 to 60 deg/s gave the highest scores regardless of the rotation types, yawing, pitching and rolling. We concluded that moving images simulating nonreciprocating rolling has robust effects on the sickness. Moreover, we speculated that the effect of rotation speed is determined by inconsistency of visual and nonvisual information, but not by retinal image speed.