Visually induced motion sickness when viewing visual oscillations of different frequencies along the fore-and-aft axis: keeping velocity versus amplitude constant.

Exposure to visual oscillations (VOs) can lead to visually induced motion sickness (VIMS). The level of VIMS among viewers has been shown to vary when the frequency of the VOs is changed either by manipulating their amplitude or velocity. The present study investigates whether the level of VIMS would change if we keep the root mean square (rms) velocity or amplitude of VOs constant while manipulating the VO frequency. A total of 25 individuals were exposed to random-dot and checkerboard VOs along the fore-and-aft axis in two experiments. Changing the amplitude (or frequency) of VOs while keeping the rms velocity constant did not affect the level of VIMS; however, increasing the rms velocity (or frequency) of VOs while keeping the amplitude constant made VIMS significantly worse. Practitioner Summary: Exposure to VOs of the same frequency can cause different levels of nausea depending on the combination of oscillation amplitude and velocity. Results suggest an opportunity for game designers to reduce symptoms of game sickness by using the correct combinations of velocity and amplitude of the visual motions.