See Section 3.7 for a description of the equipment.
In all research described in this chapter, participants were seated upright in a chair which oscillated sinusoidally in yaw (i.e., in the horizontal plane). A fan was mounted on the back of the chair to mask any vibratory or auditory noise it might produce. Participants wore a Virtual Research VR4 HMD which displayed a (non-stereographic) scene which also oscillated sinusoidally in yaw. The HMD blocked off all visual cues from the laboratory. The image motion was controlled by Warp Ltd.'s ``Virtual TV'' software, as described in Section 3.7. Both inertial (chair) and visual (HMD) oscillations were always at .1 Hz. However, the phase angle between the inertial and visual motion was varied.
The primary image used was taken from Maui, and consisted of tropical vegetation overlooking water. In separate experiments, this image was manipulated either by varying the FOV or by randomizing the location of each pixel in the image.
Reported simulator sickness data was gathered before and after every session, using the pre- and post-exposure SSQ. These data were used only as an informal diagnostic to examine whether the experiment was causing malaise and needed to be re-designed. Sickness did not appear to a problem, as long as exposures in each trial were kept to one or two minutes and separated by a brief break while conditions were altered. During the break, participants were requested to close their eyes and relax, and the chair was brought smoothly to rest.