The use of an independent visual background to reduce simulator side-effects

Background: Simulator sickness (SS) is a major problem which potentially li mits interface applications that feature simulated motion. While display im perfections play a role, a large part of SS is motion sickness (MS). Sensor y rearrangement theory holds that MS is related to conflicting motion cues; in the case of simulators, mainly a conflict between inertial cues (usuall y indicating no self-motion) and visual stimuli from the display (indicatin g self-motion). It is suggested that MS does not arise from conflicting mot ion cues per se, but rather from conflicting rest frames selected from thos e motion cues. There is strong evidence that the visual rest frame is heavi ly influenced by the Visual background. Providing an independent visual bac kground (IVB) consistent with the inertial rest frame may reduce SS, even w hen the simulator's content-of-interest (CI) is not consistent with the ine rtial rest frame. Methods: In two experiments, a circular vection stimulus was shown for 3-4.5 min in a head-mounted display, comparing see-through (i .e., IVB) to occluded (i.e., no IVB) modes. Measures included a standard SS questionnaire and a pre-exposure ataxia measure. Experiment 2 added a Visu al task which forced attention into the CI and a post-exposure ataxia measu re. In both experiments, subjects rated the CI as significantly more visibl e than the IVB. Results: A large effect was found for the reduction of SS a nd ataxia in the first experiment, and for pre-exposure ataxia in the secon d. Conclusions: Future research will further test the IVB idea and examine applications to high-end simulators.