Use of an independent visual background to alleviate simulator sickness in the virtual environments that employ wide-field displays

Simulator sickness (or so-called Cybersickness) has been a significant problem since the development of virtual reality systems. Numerous studies have investigated this problem. However, there is currently no accepted solution. This dissertation addresses development of a possible approach to alleviate simulator sickness. Prior work has suggested the method of inserting an inertially-matched reference visual background grid into a visual scene as an intervention against simulator sickness, but little work has been done to evaluate or optimize such method. This dissertation describes a series of human factors studies to examine and optimize such an “independent visual background” (IVB). Four major components are included. The first part provides a background regarding simulator sickness. The second part examines the dynamics of sensory conflict theory which has been widely accepted as a model of simulator sickness. In this regard we identified and verified a motion frequency where the summed response from the visual and inertial self-motion systems was greatest. We also investigated the effects of field-of-view of the display. The third part explores the possible characteristics of the IVB including spatial, polarity, temporal and stereographic properties of the visual display. As a means of determining subjects' reactions to moving visual stimuli, postural stability, was measured. Postural stability has been proposed as an objective measurement for simulator sickness. The fourth part explores ways that the IVB may reduce subjects' simulator sickness symptoms during the virtual environment exposure. We also consider the relationship between sense of presence and simulator sickness. We conclude that the IVB could be a useful procedure to alleviate simulator sickness and recommend future experiments regarding how the IVB should be presented to enhance users' task performance and cognitive function.