Introduction

The previous two chapters were intended to study the measurement and manipulation of selected rest frames. This chapter is concerned with the consequences when a consistent selected rest frame can not be formed. It examines a situation common with simulators, in which the visual cues imply self-motion, but the inertial cues do not.

The following questions are addressed in this chapter.

1.

Can an independent visual background (IVB) in agreement with inertial cues reduce reported simulator sickness and related side-effects?

2.

If so, can it do so without reducing the subjective impact of the scene?

3.

Can an IVB be effective even when attention is directed to the visual foreground, in which visual self-motion cues disagree with the inertial cues?

Experiment AIIIE1 explored questions 1 and 2, above. Experiment AIIIE2 was a follow-up study which added a visual task which forced attention into the visual foreground. This allowed the 3rd question to be addressed as well.

Both Experiment AIIIE1 and Experiment AIIIE2 involved a ``low-end'' virtual environment with limited FOV. A brief pilot study involving a ``high-end'' driving simulator, intended as a motion sickness experiment, is described in Appendix D because of its possible implications for an improved presence measure. See Chapter 7 for a discussion.

Human Interface Technology Lab