Current virtual interfaces imperfectly simulate the motion dynamics of the real world. Conflicting visual and vestibular cues spawned by these imperfections have been hypothesized to drive physiological adaptations and interface sickness, which raises significant health and safety issues surrounding exposure to virtual environments. This research investigates both physiological adaptation and interface sickness resulting from various simulator-induced motion cue rearrangements (termed artifacts).

We are investigating the nature of physiological adaptation to virtual interfaces through a detailed study of the vestibulo-ocular reflex (VOR). The VOR is a compensatory eye movement response that functions to keep the visual scene stabilized on the retina during head movements. The VOR was chosen for study because it is known to adapt in response to visual-vestibular sensory rearrangements and because symptomology during VOR adaptation is often quite similar to that of simulator sickness.

The main hypothesis under investigation holds that certain artifacts of virtual interfaces drive VOR adaptation processes. VR artifacts under investigation include system time delays (between head movement initiation and visual scene response) and scale-factor changes. Artifacts identified as provoking VOR adaptation will be manipulated to determine threshold values. Time courses of oculomotor readaptation to the real world following exposure will also be identified.

In addition, ratings of interface sickness will be collected during systematic manipulations of the above identified artifacts of virtual interfaces. The goal is to obtain threshold levels for each artifact (e.g. time delays, scale changes) and to compare these thresholds with those obtained for VOR adaptation processes.

Information obtained from these studies will feed design guideline for the reduction of undesired interface-generated effects.