Motion sickness and proprioceptive aftereffects following virtual environment exposure

To study the potential aftereffects of virtual environments (VE), tests of visually guided behavior and felt limb position (pointing with eyes open an d closed) along with self-reports of motion sickness-like discomfort were a dministered before and after 30 min exposure of 34 subjects. When post- dis comfort was compared to a pre-baseline, the participants reported more sick ness afterward (p < 0.03). The change in felt limb position resulted in sub jects pointing higher (p < 0.038) and slightly to the left, although the la tter difference was not statistically significant (p = 0.08). When findings from a second study using a different VE system were compared, they essent ially replicated the results of the first study with higher sickness afterw ard (p < 0.001) and post- pointing errors were also up (p < 0.001) and to t he left (p < 0.001). While alternative explanations (e.g. learning, fatigue , boredom, habituation, etc.) of these outcomes cannot be ruled out, the co nsistency of the post- effects on felt limb position changes in the two VE implies that these recalibrations may linger once interaction with the VE h as concluded, rendering users potentially physiologically maladapted for th e real world when they return. This suggests there may be safety concerns f ollowing VE exposures until pre-exposure functioning has been regained. The results of this study emphasize the need for developing and using objectiv e measures of post-VE exposure aftereffects in order to systematically dete rmine under what conditions these effects may occur. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.