Cybersickness affects the affective appraisal of a virtual environment

It is well known that navigation through VEs may have a negative effect on the physical well-being of observers, by inducing cybersickness. In this study we investigated if cybersickness interacts with the appraisal of a simulated environment. Using the Half-Life 2 level editor we created a VE representing fictitious rural and urban areas. This environment was displayed by means of back projection onto a semi-transparent (frosted) screen, and was viewed from 1 m distance. For a 17 minute period, 32 subjects passively watched a walk through this VE, where the visual scene continuously performed a quasi-sinusoidally frontal roll oscillation. Immediately after the exposure, the remaining subjects filled out an appraisal questionnaire rating the environment on 4 dimensions: arousing-sleepy, pleasant-unpleasant, exciting-gloomy and distressing-relaxing.<br />Two subjects were unable to complete the experiment due to severe nausea. When we divide our subject population into two categories: “non-sick” when the physical well-being ratings were below 2 (19 subjects), and “sick” for ratings of 2 or higher<br />(11 subjects), we find a statistical significant effect of sickness on appraisal (p<0.003). a post hoc test contributes this to the arousing-sleepy dimension (p<0.05) and the pleasant-unpleasant dimension (p<0.06): sick subjects typically<br />rate more sleepiness and unpleasantness than non-sick subjects. We conclude that cybersickness may be a confounding factor in the affective appraisal of VEs.<br />Keywords: Cybersickness, camera oscillation, affective appraisal, environmental aesthetics, virtual environments, game level editors