Motion sickness and cybersickness - Sensory mismatch.

The use of virtual reality (VR) with head-mounted displays (HMD) may cause side effects called cybersickness with symptoms comparable to those of motion sickness. In this study, we explored whether individual balance characteristics and self-reported tendency to motion sickness could be related to cybersickness vulnerability. Healthy young people (N = 45) were exposed to a VR application with HMD for four minutes, standing with no support. Balance characteristics were measured before (Sensory orientation test) and during (balance platform) the VR exposure. Symptoms of cybersickness were recorded by the Simulator sickness questionnaire (SSQ). Data were analyzed for subgroups with and without a tendency to motion sickness. The participants were negatively affected by the VR exposure: SSQ-before: 21.3 (19.5); SSQ-after: 31.8 (25.2); p<0.01, and 73% experienced increased discomfort. The SSQ sub-scores Nausea and Disorientation were affected, but not the sub-score for Oculomotor disturbance. Surprisingly, the participants described discomfort already after the initial balance assessment (Sensory orientation test). Participants with a self-reported tendency to motion sickness were relatively more affected by this challenge to their sensory integration. Increased postural instability was evident during the VR exposure, but there was a sizeable individual variance in the postural response. The study identified no individual balance characteristics which could be associated with the cybersickness vulnerability. The adverse effect of the Sensory orientation test is a novel finding and it became a bias that diminished subgroup differences in cybersickness vulnerability.