Reduction of cybersickness during and immediately following noisy galvanic vestibular stimulation

Abstract

The mechanism underlying cybersickness during virtual reality (VR) exposure is still poorly understood, although research has highlighted a causal role for visual-vestibular sensory conflict. Recently established methods for reducing cybersickness include galvanic vestibular stimulation (GVS) to mimic absent vestibular cues in VR, or vibration of the vestibular organs to add noise to the sensory modality. Here, we examined if applying noise to the vestibular system using noisy-current GVS also affects sickness severity in VR. Participants were exposed to one of two VR games that were classified as either moderate or intense with respect to their nauseogenic effects. The VR content lasted for 50 minutes and was broken down into 3 blocks: 30 minutes of gameplay during exposure to either noisy GVS ({+/-}1750 A) or sham stimulation (0 A), and 10 minutes of gameplay before and after this block. We characterized the effects of noisy GVS in terms of post-minus-pre-exposure cybersickness scores. For the intense VR content, we found a main effect of noisy vestibular stimulation. Participants reported lower cybersickness scores during and directly after exposure to GVS. However, this difference was quickly extinguished ([~]3-6 min) after further exposure to VR, indicating that sensory adaptation did not persist after stimulation was terminated. In contrast, there were no differences between the sham and GVS group for the moderate VR content. The results show the potential for reducing cybersickness with simple non-invasive sensory stimulation. We discuss the prospect that noise-induced sensory re-weighting is responsible for the observed effects, and address other possible mechanisms.