An EEG-based Experiment on VR Sickness and Postural Instability While Walking in Virtual Environments

TL;DR

This study investigates the neural and postural factors associated with VR sickness during walking in virtual environments, revealing EEG markers and stability differences that could improve VR sickness detection.

Contribution

It introduces EEG-based analysis of VR sickness during walking, linking brain activity to postural control and workload, advancing understanding of VR sickness mechanisms.

Findings

VR sickness correlates with reduced alpha power in EEG.

Participants with VR sickness show higher cognitive workload.

Postural stability differs between groups with and without VR sickness.

Abstract

Previous studies showed that natural walking reduces the susceptibility to VR sickness. However, many users still experience VR sickness when wearing VR headsets that allow free walking in room-scale spaces. This paper studies VR sickness and postural instability while the user walks in an immersive virtual environment using an electroencephalogram (EEG) headset and a full-body motion capture system. The experiment induced VR sickness by gradually increasing the translation gain beyond the user's detection threshold. A between-group comparison between participants with and without VR sickness symptoms found some significant differences in postural stability but found none on gait patterns during the walking. In the EEG analysis, the group with VR sickness showed a reduction of alpha power, a phenomenon previously linked to a higher workload and efforts to maintain postural control. In contrast, the group without VR sickness exhibited brain activities linked to fine cognitive-motor control. The EEG result provides new insights into the postural instability theory: participants with VR sickness could maintain their postural stability at the cost of a higher cognitive workload. Our result also indicates that the analysis of lower-frequency power could complement behavioural data for continuous VR sickness detection in both stationary and mobile VR setups.