Cybersickness: Linking Postural Control to User Discomfort in a Virtual Roller Coaster

Abstract

Cybersickness (CS) remains a major obstacle to the widespread use of Virtual Reality (VR), with leading explanations emphasizing sensory conflict, sensory reweighting, and postural instability. Prior research has shown that individuals who flexibly reweight visual, vestibular, and body cues report lower CS, particularly in interactive VR tasks where users can move freely. Whether this relationship generalizes to more passive, visually intense VR experiences is less clear. This thesis examined sensory cue reweighting and postural control as predictors of CS during an immersive roller coaster simulation. Nineteen younger adults completed the Oriented Character Recognition Task (OCHART) before and after VR exposure to estimate perceptual upright and quantify cue weightings. During VR exposure, postural movement was recorded using markerless motion capture, and participants reported symptoms using the Fast Motion Sickness (FMS) scale after each trial. Contrary to findings from interactive VR contexts, sensory reweighting was not significantly associated with CS in this passive roller coaster environment. In contrast, measures of postural control, particularly total path length, were robust predictors of sickness severity, with greater displacement linked to higher FMS scores. These findings suggest that in visually dominant VR tasks with limited bodily engagement, postural instability provides a more reliable marker of CS than sensory reweighting. This work clarifies that the predictive value of sensory reweighting is context dependent, emerging more clearly in interactive than passive VR tasks. It further points toward movement-based strategies for mitigating discomfort in VR experiences where movement is restricted but visual conflict is high.