Vestibulomotor Coupling and Gain Associated with Cybersickness in Virtual Reality

Area of Science:

• Neuroscience
• Human Factors Engineering
• Virtual Reality Research

Background:

• Cybersickness, or virtual reality (VR) sickness, is a significant impediment to widespread VR adoption.
• The neurophysiological underpinnings of cybersickness are not fully understood, hindering the development of effective countermeasures.
• Vestibulomotor responses play a crucial role in maintaining balance and spatial orientation.

Purpose of the Study:

• To investigate the association between vestibulomotor responses and susceptibility to cybersickness.
• To quantify vestibulomotor responses using electrical vestibular stimulation (EVS) and mediolateral centre-of-pressure (ML-CoP) measures.
• To determine if baseline vestibulomotor responses predict cybersickness severity.

Main Methods:

• Thirty-eight healthy adults underwent a VR rollercoaster task with concurrent stochastic EVS (0-25 Hz) and ML-CoP measurement.
• Cybersickness was assessed using the Fast Motion Sickness Scale (FMS), categorizing participants into non-sick, medium-sick, and high-sick groups.
• EVS-ML-CoP coherence and gain were analyzed at baseline and during VR exposure.

Main Results:

• Baseline EVS-ML-CoP coherence and gain were significantly higher in high-sick participants compared to non-sick participants.
• During VR exposure, coherence decreased in symptomatic individuals but remained stable in non-sick participants.
• Despite reduced coupling, postural sway increased in the high-sick group, indicating insufficient compensatory mechanisms.

Conclusions:

• Elevated baseline vestibulomotor responses are linked to increased susceptibility to cybersickness.
• Changes in vestibulomotor responses during VR exposure are less indicative of susceptibility than baseline measures.
• Understanding baseline vestibulomotor function may offer insights into predicting and mitigating cybersickness.