A new study on VR motion sickness concludes that certain brain activity that can be detected by EEG is strongly correlated with VR motion sickness. This finding suggests that it is possible to quantitatively measure and potentially prevent VR transport disease.
While virtual reality opens the door to incredible possibilities, what we can actually do with VR today is at least somewhat limited by comfort considerations. While developers have steadily invented new techniques to keep VR content comfortable, scientists continue to work to understand the nature of motion sickness itself.
A new study published by researchers at the University of Germany in Jena in the peer-reviewed journal, Frontiers in Human Neuroscience, deliberately induced VR motion sickness in participants while measuring brain activity.
14 subjects were connected to an EEG cap and wearing a PSVR headset. In the headset, participants were exposed to increasing levels of artificial movement to induce VR motion sickness within 45 minutes. In addition to recording brain activity via EEG, subjects also subjectively assessed their motion sickness symptoms throughout the trial.
The researchers found a common pattern in the change in brain activity that closely corresponded to the subject’s own perception of motion sickness.
Specifically, the researchers write, “relative to a baseline EEG (in VR) the power spectrum for [brain] frequencies below 10Hz increase in all brain regions. The increase in frequency strength was positively correlated with the level of motion sickness. Topics with the highest [perception of motion sickness] had the highest power gain in the theta, delta and alpha frequencies. “
Researchers Matthias Nürnberger, Carsten Klingner, Otto W. Witte and Stefan Brodoehl come to the following conclusion:
We have shown that VR-induced motion sickness is associated with clear changes in brain function and connection. Here, we proposed mismatch of visual information in the absence of sufficient vestibular stimulus as a significant cause according to the predictive coding model. […] Differentiation of which changes in brain activity are due to the sensory conflict or caused by motion sickness should be investigated in further studies. Given the growing importance of VR, a deep understanding of the limitations imposed by [VR motion sickness] is becoming increasingly important. Measures to counteract the occurrence of MS or help detect it at an early stage will undoubtedly improve the progress of this promising technology.
The results provide further evidence that motion sickness can be objectively detected through non-invasive hardware such as scalp EEG, which can be used to guide future research into VR motion sickness and VR comfort techniques.
First, such EEG measurements could be used to objectively evaluate the effectiveness of VR comfort techniques.
Currently, VR content developers use a number of well-known VR comfort techniques such as snap-turning and teleportation to reduce the chances of VR driving sickness. However, not all VR comfort techniques may be equally effective compared to each other or compared across individuals. Establishing a quantitative measurement of motion sickness via EEG can help improve VR comfort techniques or even discover new ones by providing clearer feedback while making the test more objective.
Such measurements can also inform about comfort assessments presented to end users to help those who are sensitive to VR motion sickness find appropriate content.
In addition, EEG detection of motion sickness could potentially be used on a real-time basis to predict and prevent motion sickness.
EEG brain sensor technology is becoming more and more accessible and has already been integrated into commercial VR hardware. In the future, EEG-equipped headsets will be able to allow developers to record a user’s level of motion sickness in real time, allowing content adjustments or VR comfort techniques to turn on automatically to keep users comfortable while playing or working in VR.
Thanks to Rony Abovitz for the tip!