Virtual reality. For decades before its inception, the concept of fully immersing ourselves in digital worlds has captivated our imaginations. Movies like Tron and The Matrix attempted to portray it on the silver screen, though they may have overestimated the feasibility of such deep immersion. Now that virtual reality is, well, a reality, what can we do with it?
From helping us understand human perception to assisting with teaching and therapy, virtual reality (VR) has played a key role in scientific research over the past decade. Yet one of the biggest problems plaguing this new technological medium is still puzzling scientists: motion sickness.
As immersive and realistic as these digital worlds may be, our brains still seem to understand that our bodies are not truly in them, causing what researchers call “cybersickness“. Why do some people get sick when playing VR games? What causes this feeling? A new study from researchers at the University of Waterloo may hold some answers.
According to the study, symptoms of VR cybersickness may include “nausea, disorientation, eye strain, and fatigue.” While we still don’t fully know why it occurs, one of the most convincing explanations can be found in the sensory mismatch theory. According to this theory, cybersickness can occur due to a mismatch between incoming sensory signals relating to self-motion and self-perception. In other words, our eyes may be seeing motion on the VR screen, but our vestibular systems do not sense it.
It should make sense then, that one of the ways to address cybersickness is to provide additional vestibular feedback to our brains to avoid this mismatch effect. One way is to actually make the player move in the real world, but electrical currents to the head have also been shown to reduce cybersickness.
To understand how this cybersickness occurs, and whether sensory reweighting is involved, the researchers asked 31 participants to play two VR games using the Oculus Quest: one low-intensity game (Sports Scramble) and one high-intensity game (Echo VR).
After this, the participants completed the subjective visual vertical task (SVV), which measured how they perceived the orientation of vertical lines. This also related to participants’ perception of their own positions in space. Cybersickness was measured using the fast motion sickness scale. To control for experience with VR and video games, the participants’ gaming experience was also measured.
The research team found that the participants’ perception of vertical lines was most affected after the high-intensity VR game. Interestingly, participants that felt less cybersickness experienced greater changes in the SVV task — in other words, these participants were more likely to experience a change in how they perceived vertical lines.
As one of the authors stated in a press release, “our findings suggest that the severity of a person’s cybersickness is affected by how our senses adjust to the conflict between reality and virtual reality”.
These findings may be a promising step towards better understanding cybersickness — and more crucially for those interested in VR, finding ways to design VR systems that reduce the player’s cybersickness.
This could be done by adjusting the virtual environment within the game, or as the authors suggest, by creating either training models or pharmaceutical options that can help reweigh incoming sensory information and reduce cybersickness for the player.