Cybersickness: Why People Experience Motion Sickness During Virtual Reality

Cybersickness: Why People Experience Motion Sickness During Virtual Reality lead image
Johan Larsson via flickr
(Inside Science) -- In the 1990s, early attempts at bringing virtual reality to the masses with consumer headsets like Sega VR and Nintendo’s Virtual Boy failed miserably. Bad visuals and imprecise controls contributed to an underwhelming experience. Nintendo’s console flopped and was discontinued after just a year, while the Sega system never even reached the market.
Almost three decades later, VR has made a convincing comeback. Today’s applications range from pain management
“With contemporary commercially available VR systems, the incidence of motion sickness after only 15 minutes is anywhere from 40 to 70 percent,” said Thomas Stoffregen, a kinesiologist at the University of Minnesota. For some applications nearly 100% of users get sick, he said.
On July 28, Stoffregen gathered in Los Angeles with other researchers who study “cybersickness,” as VR-related motion sickness is called, during the SIGGRAPH2019 conference. The group discussed what they can do to help prevent VR-related motion sickness, as well as various theories of why cybersickness occurs, why it only happens to some people, and what makes women especially vulnerable.
“The existing interactive technologies are sexist in their effects. That is to say, they are more likely to make women sick than men,” said Stoffregen. “But this is not limited to technology -- in general, women are more susceptible to motion sickness than men, anytime, anywhere.”
But he argues that since VR-related motion sickness is caused by hardware and software that humans design -- unlike the environmental causes of seasickness, for example -- we need to be responsible for finding a way to fix these “sexist” effects.
The leading theory behind cybersickness is based on the idea of sensory conflict
Some researchers believe that evolution has led your body to respond the way it does -- with nausea and vomiting -- because it is trying to expel an ingested, hallucination-inducing toxin.
“But we have a lot of questions based on this general theory, such as to what extent can we predict cybersickness and is that useful for us in any way?” said Séamas Weech, a researcher at the University of Waterloo.
Critics of the sensory conflict theory point out that it fails to explain individual differences in cybersickness susceptibility. If everyone is experiencing a visual-vestibular discrepancy, then why doesn’t everyone feel like throwing up? And why do women report more symptoms of cybersickness
One reason could be the way VR headsets fit. Interpupillary distance, or the distance between your pupils, can be adjusted in today’s headsets to make sure that the user’s eyes are centered with respect to the two lenses inside. But that doesn’t mean they fit everyone well.
“The default for the headset is somewhat larger than the average [interpupillary distance] of the population ... [which] matches very nicely with the average male [interpupillary distance]. It doesn’t do it so well for females,” said Bas Rokers, a psychologist at the University of Wisconsin-Madison.
Studies have found that when the headset’s interpupillary distance is too large, users experience greater discomfort. In his research
A lesser-known theory that may describe individual differences in cybersickness involves something called postural instability, which Stoffregen first published
“If I put you on a ship at sea, or if I put a head-mounted display on you, that mandates changes in the way that the body moves and the body is controlled,” he said. “Some people will make those changes quickly because they have the gift of natural fluency and skill -- you know, they’re coordinated -- and some of us will do it more slowly.”
However, other researchers at the workshop didn’t buy Stoffregen’s theory – for example, one showed data from his own experiment that showed no correlation between postural instability and cybersickness -- and so it appears the debate on the origins of cybersickness will continue.
But everyone agreed that illness associated with VR presents a serious obstacle toward widespread acceptance of the technology. This could become significant as VR moves beyond gaming and entertainment into areas such as job training, distraction therapy for pain, and other applications.