Cybersickness, a catch-all term for illness caused by using a computer display, feels similar to motion sickness and is caused by sensory conflict, an expert says.
The condition is most often associated with gamers or high users of virtual reality (VR) technology but also affects people across a range of industries and women may be more susceptible to it.
Photo: Christina @ Wocintechtchat / Unsplash
Dr Juno Kim is part of a team of Sydney researchers trying to understand what causes cybersickness and how to treat it.
He tells Kathryn Ryan that the condition manifests as nausea and dizziness and feels similar to being seasick or carsick.
“It’s really specific to people who are engaging in technology. It really is about the adverse side effects or symptoms that people have when engaging in immersive virtual reality technologies.”
As far as we know the problem has its roots in the age-old phenomenon of motion sickness, he says.
“We’ve clinically known about it for centuries. Physicians in Ancient Greece knew about this very early on.
"It’s definitely through the understanding of the aetiology of motion sickness that there’s been a lot of interest more recently in the application for immersive technologies, particularly in various defence forces interested in creating simulators for providing training to recruits to essentially provide them with the experience of a dangerous situation in a safe way.”
'Simulator sickness' was one of the first reported types of motion sickness related to technology, Dr Kim says. Its severity is measured with the Pensacola Motion Sickness Questionnaire (MSQ), which was conceived by Robert S Kennedy over two decades ago.
Today, the MSQ is also used to index the severity of cybersickness.
Photo: Varun Gaba / Unsplash
Cybersickness is associated with head disorientation within the inner ear and ‘sensory conflicts’ between different forms of data coming in, Dr Kim says.
Sensory conflict theory, or cue conflict theory, states that simulator sickness is the result of both a sensory conflict and the held expectations of the sensory system based on previous experience.
‘What we found in our research is, if we add display lags to a system, which involves increasing the time it takes to present to a user the image that is the approach for their current head orientation, then we can generate a lot of weirdness in their experience and that can lead to cybersickness.
“For example, if I’m looking to the left part of my environment and then rapidly turn my head to the right I expect to see the right side and all the motion that goes with it, But if we start using lag, holding back those frames by 10, 20 or 100 milliseconds or more then that motion is seen a lot later that results in this sensory conflict.
“There is a difference between the actual simulated viewing orientation relative to the person’s actual physical head orientation and we can quantify this to predict cybersickness."
Overcoming motion sickness in cars involves matching incoming visual information to what’s being experienced in movement.
Overcoming cybersickness involves enabling a person to match incoming artificial information with the movement and orientation of their body.
Dr Kim says this was the focus of researcher Jerrold Prothero, whose Rest Frame Hypothesis (RFH) states that our brains select a particular reference frame – the "rest frame" – as the comparator for spatial judgments.
“If you have a stable visual landmark in the environment, you can reduce the likelihood and severity of cybersickness. That’s why VR, which basically involves putting on goggles that block out the entire view of the environment, generates more cybersickness than say augmented reality, which involves putting a transparent field in front of your face that adds virtual content to your real environment that is always stable.”
Photo: RNZ / Richard Tindiller
If there was a method of projecting light from the natural environment directly into people's eyes, we couldn’t get cybersickness, Dr Kim says.
A recent study showing more females discontinued from simulations due to sickness than men suggests that women may be more susceptible to cybersickness.
Women have a narrower gap between the eyes, which may lead to more sensory conflict, he says.
“When people who have a narrower distance between the eyes try to look through these lenses they get very different images and that leads to visual information which is not consistent with what they expect from all their other senses leading to conflict.”
Virtual reality simulators are designed uniformly, instead of being personally tailored to individuals, Dr Kim says.
“I think the problem arises because developers always want to cater for the average user.”
Dr Juno Kim is a lecturer at the University of New South Wales School of Optometry and Vision Science.
