You just loaded up your favorite space opera game. Everything is great! All is fine and dandy with this immersive world. After two hours, you’ve managed to set off some sparks with your in-game love interest. A few more hours in and you’re about to set off and save the world (but not before virtually banging your alien lover). But what’s this… Suddenly you feel a sense of dizziness followed by bodily warnings of nausea. Why is this happening? Well, you’ve just experienced motion sickness first-hand.
According to Golding & Gresty (2015), motion sickness could be an evolutionary adaptation from a bodily system which was designed to protect us from potential neurotoxin ingestion. When the central nervous system (CNS) sends signals indicating poisoning, the body is prompted to vomit. This system is also activated by irregular vestibular–cardiovascular reflexes (irregular responses from the sensory system responsible for coordinating movement with balance that alters heart and circulatory functions when there is increased pressure). Golding & Gresty suggested that motion sickness evolved to prevent us from engaging in circumstances (such as climbing tall, swaying trees) to avoid experiencing disorientation or motor instability.
Motion sickness is polysymptomatic, which means along with nausea and vomiting, it can also be accompanied by other significant symptoms such as headaches, drowsiness, sweating, dizziness, and even the loss of appetite and increased sensitivity to odors. Over the years in the medical research regarding motion sickness, there have been positive gains on the understanding of environmental and behavioral circumstances, as well as the medical conditions that modulate it. By contrast, however, there has been little advancement in treatments for motion sickness. This is most likely because physiological markers for predicting motion sickness susceptibility are unreliable. Even though motion sickness produces profound autonomic characteristics, the baseline autonomic characteristics do not work as useful predictors.
What does this mean?
Well for us gamers, there is a new form of motion sickness exclusive to 3D display technology called visually induced motion sickness (VIMS). VIMS is defined as motion sickness that is purely provoked by visual motion. It affects users in virtual environments such as ones seen in immersive video games, virtual reality, simulators (flight & driving sims), and cinerama (wide-screen projection in theatres). According to researchers Guo, Tsoi, Wong, Yu and So (2013), the levels of motion sickness one could experience can be affected by factors such as susceptibility, age, gender, type of motion stimulus, as well as the duration and frequency of exposure.
Factors found to be correlated with motion sickness:
1) Field of view (FOV)
FOV is often said to affect VIMS and is characterized by Bos, Vries, Emmerick, and Groen (2010) as an internal setting used by the graphics generator and an external factor determined by screen size and viewing distance. Researchers Keshavarz, Hecht, and Zschutschke (2011) found that reducing the FOV together with the visual display angle ultimately led to significantly lower motion sickness symptoms and sensations. A possible explanation for why this may be the case is that there is a reduced feeling of vection when there is a smaller FOV for the player.
Bos, Vries, Emmerick, and Groen hypothesized that a player’s sensory incongruence with the graphics generator and viewing distance should result with motion sickness symptoms. They conducted a research study with a sample size of 20 participants that were college and university students between the ages 19 to 31. Only 6 participants specified having first person shooter (FPS) game experience, and the rest had little or no experience in FPS games. The participants passively watched a 50 minute movie generated using the graphics engine of Half Life 2. The movie was shown in an almost dark room with dimmed ceiling fluorescent lamps and consisted of 4 repetitions of a tour of a virtual environment. The camera speed was 13.6km/h to simulate a natural perception of walking pace, and consisted of pseudo-random swaying movement with the roll axis at ground level and the maximum amplitude of 16° was super imposed to provoke motion sickness. The study concluded with only 8 out of the 20 participants reporting to feel fairly nauseated. The researchers only found viewing distance to have a significant effect on motion sickness, as there was no significant indication the graphics generator had any effect on inducing motion sickness in the participants.
2) Control & passenger effect
Guo et al. speculated that players being in control of the gaming experience were more resistant towards motion sickness symptoms than those passively observing the experience. They examined the effects of having an active control versus passive watching on VIMS. The researchers reviewed a past experiment conducted in 1991 by Rolnick and Lubow, where they attempted to examine the ‘driver’ & ‘passenger’ effect in respects to motion sickness. The drivers were in control of a vehicle and drove around on a planned route. Passengers only observed and experienced the motion. The results from this study indicated that drivers (having been in charge of operating the vehicle) reported feeling less symptoms of motion sickness in comparison to the passengers. Similarly, in another study which examined this control effect, Xiao et al (2011) was interested in exploring whether this effect was exclusive to physical motion, and was curious to see if it could be replicated in a virtual environment as well. Unsurprisingly, this study yielded similar results as the study conducted by Rolnick and Lubow. It revealed that the benefits of being in control against motion sickness are not exclusive to physical motion in the real world, but also in virtual environments as well.
Driving a car is cool and all, but how about something for gamers? One neat little study — conducted by Guo et al — used Mirror’s Edge to collect and analyze data. Their participants trained for one week before the first experiment in order to familiarize themselves with the game. There were three conditions: active game playing with no eye fixation, active game playing with eye fixation (chin rests were used to stabilize their head position), and a passive viewing of recorded videos of gameplay. The participants played the game on a 27-inch monitor approximately 50cm away from their eyes. The frequency of key presses were recorded to separate the “fast” and “slow” learning players. During the third passive viewing condition, fast players would watch recorded gameplay of other fast players, and vice versa for the slow players.
The result of this study concluded with the researchers also finding that players with control over their experience had a higher tolerance against motion sickness symptoms over those passively viewing the game. It should also be mentioned here that the developers for Mirror’s Edge (DICE) actually implemented a small transparent circle as a fixation point, which was displayed in the middle of the screen to help reduce simulation sickness.
So why do passengers experience the most motion sickness symptoms? Keshavarz (2016) explains that VIMS is felt in situations where the information delivered by the senses is not synchronous. Stoffregen et al. (2008) defines this effect as sensory conflict, which is the idea that motion sickness situations are characterized by patterns of perceptual stimulation that differ from patterns expected on the basis of past experience. This means the difference between the current and expected patterns of perceptual stimulation are interpreted as sensory conflict, which attribute to motion sickness.
3) Postural instability theory
According to Stoffregen et al., the postural instability theory of motion sickness predicts that motion sickness should be proceeded by instabilities in the control of bodily orientation. Keshavarz adds that VIMS is not directly caused by sensory conflict, but is rather dependent on one’s individual ability to maintain postural stability (minimize uncontrolled body movements). This theory was tested in studies which required participants to play or watch VIMS inducing games or videos while standing or sitting with either physical restraints or freely.
The results of these studies were generally mixed, but with a special case where physical restraints during gameplay benefited older adults over younger adults. This was seen as a strange occurrence, because older adults are known to have generally reduced postural stability due to age related changes. Therefore, it can be implied that passive restraint to minimize body movement during game sessions or movie watching, under certain circumstances and for certain populations, can be beneficial. However, it is not always practical to restrict user movement, as it could limit applicability and even induce anxiety in some users.
4) Individual differences
Susceptibility to motion sickness tends to progressively decline throughout adolescence, adulthood, and old age. However, Golding & Gresty have found that very young children are relatively immune to motion sickness until age 9, where their susceptibility increases and peaks. Generally, females have been reported to be more susceptible than males to motion sickness. This effect is greater around menopause, where females’ susceptibility increases further. While researchers Golding & Gresty are unsure of the reasoning for this phenomenon, they attribute it to the number of migraine headaches that women experience more of during their menopause years. Surprisingly enough, individuals with high levels of anxiety do not have a higher susceptibility to motion sickness compared to others with low or moderate levels of anxiety.
The solution according to research?
Various studies suggested different solutions ranging from having controlled, regular breathing to adjusting your body with changes in the game environment, as well as restricting head, shoulder, hips, and knee movements to reduce motion sickness. It is also fitting that listening to pleasant music, having good air flow in the room, and pleasant smelling environments were also found to reduce VIMS. Drugs that were used to reduce symptoms of traditional motion sickness could also provide relief from VIMS, but they would not be a long term solution, because these medications very often are accompanied with undesirable side effects such as dizziness, fatigue, or impaired cognitive functions. As Keshavarz adds, while these side effects are tolerable for passengers, they are not solutions for those whom require their mental capacities intact.
But, in accordance with past studies and researchers, Golding & Gresty have found habituation (or adaptation) to be the best long term approach that is free of side-effects and superior to drug treatments. VIMS occurs when coping strategies to deal with sensory incongruence have not been adapted, therefore repeated exposure to the same stimulus should reduce VIMS symptoms after a while. In other words, getting sick from viewing dynamic image content once does not necessarily mean one will be as sick the next time. According to Keshavarz, a research study had their participants play a 20 minute video game over the course of 5 consecutive days. Their sickness severity was measured, and it was found that VIMS significantly decreased after each gaming session all the way to the 5th experimental day.
So what is the take away from all this hefty research? Motion sickness exists in both physical and virtual environments! There needs to be more research on the medicinal side of motion sickness, because traditional medication for motion sickness is not always practical due to unpleasant side effects. It is possible that reducing the field of view and minimizing uncontrolled body movement during gameplay may be beneficial towards reducing the effects of VIMS. Finally, habituation/adaptation is the only surefire way to resolve the issue without side-effects, given that you have the time, resources, and/or dedication it requires. You might ask, “What does this say about us gamers, then?” As gamers, we will put on our armor and wield our mouse or controllers (whatever your choice of weapon may be) then charge back into the gaming world to gain experience and level up! Momma didn’t raise no wimp.