Are You Sick of Games? (continued)
By Jeff "nonick" Solomon
Why is everything spinning around? In my room???
What people are experiencing when they walk away from Quake and stumble around is a variation of motion sickness that is called simulator sickness. Simulator sickness is very similar to motion sickness in terms of symptoms (nausea, loss of balance, vertigo, etc.), but has a different cause.
Motion sickness most typically results from situations where a person's inner ear is thrown off balance by physical motion; the internal fluids move around, causing the body to lose its sense of foundation. This is what usually causes the nausea and vertigo that some people experience on boats and airplanes where the basic foundation is constantly in motion (research shows that approximately 80% of people are susceptible to some form of motion sickness). This is not, however, what is happening when people become sick while playing video games.
Simulator sickness, by comparison, results from purely virtual circumstances. There's not much motion involved in playing Quake (ducking and bobbing, perhaps, but not much else), so the sickness people feel is coming purely from the screen and speakers - their virtual visual and aural environment - as opposed to their real environment. However, simulator sickness is intrinsically related to motion sickness in terms of symptoms, and studies have shown that people who are prone to getting motion sickness are also more likely to experience simulator sickness (and vice versa).
This is actually pretty amazing: a computer-driven, virtual environment can fool the body well enough to cause some of its most basic support systems to become confused. This didn't happen twenty years ago with Pong. In fact, while people have been experiencing simulator sickness for years in training environments (for commercial airline and military use), only recently have video games become sophisticated enough to produce the kind of virtual world that is realistic enough to cause simulator sickness.
Yeah, but how can a game bring this on?
What causes simulator sickness? Surprisingly, there's no simple answer, and very little research on the topic. The most popular explanation for the cause of simulator sickness is the "cue conflict theory," which states that the discrepancy between the stimuli that different senses detect causes confusion for the body. Basically, this means that if your eyes think you're moving, and your body does not feel any motion to support that claim, you can become confused and disoriented.
This makes sense, especially when applied to people who get sick while playing games like Quake and Unreal. If you're totally immersed in the game, and the game is presented in a first-person point of view that includes fast-moving audio and visual cues, your eyes and ears are reporting that you're running through hallways, jumping, ducking, and falling. Your body, however, is stationary. While this seems like an obvious distinction to the mind, it is surprisingly easy to fool your nervous system. Which can lead to simulator sickness.
Another theory as to the cause focuses on the vestibulo-ocular reflex (VOR), which is the part of the eye that is responsible for keeping eye movements in sync with head movements. When your head moves to the left, right, up, or down, your eyes move as well to compensate for the changing field of view. If you turn your head twenty degrees to the right, for example, your eyes will move twenty degrees to the left. The VOR moves your eyes the same amount that your head moves in the opposite direction.
This might not be easy to understand at first, but go to a mirror and take a look. Look straight ahead and turn your head to the left and right a few times. Your eyes remain fixed straight ahead at the mirror. Since your head is moving, then your eyes must be moving in order to appear to be staying in the same place. In fact, they're moving the same distance (in terms of degrees) as your head is moving. Pretty cool.
There is research that shows that virtual reality is not friendly to this reflex (the VOR). In most virtual reality scenarios (including computer games), there is very little eyeball or head movement; all of the action is constantly focused right in front of the player. However, when there is movement, it is most typically either only eyeball movement or only head movement- not both at the same time, since the viewing target is fixed in place.
This kind of fixed visual target forces your VOR to either keep your eyes focused on a single location while your head is moving, or to move your eyes while your head is still. While these demands are not unusual (you did the same thing when you looked in the mirror a few seconds ago), prolonged exposure to virtual reality can cause strain and possibly even damage to the VOR.
|Credits: Are You Sick of Games? is © 1998 Jeff Solomon. All other content is © 1998 loonyboi productions. Unauthorized reproduction is strictly prohibited, so don't do it, as it can make you (or us, for that matter) really sick.|