May 24, 2010
Cybersickness: A Virtual Bummer
Is a trip to the 3-D movies making you sick?
With the recent release of blockbusters such as Avatar and How to Train your Dragon and with expectations that 3-D TVs will be a big seller during the holidays, 2010 is fast shaping up to become "The Year of 3-D," at least in the world of entertainment.
If Hollywood ticket sales are any indication, folks are embracing the new technology in droves. But, while many of us watch 3-D entertainment in awe, others are compelled to look away. There just so happens to be a group of unlucky moviegoers who find that watching hyper 3-D images whiz by while sitting in the relatively still environment of a movie theater causes dizziness nausea, and other ill effects.
With funding from the National Science Foundation (NSF), experimental psychologists Frederick Bonato and Andrea Bubka of Saint Peter's College in Jersey City, N.J., study this phenomenon, known as 'cybersickness.'
"Cybersickness is a form of motion sickness that occurs in virtual reality environments," says Bonato. "We have 3-D video games and 3-D movies, and now we have 3-D television. Viewing stimuli in 3-D may lead to some motion sickness symptoms to some degree."
To understand cybersickness, you'll need a quick lesson on motion sickness. "When we move around in the natural way, which is walking or running, the senses give you agreeing inputs," says Bubka.
"But when your sense of motion doesn't match up to your sense of sight, your brain may be reacting as if it's been poisoned," adds Bonato. "The reaction is to eliminate the poison by either vomiting or having diarrhea. It's because of evolutionary hardwiring in the brain that leads the brain to mistakenly react as if poisoning has occurred."
There is no real known reason why some people are more prone to motion sickness than others, the two researchers explain, but they do note some research has found that motion sickness seems to affect more women than men, and even people of certain ethnicities more than others.
"This isn't just a human problem, either," notes Bonato. "Motion sickness is experienced by most vertebrates. When some fish are transported in tanks in aircraft, they later find fish vomit, which indicates that the fish developed motion sickness on the ride."
In the Human Perception and Performance Laboratory at Saint Peter's College, Bonato and Bubka are busy making volunteer participants dizzy in order to better understand cybersickness. One look around the lab and you cannot miss all the equipment that turns and rocks, or the whizzing images on some of the labs' computer screens. It's enough to make your head spin, which is exactly the point.
"What we do is carefully control what the person sees so that we can discover what sorts of stimuli lead to more sickness or reduce it. Our goal is to reduce it," says Bonato.
"Without drugs," adds Bubka.
In their research, the investigators look for links between image complexity and viewing speed to increase the severity of motion sickness symptoms. And, they use some rather unique equipment to do so.
Over in the far corner of the lab is what has become known as the "vomitator." The technical term is an optokinetic drum. It is a cylindrical drum, with striped or checkerboard patterns on the inside liner that rotates around a participant who is seated perfectly still. As the drum spins, the participant often starts to develop motion sickness symptoms, such as dizziness, sweating, headache and nausea.
In another experiment, participants are asked to wear a stereo head-mounted display. The participants view what looks like a 3-D virtual room in front of them. Bonato and Bubka can change the angle in which the participants see the room. As the room rotates about them, participants often start to feel ill.
Perhaps the most pronounced object in the lab is the flight simulator. It resembles the cockpit of a small Cessna and, for fun and just to be on the safe side, Bubka keeps airsickness bags in there during the experiments. To date, no one has ever had to use one.
People often get sick inside flight simulators. The big surprise is who is more prone to it. "Real pilots will actually get sick more often in a flight simulator than a novice pilot," says Bonato. "The experienced pilot is used to what the sensory inputs are in a real airplane, but the novice pilot is not, so they're actually more tolerant in a flight simulator."
So far, Bonato and Bubka's research has churned out some interesting results. "If we put someone in a virtual room that rotates around them and we put it in stereo and 3-D, they get sicker than if it's in 2-D," says Bonato. "The more colors and spatial complexity one sees also leads to more sickness."
Bonato and Bubka hope their research will lead to 3-D movies and other virtual experiences that make people less prone to becoming sick. "We want to make people learn how to adapt to situations that may provoke motion sickness symptoms without drugs," says Bonato.
The human brain is adaptable so motion sickness can often be overcome. "If you become used to a boat, for example, that doesn't mean if you go into space, you'll be immune. One situation doesn't always transfer to another one. But the good part is that the brain is adaptable, and we can build a tolerance to most situations," explains Bonato.
Bonato and Bubka also believe that their work in cyberspace could lead to breakthroughs in outer space. "Upon entering zero-gravity conditions, there is a period of two to three days where most astronauts are sick. If we can create situations where we manipulate visual input, maybe we could find ways of reducing symptoms simply by changing what the person sees or adapting them on Earth," says Bonato.
That kind of success will be good news for astronauts, pilots and moviegoers, no matter how you spin it.
Any opinions, findings, conclusions or recommendations presented in this material are only those of the presenter grantee/researcher, author, or agency employee; and do not necessarily reflect the views of the National Science Foundation.