 . . . Spring 1999
By John Woodford Epidemiologists estimate that 23 million Americans suffer from one or more anxiety disorders, including panic disorder, post-traumatic stress disorder, social phobia, specific phobia, obsessive-compulsive disorder and generalized anxiety disorder, according to an article on "fear studies" in the Feb. 28 New York Times Sunday Magazine.
Among the many clinical approaches to anxiety, perhaps the most high-tech is the research in the application of virtual reality in the treatment of phobias.
"The standard treatment for phobias is exposure therapy," says psychiatrist Milton Huang, a lecturer in the U-M Medical School. "Usually it's a gradually increasing exposure to the thing feared--spiders, height, open spaces, crowds or what have you. People learn to tolerate and then to overcome the fear, if treatment is successful. We have to generate the fear for them to master it."
Getting patients to their specific phobic environment and controlling their exposure to the source of fear can be time-consuming and expensive. That's why Dr. Huang is testing virtual reality (VR) treatment with volunteer patients at the U-M Medical Center's Anxiety Disorders Clinic. "We want to see how virtual reality compares with real-life exposure in effectiveness and expense," he says.
U-M is one of the few institutions in the world with the kind of virtual reality chamber needed for phobic therapy. The chamber, dubbed the CAVE Automatic Virtual Environment (CAVE) in North Campus's Media Union, simulates a three-dimensional, three-sided environment. College of Engineering students in the Principles of Virtual Reality class taught by Peter Beier, associate director of the Laboratory for Scientific Computation in the College of Engineering, created the CAVE environment and continue to refine it.
"I've started with fear of heights because it's easier to test," says Huang, who is in the third year of the project. "We measure patients' fear of height physiologically and behaviorally, recording their respiration and heart rates and observing certain behavior.
"In this study, we take individuals who fear heights to the U-M Hospital elevators and then go up one floor at a time. We call that an in vivo, or real-life, exposure. Here in the CAVE, we provide a virtual-reality experience of the same exposure. They can stand in a hallway or enter the elevator and ascend. We can even go up to a 20th floor even though the hospital, itself, has only eight floors. Our goal is to compare the two exposures to see what is happening to the person in each case."
People ruled by a fear of heights may consciously or unconsciously adjust to them "by seeking jobs only on the first or second floor of a building, never looking out a window if they work on a high floor, or driving around an entire bay rather than cross over a bridge," Huang says. Different stimuli trigger height phobia, he adds. Some individuals may respond to the presence of birds or to viewing objects far below them, others to sensations felt in the stomach or head.
"It seems virtual reality offers some clinical advantages---it is easier to control, permits replication of exposure to the feared experience and offers privacy," Huang says. "Our preliminary results show that some are cured after one session while several sessions don't help others. We need data to come up with a conclusion as to why this is so."
If VR therapy compares well with in vivo exposure, the cost of certain treatments should drop considerably. "To treat fear of flying, for example," Huang says, "the clinician must rent a plane and then set gradual exposures to sitting in the plane, taxiing, taking short hops off the ground and finally going up for a flight. CAVE technology can simulate these experiences, repeat certain steps like takeoffs, and even add certain special condition like storms."
Virtual reality's role in medicine is increasing. It's used for autism, impotence, movement disorder and stroke rehabilitation. Mental health professionals began to use it in 1994. Among the pioneers was a Georgia Tech team that devised a Virtual Vietnam to help treat post-traumatic stress disorder, Huang says.
Huang's own first psychiatric research was on the psychological and social implications of Internet usage. Mental health professionals, he reports, face such challenging questions as, What happens to people when they live in 'unreal' worlds? Who is more vulnerable to getting lost or addicted?
"Chat rooms are not just containers of printed messages now," Huang says. "There are 3-D rooms into which users can send their own 'avatars'--characters they select or design to serve as their own 'bodies' in the virtual environment. The figures walk into rooms and engage with avatars of other users. People who get addicted to this sort of thing tend to be males and tend to be younger people, but you don't have to be a computer whiz to do so. We don't know what drives people into addictive states and need more manpower, time and money to find out."
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