Such fear and avoidance of heights are two primary symptoms of acrophobia, which has afflicted Klock since a childhood visit to the Statue of Liberty. So intense was his phobia that it circumscribed his life, often making everyday activities difficult or impossible. Once, he had to tell a new employer that he couldn't sit within view of the office's sixth-floor window. When he checked into a hotel, he had to stay in a ground-floor room. And even when he made it to the top of the Peachtree Plaza, he had to sit with his back to the windows.
"My problem was that I just couldn't get off the ground," says Klock, a twenty-one-year-old Georgia Institute of Technology student. "As long as my feet were touching the ground, I was fine. But if I got even so much as one story off the ground, I got sweaty palms. I got weak in the knees. I just didn't like knowing I wasn't on the ground."
But after eight weekly treatments as part of a joint Emory-Georgia Tech research project, Klock's fear of heights and the problems it caused have vanished. He wouldn't care if the next party he is invited to is held on the Peachtree Plaza's elevator.
Acrophobia has long been treatable. What is unusual about Klock's case is that his cure was accomplished entirely through the use of virtual reality, a cutting-edge sector of computer technology that can recreate almost any scene or situation and make it seem real. Researchers call this characteristic "a sense of presence" and consider it essential to successful virtual reality therapy.
"There are acrophobics who will not park on the higher floors of a parking garage or close to the edge," says Emory Assistant Professor of Medicine Barbara O. Rothbaum, who co-authored the study. "Some of them will circle and circle until a spot on the middle or ground floors opens up. In hotels, they can't stay on any but the lower floors. And it restricts where they are able to work. Atlanta isn't New York, but there are a lot of high rises here, and if people aren't comfortable working anywhere but on the lower floors [they may face some difficulties]."
Rothbaum collaborated on the study with Larry F. Hodges, associate director of the Graphics, Visualizations, and Usability Center at Georgia Tech. The project was funded by the Emory/Georgia Tech Biomedical Research Consortium, which supports shared projects that apply engineering theory and practice to medical problems. It is thought to be the first controlled study of virtual reality as a treatment for a psychological disorder.
Acrophobia is defined by three elements: fear of heights, avoidance of heights, and difficulty functioning in everyday life due to height anxiety. It has traditionally been treated by a method called graded exposure, in which patients are gradually exposed to the situations they fear. This can be done either in the patient's imagination or in vivo, in real life.
"Patients begin with less threatening situations and gradually work their way up a hierarchy of more anxiety-producing ones," Rothbaum and Hodges wrote in an article in the July 1995 issue of the journal Computer. "For example, if the patient is afraid of heights, therapy sessions might begin by having the patient look through a third-floor window with the therapist present. In subsequent sessions the patient might move up to a window on the tenth floor."
If doctor and patient agree on in vivo therapy, treatment requires repeated trips to a bridge, a tall building, or a gorge or canyon, which can be costly and time-consuming. Virtual reality, on the other hand, integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse participants in a computer-generated virtual environment.
Virtual images are not as sophisticated or defined as a movie or television show would be. They look more like cartoons but feel realistic due to various cues that suggest distance and motion. Rothbaum says if continued testing validates the promising nature of their early results, virtual reality would make the treatment of acrophobia more convenient and less expensive than current approaches.
For their study, Rothbaum and Hodges screened 478 Georgia Tech students. From this group, forty-one individuals were identified as being possible acrophobics, and twenty, including Klock, eventually entered the study. Of these twenty, twelve were selected to participate in the virtual reality activities. The remaining eight were assigned to a control group and received no further treatment. To establish a baseline against which to measure the effectiveness of treatment, all twenty students completed two questionnaires--one measured their attitudes to height and another rated their level of fear.
After an orientation session, the twelve participants familiarized themselves with the project's hardware--most notably a head-mounted display and an electromagnetic sensor that was used to track the head and right hand so the user could interact with objects in the virtual environment. Participants then were told to select the least threatening of three virtual reality environments in which to confront their phobias. The first scenario placed the student at the bottom of a mountain gorge spanned by bridges seven, fifty, and eighty meters high, which the subject was expected to cross. The highest of the three was a rope bridge with widely spaced wooden slats, which one subject called "the Indiana Jones bridge." The lower bridges could be seen from the higher bridge, an effect that added to the illusion of height.
In the second model, participants were asked to stand on each of four balconies in a tall building--at ground level, two stories, ten stories, and twenty stories. The view from the balconies, which assisted in the simulation of height, was the Georgia Tech campus.
The final option was to ride in a glass elevator similar to one at the Marriott Marquis hotel in downtown Atlanta. With the press of a virtual button, the elevator ascended or descended. The sense of height and motion was enhanced by a bird's eye view of a marble-floored lobby complete with tables, chairs, greenery, and a fountain.
The reality of the latter two scenarios was heightened by the actual presence of handrails located in the same position as handrails on the virtual balcony and in the elevator. The students could actually feel something that was in the virtual reality world. They could use the railing to brace themselves or to hold on to while looking downward.
Individual treatment sessions lasted from thirty-five to forty-five minutes once a week for eight weeks. Starting at the point of lowest anxiety, the students were asked to "habituate" themselves to the scenario--to place themselves in the virtual world and stay at one level until they felt comfortable. They were encouraged to take as much time as necessary to overcome their fear before moving on. Every five minutes, the subjects were asked to describe what they were feeling. Among the responses were: "I'm feeling a little weak in the knees," "I feel like I'm on the edge . . . don't like it," and "A lot easier than last week. Last week I was terrified."
Rothbaum and Hodges are buoyed by the results. Anxiety, avoidance, and distress decreased significantly among those involved in the treatment but not among the control group. Ten of the twelve students completed the study, three of whom habituated so quickly that they completed treatment early. Significantly, and without instructions from the researchers, seven of the ten deliberately put themselves in actual height situations, such as riding the Peachtree Plaza elevator or parking on the top floor of a parking garage, even before the treatments were over. Such activities are essential to keeping phobias at bay.
Rothbaum is expansive when she talks about the future of virtual reality treatment. When funding becomes available, she and Hodges would like to explore the use of virtual reality to treat fear of flying and post-traumatic stress disorder among Vietnam veterans.
"I think it has a lot of applications," she says. "Right now the [cost] is prohibitive. The equipment it took to run this study probably cost $150,000 to $200,000. But I think it's going to go the way of the PC. At first computers were only available at large universities, but now they have become affordable and pretty much everyone has one on their desk. I think that, driven by the [video] game industry, virtual reality equipment is going to come down. We're limited only by our imagination at this point."
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