Computer games can be so realistic that they are downright scary, and that can be a good thing.

Researchers at the University of Quebec in Outaouais found that video games can be more effective in treating patients with phobias than commercially developed virtual environments costing as much as $10,000, and the games do it at a fraction of the cost.

"In some respects, despite their low cost, therapeutic virtual environments derived from games are superior to their commercial counterparts," researchers reported in a study published in the November 5th issue of the journal CyberPsychology & Behavior.

Using map editing programs for 3D games retailing for less than $50, the environments created for the experiment are more flexible than their clinical counterparts and the graphic quality can be superior, providing a more realistic immersion for the patient.

"With a total investment of $2,500, a therapist can provide clients with the benefits of virtual reality exposure," the study concluded. "All that is required is a PC, a head-mounted display, a PC gamepad and a freely distributed therapeutic virtual environment derived from a game."

Therapists often treat phobias, such as fear of spiders, heights and enclosed spaces, by exposing patients to the stimulus under controlled conditions so they can learn to control their responses. This is not always safe or practical in the real world, so computer-generated virtual environments sometimes are used to bring patients face-to-face with their fears. But the clinical software, in addition to being expensive, is difficult to modify for individual patients and compatible with only limited hardware platforms. So Genevieve Robillard, Stephane Bouchard, Thomas Fournier and Patrice Renaud experimented with modified computer game environments on a handful of phobic patients and a small control group.

For patients with arachnophobia-a fear of spiders-the researchers used an environment derived from Half-Life from Valve Corp. Acrophobia and claustrophobia-fear of heights and enclosed spaces-environments were created from Unreal Tournament, developed by Epic Games Inc. Using editing programs, a computer graphic artist populated the Half-Life environment with spiders of various shapes and sizes and the Unreal Tournament environments were selected and altered to provide the needed heights and small spaces.

"In each of the environments, irrelevant distractions such as guns, explosions and enemies were deleted," the authors said.

The platform for immersing patients consisted of a PC with a Pentium III 866 MHz processor, 128M of RAM and a 64M Radeon graphics card from ATI Technologies Inc. The display was via a two-dimensional I-Glass head-mounted system with a resolution of 480 by 640 pixels from i-O Display Systems Inc., equipped with an Intertrax2 tracker from InterSense Inc. to track head movements. This enabled the view in the headset to follow the patient’s side to side and up-down movements. A handheld Sidewinder gamepad from Microsoft Corp. controlled forward and backward motion through the virtual environment.

Patients were given a chance to get used to the environments without anything to trigger phobias, and then exposed to the stimulus. The researchers found there was little simulator sickness, which can be common in virtual realities, and that the programs stimulated the right level of anxieties for use in therapy.

The modified therapeutic environments, which under the game licenses must be distributed for free, can be downloaded from the University of Quebec at Outaouais’s Cyberpsychology Laboratory Website at www.uqo.ca/cyberpsy.