Virtual Reality Finding Role In Psychological Evaluation

"Researchers and clinicians using virtual reality techniques can more precisely assess a wider range of behavioral responses than they could with the standard "pen and paper" psychological tests, some of which have not changed in 30 years, says psychologist Albert Rizzo, Ph.D., a researcher in USC's Alzheimer's Disease Research Center.

Dr. Rizzo, who is also a research assistant professor of electrical engineering in the Integrated Media Systems Center at the USC School of Engineering, tested the mental-rotation abilities, or spatial cognition, of 60 men and women, all between the ages of 18 and 34, first with a "pencil and paper" test and then with a virtual reality system. Both tests are designed to measure a subject's ability to orient objects spatially in his (or her) mind.

Subjects taking the "pencil and paper" test looked at a series of line drawings depicting five objects shown side by side -- but spatially rotated in relation to one another. Two of the objects depicted are the same as the target object on the left but shown from different angles, while the other two objects were mirror images or only similar to one another. Subjects were asked to identify the matching sets as quickly as they could.

In the virtual reality test, the subjects wore special eye glasses to look at a large, computerized projection screen. There they saw two large, three-dimensional objects, similar to the ones in the paper test, which were identical but presented from different angles. With a hand control like a tennis ball, subjects manipulated one of the objects to superimpose it on the target object. Then two more objects appeared for them to match. The computer kept track of the strategies they employed to fit objects together and how quickly they did it.

Rizzo found no significant difference between men's and women's performance on the virtual reality tests.

"Women can see and manipulate the three-dimensional objects as efficiently and as quickly as men," he reports, "but they cannot visualize the same process as well on paper. We believe the virtual reality provides more insight into the nature of gender differences in spatial cognition."

Rizzo says the researchers were surprised to find no gender differences on the virtual reality tests. Their second surprise came when subjects were asked to retake the "pencil and paper" test.

"Everyone who had scored below the halfway mark the first time improved, and the gap between men and women narrowed so that the difference was no longer statistically significant," says Rizzo. "This suggests that virtual reality techniques can help people improve their rotational skills. Indeed, we think this technology shows great promise as a rehabilitation tool for people with many different kinds of cognitive impairments."

People use spatial cognition in such everyday tasks as driving a car, playing a game of tennis or packing dishes in a crate. Spatial cognition has been linked to high-level mathematics performance as well.

Rizzo says that low scores on mental rotation tests may be one reason why women are underrepresented in such fields as engineering design and architecture, because such tests are commonly included in the admission tests to those programs.

And mental rotation tests are an important tool for clinicians in diagnosing traumatic brain injuries and distinguishing between Alzheimer's disease and other dementias. Most Alzheimer's patients have significant spatial orientation impairments, while those with some other forms of dementia do not.

Some people experience a form of motion sickness called cybersickness when using fully immersive virtual reality, and Rizzo says military research indicates that women are more susceptible to all forms of motion sickness.

"But we found no gender differences, and our subjects had almost no problems with side-effects," he says. The researchers believe side-effects were limited because their virtual reality system is only semi-immersive, as opposed to a fully immersive head-mounted display system. "We're encouraged because we want to use this technology to work with persons with neurological impairments, some of whom have equilibrium, balance and orientation difficulties, and they might have a difficult time handling side-effects."

In future studies, Rizzo plans to administer the standard and virtual reality tests to subjects 65 and older, as well as to Alzheimer's disease patients, patients with other dementias and patients with head injuries. He and other USC researchers are currently designing a virtual environment to test children with attention deficit disorder.

"Virtual reality technology is emerging as a serious tool for mental health applications, and it has the potential to benefit patients with a wide range of cognitive impairments," says Chrysostomos "Max" Nikias, Ph.D., director of the USC School of Engineering's Integrated Media Systems Center.

The virtual reality research has been published in CyberPsychology and Behavior and the Journal of Head Trauma Rehabilitation. The study on gender differences was presented at a recent conference, "Medicine Meets Virtual Reality," by USC graduate student Peter Larson.

Other USC researchers working on the virtual reality project include research assistant professor Galen Buckwalter, Ph.D.; assistant professor Ulrich Neumann, Ph.D.; computer scientist Carl Kesselman, Ph.D.; and programmer Marcus Thiebaux.

The virtual reality tests were conducted at the Information Sciences Institute, which is part of USC's School of Engineering. The research is funded by the National Institute of Aging.