I have been playing computer games since the late 1980s. The first computer game I played, Sleuth, was composed of ASCII graphics and text. You were trapped, Agatha Christie style, in a mansion with several other houseguests, one of whom was a killer. It was fun, but you definitely couldn't say that the graphics were immersive or anything approaching virtual reality. In Sleuth, your viewpoint was an overhead view of a very simple floor plan. But since then, computer games have evolved, and graphically they are now as far from Sleuth as the space shuttle is from a caveman's wheel.
As I said in a recent blog piece, I have often used computer games to escape from depression in the past. In fact, an increase in my computer game time is often my first indication that I've become depressed. So, as you can imagine, I was intrigued when I heard that scientists from the National Institute for Mental Health (NIMH) had done a study utilizing virtual reality technology from a computer game to measure the severity of depression in the study's subjects.
Several studies have demonstrated a correlation between depression and the size of the hippocampus, showing that someone with a mood disorder often has a smaller than normal hippocampus. It is believed that the hippocampus is a part of the brain that, among other things, controls spatial memory Our spatial memory records and stores information about our surroundings. Animals such as squirrels that hide caches of food often have larger hippocampi than animals that don't.
The study researchers wanted to test the hypothesis that an association exists between depression and the cognitive deficits that may result from this shrinkage or dysfunction. Previous studies of the impact of depression on spatial memory had not shown a difference between the depressed and healthy subjects. But the test utilized for these studies was a traditional two dimensional memory test, as opposed to a navigation exercise, which the NIMH study was based on. The researchers felt that involving navigation would utilize more of the hippocampus and demonstrate a difference between the depressed and non-depressed brain.
The researchers explained:
"Because of their multi-faceted nature, navigational tasks based on virtual reality may provide a more consistent, sensitive measure of spatial ability and are more likely to require hippocampal involvement, thereby increasing their sensitivity to the impact of depression on this cognitive domain."
Thirty subjects with depression (both unipolar and bipolar) and 30 non-depressed "comparison" subjects were given the task of navigating through a virtual reality "town" on the computer. Subjects who demonstrated a high expertise with video and computer games were excluded.
The town was modeled after a first-person shooter game called "Duke Nukem." First-person games are played from a first-person perspective as opposed to a overhead or aerial view. The first-person perspective gives you less information about where you are in the town than an overhead view would, and therefore more closely resembles a real-life navigational situation.
The subjects were given 20 minutes to familiarize themselves with the virtual reality town. They were then given 30 minutes to find at least three pre-determined locations. The researchers found that there was indeed a substantial difference in the amount of success in navigating the town between the healthy and depressed subjects. The healthy subjects found an average of 3.8 locations and the depressed subjects found an average of 2.4 locations.
On its own, this test is not particularly useful as a tool in diagnosing depression. But as a potential method of measuring the level of depression in someone who already has been diagnosed, it is definitely interesting. And speaking as someone who has gone through neuropsychological testing (to establish a baseline for my Multiple Sclerosis, not depression) it sounds like it would be a lot more fun.
Published On: June 28, 2007