Iraq war veterans are revisiting the combat zone with the help of virtual-reality; helping researchers understand how post-traumatic stress disorder develops…
Virtual reality therapy has been used to treat combat veterans suffering from post-traumatic stress disorder since the late 1990s. Now a researcher in New York City is using it to see how the problem might develop.
Loretta Malta, a psychologist who teaches at the Weill Cornell Medical College in Manhattan, is conducting a study that focuses on soldiers who served in the Iraq and Gulf wars.
Each veteran watches a clip from a digital simulator called “Virtual Iraq” while heart and respiratory rates are monitored. Afterward, participants talk about their emotional responses to the scenes.
“We’re trying to find out what might contribute to post-traumatic stress disorder, and what might predict its onset,” Malta said.
Post-traumatic stress disorder, or PTSD, can develop after someone has endured a terrifying ordeal in which she is physically harmed or threatened with harm. Sufferers have scary flashbacks, become numb, irritable and disconnected, and may have violent outbursts.
Studies have shown a genetic susceptibility to PTSD, though not everyone develops the condition after a traumatic experience.
For the current study, each subject wears a headset wired with headphones that block out noise and immerse its wearer in sounds typical of combat zones—machine-gun fire, men yelling orders, the rapid footsteps of soldiers running for cover.
The connected goggles look like hardware right out of Vonnegut’s “Harrison Bergeron”—a wired assemblage of two plastic boxes hooked to suction-cup eyepieces. Those boxes hold small screens that give the patient a 3-D view of the virtual battle scene.
Similar headgear is used in treatment, but there a therapist works with software that features a variety of combat scenarios. The latest programs rely heavily on recycled graphics and audio from the military training video game “Full Spectrum Warrior.”
A scene might unfold at a military checkpoint, a building’s interior or the ruins of a desert town where ambushes might occur—scene choices abound, as do the number of ways each can be tinkered with.
Patients see the blasted wreckage of tanks and Jeeps. They might scour minefields or run into wounded civilians crying for help. Also, inevitably, each will encounter battle-torn corpses, including those of American soldiers.
Treatment programs often feature bass shakers that set the patient’s chair trembling, echoes of a Humvee or helicopter ride. Also, a USB-driven Scent Palette releases war-zone odors such as gunpowder, diesel fuel, body odor and even a whiff of Iraqi cooking spices.
In these sessions, replaying simulated battle scenes helps patients dredge up memories of their combat experiences in order to get to the bottom of what haunts them.
For Malta’s study, subjects watch one virtual scenario. Then, half of the group is asked to talk about the scenes while the others are asked to suppress them.
According to Malta, when a soldier tries to forget about a traumatic experience, whatever he felt at the time also gets tamped down, rather than examined and let go.
"Theories of PTSD propose that initially suppressing thoughts about the trauma maintains the level of fear and anxiety associated with the trauma," Malta said. “If they can’t access their memories, then they can’t work through them and get better.”
Sometimes access isn’t the problem—it’s not having control of that access.
Previous research suggests that patients who suppress memories tend to have “rebound” thoughts. That is, if a soldier kills someone in battle, then later tries not to think about it, sometimes those censored images end up intruding anyway.
Symptoms of PTSD usually pop up within months of the traumatic event. However, years have been known to pass before something – a flashback, say, or a visceral image or even a certain odor – sets those symptoms in motion.
Malta hopes to verify this hypothesis in her study as well as examine how initial emotional reactions play a part in the onset of PTSD. She said she expects to publish the study’s findings by the end of 2008.
