By DAVID KOHN THE BALTIMORE SUN
Published Wednesday, July 2, 2008 at 4:30 a.m.

WASHINGTON — To a soldier who has been in Iraq, the sights, sounds and smells are familiar: the pop of an AK-47, the flash of a bomb, the stench of cordite.

The actual location, however, is not.

Here, in a small, windowless room at the Walter Reed Army Medical Center, researchers are using the latest video game technology -- plus a smell machine and a vibration platform -- to help patients suffering from post-traumatic stress disorder.

Known as "Virtual Iraq," the treatment could help many soldiers who do not find relief from medication or traditional psychotherapy.

"It really jogs their memory," says Col. Michael Roy, who runs the digital therapy program at Walter Reed. "It puts them back there very powerfully and makes them realize a lot of things they had consciously or subconsciously repressed."

Proponents of the new treatment say that once these memories are available, patients can begin to talk with therapists, eventually rendering the phantoms less terrifying.

Nationwide, only about 50 soldiers have undergone the treatment in the past three years -- leading some critics to say the treatment is still unproven.

In Iraq, Lt. Cmdr. Robert McLay, a Navy psychiatrist stationed at Camp Fallujah in Anbar province, has used the treatment on eight soldiers. He says all have gotten better.

"I'm getting very good success," he said.

The number of potential patients is enormous. Experts say post-traumatic stress disorder -- a debilitating ailment that leaves patients panicky, angry and haunted by battle memories -- is or will be a significant problem for many of the 1.7 million soldiers who have served in Iraq and Afghanistan. A study in the New England Journal of Medicine found that between one-quarter and one-third of all veterans from these conflicts will suffer from the disorder and other mental health problems.

In May, the Rand Corp. estimated that as many as 300,000 soldiers will experience post-war mental health problems.

"Virtual Iraq" immerses patients in the harsh world that produced their symptoms. After putting on virtual-reality goggles and earphones, patients are transported to two scenarios: a Humvee convoy through the desert or a foot patrol through a desolate city. They use a video game handset to control their movements, and by turning their heads, they can change what they see within that environment.

The therapist, who controls all variables in the environment except the patient's movement, slowly ratchets up the stress level by adding sirens, sniper fire and explosions.

This digital world is not only full of threats and stressors -- roadside bombs, insurgents firing grenades, a bleeding U.S. soldier slumped in the Humvee's passenger seat -- but also details that evoke everyday life for a soldier in Iraq.

Patients hear the sound of a Muslim prayer call and see Iraqi women walking to market in traditional clothes.

The setup also engages other senses. Under the patient's chair are powerful bass speakers embedded in a platform; when a bomb explodes onscreen, the concussion is palpable. Next to the computer console is a toaster-size odor machine; by inserting pellets, Roy can create a variety of aromas, including sweat, burning trash and Middle Eastern spices. He suspects that the scents and noise might be the most effective elements in evoking Iraq. The brain areas that process odor and sound are networked closely with the regions that play a key role in fear and memory -- two key components of post-traumatic stress.

The originator of "Virtual Iraq" is Albert "Skip" Rizzo, a psychologist and researcher at the University of Southern California. He got interested in the approach 15 years ago, while trying to rehabilitate people who had suffered traumatic brain injuries.

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