A soldier is riding in a humvee convoy through a Middle Eastern city where the smell of exotic spices and cooked lamb waft through the truck as it rumbles past burned out cars and bombed out buildings. In an instant, a second humvee explodes in front of the soldier's vehicle and the concussive force of the bomb shakes the truck.
This scenario is part of a new virtual reality system developed by researchers to help soldiers who are suffering from post-traumatic stress disorder (PTSD) brought on by their service in the Iraq war.
The goal of the system is to gradually expose the returning soldiers – by wearing the system's goggles and head phones – to the sights, sounds and smells that traumatised them in Iraq, said Albert Rizzo, research assistant professor at the Institute for Creative Technologies at the University of Southern California. The exposure should help ease the PTSD symptoms, he said. The Institute is developing the system jointly with the US Navy's Office of Naval Research.
Since beginning clinical trials using the system at the end of last year, six soldiers have been treated on it, Rizzo said. Four of those have seen "dramatic improvements," he said. In fact, he added, one of the treated soldiers has returned to Iraq and a second will soon go back.
The virtual reality system is based on a video game called Full Spectrum Warrior that was developed by the Army as a training tool. The researchers added graphics, sounds, vibrations and smells to the original game to create various scenarios mimicking those experienced by soldiers in Iraq, Rizzo said.
The scenarios include soldiers being shot at by insurgents, crashing in a helicopter or witnessing a bomb exploding. To help make the experience more real, the platform where the soldier sits can vibrate during a humvee ride and provide the smell of human sweat, gunpowder or burning rubber, Rizzo said.
"We're basically trying to use computer systems to create as immersive an environment as we can," he said. "The sense of smell is directly tied to areas of the brain that are responsible for memory and emotion."
Using a tablet PC, the person treating the soldier can gradually add more frightening stimuli. “With this technique, a person experiences a little bit of anxiety and they stick with it and talk about it, and eventually that anxiety extinguishes," Rizzo said.
Based on feedback from soldiers themselves, researchers have plans to enhance the realism of the system by adding more wounded people when a vehicle explodes or a building blows up, Rizzo said. They also plan to add specific emerging attack scenarios such as insurgents coming out of houses or attacking from rooftops and bridges, he added.