"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.