High-tech simulators and physical tests are used to measure a soldiers’ readiness for combat. Now, however, researchers are also examining how soldiers’ brains react to fear in order to determine how they will react on the battlefield and subsequently recover when their tour of duty is over. Reader’s Digest delved into the concept of “warrior brains,” minds that assess accurately and act cognitively when faced with risk, and explored how scientists are using this idea to help soldiers recover from and prevent post-traumatic stress disorder.

To understand what goes wrong in the brains of combat veterans who develop PTSD, and to try to prevent it from happening to others, neurobiol­ogist Lilianne Mujica-Parodi, PhD, has spent years tossing volunteers with sensors all over their bodies out of airplanes. Her Navy-funded research measures physical fear responses, comparing sheer fright factors to the results of mental-processing tests she administers before, during, and after the skydiving flight.

Mujica-Parodi has discovered that in most cases, the brain does some predictable things when a hu­man jumps out of a perfectly good airplane. Stress hormones flood the fear-response system, and thoughts narrowly focus on one thing: getting out of the air and onto the ground.

There are, however, the unflap­pable few subjects who don’t experi­ence this wild swing of mental and physical reactions. They demon­strate some of their clearest thinking in the middle of a plunge, and when it’s over, their fear-response systems quickly return to normal.

“You don’t want someone without a fear response at all,” Mujica-Parodi says. “That’s not brave; that’s just abnormal. But a high stress response is also unhealthy.” The optimal fear response, she says, accurately as­sesses risk, saves room for cognitive thought, and rapidly returns to base­line when the danger passes. Brains that can do this are a gift of DNA, ac­cording to Mujica-Parodi, what she calls warrior brains. The soldiers who possess them benefit from an ideal balance of neurological and biologi­cal responses.

Using brain scans, Mujica-Parodi has seen how the fear-response sys­tem “cools down” faster in warrior brains than it does in the brains of more vulnerable subjects.

While her research is still experi­mental, Mujica-Parodi maintains that it’s now possible to identify someone with either a warrior brain or a vul­nerability to stress disorders with the same certainty that we can diagnose an increased risk for diabetes. She en­visions a day in the future when a brain scan will be part of military training, though there are no plans in any branch for such screening, which would surely raise a host of ethical is­sues. “You wouldn’t accept someone in Special Forces if he had weak legs,” she says. “Soon we’ll be able to screen people for emotional weaknesses. A person with an incapacitating fear response is a danger to himself, his team, and the mission.”

Read the rest of this article at Reader’s Digest.