At least 47 medical studies are slated for this year, up from 40 last year and 20 in 2010, according to Army Lt. Col. Kevin Chung, who is coordinating the efforts. "This is the largest number of total projects we've had going," he says.

The studies look at the process of battlefield care, test new forms of treatment and diagnosis, or attempt to enhance understanding of brain injury.

Proponents of battlefield research cite a storied history of breakthroughs that included field ambulances in the Civil War and the discovery of the causes of yellow fever following the Spanish-American War.

"It's a real opportunity," says Maj. Gen. Richard Thomas, a doctor who returned from Afghanistan in February. "Combat is the greatest catalyst to medical innovation."

This year, hundreds of soldiers and Marines off the front lines are carefully being asked for consent to have their brains scanned, blood taken or reaction time monitored.

"They have to volunteer to participate," says Navy Lt. Cmdr. Octavian Adam, a neurologist leading efforts at a military hospital in Kandahar that involve imaging the brains of troops exposed to blasts. "Most of them … want to help."

Adam's research uses advanced techniques for magnetic resonance imaging (MRI), to, for the first time, actually see evidence of mild traumatic brain injury or concussion caused by exposure to the many buried explosives that detonate during foot patrols by troops in Afghanistan.

More than 400 U.S. servicemembers suffered these wounds last year. Three MRI machines were installed in the Afghanistan war zone for the first time last fall.

Some of the other research:

•Scientists will draw blood from troops who suffer concussions to test for proteins released when brain damage occurs — signs of a potential biomarker for future diagnostic help.

•An Air Force study will try to understand how damaged brains react to lower external pressure during high-altitude medevac operations.

•The Army plans to conduct what may be its final field study into the behavioral health and psychological treatment of troops in combat, an effort where hundreds are surveyed or participate in focus groups.

"It is a huge challenge, as you can imagine, to try to do things like this in a war zone," says Army Col. Dallas Hack, director of the Pentagon's trauma research.

While the research costs are minimal because scientists often double as medical care officers for the troops, the logistics can be daunting.

With Afghan troops slated to take over combat operation next year and U.S. troops withdrawing in 2014, the chance to better understand the effects of combat is quickly passing away, Hack says.

"It's a shame for these injuries to occur and not learn as much from them as we can," he says.