Everyone knows there are some instinctual reactions to threats. It could be anxiety from standing too close to the edge of a cliff, or a flinch from a punch. But the exact neuroscience behind those reactions are still something of a mystery.

Darpa, the Pentagon's advanced research division, now wants to find out. The agency has awarded a $300,000 grant over two years to a researcher from the University of Colorado at Boulder, to use neuroeconomic models to study how the way we move changes when faced with threats. Dr. Alaa Ahmed, a professor of integrative physiology, hopes to eventually change – and improve – those reactions. There's even a chance that this could inform the development of new weapons.

"Traditionally, in movement control, it's always been assumed that we're rational decision makers, that we have a good estimate of the movement uncertainty – like how accurate I am – and that we have a good estimate of the reward structure in the task, whether it's explicit or implicit," Ahmed tells Danger Room.

Of course, people are not that rational. Instead, Ahmed says, "people seem to be irrational in their movement decision, which suggests that risk is influencing the decision." There's no confirmed link between the threat and movement, but one way to find out is to study the different ways the risk-seekers and risk-averse among us physically react when faced with a threatening situation.

For soldiers, it could mean overreacting – or underreacting – when making decisions during combat, which could have potentially lethal repercussions such as pulling a trigger. "In an environment of COIN [counterinsurgency] or stability operations, a split-second decision by a corporal under stress can have significant and profound consequences on the whole of U.S. interests in a given theater," (.pdf) wrote Col. Kevin Felix in a 2011 paper arguing for increased military research on decision science.

Ahmed plans to test the theory – the link between threat and movement is still largely unexplored – in a laboratory equipped with movement games designed to test motor and non-motor skills. In one test, participants stand on a platform and control a cursor on a screen. The participants control the cursor by leaning forward, and have to reach a target. Ahmed wouldn't say what the target is, exactly, but she gave an example of a cliff. The closer you move the cursor to the edge of the cliff, the more points you get. But if you get too close and fall off the cliff, you lose. Another game operates along a similar design, but uses a joystick to control a robotic arm.

The tests use fairly simple economic models. When we're faced with a task that has a high degree of uncertainty, and given the choice between a high-risk reward and a sure bet, risk-seekers could be more likely to go for broke. For the risk-averse, or those with a tendency to avoid risky situations, it could mean being needlessly cautious.

If a link between those models and how we move is found, then one outcome might be updated military training programs. It's not specifically included in the grant, but one possibility is creating physical simulations to provoke moderate stress in soldiers, then placing the soldiers into a high-stress environment, studying the results, and then training troops' minds to reach the best outcome.

But it may have more uses beyond improving troops' mental and physical performance. It could also be used against an enemy. "This proposal is about decision making, we want to understand the decision making process," Ahmed says. "So it stands to reason that if you can understand it, then you can manipulate it, whatever, whoever it is can be manipulated. So it's not just about our troops, and our side. But it also means you can expand that to the other side as well," she says.

Ahmed cautions that using neuroscience against an enemy is speculative, and that the link between threat and movement has yet to be deduced. Still, it's not the first time the military has taken an interest in using neuroscience to read minds – and perhaps one day weaponize fear. In 2010, the Pentagon outlined plans for embedded body sensors to determine mental alertness. Darpa has also fielded ideas for interest in a system to boost memory recall.

During the 2000s, Darpa spent tens of millions of dollars researching brain activity in pilots. Called Augmented Cognition, the idea has run its course but attempted to build computers that can interact with human brains. The computer interfaces, Darpa hoped, would read a pilot's brain and then use the data to determine which information to display. In 2009, the Air Force unveiled an effort to research bio-science to improve cognition and "degrade enemy performance" by manipulating the brain's chemical pathways to "overwhelm enemy cognitive capabilities."

Darpa's look into how we respond to threats might not be as far-flung, although the research is still in the very early stages. Whether – and how – the research could be used as a weapon is hypothetical. But the military might not need to go as far as that, if there are troops handling threats better than their foes.