U.S. Department Of Defense Brain Study Seeks To Boost Learning In Soldiers

By Nicholas Gerbis
Published: Thursday, July 27, 2017 - 6:05am
Updated: Friday, May 18, 2018 - 4:02pm

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Posterior Parietal Cortex
(Image courtesy of Stephen Helms Tillery - Arizona State University)

Whether mathematicians or marathoners, those who chase mastery often run into a wall that blocks further progress. Now, eight U.S. Department Of Defense brain studies, one at Arizona State University, aim to help soldiers break through that barrier.

The research, called Targeted Neuroplasticity Training (TNT) joins a range of Defense Advanced Research Projects Agency (DARPA) programs related to the White House BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative.

Announced by President Barack Obama in 2013, the BRAIN Initiative supports research into new treatments, cures and prevention strategies for brain disorders.

The agency hopes not just to make better sharpshooters, but also to shorten training periods for translators, analysts and cryptographers — and, perhaps, to improve outcomes for soldiers with brain injury and memory loss.

ASU’s team will concentrate on physical and motor functions among experts.

“Our focus is really on enhancement, and enhancement in people who are superior performers already,” said Stephen Helms Tillery, an associate professor in the School of Biological and Health Systems Engineering at ASU.

Helms Tillery leads the project, which studies how a key brain chemical, norepinephrine, affects skills — like marksmanship — that link senses, decisions and actions.

“Norepinephrine is essentially the fight-or-flight neuromodulator," said Helms Tillery.

When you wake up to a strange sound — tense, eyes wide, ears straining — that’s norepinephrine flooding your brain. Chris Buneo, an associate professor in ASU’s School of Biological and Health Systems Engineering who also works on the project, explained the educational advantage of alarm.

“You’re able to attend more to what you’re doing; that will accelerate the learning process,” said Buneo.

Norepinephrine also affects neuroplasticity — the brain’s ability to rewire itself to react, repair and learn. The mechanisms involved remain unclear, but Helms Tillery expressed one possibility.

“One of the things that we think happens with norepinephrine is that it sort of enhances what we call the ‘signal-to-noise ratio,’” Tillery said.

The brain is organized chaos. It’s noisy — not just with the voices of doubt and recrimination that we hear inside our minds, but with random electrical static that impedes neurons as they pass signals in the brain itself.

“For something of interest to come to your attention, it has to step out of that noise a little bit,” said Helms Tillery.

If noise is a complex, chaotic music, then signal is a melody or bass line, boosted by norepinephrine from the brain’s locus coeruleus. Scientists can trigger this area of the brain stem nonsurgically by “zapping” certain nerves. The zap is provided by the laboratory equivalent of the electrical stimulation machines that physical therapists use for treating pain and muscle spasms.

Trigeminal nerve
(Image courtesy of Stephen Helms Tillery - Arizona State University)

Previous research has focused on the vagus nerve, a large neck nerve that regulates vital body functions, but ASU will use the trigeminal nerve in the face.

Canadian artist The Weeknd probably wasn’t talking about the trigeminal nerve when he sang, “I can’t feel my face when I’m with you,” but he could have been. Its three branches enable the brain to sense the face — when someone touches it, where its various parts are located relative to one another, when it experiences heat or cold, and so on.

Such peripheral nerves can also act as a hotline between sensory input and the central nervous system.

“Actually, this is kind of the big gap, is the link between the stimulation of these peripheral nerves and the cortical changes,” said Buneo.

Helms Tillery said that researchers can detect whether the stimulation has succeeded by watching for physical cues.

“Your pupils dilate; the skin on your nose actually cools down, so we can measure the temperature on your nose; you get changes in sweat pores that we can measure using high resolution cameras," said Helms Tillery.

So, to recap, electrically stimulating a facial nerve triggers the brain to release a chemical that improves learning. But, as Buneo explained, another element is required to ensure that they boost the signal and not the noise.

“It’s going to be equally important to devise tasks that challenge the brain while you’re providing the stimulation, and find the right type of task," he said.

For example, a sharpshooter might play a computer-based aiming game with ever-changing physics rules.

“So people always have to be on their toes and capable of learning this new task,” said Helms Tillery.

TNT Concept graphic
(Image courtesy of U.S. Department of Defense)

But that’s just the first step, as Buneo explained.

“Later on, we’ll add other tasks that involve explicit decision-making," Buneo said.

In this case, that will mean a virtual shooting range, where sense input, body awareness and muscle control meet decision making.

“It’s a beautiful task, because it combines the decision making with this sensorimotor interface and sensory perception,” said Helms Tillery.

Effective or not, such research raises ethical questions; it dips its toe into the vast ocean of possibility — and societal ripples — that brain augmentation represents.

In the short term, despite precautions and monitoring, side effects remain a possibility. Buneo expects minor effects at worst, and said that routine checkups following each session should reveal any potential issues. Helms Tillery agreed.

“We don’t really anticipate those kinds of risks. People have been doing this kind of stimulation for a long time in lots of different environments,” he said.

Helms Tillery admitted that it’s impossible for such research to eliminate risk, including that of addiction.

“We do think that we’ll probably be activating rewards circuits as well. And so, if you’re activating reward circuits and hedonic circuits, then the possibility for addiction potential — it’s not zero,” he said.

And, for some, using such techniques to “build a better soldier” only deepens the moral fog.

“Of course we should be worried about building better warfighters,” said Jason Robert, director of the Lincoln Center for Applied Ethics at ASU. “At the same time, we also should be worried about making sure that the warfighters we have are not being inappropriately sacrificed because we haven’t done what we could do.”

Review boards weigh such risks against benefits before signing off on work with human or animal subjects. But some questions reach beyond their purview. Robert listed a few.

“What it means to be human, what it means to learn, what it means to function as part of a civilization,” he said.

How the team’s work will ultimately figure into those answers, only time will tell. But the researchers hope it might one day help people with cognitive declines and impairments.

“Could be Alzheimer’s, could be stroke, could be anything where enhancing the learning process would be beneficial,” said Buneo.

Many “ifs,” and quite some time, stand between this work and those possibilities. But hope, too, is good for the brain.

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