Monday, November 16, 2015

EEG may someday boost Soldiers' cognitive ability | Article | The United States Army

EEG may someday boost Soldiers' cognitive ability | Article | The United States Army

New and complex technology for Soldiers can tax their mental ability, since the brain has finite processing capability, said David Hairston, a neuroscientist.

Hairston and his colleagues at the Army Research Lab's Human Research and Engineering Directorate want to someday use electroencephalogram, or EEG, to aid Soldiers in those mental tasks. He's leading the Real-World Neuroimaging program to make that happen.

The EEG, which has been in use now for more than 60 years in clinical practice, measures and records voltage fluctuations in different parts of the brain to determine a person's neural patterns. Those patterns provide insights into what a person is seeing, hearing, thinking and feeling - like peering into an individual's mental and emotional state, he said.

For instance, if a Soldier is fatigued, a unique EEG pattern will be produced, he said. That sort of information could be useful for a commander, who could rotate in a more rested Soldier for a critical mission requiring alertness.

Unfortunately, there's currently no way to monitor a Soldier's neural pattern out in the field, since EEG equipment is bulky and it's located in laboratories or a medical facilities.

Hairston's goal is provide positive results to Soldiers by leveraging what can be learned from an EEG. The challenge, Hairston said, is that science currently has very little understanding of how the brain works outside of the laboratory, because the brain is very rarely measured outside a clinical setting. He compared that task to putting together a giant jigsaw puzzle that's missing many of the pieces. "We have to create the pieces as we go along."


The first puzzle piece Hairston's team created was a simplification of how the EEG is hooked up to a person's head. The traditional method is attaching wired sensors to different parts of a person's scalp. A gooey gel is used on the person's head to facilitate electrical conductivity.

That gel and all those wires are messy, bulky, invasive, uncomfortable and time-consuming to connect, he said.

Instead of using gel, ARL researchers invented new sensors based on spring-loaded pins. "The pins wiggle their way through your hair to make contact, so you don't need gel." he said.


The second piece of the puzzle involved removing all the individual, separate wires and sensors from the scalp and encasing them in a custom-fitting, lightweight cap made of plastic that's fitted over the head.

The cap could be worn, he said, by an image analyst sitting in front of a computer, looking through images from an unmanned aerial vehicle, searching for a pattern, which might be, for example, an enemy emplacement or a tank.

When the analyst is pouring over thousands of images, he might miss something important because of the immense amount of cognitive processing required. Plus, it is a very time-consuming and tiring process.

Wearing the cap would facilitate that task with EEG, since "we can pick out that sort of ah-ha, pop-out moment in your brain, which happens very quickly," he said.

In other words, the Soldier's brain subconsciously picked out the signal, but the brain's internal communication didn't elevate it to the conscious level, he said.

Using an algorithm, a computer that's hooked up to the EEG would then process that information and quickly figure out that of 1,000 images, perhaps 10 are likely very important based on the EEG pattern, he said. Those could then be re-presented back to the Soldier very slowly so they can look for the target.

One problem though is that most EEG caps are not comfortable because they are designed as "one-size fits all," so people will not wear them long. As an alternative approach, Hairston picked up a prototype of a custom-fit cap that had been printed out by one of ARL's 3-D printers. The Soldier's head had first been measured in 3-D by magnetic resonance imaging, or MRI. The cap felt lightweight, spongy and comfortable, and would be a perfect fit for that Soldier.


Puzzle piece number three involved completely ditching the cap and wirelessly transmitting EEG data via a microprocessor. This is one of the most challenging stages.

ARL's material scientists are looking at a number of materials to make non-metallic polymer sensors that are stretchable and pliable so they'll be comfortable and lightweight, he said. "In order to do this, we must work as a multi-disciplinary, collaborative team, involving members from other areas including material science, aerospace engineering and electronics engineering."

The material holding the sensors and the sensors themselves would need to be thin enough to fit inside a Soldier's helmet safely, and the electronics operate only on locally-harvested power to alleviate the need for a bulky battery.

Hairston held up an example of one that's being tested. It was lightweight and comfortable. "We don't want to burden Soldiers with more equipment," he said.

The other parts of the puzzle would be getting the sensors to transmit on ultra-low power and getting the algorithms needed to assist Soldiers in a variety of tasks.

It's probably still years away from happening, he said.

But at ARL, it's about "taking what we know from basic neuroscience research and finding ways of turning that into useful applications for Soldier systems and future scientific methods and understanding of how the brain actually works in real, dynamic environments."