At a conference near Washington, D.C., in February, Military.com's Hope Hodge Seck reports that the commander of all Navy special operations units made an unusual request to industry: Develop and demonstrate technologies that offer "cognitive enhancement" capabilities to boost his elite forces' mental and physical performance.

"We plan on using that in mission enhancement," Rear Adm. Tim Szymanski said. "The performance piece is really critical to the life of our operators."

Seck reports that Szymanski expanded on his remarks in a brief interview later, saying he has his eye on a number of technologies, including pharmaceutical aids. But the results of one breakthrough involving the direct application of electrical stimulation to the brain have particularly caught his eye.

"In experiments, people who were watching these screens ... their ability to concentrate would fall off in about 20 minutes," Szymanski said. "But they did studies whereby a little bit of electrical stimulation was applied, and they were able to maintain the same peak performance for 20 hours."

Transcranial electrical stimulation was one of the technologies touted by then-Defense Secretary Ash Carter in July 2016 as part of his Defense Innovation Unit (Experimental), or DIUx, initiative. Since then, multiple SEAL units have begun actively testing the effectiveness of the technology, officials with Naval Special Warfare Command told Military.com.

"Earlier this year, Naval Special Warfare units, working with DIUx, began a specific cognitive enhancement project with a small group of volunteers to test and evaluate achieving higher performance through the use of neuro-stimulation technology," Capt. Jason Salata, a spokesman for the command, said in a statement.

The elements testing the technology include Naval Special Warfare Development Group, the unit known more popularly as SEAL Team Six. Other teams are also conducting tests, Salata said. He declined to confirm how many operators are participating in the testing, or to cite specific findings to date. But there have been positive outcomes so far, he said.

"Early results show promising signs," he said. "Based on this, we are encouraged to continue and are moving forward with our studies."

The company that makes the brain-stimulating device -- a headset that could be mistaken for a pair of Beats by Dre headphones -- is Halo Neuroscience. And the technology offers not cognitive enhancement, but neuro-priming, Chief Technology Officer and Company Co-Founder Brett Wingeier told Military.com.

Developed for elite athletes, the headset purports to work by stimulating the brain to enter a state of hyper-elasticity, allowing users to learn better and more efficiently. In physical training, he said, the technology has proven useful in developing explosive power for athletes whose sports require vertical leaps or sudden starts.

For operators, the same system could improve shooting performance, Wingeier said.

"Whatever you're training on as far as a movement-based skill," he said, "if you do deep practice, hard repetition, this accelerates the benefit of that."

Regardless of the technology or method, he said it is important that the military conduct robust tests and demonstrations on aids to human performance, contributing resources to making the warfighter stronger and more resilient the way it did to developing cutting-edge aircraft and gear.

"You really want to test these things in high-end training environments, which could tell you, do these matter in a warfare scenario," he said. "We need to really believe that investing in the human makes sense."

Szymanski signaled an interest in testing other performance-enhancement technologies, as well as pharmaceutical aids such as blood testosterone in the future. But he said he's approaching the field of enhancements carefully, with an eye to side effects, and warning operators not to take the first steps on their own.

"I'm always anxious, because I'm in a community of risk-takers," he said. "Guys may want to try experimenting on their own, which is against policy and has to be completely drug-tested and those types of things. So I'd want to do that in a very systematic kind of way."