The $749 Halo Neuroscience headset (below) looks a lot like regular headphones, and does actually play music. However, it also has silicon spikes on the band called "neuroprimers" that contact a wearer's head. Those emit electrical impulses that supposedly stimulate the motor cortex, a part of the brain that's key for athletes, soldiers and others who perform physically demanding tasks.

The soldier or athlete simply sprays the spikes with saline solution to ensure good electrical contact, then wears the headset during warmups. The tingling they feel on their scalp supposedly increases the "neuroplasticity" of the brain, making it more receptive than usual to training. The company insists that they're ideal for elite athletes or soldiers, where a small improvement in performance can make the winning (or living) difference.

The idea is to make training shorter and more efficient for Navy SEALs, who are already running on the ragged edge. "They're training at this amazingly high level, and the amount they can train is actually limited by things like physical recovery," Halo Co-founder Bret Wingeier told Military.com. "They want to build and maintain these amazing physical skills, but do so just as efficiently as possible."

The effort is part of Navy Special Operations Commander Tim Zymanski's industry challenge to develop "cognitive enhancement" technology for soldiers. While that could include pharmaceutical aids and other things, the military is particularly interested in neuro-stimulation tech as a way to enhance both performance and learning.

Halo claims that the devices have improved the performance of Olympic and professional athletes (like the San Francisco Giants, above), but they can't necessarily prove that those gains are the direct results of the headset and not, say, a placebo effect or that "Workout Twerkout" Spotify playlist. For now, however, the military is convinced, and thinks its a better option than "smart drugs" like Modafinil or amphetamines.

"In experiments, people who were watching these screens ... their ability to concentrate would fall off in about 20 minutes," said Szymanski. "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."