Brain Zapping is the Latest Weird Thing Pro Athletes Are Trying

Athletes are a superstitious lot. Think of a batter at the plate, adjusting his gloves, grinding his toe into the dirt, his motions as regimented as the rosary. Think of Michael Phelps, his back spotted with cupping bruises, his teammates striped with kinesiotape. Among the world's top authentic performers, the quest to outpace the competitors without doping often leads down strange, sometimes pseudoscientific paths.

The latest entry into this bizarro world is Halo Sport, a set of headphones that doubles as a brain enhancement tool meant to strengthen the neural pathways that connect your muscles to your motor cortex. After wearing the device for 20 to 30 minutes a few times a week during workouts, some users reported increases in strength, endurance, speed, and focus. They credit the benefits to a neurostimulation technology called tDCS, or transcranial direct current stimulation, which sends small electric jolts into your brain. Halo's users include the US Ski Team, several Olympic track and field athletes, and a handful of NFL players. The device became available to the public in November for the steep price of $749. (Though it's currently on "sale" for $699.)

Experts I spoke with, however, were skeptical of Halo Sport and its tDCS technology. There's no compelling evidence that low-dose electricity leads to performance gains. One researcher, Jared Horvath, became interested in neural enhancement as a PhD student at Melbourne University in Australia. There are several ways to administer tDCS's mild electric shocks, and eager to determine which one had the greatest impact on learning—and which he should focus his PhD on—he conducted a meta-analysis of the published results. The answer: None of them were any good. He's now a vocal skeptic.

Still, tDCS has generated enormous interest, much of it fueled by its low cost and harmlessness compared to other neurostimulation technologies such as TMS (transcranial magnetic stimulation) and ECT (electroconvulsive therapy, also known as electroshock). Unlike those techniques, which force-fire neurons, tDCS works with a much lower dosage of electricity that simply makes neurons more or less likely to fire, depending on the charge used. (Anodal excites, cathodal quiets.)   Because of inconsistencies in tDCS results, Halo, the company responsible for Halo Sport, functioned more like a research institute than a corporation for the first year of its existence, says company founder Daniel Chao. He and his team ran tests on "about a thousand people," trying to see which tDCS applications would bear marketable fruit. Some generated results, he says, but most were difficult to reproduce. Eventually they settled on a version that they decided showed the most consistency and promise in stimulating the motor cortex, the part of the brain dedicated to movements, like those necessary in athletics.

The very broad basis of Halo's claim is—sort of—borne out in the literature. The increased excitability of subjects' motor cortex is the single reproducible effect of tDCS. But it's imperceptible: Even if your motor cortex is excited, you won't feel any subjective cognitive results, Horvath says. You also won't jump higher or throw a baseball faster. "Motor excitability, at the end of the day, has nothing to do with motor learning or motor performance," he says.

Taking a more compromising stance, Marco Iacoboni, director of the neuromodulation lab at UCLA, thinks tDCS still might show promise. He echoed Horvath's assessment of the literature, calling it "a mess" and saying that any positive outcomes reflect less on the effectiveness of the technology and more on researchers' bias toward positive results. But the fact that tDCS is demonstrably stimulating motor cortexes means that the technology is doing something. It's just not clear exactly what. If nothing else, it provides a story that gives its users hope.

I sent Iacoboni a product description for Halo Sport. He thought it sounded like "a tiny bit of science and loads of induced expectations." And that might be the technology's secret weapon.

Expectations work quite well at creating results. In his studies, lacombi primes his subjects for tDCS treatment by giving them literature on the technology—one group reading that tDCS works brilliantly, the other that it's rubbish. And as a result, they perform differently on cognitive tests. Those who expect the device to work focus better, and those who are told it won't do not. His subjects, in other words, are responding to a very strong and convincing placebo effect.

"We are inducing beliefs in people such that they are more on task, more attentive," Iacoboni says. "And really there is nothing wrong with that."

It is worth remembering that nearly 50 percent of pharmaceuticals fail to reach market because they perform worse than placebos in clinical trials. Maybe that's less of a comment on the relative weakness of pharmaceuticals than on the very real physiological power of the placebo response. tDCS has made its own contributions to this body of work; research indicates that the technology may allow patients to lower their doses of pain meds or anti-depressants, for instance. And it may be because zapping your brain is a very effective placebo. So if a pair of fancy headphones can induce us to train harder or focus longer without the side effects of steroids or stimulants, who cares if it's all in our head? That brain boost—real or otherwise—may help explain why, in addition to pro athletes, Halo has also found an unexpected but enthusiastic market in musicians. One of the company's most vocal converts is spokesman Mario Marzo, a Spanish pianist who's been playing for 14 years. Musicians, like athletes, rely on motor learning. But unlike athletes, they don't often see performance benefits from technology. Football players get better shoes and sweat-wicking jerseys, but pianists won't play better with aerodynamic pedals or carbon-fiber keys.

Neuromodulators were the first products Marzo had seen that had the potential to accelerate his training. He says he uses his Halo Sport weekly—whenever he needs to learn a new piece. He published a video of his results, in which he learns two Bach preludes, one with the Halo, one without. His performance with the Halo, even to the untrained ear, blows the other away. Marzo claims he can tell the difference between "just concentration" and something beyond the norm. "I played a Bach prelude in three days, for 20 minutes a day," he says of his experience with Halo. "I don't know any one of my friends that could do that." Marzo also insists that Halo didn't approach him about the Sport. He conducted his own research on tDCS, and then found the company. Most of Chao's clients do this—invest in self-education before embarking on their own Halo journey. "The vast majority of the people we talk to come to us with a built-in interest in what we're doing," he says.

And that could be the key right there: The built-in interest of the people who buy it might, in its own way, mirror the manipulation that Iacoboni tests in the lab. In other words, if you expect Halo Sport to make you a better pianist or ski jumper before you put it on, then odds are, it will.