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Whether it’s hitting a golf ball, playing the piano, or speaking a foreign language, becoming really good at something requires practice. Repetition creates neural pathways in the brain, so the behavior eventually becomes more automatic and outside distractions have less impact. It’s called being in the zone.
But what if you could establish the neural pathways that lead to virtuosity more quickly? That is the promise of transcranial direct current stimulation, or tDCS — the passage of very low-level electrical current through targeted areas of the brain. Several studies conducted in medical and military settings indicate tDCS may bring improvements in cognitive function, motor skills and mood.
Some experts suggest that tDCS might be useful in the rehabilitation of patients suffering from neurological and psychological disorders, perhaps even in reducing the time and expense of training healthy people to master a skill. But the research is preliminary, and now there is concern about a growing do-it-yourself community, many of them video gamers, who are making tDCS devices with 9-volt batteries to essentially jump-start their brains.
“If tDCS is powerful enough to do good, you have to wonder if, done incorrectly, it could cause harm,” said Dr. H. Branch Coslett, chief of the cognitive neurology section at the University of Pennsylvania School of Medicine and a co-author of studies showing that tDCS improves recall of proper names, fosters creativity and improves reading efficiency.
Even the tDCS units used in research are often little more than a 9-volt battery with two electrodes and a controller for setting the current and the duration of the session. Several YouTube videos show how to make a rough facsimile.
“I’m stimulating my parietal lobes right now because I ran across some research that it increases mathematical abilities,” says a user in one such video, in which he appears with wires from a homemade tDCS device sprouting from his head. The video ends with him claiming to have improved his score in an online math game, although he reports feeling a little “wobbly” after removing the electrodes.
Others seeking a cognitive edge are rushing to buy a ready-made version called Foc.us, which costs $249. A sort of futuristic-looking headband with button-size electrodes, Foc.us is not approved by the Food and Drug Administration, and the London-based manufacturer does not make any medical claims. But fans posting on the tDCS forum on Reddit claim the device improves reaction time, mood, computational ability and memory.
Available online since May, the device was sold out of its first production run of 3,000 in less than a month. “The response has been overwhelming,” said Michael Oxley, a mechanical engineer who is the company’s founder and president.
Low-level electrical stimulation is thought to lower the threshold at which neurons fire, priming the brain to learn and retain information. Delivering 0.1 percent of the charge used in electroconvulsive therapy, which actually forces neurons to fire en masse, tDCS in clinical settings is generally recognized as safe.
About 30 clinics offer the treatment in the United States for various brain and neurological disorders, usually in a research context. Itching and redness under the electrodes are the most common side effects. Still, brain researchers warn that people who try experiments with homemade or Foc.us devices are risking injury.
There is little data on the long-term use of tDCS, and some experts worry is that in addition to serious external burns, people who self-administer could permanently damage their brains, impairing cognitive and motor function in subtle and not-so-subtle ways.
“What makes me very nervous about the Foc.us and homemade tDCS devices is the intensity and duration of current people are getting,” said Dr. Michael Weisend, a cognitive neuroscientist at Wright State Research Institute in Beaver Creek, Ohio, who conducts tDCS research for the Defense Advanced Research Projects Agency and the Air Force. “We have zero data on long-term use on anybody’s brain, and I have scars to prove that you can burn yourself pretty badly with tDCS.”
In the lab, researchers have been careful to place electrodes precisely in order to stimulate particular brain regions. Home users are likelier to guess by taking a quick look at an anatomy book. And the research experiments usually include instruction on how to perform the tasks.
“It’s not black magic,” said Dr. Roi Cohen Kadosh, a neuropsychologist and co-author of the University of Oxford study. “tDCS needs to be coupled with adequate cognitive training.”
Dr. Kadosh also warned that electrically juicing one area of the brain might degrade function in another part. “What we’ve found is brain power is like a blanket,” he said. “You pull it over to one side and something else is not covered.”
Because studies have shown that tDCS may be useful in treating people debilitated by stroke, Parkinson’s disease, depression, and obsessive-compulsive disorder, clinicians fear that in addition to competitive healthy people, severely compromised people may be tempted to experiment with brain stimulation at home.
“There’s a growing body of literature about tDCS, but there’s still so much to learn,” said Dr. Sarah Lisanby, a psychiatrist and director of the brain stimulation and neurophysiology division at Duke University School of Medicine in Durham, N.C.
“People should not be tempted by devices they can order online,” she said, nor buy do-it-yourself tDCS devices — no matter how often they’ve lost at Halo.