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 that the device improves reaction time, mood, computational ability and memory. . . .
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 Beavercreek, 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.”
Read more at NYTimes.com.