Nigel Parry for The New York Times
This couldn't possibly be a good idea. On Friday the 13th of September, in an old brick building on 13th Street in Boston's Charlestown neighborhood, a pair of electrodes was attached to my forehead, one over my brain's left prefrontal cortex, the other just above my right eye socket. I was about to undergo transcranial direct-current stimulation, or tDCS, an experimental technique for delivering extremely low dose electrical stimulation to the brain. Using less than 1 percent of the electrical energy necessary for electroconvulsive therapy, powered by an ordinary nine-volt battery, tDCS has been shown in hundreds of studies to enhance an astonishing, seemingly implausible variety of intellectual, emotional and movement-related brain functions. And its side effects appear limited to a mild tingling at the site of the electrode, sometimes a slight reddening of the skin, very rarely a headache and certainly no seizures or memory loss. Still, I felt more than a bit apprehensive as I prepared to find out if a little bit of juice could amp up my cognitive reserves and make me, in a word, smarter.
Nigel Parry for The New York Times
Dan Hurley sits for a brain-stimulation session.
With the electrodes in place, J. León Morales-Quezada, senior research associate at Harvard's Laboratory of Neuromodulation, pressed a button on his computer and I felt . . . absolutely nothing. No pain. No tingling. Not even a little muscle twitching.
"Is it on?" I asked.
Morales-Quezada assured me it was. For proof, he pointed to a flat-screen on the wall, displaying signals from six electroencephalogram (EEG) monitors also attached to my head.
After 10 minutes of charging my brain, he turned on a computerized exercise I was supposed to practice while the current continued flowing. Called an attention-switching task, it's used by psychologists as a measure of "executive function" or "cognitive control": the ability to overrule your urges, to ignore distractions and to quickly shift your focus. Young adults generally do better than older people; people with greater overall cognitive abilities generally perform better than those with less.
Scientific papers published in leading peer-reviewed journals since 2005 have shown that tDCS can improve the speed or accuracy with which people perform this attention-switching task. Other studies have found it can improve everything from working memory to long-term memory, math calculations, reading ability, solving difficult problems, piano playing, complex verbal thought, planning, visual memory, the ability to categorize, the capacity for insight, post-stroke paralysis and aphasia, chronic pain and even depression. Effects have been shown to last for weeks or months.
For my attention-switching task, Morales-Quezada explained that if I saw a plus sign on the computer screen, I had to decide whether the number of letters shown immediately after was odd or even, and then press either the "A" key with my left hand, or the "L" key with my right. But if I saw a triangle, he said, I had to decide whether the letters (all of them the same) were vowels or consonants, again by pressing either the "A" or "L" key.
Because I had only a few seconds to respond each time, and because the rule switched back and forth between odd-or-even and vowel-or-consonant, I found my fingers sometimes pressed the wrong key with a seemingly involuntary twitch, even when my conscious mind knew the correct response. It was the same maddening experience many of us have when fooling with our smartphones: meaning to press the camera icon, say, but hitting the calendar instead.
After 20 minutes of stimulation, Morales-Quezada checked my results: I gave 53 correct responses, seven wrong ones, and had an average reaction time of 3.1 seconds. Over five days, I would be stimulated with tDCS for eight 20-minute sessions. If my experience matched those of participants in his studies, I was supposed to either make fewer mistakes, or get faster, significantly more so than if I were not getting stimulated.
Dan Hurley is the author of ''Smarter: The New Science of Building Brain Power,'' which will be published next month by Hudson Street Press.
Editor: Ilena Silverman
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