You Can't Really Get Smarter by Zapping Your Head With Electricity, Can You?

The quest to build better people.
April 1 2013 2:30 PM

Spark of Genius

A new technology promises to supercharge your brain with electricity. Is it too good to be true?

A doctor demonstrating a technique called transcranial magnetic stimulation, which affect neurons in the brain.
A doctor demonstrating a technique called transcranial magnetic stimulation, which affect neurons in the brain.

Courtesy of the Center for Brain Health

Scientists have rediscovered a centuries-old procedure for supercharging your brain. Depending on how it’s used, it could improve anything from focus to motor control to mathematical or even moral reasoning. It’s simple. It’s relatively cheap. The known side effects are minimal. And it’s so easy that you can do it in your own home, anytime you want. All you need are a pair of electrodes and a power source.

Will Oremus Will Oremus

Will Oremus is Slate's senior technology writer. Email him at or follow him on Twitter.

Happy April Fools’ Day, right?

Maybe. Incredible as it sounds, though, every claim in the paragraph above has been supported by experimental evidence. The procedure is called transcranial direct-current stimulation, or tDCS, and the idea has been around for 200 years, though it languished in disrepute until recently. The setup: You attach one electrode to your scalp above the part of the brain you’re trying to stimulate, and another electrode on the other side of your head, to complete the circuit. Then you turn on a milliampere or two of juice, and watch the mental sparks fly—figuratively, if you’re doing it right.


Almost every expert who talks about tDCS will tell you, “Don’t try this at home.” But a lot of people are starting to do just that. And it’s no wonder, given the parade of amazing results that researchers have reported achieving on subjects in the lab. It seems like you can make people better at just about anything if you just put the electrodes in the right place. To name just a few of the findings:

The potential applications for tDCS (and a related technology called repetitive transcranial magnetic stimulation, which uses magnets to induce a current) range from healing to educating to killing. Doctors are experimenting with tDCS to treat severe depression and help stroke victims regain their speaking skills. Students in theory could use it to solve math problems or pick up Russian. Air Force researchers are using it to make people better at guiding killer drones, and DARPA has found it could improve snipers’ marksmanship.

A few studies claim results that are even more jaw-dropping. In Neuroscience Letters last year, Australian researchers reported applying tDCS to 33 people as they tried to solve the notoriously tricky “nine-dot” logic problem. Not one was able to crack it without stimulation, or with “sham” stimulation (in which electricity is applied only briefly to mimic the feeling of tDCS). With current coursing between their left and right anterior temporal lobes, 40 percent solved it.

You might suspect the procedure would be painful or unpleasant. Many subjects report a tickling or burning sensation from the electrodes, and some say they feel different when the current is flowing, with time seeming to pass quickly. But far from finding it painful, an editor at New Scientist who tried it out during a marksmanship test described tDCS as “the most powerful drug I’ve ever used in my life” and “a near-spiritual experience.” The editor, Sally Adee, wrote:

“When a nice neuroscientist named Michael Weisend put the electrodes on me, what defined the experience was not feeling smarter or learning faster: The thing that made the earth drop out from under my feet was that for the first time in my life, everything in my head finally shut up. …  I felt clear-headed and like myself, just sharper. Calmer. Without fear and without doubt. From there on, I just spent the time waiting for a problem to appear so that I could solve it.”

Oh, and she nailed the target.