How electrical brain stimulation can change the way we think
After my brain was jolted, says Sally Adee, I had a near-spiritual experience
Researchers have found that "transcranial direct current stimulation" can more than double the rate at which people learn a wide range of tasks, such as object recognition, math skills, and marksmanship.
Researchers have found that "transcranial direct current stimulation" can more than double the rate at which people learn a wide range of tasks, such as object recognition, math skills, and marksmanship.
Adrianna Williams/Corbis

AVE YOU EVER wanted to take a vacation from your own head? You could do it easily enough with liberal applications of alcohol or hallucinogens, but that's not the kind of vacation I'm talking about. What if you could take a very specific vacation only from the stuff that makes it painful to be you: the sneering inner monologue that insists you're not capable enough or smart enough or pretty enough, or whatever hideous narrative rides you. Now that would be a vacation. You'd still be you, but you'd be able to navigate the world without the emotional baggage that now drags on your every decision. Can you imagine what that would feel like?

Late last year, I got the chance to find out, in the course of investigating a story for New Scientist about how researchers are using neurofeedback and electrical brain stimulation to accelerate learning. What I found was that electricity might be the most powerful drug I've ever used in my life.

It used to be just plain old chemistry that had neuroscientists gnawing their fingernails about the ethics of brain enhancement. As Adderall, Ritalin, and other cognitive enhancing drugs gain widespread acceptance as tools to improve your everyday focus, even the stigma of obtaining them through less-than-legal channels appears to be disappearing. People will overlook a lot of moral gray areas in the quest to juice their brain power.

But until recently, you were out of luck if you wanted to do that without taking drugs that might be addictive, habit-forming, or associated with unfortunate behavioral side effects. Over the past few years, however, it's become increasingly clear that applying an electrical current to your head confers similar benefits.

U.S. military researchers have had great success using "transcranial direct current stimulation" (tDCS) — in which they hook you up to what's essentially a 9-volt battery and let the current flow through your brain. After a few years of lab testing, they've found that tDCS can more than double the rate at which people learn a wide range of tasks, such as object recognition, math skills, and marksmanship.

We don't yet have a commercially available "thinking cap," but we will soon. So the research community has begun to ask: What are the ethics of battery-operated cognitive enhancement? Recently, a group of Oxford neuroscientists released a cautionary statement about the ethics of brain boosting; then the U.K.'s Royal Society released a report that questioned the use of tDCS for military applications. Is brain boosting a fair addition to the cognitive enhancement arms race? Will it create a Morlock/Eloi–like social divide, where the rich can afford to be smarter and everyone else will be left behind? Will Tiger Moms force their lazy kids to strap on a zappity helmet during piano practice?

After trying it myself, I have different questions. To make you understand, I am going to tell you how it felt. The experience wasn't simply about the easy pleasure of undeserved expertise. For me, it was a near-spiritual experience. 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.

The experiment I underwent was accelerated marksmanship training, using a training simulation that the military uses. I spent a few hours learning how to shoot a modified M4 close-range assault rifle, first without tDCS and then with. Without it I was terrible, and when you're terrible at something, all you can do is obsess about how terrible you are. And how much you want to stop doing the thing you are terrible at.

Then this happened:

THE 20 MINUTES I spent hitting targets while electricity coursed through my brain were far from transcendent. I only remember feeling like I'd just had an excellent cup of coffee, but without the caffeine jitters. 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.

It was only when they turned off the current that I grasped what had just happened. Relieved of the minefield of self-doubt that constitutes my basic personality, I was a hell of a shot. And I can't tell you how stunning it was to suddenly understand just how much of a drag that inner cacophony is on my ability to navigate life and basic tasks.

It's possibly the world's biggest cliché that we're our own worst enemies. In yoga, they tell you that you need to learn to get out of your own way. Practices like yoga are meant to help you exhume the person you are without all the geologic layers of narrative and cross talk that are constantly chattering in your brain. I think eventually they just become background noise. We stop hearing them consciously, but believe me, we listen to them just the same.

My brain without self-doubt was a revelation. There was suddenly this incredible silence in my head; I've experienced something close to it during two-hour Iyengar yoga classes, or at the end of a 10k, but the fragile peace in my head would be shattered almost the second I set foot outside the calm of the studio. I had certainly never experienced instant Zen in the frustrating middle of something I was terrible at.

WHAT HAD HAPPENED inside my skull? One theory is that the mild electrical shock may depolarize the neuronal membranes in the part of the brain associated with object recognition, making the cells more excitable and responsive to inputs. Like many other neuroscientists working with tDCS, Weisend thinks this accelerates the formation of new neural pathways during the time that someone practices a skill, making it easier to get into the "zone." The method he was using on me boosted the speed with which wannabe snipers could detect a threat by a factor of 2.3.

Another possibility is that the electrodes somehow reduce activity in the prefrontal cortex — the area of the brain used in critical thought, says psychologist Mihaly Csikszentmihalyi of Claremont Graduate University in California. And critical thought, some neuroscientists believe, is muted during periods of intense Zen-like concentration. It sounds counterintuitive, but silencing self-critical thoughts might allow more automatic processes to take hold, which would in turn produce that effortless feeling of flow.

With the electrodes on, my constant self-criticism virtually disappeared, I hit every one of the targets, and there were no unpleasant side effects afterwards. The bewitching silence of the tDCS lasted, gradually diminishing over a period of about three days. The inevitable return of self-doubt and inattention was disheartening, to say the least.

I HOPE YOU can sympathize with me when I tell you that the thing I wanted most acutely for the weeks following my experience was to go back and strap on those electrodes. I also started to have a lot of questions. Who was I apart from the angry bitter gnomes that populate my mind and drive me to failure because I'm too scared to try? And where did those voices come from? Some of them are personal history, like the caustically dismissive 7th grade science teacher who advised me to become a waitress. Some of them are societal, like the hateful lady-mag voices that bully me every time I look in a mirror. An invisible narrative informs all my waking decisions in ways I can't even keep track of.

What would a world look like in which we all wore little tDCS headbands that would keep us in a primed, confident state, free of all doubts and fears? I'd wear one at all times and have two in my backpack ready in case something happened to the first one.

I think the ethical questions we should be asking about tDCS are much more subtle than the ones we've been asking about cognitive enhancement. Because how you define "cognitive enhancement" frames the debate about its ethics.

If you told me tDCS would allow someone to study twice as fast for the bar exam, I might be a little leery because now I have visions of rich daddies paying for Junior's thinking cap. Neuroscientists like Roy Hamilton have termed this kind of application "cosmetic neuroscience," which implies a kind of "First World problem" — frivolity.

But now think of a different application — could school-age girls use the zappy cap while studying math to drown out the voices that tell them they can't do math because they're girls? How many studies have found a link between invasive stereotypes and poor test performance?

And then, finally, the main question: What role do doubt and fear play in our lives if their eradication actually causes so many improvements? Do we make more ethical decisions when we listen to our inner voices of self-doubt or when we're freed from them? If we all wore these caps, would the world be a better place?

And if tDCS headwear were to become widespread, would the same 20 minutes with a 2 milliamp current always deliver the same effects, or would you need to up your dose like you do with some other drugs?

Because, to steal a great point from an online commenter, pretty soon, a 9-volt battery may no longer be enough.

©2012 by Sally Adee, reprinted by permission of New Scientist. The full article can be found at



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