Does Passing A Small Current Through Your Brain Really Make You Smarter?

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Want to be smarter, solve difficult puzzles, learn the piano in half the time? All you need is a little shock. A growing number of scientists are claiming that passing a small current through the brain increases our aptitude. One need only to strap on the headgear, press the button, and sit back while mediocrity is zapped from your brain.

The ‘miracle’ boost is supposedly delivered through what’s called transcranial direct current stimulation (tDCS). The stimulation is a steady current of 2 milli-amps – about the same as a 9-volt battery – delivered through electrodes worn on the head and arm. The mild electric current is enough to depolarize neurons in the cerebral cortex and supposedly make it more receptive to new input. That is, the brain is primed to learn more easily.

At first blush this might sound more like psuedoscience than science. But several studies have shown that people learn faster with the battery strapped to their heads, giving new meaning to getting “the juices flowing.”

Last year scientists at the Mind Research Network in Albuquerque, New Mexico tested the ability of tDCS to improve people’s performance on a threat identification task. Participants were trained on the virtual reality simulation DARWARS AMBUSH! that the US military uses to train soldiers how to recognize and react to enemy ambushes and improvised explosive devices (IEDs). A baseline performance level was assessed, followed by a 1-hour training session, then a post-training test session in which participants were asked whether or not a threat was present. One group of participants received 2 mA tDCS for the first half and hour of the training session while another group received a meager 0.1 mA dose as a negative control.

tDCS enhanced participants' ability to identify threats in the simulation game DARWARS AMBUSH!

Turns out that tDCS enhances training. The high dose group performed better at threat identification than the the group with the low dose. The enhanced performance is also accompanied by an altered state of awareness. “The number one thing I hear people say after tDCS is that time passed unduly fast,” lead scientist of the study, Michael Weisend, told New Scientist. They feel more focused and calm, he says, and their performance certainly makes it seem as though they were.

Previous studies show similar results. A 2005 study showed tDCS improved working memory, and a 2008 study showed tDCS improved language learning. A third study published earlier this year showed that tDCS delivered to the parietal cortex, a part of the brain through which visual information flows, enhanced visual short-term memory compared to placebo.

So if the effects are real, what are the 2 mA of current doing to the brain? Weisend and colleagues have tried to answer that question with brain imaging.

The brain’s magnetic field changes in response to sensory stimulation such as with sound, touch and light. With magnetoencelography (MEG) Weisend’s group showed that response magnetic fields of individuals who had received tDCS had amplitudes six times greater than baseline amplitudes. By contrast, individuals who had received a mock tDCS that gave the same sensation (it tingles) showed no boost over baseline. Furthermore, the tDCS group still showed a 2.5-fold boost in their magnetic fields 50 minutes after stimulation.

Trying to uncover anatomical changes, the group then conducted a study using diffusion tensor imaging (DTI) scans that can visualize the white matter fiber tracts connecting different parts of the brain. DTI showed clear changes in brain structure only five days following stimulation. White matter nerve fiber tracts were “more robust and more highly organized” in the hemisphere which had received tDCS. In contrast, the side of the brain that did not receive stimulation showed no structural changes in the white matter.

Anyone who pays attention to the neuroscience of cognitive performance research might be reminded of the studies that tried to unlock they mystery of “the zone,” that Zen-like mental state that athletes seem to achieve for a time to elevate their performance head and shoulders above their peers. Except it wasn’t called the zone back in the seventies when the research began. It was called the similarly enigmatic “flow.”

The Hungarian psychologist and pioneer into “flow” research, Mihaly Csikszentmihalyi, performed EEG brain recordings on world class chess players engaged in a game. The recordings showed decreased activity in the prefrontal cortex, the part of the brain nicknamed the “CEO of the brain” for its role in higher cognitive processes such as analysis and abstract thought. Csikszentmihalyi surmised that the decreased prefrontal activity during high level chess play suppressed self doubt and allowed a more unguarded, automatic type of performance.

More recently, in 2010, Chris Berka, co-founder of Advanced Brain Monitoring performed EEG scans on professional golfers and Olympic archers. The scans showed that, in the moments before hitting a golf ball or firing off an arrow, the athletes’ brains produced more alpha waves. The alpha waves are produced by the aggregate activity of all the brain’s neurons. Alpha waves have also been shown to be associated with decreased activity in the cortex so that, as Csikszentmihalyi thought, distracting thoughts could be tamped down to make way for physical command made intuitive through extensive practice. “We think this represents focused attention on the target, while other sensory inputs are suppressed,” Berka told the New Scientist. The alpha spike was more pronounced in experts compared to novices as if the longterm nurturing of the high-performance alpha waves yield more reward when uncovered. One might think it the brain scan imagery for Timothy Gallwey’s “The Inner Game of Tennis.”

The Focus v1 awaits FDA approval in the US.

No matter what it’s called, it should come as no surprise that companies are already straining their own intellect to find ways to market devices that unleash our mental potential between a pair of electrical leads. The Focus v1 is a transcranial direct current stimulator that looks like a headband. Worn above the temples, the v1 delivers 2 mA of tDCS current for “enhanced concentration.” tDCS – or the Focus v1 – is not recognized by the FDA as a treatment and thus is not available in the US. But the v1 appears to be available outside the US.

So, with tDCS, will psychologist Anders Ericsson’s 10,000 hour rule, that asserts as many hours of practice is required before expertise is achieved, need to be revised? New version: 10,000 hours, or 5,000 with a steady flow of 2 mA current flowing through your skull.

While not yet approved by the FDA, the US Air Force is certainly giving tDCS its stamp of approval. At this year’s Society for Neuroscience meeting, Air Force Research Laboratory scientists reported that they’ve been using tDCS to cut down on the time needed to train drone pilots how to identify targets in radar images. Apparently training pilots to pick out targets within the complex images is a major rate-limiting step in being able to deploy the attack drones. As with the DARWARS AMBUSH! simulation training, performance improved with just 30 minutes of 2 mA stimulation. And not only did the tDCS help pilots learn faster, they retained their new skills longer too. Target identification accuracy typically drops at 20 minutes after training. Pilots who had trained with tDCS retained high accuracy up to 40 minutes after training.

The number of studies that explore the cognitive effects of tDCS is still admittedly low. And it is certainly possible that the 2 mA current flowing through the cortex doesn't rewire the brain to think better or make our neurons more receptive to input. It could just be, Ramon y Cajal forbid, that zapping your brain just makes you more alert because, well, it kinda hurts. Coffee enhances our cognitive prowess by making us more alert (and as long as we're careful, without the hurt). Could the secret of tDCS be that simple? Where there's a possible breakthrough – and a possible market – brain researchers and companies are sure to go. My guess is that if the explanation has more to do with attentiveness than acumen, the researchers will be disappointed. The companies, not so much.

Peter Murray

Peter Murray was born in Boston in 1973. He earned a PhD in neuroscience at the University of Maryland, Baltimore studying gene expression in the neocortex. Following his dissertation work he spent three years as a post-doctoral fellow at the same university studying brain mechanisms of pain and motor control. He completed a collection of short stories in 2010 and has been writing for Singularity Hub since March 2011.

Discussion — 15 Responses

  • tdcs January 14, 2013 on 9:31 am

    There are already many tDCS devices on the market and being sold “over-the-counter” in the U.S. without FDA approval:!buildbuy/c1sdn

  • vmagna January 14, 2013 on 11:57 am

    You hit the nail on the head with that BTTF picture. It seems this technology is an indirect approach to solving a problem by poking it with a long stick like those in the 19th century thought we would.

    Lets back up more ingenious efforts like microarchitecture or bioengineering eh?

  • lyrralt January 14, 2013 on 1:43 pm

    I was laughing a lot during this. I was looking at it more like negative reinforcement therapy. Think like the beginning of Ghostbusters when he’s shocking the crap out of the guy that is potentially psychic.

  • Robert Schreib January 14, 2013 on 8:26 pm

    ??So, if you get hit by lightning, you get superpowers!!

    • blanka Robert Schreib November 20, 2013 on 10:13 am

      Only 2 mA 9v lightning. For 20 minutes. In the right brain s position.
      But where they found this 2mA ? What about 10 or 100 or 1000 mA? They forgot the potency. If u open 9 v batery square, you will find 6 1,5 volts batteries in serie. 2 mA from 9v is different from 2mA from 1,5v. The variation potency is variation of current x variation of voltage.
      I am nnot talking about the battery performance and internal resistance (which de s high in alcaline batteries)

  • Alex Mark January 15, 2013 on 5:14 pm

    I have used TDCS your conclusion where you state that you guess is right on the mark. You are guessing. A bit of Googling would have led you to find a number of studies affirming the effectiveness of of the procedure. On an anecdotal basis I find that it works and different electrode placements give you very different results. It amps up aspects of your intelligence. As an example the area commonly affecting depression has he side affect of increasing verbal memory. It is odd when one unexpectedly becomes more polysyllabic It is not as if you are going to have a 20 pt increase in IQ. If you get the opportunity to try it give it a shot. Otherwise I think your article is well written and covers a lot of valuable areas.

    The other factor as stated is that one of these devices can be built for about 30 dollars. the device I use is a commercially available device. which cost me a lot more but I wanted to avoid potential problems due to problems with my own craftsmanship.

    • buddy6713 Alex Mark January 24, 2015 on 11:15 am

      Alex, I have a twitch that accompanies my golf swing. It’s anxiety produced as I rarely have it on the practice range. I’m an above average golfer with a 1.0 handicap but the twitching (which feels like holding onto a wriggling snake throughout the swing and at impact the snake violently thrusts sideways—yes, I know sounds funny but believe me it’s not) makes me score 30 strokes above my handicap (if you are a non golfer all I can say is that is extremely bad). I’ve tried so many psychological approaches it’d make your head spin–but this TDCs caught my eye for its potential calming effect.

      I know it’s worth a try, pretty much anything is, but is the current possibly strong enough to warrant concern about brain tumors?

  • Colleen Fegan January 19, 2013 on 12:04 pm

    I wonder does it work for us folks who are losing capacity due to neuro-degenerative diseases like MS, if so SIGN ME UP!

    • Alex Mark Colleen Fegan January 19, 2013 on 3:32 pm

      Colleen Google MS and Viagra There has been some work on female rodents that had very good results and really fast. . Now of course you would want to talk to your doctor about this. but if there are no negative health affects then it might be worth a try. I have no idea why it works.

      As far as tdcs and ms it might be worth a try but I think you would have to really read up on it and discuss it with someone who understood the illness. Best of luck.

  • Improbus Liber January 22, 2013 on 11:19 am

    I don’t know about smarter but how about more gullible?

    • Alex Mark Improbus Liber January 24, 2013 on 3:00 pm

      I would like to suggest you take a look at You can read some additional articles such as the Scientific American article and others. If you scroll down the page you can find a variety of articles and videos from a diverse number of sources. I think you may have come to the wrong conclusion about tdcs. So I figured you needed to have the opportunity to take a look at other sources of information and come to your own conclusion. I think you will come to find it goes beyond hocus pocus snake oil and is actually a subject of many completed and ongoing studies Best of luck no matter what your conclusion might be.

    • Richard Griffiths Improbus Liber May 10, 2013 on 2:42 pm

      I have been using this for four days. Place the electrodes wrong and bad mood follows the following day! No placebo here, I was expecting creativity 😛

      On the positive, it feels good, more focussed and quite real. Highly recommended and few, if any, snake oil salesmen in this stuff. Probably because the circuit is so basic, it’s quite cheap and simple to find out for yourself. Safer that any pills I’ve tried by far.

      So, gullible can be addressed quite easily by real world TIY. Much better than speculation and argument without testing,

  • Stewart Mitchell January 24, 2013 on 10:17 am

    Electron flow can be boosted by the “Earthing technique. ” Take your footwear off and walk on the earth.

  • Preston Phillips March 9, 2013 on 6:12 pm

    Note: a 9v battery does not run at 2 milli amps, you need about 4500 ohms of resistance to obtain that.

  • twohobos June 15, 2013 on 5:12 pm

    If anyone was thinking of purchasing the device (at the moments it’s preorder which you can cancel until july), would you mind allowing me to refer you? You just gotta send me your email and it saves about $50.