Wire together some resistors, current regulators, and a 9-volt battery, then connect the slapdash device to your head with saline-soaked sponges that serve as electrodes and get ready. A mild current will flow across your skull.
According to some research and anecdotes, this exercise could help you enter a flow-state that enhances meditation or zap your neurons enough to master a video game or wrench you out of the extreme mood swings that characterize bipolar disorder.
Those are just a few of the achievements hinted at by a technology called transcranial direct current stimulation, or tDCS. Since the early 2000s, scientists have documented that electrical stimulation of just a few milliamps could improve learning, alleviate depression, sharpen reflexes, and lessen cravings for alcohol, sweets, and cigarettes, among other benefits. Those findings, along with the ease with which a device can be assembled, have encouraged a mix of technophiles, hackers, and self-improvement hopefuls to jump into DIY brain enhancement.
The enthusiasm behind this movement is evident in the scores of videos posted on YouTube, a dedicated section on the social news aggregator Reddit, and specialized sites exploring DIY tDCS. Every article covering the flurry of interest around the research and use of this technology is careful to throw in the apparently obvious warning that applying electricity to your brain is risky. Journalists are careful to quote at least one expert who expresses safety concerns at the DIYers, but most recognize that people can’t resist the allure of a cheap brain boost.
The typical video features a close-up of the poster, often a youngish male, talking through his homemade or purchased tDCS device. Often, they sport electrodes strapped to their head and flip on the machine as we watch.
“I’m turning it on, moment of truth,” says one vlogger with the handle anthonynlee. He pauses and blinks before continuing: “White flash, really brief, really quick, that’s cool.”
“After I do it, my thinking might become more fluid.”
He just experienced a phosphene—the phenomenon of seeing light without actual light entering the eye—a known side effect during electrical stimulation of the brain region that processes visual stimuli.
With the wires hanging in front of his face, anthonynlee explains that he doesn’t feel much else other than elevated pulse, which he knows might just be due to excitement. His video, the first of 13 on tDCS, is titled “I Zapped My Brain With tDCS and LIVED!”
Caution: Contents may be electrified
A 2013 article in the New York Times described the YouTube videos as having been posted by “young men experimenting on their own brains, looking more foolhardy than the cast of ‘Jackass.’ What they fail to realize is that applying too much current, for too long, or to the wrong spot on the skull, could be extremely dangerous.”
What the reporter apparently failed to do is actually interview any of these video-posters or read the detailed write-ups, reviews of literature, and cautions posted by serious DIY tDCS experimenters. While some of the tDCS users may in fact be foolhardy, others are proceeding with as much caution as they can muster.
“One thing I get upset about is when people say things or give advice that might be bad for a person,” said Alex Mark, a 61-year-old who lives in Michigan and is an active poster on the tDCS subreddit. “Their statements are based not on knowledge but on opinion.” Mark uses his device to address his bipolar disorder and chronic pain.
Plugging a 9-volt battery directly into your head is a bad idea, of course. Uninformed tDCS newbies are in danger of doing just that if they don’t know how to set up the correct circuit on their homemade device. Incorrect placement of the positive and negative electrodes on the scalp can also cause headaches, dizziness, irritability, and worse.
Plugging a 9-volt battery directly into your head is a bad idea.
“Someone from England connected coins to a battery and couldn’t see temporarily,” Mark said. Other people have reported passing out.
For these reasons, Mark shelled out the money to buy a high-quality medical apparatus that can be modified to create a tDCS device. He used a Chattanooga iontophoresis machine, which runs at about $300 new. Iontophoresis therapy—the passage of an electrical current across the skin—can treat excessive sweating and appears to help deliver certain medications to muscles during physical therapy. All Mark needed to do was modify the wires and add some sponges to make it tDCS-ready. One advantage this more pricey option offers is smart voltage metering, which varies the electrical output to compensate for any resistance the device encounters.
The informed tDCS-er, as all people who are trying to juice their brain with electricity should attempt to be, can find plenty of resources online: cautions about a commercial device that claims its headsets are for video game use only (this circumvents the need for the FDA to regulate the sets as medical devices), a code of safety put forth by one of the most active blogs on tDCS, in-depth videos by experts willing to talk you through the risks and limitations of such cognitive enhancement, guides for newbies, and even extensive research literature on tDCS (though scientific studies are tricky to parse even for experts).
Given the safety concerns and challenges, the best question to ask remains: Does tDCS work? The answer depends on what you are trying to accomplish.
Take a zap of medicine and call me in the morning
Any finding in biology—medicine X appears to improve the symptoms in people who have Y—needs to be backed up by a plausible reason that X could do that to Y. Researchers are always striving to find the underlying biological mechanism. For example, evolution is a pretty kick-ass idea to explain how life forms change over time, but it really gets its strength when you start explaining how it works: through mechanisms such as natural selection, gene flow, mutation, and genetic drift.
So far, researchers don’t know exactly how tDCS works in the brain.
“The one or two milliamps of current typically used in tDCS isn’t enough to make neurons fire,” writes Greg Miller in Wired. “Instead, it seems to put them in an altered physiological state that makes them more or less likely to fire (depending on how the current flows) and more or less prone to rewire their connections with one another.”
Miller explains that tDCS users typically put the positive electrode over a brain region that they want to excite and the negative over a region they want to inhibit. However, the complex, higher-order brain functions involved in learning and memory simply don’t take place in one region of the brain, and individual variation must also play a role.
The condition that tDCS seems to influence the most—depression—is strongly influenced by the placebo effect. Still, for those that it does help, tDCS can be huge.
Bipolar disorder is a serious mental illness characterized by periods of depression and periods of elevated mood sometimes called mania. Mood stabilizers, antipsychotics, and antidepressants are all used to help people with bipolar disorder manage their symptoms. However, the complex nature of this illness and the medications’ side effects can make treatment extremely difficult for some.
“The only drug that had previously worked at all, I turned out to be allergic to,” said Mark. “I wanted to find something that would alleviate those symptoms of depression.” His psychiatrist, who had used tDCS devices during his graduate work in the 1970s, encouraged Mark to try it.
Given the safety concerns and challenges, the best question to ask remains: Does tDCS work?
The typical electrode arrangement to treat depression with tDCS is to place the positive electrode on the upper left side of the forehead and the negative above the right eye. Mark used to sit down every day, wet his electrodes with saline, wring out the excess water, plug the lead wires into the iontophoresis machine, and secure the electrodes to his head with the aid of a sports band or audio headset. He used the set every day for the first year, far beyond the level of typical research trials, which often span only two weeks.
The set up worked fairly well for him, but he kept reading the literature. When researchers in South Korea published work on a pattern of electrode placement, called a montage, used to treat children with epilepsy, Mark had an idea. Anti-seizure medications are sometimes used to treat people with bipolar disorder. “I took this leap and said, ‘Gee, well if tDCS might work for epilepsy then I wonder if using a similar approach would work for bipolar disorder,’” he said.
Remarkably, when he started using the new montage, Mark stopped having the mood swings that characterize bipolar disorder. “My wife said, ‘Get a back-up machine,'” he said.
Mark observes a distinct separation between people who use tDCS to treat depression and those who are hoping to enhance their thinking abilities. He has tried to use tDCS to enhance his verbal ability but finds that he doesn’t always like the feeling. Placing the electrodes properly can be a challenge. During his first try, he inadvertently changed his vision. “I was really good at looking at details,” he recalled. “This was all brain changes, not eyes—I wasn’t good at looking at the whole scene. It was forest for the trees stuff. It was a very annoying thing not used to having the brain like that.” Six hours later, his vision returned to normal.
Still, he can see the allure.
“We don’t use a lot of words to describe thinking in English,” he said. “Basically after I do it, my thinking might become more fluid. Things might be working a little faster. I’m not trying to make a claim that a person could be a genius, just that thoughts are flowing a little easier.”
“Unleash the mind’s potential”
“I instantly feel very good, very calm, very safe, not really worried about anything,” says YouTuber Elizabeth A. in her first video on tDCS. “At first I was a little drowsy. I think I had it a little high, but that could also be because it is 2:55am.”
Though some people are tempted to dismiss these DIYers seeking neuroenhancement, tDCS has a not insignificant amount of serious researchers interested as well. “There has been a lot of hokey stuff, frankly, and it affects the credibility of the entire field,” Marom Bikson, a biomedical engineer at the City College of New York, told NatureNews in 2011. Studies are now being much more careful to approach the question rigorously, he added. And the cognitive effects, though mild, seem to be true.
Many tDCS users report feelings similar to Elizabeth A.’s. Science journalist Sally Adee strapped on a device while reporting on the U.S. military’s research into tDCS. She fired a modified M4 close-range assault rifle during a training simulation with and without tDCS and was shocked by the results.
“The experience wasn’t simply about the easy pleasure of undeserved expertise,” she wrote in a post for The Last Word on Nothing, a blog run by a group of stellar science journalists. Her story was reported again recently on RadioLab. “When the nice neuroscientists put the electrodes on me, 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 the fuck up.”
“I think that the goal at the end of the day is to learn how to make your body a better body, not a body that will depend on a device.”
That clearing of the head is what drew Mario Abundis, a 30-year-old software engineer based in Los Angeles, Calif., to the technology. “I firmly believe we don’t know even one percent of our potential or what we can do with a healthy mind,” he said.
Abundis uses the commercially available Foc.us headset marketed for gaming. He described the effects of tDCS as if his brain suddenly did not need to hold information in RAM to be available. Instead, “you are in such a perfect calm state. Anything you need you can go and grab from the hard drive right away,” he said.
Abundis’s goal is to make himself and others happier and smarter by unleashing their minds. He has used tDCS primarily to aid in meditation. The side effects don’t worry him because he has always done risky things. “I trust a lot in my intuition,” he said. “When you start doing this kind of stuff, you start to develop intuition.” He has also experimented with biofeedback tones to achieve different brainwave states and sun gazing to stimulate and heal the mind and body.
Since posting several videos, Abundis has stopped using tDCS because he found he was able to meditate even without the aid of electrical simulation. “I think that the goal at the end of the day is to learn how to make your body a better body, not a body that will depend on a device,” he said.
Invariability, both enthusiasm and concern surround discussions of tDCS. Just take a look at the commenters on the aforementioned RadioLab story—the site is one of those rare places on the Internet where you might learn something by reading the comments. Many called for more disclaimers to balance out the story’s “wow” factor. Certainly, when the benefits seem so alluring and the device is apparently easy to make, caution is advised.
As Mark said, “This is your brain. You don’t really want to mess it up.”
Illustration by Max Fleishman