Zap Those Neurons: Gentle Current Makes Brain Stand to Attention

Lining up the neurons

How a gentle electrical jolt can focus a sluggish mind
March 31, 2015 at 6:20 PM EDT

JUDY WOODRUFF: Next: a report on how researchers are exploring whether a small zap to the brain may actually be helpful. The idea? Possibly boosting performance and improving brain activity in some cases.

Our guide is our science correspondent, Miles O’Brien.

MILES O’BRIEN: If you’re like me, you really can’t start the day without a little jolt.

MAROM BIKSON, The City College of New York: This is the simulator itself that’s going to be providing the actual current that’s going to your head.

MILES O’BRIEN: But step aside, grande latte. There’s a new kid on the block.

MAROM BIKSON: So, current is going to come out of the device to the electrodes on your forehead and it’s going to flow through your head.

MILES O’BRIEN: Biomedical engineer Marom Bikson at the City College of New York is prepping me for a dose of transcranial direct current stimulation, or TDCS, a jump-start for my brain.

MAROM BIKSON: It can make the brain perhaps function information more effectively and therefore make you, let’s say, better at things. Or it can make the brain more likely to undergo plasticity, more malleable, more able to learn.

MILES O’BRIEN: A human brain has 100 billion nerve cells or neurons. Neurons are networkers. They make multiple connections with each other via synapses. We have about 100 trillion of them. All of this runs on electricity that we generate ourselves.

MAROM BIKSON: Now, this was the montage that we tried on you.

MILES O’BRIEN: It turns out each of our neurons is a microscopic battery with a-tenth of a volt of electricity. When we’re using them to remember things or do math or write this story, they fire electrical spikes.

MAROM BIKSON: When we’re adding electricity to the brain with TDCS, instead of a tenth of a volt, we’re producing a 1,000th-of-a-volt change, so it’s not enough to trigger a spike. It’s not enough to generate a spike, but it’s enough to modulate the spikes, to maybe get more spikes or to get less spikes.

ACTRESS: This will keep you from biting your tongue. Now just bite down on it.

MILES O’BRIEN: When you think of the human brain and electricity, there is a good chance you might conjure up this intense image. The treatment powerfully depicted in the 1975 Oscar-winning movie “One Flew Over the Cuckoo’s Nest” is called electroconvulsive therapy.

It’s delivers big jolts of alternating current to treat severe depression. It is still used as a last resort, but in reality it is painless. So is TDCS, which uses direct current, roughly equivalent to a nine-volt battery.

The basic idea goes back to the Romans, who used electric fish as a headache cure. But in 2000, some German scientists published this paper, which proved weak electrical current can modulate brain activity. Ever since, scientific interest in TDCS has amped up steadily.

MAROM BIKSON: So that’s it.

MILES O’BRIEN: My TDCS session lasted 20 minutes. All I felt was a little bit of tingling in my scalp. It didn’t hurt a bit.

MAROM BIKSON: You may need a paper towel.

MILES O’BRIEN: OK. I got one here.

I felt great. It was like I had a jolt of caffeine without the tense feeling. And for several hours afterwards, I felt extremely clear-headed. But is that all there is?

MAROM BIKSON: The theory is that when you now combine TDCS with things like training or clinical therapy, you can make those things more effective. You sort of prime the brain, and now you’re combining it with some other intervention, like trying to learn something.

MILES O’BRIEN: With that much promise, there should be no surprise TDCS has captured the attention of serious researchers. But it has also inspired a lot of people looking for fast cash or a fast way to try and juice their gray matter. You can buy the TDCS device online for about $100. Or you can go to YouTube and see how to build one yourself.

MAN: So, a cathode goes above the right eye. Learned this from a TDCS video montage I watched.

MILES O’BRIEN: What could go wrong with that?

James Giordano runs the Neuroethics Studies Program at Georgetown University.

JAMES GIORDANO, Georgetown University: Are we just going to sit back and say caveat emptor? But I think that that’s irresponsible. I think much more important is to create particular parameters, perhaps even including a surgeon general’s warning, that says, these are the ways that you should use this. These are the ways that you shouldn’t.

MILES O’BRIEN: At Wright-Patterson Air Force Base in Dayton, Ohio, biomedical engineer Andy McKinley is exploring ways for the military to exploit TDCS. The Air Force mission has change dramatically in the past decade with the rapid rise of unmanned aerial vehicles. It demands a new kind of right stuff.

ANDY MCKINLEY, 711th Human Performance Wing: It’s like looking through a “Where’s Waldo” book, but Waldo may not be in the book. Keeping your attention for that long, for doing that for an entire shift of eight or 12 hours, is extremely difficult.

MILES O’BRIEN: So he recruited volunteers for some studies.

ANDY MCKINLEY: In this scenario, what you are going to be doing is, there is a market square with a bunch of people milling around.

MILES O’BRIEN: Using software called Vigilant Spirit, sleep-deprived volunteers spend hours looking at a crowded village square trying to identify people carrying guns and a high-value target with a purple hat. Some got stimulation, some coffee, some a placebo.

ANDY MCKINLEY: We found that people that got the stimulation performed about twice as well as the folks that got either caffeine or no stimulation. And that effect lasted about three times as long as caffeine.

MILES O’BRIEN: At this point, Andy had my full attention as well. So he gave me a demo, lacing me up for vigilance assessment called the Mackworth Clock test. Red dots move around the screen like a sweep secondhand, and then, randomly and infrequently, there’s a skip.

ANDY MCKINLEY: So, if it skips a spot, you just push the spacebar to indicate that you saw that.

MILES O’BRIEN: It was mind-numbingly boring. I spent most of my energy just trying to keep my eyes open.

How did I do?


ANDY MCKINLEY: You got about half of them.


ANDY MCKINLEY: Actually, you got exactly half.

MILES O’BRIEN: Then he turned on the juice. My brain seemed to switch on like a lightbulb. It was still boring, but I was on it, a red dot watching machine.

ANDY MCKINLEY: You got all but one, and I think that one you missed…

MILES O’BRIEN: … spacebar?

Wow. That’s pretty amazing.

ANDY MCKINLEY: That’s pretty amazing.

MILES O’BRIEN: That’s pretty amazing.

There’s no doubt in my mind it works. The question is, how will we use it?

Michael Weisend is a neuroscientist at Wright State University.

MICHAEL WEISEND, Wright State Research Institute: But I think, in 10 years, we will have some reliable applications that will come — where this will be prescribed, actually. And I think those will be things like depression. Those will be things like ADHD. Who will be things like motor problems that people have.

MILES O’BRIEN: At the University of Minnesota, neuroscientist Bernadette Gillick works with young people, like 20-year-old Maddy Evans, who suffered a stroke in utero. The unaffected side of her brain has taken up the slack and is doing work the stroke side would normally do. ‘

Dr. Gillick thinks TDCS could help rebalance Maddy’s brain, so both hemispheres can contribute to movement.

BERNADETTE GILLICK, University of Minnesota: We’re trying to simultaneously excite brain cells that are still alive in the stroke hemisphere, while inhibiting brain cells on the non-stroke hemisphere.

MILES O’BRIEN: Awakening dormant, yet viable neurons that are best suited for the job could make Maddy’s paralytic hand more active and nimble.

BERNADETTE GILLICK: I think what we’re finding more information out about is, what areas of the brain respond better for what function? It might be that we can move better because we’re doing this, think better, read better, speak better. I think what we’re doing right now is the tip of the iceberg.

MILES O’BRIEN: But there’s still much to learn.

Back at Marom Bikson’s lab, they’re studying rat brains to try and determine exactly what’s happening to the neurons and synapses while they’re stimulated with electricity. It’s important research, but I would rather not wait for it. I want my venti voltage now.

Miles O’Brien, the PBS NewsHour, New York.

Not long ago, the NewsHour’s science correspondent Miles O’Brien tested the effectiveness of brain stimulation by performing a tricky helicopter landing with — and without — a jolt to the brain.

In a simulator at Ohio’s Wright Patterson Air Force Base, Miles maneuvered around obstacles to land at a remote desert landing pad. Then, scientists delivered a 20-minute dose of current roughly equivalent to a 9-volt battery to his brain, turning it on “like a lightbulb.” He returned to the cockpit after getting zapped.

Transcranial direct current stimulation, he explains, relies on direct current to inhibit brain activity in the frontal cortex, the place where we consolidate declarative memories, improving alertness and blocking out distractions. This is just one example of how scientists use weak electrical current to modulate brain activity and boost human performance.

Watch Miles O’Brien’s full report on tonight’s PBS NewsHour.

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