Science Seeks to Rein In the Brain
To somebody peeking into this little room, I’m just a middle-aged guy wearing a polka-dotted blue shower cap with a bundle of wires sticking out the top, relaxing in a recliner while staring at a computer screen.
But in my imagination, I’m sitting bolt upright on a piano bench playing Chopin’s Military Polonaise.
Why? Because there’s a little red box motoring across that screen, and I’m hoping my fantasy will change my brain waves just enough to make it rise and hit a target.
Some people have learned to hit such targets better than 90% of the time. During this, my first of 12 training sessions, I succeed 58% of the time -- not much better than the 50% I could get by chance alone.
Bottom line: Over the last half-hour, I’ve displayed just a bit more mental prowess than you’d expect from a bowl of Froot Loops.
This isn’t some far-out video game. I’m visiting one of many labs that are pursuing a complex but straightforward goal: to use electrical signals from the brain as instructions to computers and other machines, allowing paralyzed people to communicate, move around and control their environment literally without moving a muscle.
Volunteers working elsewhere on such projects have done more impressive things with their brain signals lately than I have:
* A quadriplegic man in Massachusetts has shown he can change TV channels, turn room lights on and off, open and close a robotic hand and sort through messages in a mock e-mail program.
* Seven paralyzed patients near Stuttgart, Germany, have been surfing the Internet and writing letters to friends from their homes.
* At a lab in Switzerland, two healthy people learned to steer a 2-inch, two-wheeled robot -- sort of like a tiny wheelchair -- through a dollhouse-sized floor plan.
And at labs in several universities, monkeys operate mechanical arms with just their brains.
Some researchers talk about taking the technology much farther someday: using brain signals to reanimate paralyzed limbs, for example, or to control “wearable robots,” mechanical devices worn over arms or legs to restore movement. And although today’s brain-driven typing programs produce only a few characters per minute, future technology might use brain signals to operate a speech synthesizer, restoring the ability to talk.
Research into harnessing brain signals goes back about 20 years. But lately advances in brain science, electronics and computer software have combined to push the field forward.
In fact, far more than half the scientific reports ever published in this area have appeared in the last three years alone, says researcher Dr. Jonathan Wolpaw. Although about half a dozen labs seriously worked in the field as late as the mid-1990s, now about 60 labs have gotten into it, he says.
“The field, in the last four or five years, has kind of exploded,” he says.
To see firsthand what all the excitement is about, I signed on as an able-bodied research subject at Wolpaw’s Brain-Computer Interface lab, part of the Wadsworth Center of the New York Department of Health.
That blue shower cap is actually stretchable nylon mesh, polka-dotted with 64 round white electrodes that eavesdrop on the electrical activity near the surface of my brain. They pass their measurements to a computer, which calculates the strength of one particular rhythm, called the “beta” rhythm. And the computer tells that little red box to either rise or fall, depending on how strong my beta rhythm is from moment to moment.
My job, then, is to learn to control the strength of my beta rhythm. It’s an “idling” rhythm, sort of like engine noise, with no particular function in normal life. It comes from the portion of my brain that tells limbs to move and receives information related to movement. And it should get weaker when I imagine moving.
So on the first day Bill Sarnacki, the senior research technician who will guide me through the training, suggests that when the computer tells me to aim at the lower target I should let my mind go blank to make the little red box fall. When I’m supposed to aim at the upper target, I should imagine moving my hands to make the box rise.
That’s why I found myself imagining I was playing Chopin.
Before long I seek some advice from Scott Hamel, 44, of Averill Park, N.Y., who long ago mastered this task and moved on to tougher ones.
I’d watched him move that box vertically, horizontally and diagonally, by controlling two of his brain rhythms. He doesn’t bother summoning up images anymore, he says; “I just know how to make myself feel to make things happen.”
On a good day, he says, “I can manipulate that thing around the screen almost like pushing something around a desk.”
As for me, he suggests relaxing.
Before long, I find out I’m good at making my mind go blank.
I imagine my brain is a chunk of cold white marble for the four seconds the little red box takes to cross the screen. More often than not, it seems, the box sinks and hits the lower target.
Making that box rise, however, is a problem. Imaginary piano-playing works for a while, then seems to abandon me. I add an imagined jerk of my left wrist, which initially yanks the box to the top of the screen, but then loses its effectiveness too. Next I imagine both hands tickling the bottom of that danged box. Doesn’t work.
Scooping up a hard-hit ground ball and throwing to first ... directing a Sousa march in a gazebo of a town square ... whacking a golf ball ... clawing at a dirt wall ...
None of these works very well over my first few days of training, and my overall accuracy hasn’t improved a lot either.
But eventually I settle on the thought of waggling a baseball bat around for the upper target, and it seems to work pretty well. Between that and chunk-of-marble, I find myself enjoying occasional streaks of control, hitting two-thirds of the targets and sometimes much better.
I can’t stay in the groove as long as I’d like. Usually, under my uncertain command, the red box flits across the screen like a butterfly buffeted by a summer breeze.
But when I’m at my best, I can make it glide upward like a party balloon or even jump as if I’d punted it. And when I aim at the lower target, the box bumps its way downward, sometimes even dropping and running like a fumbled nickel.
There might be an easier way to control this box, but it requires surgery.
When surgeons at Washington University in St. Louis, in cooperation with Wolpaw, placed tiny electrodes on the surface of the brains of four people recently, they achieved accuracies of 74% to 100% with three to 24 minutes of training.
Some researchers put electrodes into the brain. The quadriplegic in Massachusetts, for example, uses a chip about the size of a baby aspirin with 100 wire-like sensors, each thinner than a hair. The chip goes on the surface of the brain and the sensors extend a little below the surface. Rather than monitor brain waves, the device intercepts a sample of the signals that command arm movement.
Scientists are still debating the merits and drawbacks of the various strategies for where to put the electrodes. But the verdict on my own performance is pretty clear.
“You’re a success; you’re just not a stellar success,” Wolpaw says. “You’re at the lowest level we would call actual control.”
That is, my accuracy had climbed to around 65%. About 80% of people reach or surpass that level within 10 sessions. But my 12 sessions were just an introduction, and I’d probably get better if I stuck with it, Wolpaw says.
There is one consolation. I was eventually able to make that red box sink fairly often without any need for imagery.
That may not sound like much. But in an area of brain science that’s still in its infancy, how many people on Earth can say they’ve accomplished that?
