Training Brains May Help Paralyzed

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 mind's eye, I'm a teenager sitting bolt upright on the black piano bench of my boyhood home, expertly pounding out the stirring opening chords of Chopin's Military Polonaise.

Not that I've ever actually played that well. But there's a little red box motoring across that computer 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 percent of the time. During this, my first of 12 training sessions, I succeed 58 percent of the time.

But my targets are so big that I could have reached 50 percent by random chance alone.

Bottom line: Over the past half-hour, I've displayed just a bit more mental prowess than you'd expect from a bowl of Froot Loops.

Take a look at what other people have accomplished lately with signals from their brains:

  • 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 volunteers 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. At the University of Pittsburgh, a monkey can feed itself chunks of zucchini and orange slices this way.
There's nothing supernatural here. These are early steps toward a complex but straightforward technological 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.

Most dramatically, that could help "locked-in" patients — those who've lost all muscle movement because of conditions like Lou Gehrig's disease or brainstem strokes.

Research into harnessing brain signals goes back some 20 years. But lately it seems the research pot is starting to come to a boil, as 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. And while only about a half-dozen labs seriously worked in the field as late as the mid-1990s, now about 60 labs have gotten into it, he said.

"The field, in the last four or five years, has kind of exploded," he said.

Some scientists envision taking the use of brain signals way beyond what's been done so far.

John Donoghue, chair of Brown University's neuroscience department and chief science officer of Cyberkinetics Neurotechnology Systems Inc. of Foxboro, Mass., talks about giving disabled people use of their arms and legs someday by using brain signals to drive their muscles.

Eventually, paralyzed people might even wear lightweight mechanical arms and legs that fit over their own limbs and would enable them to walk and reach for things, says Miguel Nicolelis of Duke University, who calls such devices "wearable robots." Nicolelis has done robot-arm work in monkeys and hopes to start studies in severely paralyzed people this year.

And Dr. Philip Kennedy of Neural Signals Inc. in Atlanta, who has tested brain sensors in seven locked-in patients since 1996, ponders the notion of helping such people speak someday. That would require planting electrodes in speech areas of the brain to give people control over 30 or so speech sounds, which would be produced by a synthesizer.

"It's not an insurmountable problem," Kennedy says.

That would be a huge jump from today's brain-controlled programs that can spell out words, but only a few letters per minute. The paralyzed patients near Stuttgart use such a program.

But even a relatively slow spelling device could make a huge difference to people with no good alternative to communicate, says Dr. Terry D. Heiman-Patterson. She is working with Wolpaw's laboratory in a project with her Lou Gehrig's disease patients at Drexel University.

That disease, formally called amyotrophic lateral sclerosis or ALS, gradually robs people of their ability to use their muscles. Eventually their breathing muscles stop working, and late-stage patients have to decide whether to go on a ventilator to stay alive.

"One of the reasons people choose to die over live is that they can no longer communicate," Heiman-Patterson said. "If we can unlock the ability to communicate with others ... we may be able to change some of the choices people are making."

Even for people who can blink or direct their gaze to send signals, it may take 20 laborious minutes to ask to be taken to the bathroom or be turned over, she said "The difficulty becomes so great just to do that," she said, "that people say, 'I can't deal with this any more.'"

here might be an easier way to do this, if you're willing to have 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 percent to 100 percent with just three to 24 minutes of training.

Some researchers put electrodes into the brain. Donoghue's Cyberkinetics system includes 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 about .04 inch below the surface.

Rather than monitor brain waves, the device intercepts a sample of the very signals that command arm movement, Donoghue said. So a patient doesn't have to learn how to control his brain waves, he just has to imagine moving his arm. "At that point," Donoghue said, "it works."

That's been the experience with the quadriplegic volunteer in Massachusetts, who showed he could move a cursor around a screen effectively, though less smoothly than healthy people can, Donoghue said. Cyberkinetics hopes to try its "BrainGate" system in four more patients this year and bring a product to market by 2007 or 2008.
By Malcolm Ritter