It is not a magic act, although magic it appears to be. In a graphic demonstration, a totally paralyzed man with a "BrainGate" implant was able to work a computer, play a game of Pong, open and close a prosthetic hand, and pick up hard candy with a robotic arm. He did these things with his thoughts — without moving a muscle.
The device — or ones like it — may one day give paralyzed people the ability to operate multiple tools such as wheelchairs and computers, says researcher John Donoghue, Ph.D., director of the brain science program at Brown University. Donoghue is also chief scientific officer at Cyberkinetics Neurotechnology Systems Inc., the company that is developing the BrainGate.
"Limb movement originates in the brain as distinct patterns of neural activity," Donoghue says in a news release. "These patterns can be changed by imagining movement — and can also be quickly translated into a control signal by computer algorithms."
By turning thoughts into a control signal, the BrainGate device allows a person to operate computer-controlled devices. Some day, it may do more. The BrainGate signal may be used to bypass broken nerve connections in the body, letting paralyzed people move again.
"One day [we may] be able to activate limb muscles with these brain signals, effectively restoring brain-to-muscle control via a physical nervous system," Donoghue says.
Donoghue and colleagues report their findings in the July 13 issue of Nature.
The Brown researchers aren't the only ones working on these kinds of devices. In the same issue of Nature, Stanford researcher Krishna Shenoy, Ph.D., and colleagues report successful monkey studies of a high-speed "brain-to-computer" device.
The findings greatly increase the power of these devices. The Shenoy team's penny-sized device was able to retrieve 6.5 bits of information per second from the brain. That would let a person type about 15 words a minute.
That's pretty good. But the researchers think they can do better.
"We really are viewing this as a starting point," Shenoy said, in a news release.
SOURCES: Hochberg, L.R. Nature, July 13, 2006; Vol. 442: pp. 164-171. Santhanam, G. Nature, July 13, 2006; Vol. 442: pp. 195-198. News release, Brown University. News release, Stanford University Medical Center. News release, Cyberkinetics Neurotechnology Systems Inc. News release, Massachusetts General Hospital.
By Daniel J. DeNoon
Reviewed by Louise Chang, M.D.
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