Devices that read human thought now possible, study
Brain implants could help severely disabled
Carl T. Hall, Chronicle Science Writer
Monday, November 10, 2003
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New Orleans -- Less than a month after a widely heralded experiment showed how thought-reading implants can work in monkeys, scientists presented new findings Sunday suggesting such machines could work in people, too.
Dr. Miguel A.L. Nicolelis of Duke University said previously unreported human experiments demonstrated success with one type of a so-called brain computer interface, or BCI.
He and others discussed their latest findings Sunday at the annual meeting in New Orleans of the Society for Neuroscience, the world's largest gathering of brain researchers. About 28,000 people are attending the weeklong event.
Much of the attention on Sunday was given to technology designed to overcome paralyzing injuries or illnesses afflicting the nervous system. About 11,000 new cases arise every year, adding to a total estimated at more than 200,000.
Nicolelis said the new study had been done in a few Parkinson's disease patients while they were undergoing open-skull neurosurgery for their disease.
Full results, he said, have been submitted for peer review to a scientific journal and were not a formal part of the program, in which he and colleagues reported new details from the monkey experiments already published.
Nicolelis said the important point was that the principle had been shown to work: People can control devices merely by thinking.
Ultimately, it may be possible to design high-tech implants that can read and direct the muscles using the patient's own intentions and natural sensory equipment.
For now, it's a much less grandiose business of just tuning the equipment to the human brain's frequency.
In the Duke experiments, patients were being fitted with standard electrical stimulator devices, which can help to control Parkinson's symptoms.
This procedure requires the patient to be awake while the surgeon identifies a safe route through brain tissue, taking care not to harm brain cells needed for essential functions. As part of that process, the surgeon periodically asks the patient to speak or move while recording localized brain activity.
Nicolelis and his colleagues took advantage of the opportunity and recorded the information the surgeon was obtaining. Then, for five-minute periods while the patient was being operated on, they conducted simple reaching-and-grasping experiments to determine whether the patient's intentions could accurately be read -- the first essential step in controlling a limb by computer implant.
That's a far cry from proving that a workable long-term implant would be safe and effective. Nicolelis said it was much too soon to "even think about" moving any particular device into full-blown clinical trials.
A competing group, however, led by founders and collaborators of a company called Cyberkinetics Inc., has announced plans to begin a small safety study next year of an implant designed to allow a paralyzed patient to control a desktop computer.
That device, called "BrainGate," is based on research at Brown University,
led by scientist John Donaghue. He and other company officials described the technology on Sunday as a "novel gateway" for people with no other options.
"These are the opening days of a new era in neurotechnology," Donaghue said.
The competition, however, has gotten somewhat testy of late amid an explosion of interest. Some scientists accuse Nicolelis of overreaching, noting that his latest monkey experiment actually wasn't the first to show a "thoughts-into-action" device could function in a primate; he was merely the first to show that a monkey's brain firings could be harnessed to direct complicated movement, involving both reaching and grasping.
Meanwhile, Nicolelis decried the entry of corporate interests into a field once thought to be purely science fiction, now being taken seriously as modern medicine at the cutting edge of technology.
"I am a university professor," Nicolelis said. "I have no interests in any business. I am Brazilian -- I want to have fun, I don't want to make money. What I am very afraid of is that people who really want to make a buck out of this will be rushing into the clinical thing. I don't believe in that. A lot of important science needs to be done, and we need to go step by step in a very careful way."
All the labs claim to be pursuing the technology responsibly.
Donaghue and his colleagues pointed out they were also university scientists who realized the only way to fully exploit the technology was to form a company capable of raising the money needed to carry out very expensive clinical studies. Cyberkinetics is proceeding with the guidance of the U.S. Food and Drug Administration.
In the latest studies on people, Nicolelis' Duke group had to use a simplified version of the animal study protocol to stay within the bounds of a five-minute surgical window. But that was still enough, Nicolelis said, to show animal and human brains can be read much in the same way.
"We are showing the same computational algorithms work, the same technology in general works, suggesting the principle would work in a patient that is severely handicapped," Nicolelis said. "We are able to predict the hand position, and the hand force, while they are doing the task during the surgery."
Before you can lift even a finger, nerves fire in the brain, along the spinal cord and nerve pathways of the arm, then back again in a tightly controlled feedback loop.
Douglas J. Weber, of the University of Alberta in Edmonton, reported new research Sunday suggesting that the motion of a limb can be accurately predicted by reading the firings of just a handful of brain cells -- only 10 or so in one case.
That means it may be simpler than once imagined to tap into the body's own sensory apparatus to keep some natural motion going with a brain implant merely as a detour around a damaged spinal cord or other problem in the brain's natural circuitry.
Dr. Jonathan Wolpaw of the New York State Department of Health's Wadsworth Center described new methods of reading signals that can be detected outside and just beneath the surface of the skull, suggesting the possibility that some devices may not even have to be implanted into the brain. Implants run some risk of infections and other problems.
But he and others emphasized it might be several years before the first such devices were ready for widespread use, and they noted that the technology worked only in individuals who might be utterly disabled and "locked in," with no ability to move even their eyes, and yet had enough healthy brain activity to drive the implants.
The revolution will start slowly, Wolpaw said, in a few people "who are the most disabled and who have no other options."
E-mail Carl T. Hall at email@example.com.
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