There are several groups researching ways to tap the brain to move a computer
cursor. This approach was reported in the current issue of Nature.
Alan
Alan Cantor
Cantor + Associates Inc.
Workplace Accommodation Consultants
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From: Discussion of Carpal Tunnel Syndrome, Tendonitis etc..
[mailto:[log in to unmask]]On Behalf Of Scott W.
Sent: 14 March 2002 9:10 a.m.
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Subject: The Ultimate Alternative Input Device
Researchers Demonstrate Direct, Real-Time Brain Control Of Computer Cursor
It is the stuff of science fiction: Researchers at Brown University have
used a tiny array of electrodes to record, interpret and reconstruct the
brain activity that controls hand movement - and they have demonstrated that
thoughts alone can move a cursor across a computer screen to hit a target.
The research was conducted using a primate model. Three Rhesus monkeys
received brain implants similar to those used in treating certain human
Parkinson's patients.
"We substituted thought control for hand control," said John Donoghue, chair
of the Department of Neuroscience and the project's senior researcher. "A
monkey's brain - not its hand - moved the cursor. Use of a reconstructed
signal to allow the brain to accomplish immediate, complex goal-directed
behavior has not been done before. We showed we could build a signal that
works right away, in real time. And we can do it recording from as few as
six neurons."
This work is a step toward enabling paralyzed humans to use thoughts to
control a cursor that would allow them to read e-mail, surf the World Wide
Web, or perform other functions through a computer interface.
Eventually, the technology may help individuals who have a spinal cord
injury, Lou Gehrig's disease or muscular dystrophy, the researchers said.
The researchers hope to apply the technology to restore some movement
control in paralyzed patients. That step would entail seeking approval from
the Food and Drug Administration. The FDA has not approved this
"instant-control brain cursor" technique for human use.
The findings are described in the current issue of Nature. The lead author
is Mijail D. Serruya, a graduate student enrolled in the M.D./Ph.D. program
at Brown. Serruya performed the work as part of his Ph.D. research. As a
medical student, he assists paralyzed patients. Serruya and Donoghue
conducted the research with colleagues Nicholas Hatsopolous, a former Brown
professor now at the University of Chicago; former Brown undergraduate Liam
Paninski, now at New York University; and current Brown graduate student
Matthew Fellows.
"This implant is potentially one that is very suitable for humans," Serruya
said. "It shows enough promise that we think it could ultimately be hooked
up via a computer to a paralyzed patient to restore that individual's
interaction with the environment. Our goal is to make sense of how the brain
plans to move a hand through space and to use that information as a control
signal for someone who is paralyzed. We want to provide some freedom to this
individual."
The device "would work for anything you can do or you can imagine doing by
pointing and clicking," Donoghue said. 'This includes reading e-mail. Or
imagine an onscreen keyboard that someone can use to type sentences or issue
commands by pointing and clicking. We would be extraordinarily pleased if
this system could allow a patient to become somewhat autonomous. It would
restore some independence to paralyzed patients who are cognitively normal
people unable to carry out their movement intentions."
The research involves use of thin electrodes to record the activity of a few
neurons in the brain's motor cortex. This area contains the cells that fire
when a hand moves. Activity of the neurons is first recorded while a cursor
on a computer screen is moved to hit a target using a mouse-like handle.
The scientists built a series of mathematical formulas, called linear
filters, to create a model that related the firing of the neurons to a
cursor's target position. These linear filters then allowed the researchers
to reconstruct hand trajectory from any new neural signals.
The electrode array was connected to a computer by thin cables. While the
subject played a simple pinball-like video game, the researchers turned off
the hand control and substituted the reconstructed signal. While the primate
continued to move its hand as if playing the game, cursor motion actually
was controlled solely by brain signals associated with moving the hand.
The subject then used its thoughts to move the cursor to different targets
for periods averaging two minutes in length. While this instant-control
brain cursor was active, the real-time signals allowed the animal to correct
wayward cursor movements "on the fly" in order to strike the target, the
researchers said. This entire processing took place nearly as fast as the
hand responds to the brain's movement commands.
The research suggests that subjects can use visual and other feedback to
compensate for inaccuracies in the mathematical model - in effect, to learn
how to improve the brain's control of cursor movement, researchers said.
"Our results demonstrate that a simple mathematical approach, coupled with a
biological system, can provide effective decoding for brain-machine
interfacing, which may eventually help restore function to neurologically
impaired humans."
The work was funded in part by the National Institute of Neurological
Diseases and Stroke, the Defense Advanced Research Projects Agency and the
Burroughs Welcome Foundation.
Last year, Donoghue, Hatsopolous and others formed a company to transfer the
technology to help patients who suffer from injuries and neurological
disorders that result in paralysis. That firm is called Cyberkinetics.
Editor's Note: The original news release can be found at
http://www.brown.edu/Administration/News_Bureau/2001-02/01-098.html
Note: This story has been adapted from a news release issued by Brown
University for journalists and other members of the public. If you wish to
quote from any part of this story, please credit Brown University as the
original source. You may also wish to include the following link in any
citation:
http://www.sciencedaily.com/releases/2002/03/020314080832.htm
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