New way for paralyzed people
to control movements
Posted Dec. 6,
2004
Courtesy Proceedings of the National Academy of Sciences
and World Science staff
It
wasn’t long ago that scientists devised techniques by which apes could move
things just by thinking about them. It was thought the technology could be
useful for paralyzed people, except for one inconvenience: the technologies
involved inserting wires into the brain.
Now,
researchers have found a way to avoid the wires.
Scientists
have developed what they call a noninvasive brain-computer interface (BCI),
allows a person to move a cursor across a computer screen by thinking about it.
BCIs
translate electrical signals in the brain into physical outputs, which could
help people paralyzed by stroke, spinal cord injury, or Lou Gehrig’s disease.
In the
study, Jonathan Wolpaw and Dennis McFarland of the New York State Department of
Health and State University of New York found that humans can control
two-dimensional movement with a noninvasive BCI that analyzes human brain waves.
The brain waves are caused by electrical signals transmitted between brain cells
as the thinking process takes place.
In the
study, individuals with and without spinal cord injuries wore a cap of
electrodes that transmitted brain wave activity to a computer. The individuals
learned to use their thoughts to direct a cursor on a computer screen, often by
imagining specific actions.
A computer
program analyzed the EEGs, selected the brain waves the person was best able to
control, and translated them into cursor movement. Individuals with spinal cord
injuries actually performed better than uninjured users, possibly reflecting
greater motivation or injury-associated brain changes, the researchers said.
They
predict that future improvements of this noninvasive BCI will focus on
three-dimensional movement.
The
findings are to be published this week in the early online edition of the
research journal Proceedings of the National Academy of Sciences.
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