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PARIS: Monkeys are now trained to perform a more advanced trick:
Manipulating a robotic arm solely with brain power that could soon
help amputees and paralyzed stroke victims do the same.
According to a study released Wednesday,
immobilized monkeys with electrode filaments inserted into their
cerebral cortex learned in only days to reach out with the
free-standing prosthesis, pluck a tasty morsel with a pincer-like
claw, and pop it in their mouths.
When the path of the arm, positioned next to the
shoulder, was deliberately blocked, the animals simply willed it
around the obstacle with their minds, says the study, published in
Nature.
“The entire task is now performed with brain
control,” Andrew Schwartz, the lead researcher and a professor at
the University of Pittsburgh, told Agence France-Presse.
In preliminary experiments, also with Macaca
mulatta monkeys, computers assisted with various parts of the task,
he explained.
The study’s findings are the first reported
use of a so-called brain-machine interface (BMI) to perform a
practical action in three dimensions—in this case feeding
oneself—purely via brain control of a computerized arm, noted John
Kalaska, an expert on the central nervous system at the University
of Montreal.
Strokes, spinal cord injuries and degenerative
neuromuscular diseases cripple tens of thousands of people every
year, rendering the simplest of actions—opening a door, scratching
an itch, drinking a glass of water—frustratingly difficult or
impossible.
Those afflicted with the most severe form of
paralysis, known as locked-in syndrome, are fully conscious
prisoners inside a body that no longer responds to the most basic of
commands.
“These patients are still able to produce the
brain activity that would normally result in voluntary movements,
but their condition prevents those signals from either getting to
the muscles or activating them,” he said in a commentary, also in
Nature.
Schwartz’s experiments provided the most
tantalizing hope to date that paralysis victims can one day
short-circuit their own nervous system by hardwiring their brains
directly to a computerized robot.
“Hopefully we will be implanting
microelectrode arrays [in humans] in the next two years,” Schwartz
told Agence France-Presse.
“At that point it should be relatively easy to
perform this kind of task,” he said.
In the meantime, Schwartz and his team are
making improvements on the robotic arm, adding points of
articulation in the wrist and hand to the five already built
in—three at the shoulder, one at the elbow, and one at the hand.
-- AFP
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