Monkey Brain
Operates Machine
Wednesday, 15 November, 2000, 19:37 GMT
From the BBC
Scientists
have used the brain signals from a monkey to drive a
robotic arm.
As the animal stuck out its hand to
pick up some food off a tray, an artificial neural
system linked into the animal's head mimicked the
activity in the mechanical limb.
The system was even used to remotely
control another robot arm 950 kilometers (600 miles)
away in a different lab.
This is not the first time that a
device has been operated by "brain power"
alone, but the experiment marks a significant step
forward in sophistication.
It holds out the prospect that, one
day, paralyzed patients might be able to command the
movement of prosthetic limbs that have been
"wired" into their brains.
Commenting on the research, Sandro
Mussa-Ivaldi, of the Northwestern University Medical
School, and the Rehabilitation Institute of Chicago,
Illinois, US, said: "The idea of driving robotic
limbs with what effectively amounts to the mere power of
thought was once in the realm of science fiction. But
this goal is edging closer to reality."
Net connection
Miguel Nicolelis, of Duke University,
Durham, North Carolina, US, and colleagues, implanted an
array of electrodes in several areas of a monkey's brain
known to be involved in motor function.
Miguel Nicolelis, his monkey
and the robotic arm
|
The electrodes were used to record brain
activity as the animal learned reaching tasks, including
reaching for small pieces of food placed randomly at
four locations on a tray.
The mass of neural signal data
generated during many repetitions of these tasks was fed
into a computer, which analyzed the information and
matched it to the trajectory of the monkey's hand.
Every time the monkey then moved its
hand to grab the food, the computer was able to process
the brain signals to make similar, real-time,
three-dimensional movements in a robotic arm. The
signals were even sent over a standard internet
connection to control another arm in the Massachusetts
Institute of Technology's "Touch Lab".
"It was an amazing sight to see
the robot in my lab move, knowing that it was being
driven by signals from a monkey brain at Duke,"
said Touch Lab director and co-researcher Mandayam
Srinivasan. "It was as if the monkey had a
600-mile- (950-km-) long virtual arm."
Brain study
In previous research, it has been
shown that a rat wired into an artificial neural system
can make a robotic water feeder move just by willing it.
But the latest work sets new
benchmarks because it shows how to process more neural
information at a faster speed to produce more
sophisticated robotic movements. That the system can be
made to work using a primate is also an important proof
of principle.
Miguel Nicolelis told BBC News Online
that people would obviously focus on possible future
applications for quadriplegics but he said the system
also offered a new way to probe the workings of the
brain.
"We have designed a new paradigm
to study how the brain processes information," he
said.
"Until fairly recently, we tried
to understand the brain by looking at one neuron at a
time, but we all know the brain works in a parallel mode
requiring the activation of huge numbers of cells to
produce any behavior.
"So the implementation of this
technique for recording up to a 100 neurons in primates
is a big deal for science."
