Brain implants 'read' monkey minds

Brain implants have been used to "read the minds" of monkeys to predict
what they are about to do and even how enthusiastic they are about
doing it.

It is the first time such high level cognitive brain signals have been
decoded and could ultimately lead to more natural thought-activated
prosthetic devices for people with paralysis, says Richard Andersen
project leader at the California Institute of Technology, in Pasadena,
US.

By decoding the signals from 96 electrodes in a region of the brain
just above the ear – called the parietal cortex - the researchers were
able to predict 67 per cent of the time where in their visual field
trained monkeys were planning to reach.

They also found that this accuracy could be improved to about 88 per
cent when the monkeys expected a reward for carrying out the task.

The team were even able to predict what sort of reward the monkeys were
expecting - whether it was juice or just plain water – from their brain
signals.

"In the future you could apply this cognitive approach to language
areas of the brain," says Andersen. By doing so it may be possible to
decode the words someone was thinking, he says.


'Reach region'

Previous research by Miguel Nicolelis at Duke University in Durham,
North Carolina, has shown how electrodes implanted in the motor
cortices of monkeys can be used to control a robot arm. But this
involved recording signals used to control muscles to move the monkey's
arm.

The new findings could in theory make this simpler by allowing, say, a
paralysed patient to merely specify which object to reach for, and let
the robot worry about how it gets there.

The monkeys were trained to think about a particular point in their
visual field before reaching for it while the researchers recorded
signals in an area Andersen calls the "reach region".

This area is associated with planning, he says. "It takes information
from the sensory system and forms early plans for intention."

Previously it has not been clear whether these signals were cognitive
or simply related to where the monkey was looking, says John Chapin, at
State University of New York who is carrying out related work using a
different part of the brain.

Andersen believes this work shows the signals are cognitive because the
monkeys were trained not to move their eyes during their experiments so
the signals are not linked directly to sensory input.

Ultimately the only way to be really sure, says Chapin, is to try it on
humans.

The work was also carried out with researchers in Canada and
Switzerland.

Journal reference: Science (vol 305, p 258)

Duncan Graham-Rowe

http://www.newscientist.com/news/news.jsp?id=ns99996127

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Weblinks  

Andersen's Lab
John Chapin's Lab
Miguel Nicolelis's Lab