Monkeys control a robotic arm by brainpower alone in scientific study that
has implications for humans with spinal cord injuries.

PITTSBURGH, PENNSYLVANIA, USA (COURTESY of 'MOTORLAB
SCHOOL OF MEDICINE, UNIVERSITY OF PITTSBURGH')
Using only its brainpower, a monkey can direct a robotic arm to
pluck a marshmallow from a skewer and stuff it into its mouth, U.S.
researchers said on Wednesday.
    The research was led by Dr. Andrew Schwartz of the Motorlab, University
of Pittsburgh School of Medicine. His study will appear in an upcoming issue
of the journal Nature.
    Schwartz said the technology behind this feat may lead to brain-powered
prosthetic limbs for people with spinal cord injuries or disabling diseases
that make such simple tasks impossible.
    Until now, such brain-machine interfaces have been used to control
cursor movements on a computer screen. Schwartz and colleagues wanted to apply
the technology to real-world tasks.
    The monkey guides the robot arm the same way it does its natural limbs,
through brain signals.
    Schwartz' team picks up those signals through an array of
microelectrodes half the size of a thumbtack that has been implanted in the
monkey's brain. These signals are amplified and relayed to a computer that
operates the robotic arm.
    So far, they have trained two monkeys to feed themselves with the
robotic arm. The monkeys sit in a chair with their arms gently restrained in
sleeves that keep them from simply grabbing the food on their own. "These
animals will just relax their arms as they control these devices,"
Schwartz said.
    The ultimate goal is to develop a brain-powered prosthesis that can
restore near-natural function to an amputee or person with a spinal cord
injury.
    But first, they want to refine the system. The next step is to develop
an operating wrist and jointed fingers to add dexterity to the device.
    The researchers must overcome several engineering challenges, including
developing more durable electrodes that do not lose their signal over time,
but Schwartz believes such devices are feasible.