[neuroling] Re: Intersting Possibilities for study of tool use and recognition
- From: "Giancarlo Buoiano" <rolf90@xxxxxxxx>
- To: "Andrew Siegal" <asiegal1@xxxxxxxxxxxx>
- Date: Thu, 29 May 2008 20:15:18 +0200 (ora legale Europa occidentale)
Very interesting indeed.
So it seems that when an action sequence is rightly planned,
brain-controlled prosthetics can be used instead of real limbs. In other
words thought may actually be converted into action using prosthetics. It is
really good news for spinal-injured patients.
Neuroscience Converting thoughts into action
Stephen H. Scott
SUMMARY: There is a clear need to help people who have brain or spinal-cord
damage to communicate and interact with the outside world. Progress to that
end is being made with brain-implantation technology
CONTEXT: Using our thoughts to control a computer or robot used to be the
realm of science-fiction writers. But scientists have been making concerted
efforts to develop the technology required to convert brain signals into
commands, to support communication, mobility and independence for paralysed
people.
Nature 442, 141 - 142 (12 Jul 2006), doi: 10.1038/442141a, News and Views
http://www.nature.com/nature/journal/v442/n7099/full/442141a.html
-------Original Message-------
From: Andrew Siegal
Date: 28/05/2008 21.55.11
To: Giancarlo Buoiano
Cc: neuroling@xxxxxxxxxxxxx
Subject: Intersting Possibilities for study of tool use and recognition
May 29, 2008 NYTimes
Monkeys Control a Robot Arm With Their Thoughts
By BENEDICT CAREY
Two monkeys with tiny sensors in their brains have learned to control a
prosthetic arm with only their thoughts, using it to reach for and grab food
and even to adjust for the size and stickiness of morsels when necessary,
scientists reported Wednesday.
The report, released online by the journal Nature, is the most striking
demonstration to date of brain-machine interface technology, which
scientists expect will eventually allow people with spinal cord injuries and
other paralyzing conditions to gain more control over their lives. The
findings suggest that brain-controlled prosthetics, while not yet practical,
are at least technically within reach.
In previous studies, researchers showed that humans who had been paralyzed
for years could learn to control a cursor on a computer screen with their
brain waves; and that thoughts could move a mechanical arm, and even a robot
on a treadmill.
Yet the new experiment demonstrates how quickly the brain can adopt a
mechanical appendage as its own, refining movement as it interacts with real
objects in real time. The monkeys in the experiment had their own arms
gently restrained while they were learning to use the prosthetic one.
?In the real world things don?t work as expected, the marshmallow sticks to
your hand or the food slips, and you can?t program a computer to anticipate
all of that,? said the paper?s senior author, Dr. Andrew Schwartz, a
professor of neurobiology at the University of Pittsburgh. ?But the monkeys?
brains adjusted; they were licking the marshmallow off the prosthetic
gripper, pushing food into their mouth, as if it were their own hand.?
Dr. John P. Donoghue, director of the Institute of Brain Science at Brown
University, said that the new report ?is important because it?s the most
comprehensive study showing how an animal interacts with complex objects,
using only brain activity.? Dr. Donoghue was not involved in the research.
The researchers, from the University of Pittsburgh and Carnegie Mellon
University, first had the two macaque monkeys use a joystick to get a feel
for the prosthetic arm, which had shoulder joints, an elbow, and a grasping
claw with two mechanical fingers.
Then, inside the monkeys? skulls, the scientists implanted a small grid,
about the size of a large freckle. The grid sat on the monkeys? motor cortex
over a patch of cells known to signal arm and hand movements. It held 100
tiny electrodes, each connecting to a single neuron, its wires running out
of the brain and to a computer.
The computer was programmed to analyze the collective firing of these 100
motor neurons, translate this sum into an electronic command and send it
instantaneously to the arm, which was mounted flush with the monkeys? left
shoulder. The scientists used the computer to help the monkeys move the arm
at first, essentially teaching them with biofeedback.
After several days, the monkeys needed no help. They sat stationary in a
chair, repeatedly manipulating the arm with their brain to reach out and
grab grapes, marshmallows and other tasty nuggets dangled in front of them.
The snacks reached their mouths about two-thirds of the time ? an impressive
rate, compared with earlier work. The monkeys learned to hold the grip open
on approaching the food, close it just enough to hold the food and gradually
loosen the grip when feeding.
On several occasions a monkey kept its claw open on the way back, with the
food stuck to one finger. It had apparently learned through experience that
it was not always necessary to close the grip, ?illustrating the importance
of working within a physical environment? as opposed to a virtual one, the
researchers concluded. Dr. Schwartz?s co-authors were Meel Velliste, Sagi
Perel, M. Chance Spalding and Andrew Whitford.
Scientists must clear several hurdles before this technology becomes
practical, experts say. Implantable electrode grids do not generally last
more than a period of months, for reasons that are still unclear. The
equipment needed to read and transmit the signal is cumbersome, and in need
of continual monitoring and recalibrating by technicians. And no one has yet
demonstrated a workable wireless system, which would eliminate the need for
connections coming through the scalp.
Yet Dr. Schwartz?s team, Dr. Donoghue?s group and others are working on all
of these problems, and the two macaque monkeys? rapid learning curve in
taking ownership of a foreign limb gives scientists confidence that the main
obstacles are technical and thus negotiable.
In an editorial accompanying the Nature study, Dr. John F. Kalaska, a
neuroscientist at the University of Montreal, argues that once such bugs are
worked out, scientists may even discover areas of the cortex that allow more
intimate, subtle control of prosthetic devices.
Such systems, Dr. Kalaska wrote, ?would allow patients with severe motor
deficits to interact and communicate with the world not only by the
moment-to-moment control of the motion of robotic devices, but also in a
more natural and intuitive manner that reflects their overall goals, needs
and preferences.?
Andrew W. Siegal Ph.D.
Post Office Box 788
Glens Falls NY
12801-0788
(518)793-7538
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