Jan. 10, 2007 — Forget the remote control — scientists are learning how to let you control a robot with signals straight from your brain.
Eventually, the technique could lead to semi-autonomous robots able to assist disabled people or
perform routine tasks in the home.
"We're using a well-known, well-characterized response that occurs in
the brain to control a physical device in the world," said research
leader Rajesh Rao, an associate professor of computer science and
engineering at the University of Washington in Seattle.
That brain "response" is the same one triggered whenever you
lose and then find your car keys, said Rao.
As you scan tables, desks and bureaus for lost keys, you're focused on a mental image of them. When you
finally spot your keys, your brain's reaction is known to scientists as a P300 response ("P" is
for positive and 300 for the number of milliseconds it takes your
neurons to produce the reaction).
The P300 response is strong and distinctive, and therefore can be
picked up by external sensors. And because it is such a
well-characterized response, it can be used reliably again and again.
Rao and his team wrote software that allows a computer to
recognize the P300 response, and use it to guide a robot.
The person controlling the robot is fitted with an electrode cap designed to pick up brain waves.
The person focuses on an object, for example a banana, displayed on a monitor. The computer
flashes the boundaries of random objects one object at a time. When
the banana flashes, the subject's P300 response triggers and the
computer picks it up. After about 10 minutes of training with
different objects, the computer becomes calibrated to the person's unique P300 signal.
After that initial callibration, the controller can interact with the robot.
To make the robot walk toward
a table, for example, the wearer then focuses on an image of the table. Meanwhile, random images flash on the monitor. Each time the table flashes, the operator's P300
sparks. It takes 5 to 10 seconds for the computer to confirm that
"table" is correct and then directs the robot to walk toward it.
