Brown researchers have enabled a monkey to move a computer cursor just by thinking about it using a computer implant.

See the article:
The power of a thought,
by Felice J. Freyer for Projo.com.

The researchers implanted a tiny silicone chip, containing 100 hair-thin electrodes, in the brains of three rhesus monkeys that had learned to play a simple video game with a specially designed joystick.

They connected one monkey's implant via 100 wires to a computer system, and then disconnected the joystick. Manipulating the now-useless joystick, the monkey was instantly able to move the cursor toward a target simply by thinking. Sometimes it let go of the joystick while continuing to play. The cursor responded just as quickly, but not quite as smoothly, as when the animals had used their hands to control it.

"We substituted thought control for hand control," said John Donoghue, chairman of Brown's department of neuroscience and the project's senior researcher.

Although other researchers have used brain implants to produce motion, the Brown work is remarkable for the speed and accuracy of the monkey's cursor control, said Dr. William Heetderks, director of the neuroprosthesis program at the National Institute of Neurological Disorders and Stroke. "The quality of the movement is in a sense competitive with using your hand to produce a movement," he said.

If such a system is eventually found to be safe and reliable in people, it could unlock a vast potential for paralyzed people, who would be able to do anything that can be accomplished by moving a computer cursor.