DOCTORS at a US hospital have wired the brain of a quadriplegic man to a computer, enabling him to turn his television on and off and play the video game Pong.

Matthew Nagle, 25, has been a quadriplegic since a knife attack four years ago. He is now the first patient to control external devices by means of electrodes implanted in his brain.

Neurotechnology expert John Donoghue of Brown University in Rhode Island, is behind a system called BrainGate used by Mr Nagle, a former football star who will spend his life in a wheelchair.

"By understanding how the plasticity of the brain can be captured and controlled, I believed we could promote the recovery of function in severely impaired patients," Professor Donoghue said.

BrainGate comprises about 100 hair-thin electrodes implanted a millimetre deep into part of the motor cortex of Mr Nagle's brain. These wires lead to a computer, which interprets the signals and translates them into movements of a cursor.

Professor Donoghue said in order for Mr Nagle to indicate a selection he merely has to pass the cursor over an icon on the computer screen.