Movements controlled by thoughts alone, neuroscientists show

A paralyzed man is able to use a sensor to control objects, allowing him toopen e-mail or adjust the volume on a TV set using only his thoughts, neuroscientists say.

"We believe these advances could ultimately enable a paralyzed person to control communication devices, medical devices, computer-controlled robotics, wheel chairs and even their own limbs," said Timothy Surgenor, president and CEO of Cyberkinetics, which developed the sensor.

Scientists implanted a tiny silicon chip with 96 electrodes into the motor cortex, the part of the brain responsible for voluntary movement.

A 25-year-old research subject who was paralyzed after a spinal cord injury three years ago was able to open e-mail, work a TV and open and close a prosthetic hand by imagining movement, the team reports in Thursday's issue of the journal Nature.

The sensor, called BrainGate, picks up thousands of brain signals that are decoded by a computer and translated into movement commands.

"We're finding that, even years after spinal cord injury, the same signals that originally controlled a limb are available and can be utilized," Leigh Hochberg of Massachusetts General Hospital, the study's lead author, said in a release.

This isn't the first time scientists have used brain activity to move a cursor, but the study describes advances in the technology, said Stephen Scott of Queen's University in Kingston, Ont.

"This research suggests that implanted prosthetics are a viable approach for assisting severely impaired individuals to communicate and interact with the environment," Scott wrote in a journal commentary.

A second study on monkeys by researchers at Stanford University reported a way to speed up processing of signals from the brain to control a computer or prosthesis.

The technology isn't ready for widespread use, cautioned the researchers, who said the studies are meant to benefit humanity, not the volunteersparticipating in the experiments.

The device is bulky and cumbersome,and the quality of the signal can vary between research subjects or from day to day, they said.

Developing a wireless version would also reduce risk of infection, Scott noted.