[games_access] Brain sensor allows mind-control

[Barrie Ellis]

http://news.bbc.co.uk/2/hi/health/5167938.stm


Brain sensor allows mind-control

Mr Nagle was the first patient to trial the device

A sensor implanted in a paralysed man's brain has enabled him to control 
objects through just the power thought.
The experimental set-up allowed the man, who has no limb movement at all, to 
open e-mail, play a computer game, and pinch a prosthetic hand's fingers.

The US team behind the sensor hopes its technology can one day be 
incorporated into the body to restore the movement of paralysed limbs 
themselves.

The group's study is published in the journal Nature.

 It's just wild

Matthew Nagle

Matthew Nagle, 25 at the time of the trial, was left paralysed from the neck 
down and confined to a wheelchair after a knife attack in 2001. He was the 
first patient to try out the brain sensor.

A team of scientists inserted the device, called a neuromotor prosthesis 
(NMP), into an area of the brain known as the motor cortex, which is 
responsible for voluntary movement.

The NMP comprises an internal sensor that detects brain cell activity, and 
external processors that convert the activity into signals that can be 
recognised by a computer.

Although the patient's spinal cord had been severed for three years by the 
time of the trial, the scientists found that brain cell activity - or neural 
firing patterns - persisted in the patient's motor cortex.

The electrodes in the NMP were able to record this activity and send it to a 
computer. The computer then translated the firing patterns into movement 
commands which could drive computer controls or artificial limbs.


Regained independence

Using the device, Mr Nagle was able to move a computer cursor to open an 
e-mail, play simple computer games, open and close a prosthetic hand, and 
use a robot limb to grasp and move objects. He could do this simply by using 
his thoughts.

Mr Nagle said the sensor had restored some of his independence by allowing 
him to carry out a number of tasks - such as turning the lights on - that a 
nurse would normally do for him.

He told the BBC: "I can't put it into words. It's just wild."

Lead researcher Dr Leigh Hochberg, a neurologist at the Massachusetts 
General Hospital, said: "One of the exciting results from the trial is that 
this part of the brain, the motor cortex, could still be activated 
voluntarily by this gentleman with spinal cord injury.

"The fact that this activity was still there, despite the injury that had 
occurred several years ago, is very encouraging for our potential ability to 
harness those signals to control an external device."
Co-author Professor John Donoghue is director of the brain science programme 
at Brown University and chief scientific officer of Cyberkinetics, the 
company that created and trialled the sensor.

He said: "The results hold promise to one day being able to activate limb 
muscles with these brain signals, effectively restoring brain-to-muscle 
control via a physical nervous system."

The sensor is inserted directly into the brain

The team also looked at a second, 55-year-old patient, but said technical 
issues meant the sensor could not record brain activity.

Professor Stephen Scott, from Queen's University, Ontario, Canada, said in a 
related article: "This research suggests that implanted prosthetics are a 
viable approach for assisting severely impaired individuals to communicate 
and interact with the environment."

But he warned that considerable problems needed to be overcome before this 
technology could be put into regular use.

He said problems such as the device's longevity, infection risks, and data 
transfer methods needed to be looked at.

Tested too early?

Professor Igor Aleksander, an expert in neural systems engineering at 
Imperial College London, UK, said: "I think this is enormously important 
stuff because there is real potential for helping people that have had 
severe neural disabilities."

But Professor Miguel Nicolelis, a neurobiologist from Duke University, was 
critical of the research.

He told the BBC's Science in Action programme that although some positive 
signs had been seen for one patient, the paper showed that the technology 
did not work in the second, older patient.

He said: "When you decide, like this company did, to go into clinical trials 
for an invasive technique the stakes are very high.

"They should have demonstrated something that lasts for a long period of 
time, that it is reliable and safe, and that it can restore much more 
elaborate functions. I don't think that this paper shows that.
"I think it was too early to use this kind of technology in this kind of 
clinical trial."