By simply placing some electrodes on the surface of the brain, four volunteers have already been able to control their game consoles, US researchers reported on Monday.
   
"We are using pure imagination. These people are not moving their limbs," said Dr Eric Leuthardt, a neurosurgeon at Barnes-Jewish Hospital in St. Louis who worked on the study.
   
Their findings add to work being done at several centres and are aimed at finding ways to help people control computers or machines using brainpower alone.

Potentially, people paralyzed by disease or accidents could use such devices to work, read, write and even possibly to move around. 
   
Easy to use

Writing in Monday's issue of the Journal of Neural Engineering, Leuthardt and Daniel Moran, an assistant professor of biomedical engineering at Washington University in St Louis, said the patients learned in minutes how to control a
computer cursor.
   
"It took six minutes of training and they all achieved control in less than 24 minutes," Leuthardt said. 
   

"There will have to be a rigorous study on monkeys for an indeterminate number of years before we can consider permanent implants in human subjects"

Dr Eric Leuthardt,
neurosurgeon

"After a brief training session, the patients could play the game by using signals that come off the surface of the brain," added Moran.

"They achieved between 74 and 100% accuracy, with one patient hitting 33 out of 33 targets correctly in a row."
   
During the study their patients were forced to stay in bed tethered to a computer for up to two weeks, but Moran and Leuthardt hope to develop electrodes that can transmit signals without physical connections. 
   
Wireless technology needed

"You can't keep wires directly from the brain to the outside world indefinitely because of the increased risk of infection," Leuthardt added. "We have to create a wireless system."
   
Leuthardt and Moran centered about 32 electrodes over the sensory motor cortex of the brain and a region called Broca's area, which is associated with speech.
   
The pair did their work on a small amount of money - about $20,000 for the whole study, they said. "We really built this from matchsticks and paperclips," Moran said.
   
"There will have to be a rigorous study on monkeys for an indeterminate number of years before we can consider permanent implants in human subjects, but we're really excited about this advance," he added.
   
A team at Duke University in North Carolina reported in March they had used electrodes implanted deep in the brains of Parkinson's disease patients to transmit signals that might someday be used to operate remote devices.