It might even be possible to apply the technology to stroke victims whose language center has been injured. Other areas of the brain may be able to compensate, Shih said. "We actually found that these types of signals can be reported not only from the language center, but from other portions of the brain," he said. "So this still might work even for people whose language area has been destroyed."
The researchers hope to study more patients, but are likely to confine their research - for now - to patients who already have implanted electrodes. Ethically, they cannot justify performing a craniotomy on people who don't otherwise need it, Shih said. Still, "we want to do this with more people and refine the process so that the communication route can be improved," he said.
Ultimately, once the technique is perfected, patients will have to undergo the surgery; also software would have to calibrate each person's brain waves for the desired action - language, for example, or the movement of a prosthetic arm.
"These patients would have to use a computer to interpret their brain waves, but these devices are getting so small, there is a possibility that they could be implanted at some point," Shih said.
"We are only limited by our understanding of the technology," he added. "I foresee, if we make this technology really work, we can safely implant it in a small area of the brain - and any person who needs it will be able to use it."
The research, presented at the 2009 annual meeting of the American Epilepsy Society, was funded by the National Science Foundation.
—By Marlene Cimons, NSF ---