Researchers used a simple brain-computer interface to post a message on the social networking website Twitter, an achievement that shows the potential for developing new communications systems for people whose bodies don't work but who have normal brain function.
This includes people with high spinal cord injury, brain-stem stroke, and amyotrophic lateral sclerosis (ALS). Current brain-computer interface systems use an electrode-studded cap that's attached to a computer. The electrodes detect electrical signals in the brain and translate them into actions, such as moving a cursor on a computer screen.
"We started thinking that moving a cursor on a screen is a good scientific exercise. But when we talk to people who have locked-in syndrome or a spinal cord injury, their major concern is communication," Justin Williams, an assistant professor of biomedical engineering at the University of Wisconsin-Madison, said in a school news release. He and his colleagues designed an interface based on brain activity related to a keyboard displayed on a computer screen.
Change in brain activity
"The way this works is that all the letters come up, and each one of them flashes individually," Williams said. "And what your brain does is, if you're looking at the 'R' on the screen and all the other letters are flashing, nothing happens. But when the 'R' flashes, your brain says, 'Hey, wait a minute. Something's different about what I was just paying attention to.' And you see a momentary change in brain activity."
Twitter messages, called tweets, have a 140-character limit, a message length that's within locked-in users' capabilities, said Williams. Tweets are displayed on the user's profile page and delivered to other Twitter users who've signed up to receive them.
"So, someone could simply tell family and friends how they're feeling today," Williams said. "People at the other end can be following their thread and never know that the person is disabled. That would really be an enabling type of communication means for those people, and I think it would make them feel, in the online world, that they're not that much different from everybody else."
Widespread use of brain-computer interface technologies is still many years away, but Williams hopes this Twitter application will help push researchers to develop in-home technologies. - (HealthDay News, April 2009)
Brain signals of quad move cursor