Researchers use brain interface to post to Twitter.
In early April, Adam Wilson MS’05, PhD’09 posted a status update on the social networking Web site Twitter — just by thinking about it.
Only twenty-three characters long, his message, “using EEG to send tweet,” demonstrates a manageable way for “locked-in” patients to couple brain-computer interface technologies with modern communication tools.
Wilson is among a growing group of researchers worldwide who aim to perfect a communication system for users whose bodies do not work, but whose brains function normally — people, for instance, who have amyotrophic lateral sclerosis (ALS), brain-stem stroke, or high spinal-cord injury.
Some brain-computer interface systems employ an electrode-studded cap wired to a computer. The electrodes detect electrical signals in the brain — essentially, thoughts — and translate them into physical actions, such as moving a computer’s cursor. “We started thinking that moving a cursor on a screen is a good scientific exercise,” says assistant professor Justin Williams, Wilson’s adviser. “But when we talk to people who have locked-in syndrome or a spinal-cord injury, their number-one concern is communication.”
In collaboration with scientist Gerwin Schalk and colleagues at the Wadsworth Center in Albany, New York, Williams and Wilson began developing a simple, elegant communication interface based on brain activity related to changes in an object on screen.
The interface shows a keyboard displayed on a computer screen. “The way this works is that all the letters come up, and each one of them flashes individually,” says Williams. “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.”
Wilson, who used the interface to post the Twitter update, likens it to sending a text message on a cell phone. “You have to press a button four times to get the character you want,” he says of texting. “So this is kind of a slow process at first.”
However, use improves with practice. “I’ve seen people do up to eight characters per minute,” says Wilson.
Williams hopes the Twitter application will nudge researchers to refine the in-home technology. “A lot of the things that we’ve been doing are more scientific exercises,” he says. “This is one of the first examples where we’ve found something that would be immediately useful to a much larger community of people with neurological deficits.”
Published in the Fall 2009 issue