Researchers at the University of Wisconsin-Madison have created a revolutionary new way for sufferers of locked-in syndrome to communicate using only their brainwaves...and, even more shockingly, found a use for Twitter that's actually worthwhile.

Adam Wilson, a biomedical engineering doctoral student, has developed a system in which a person can write using only his or her brain. By attaching an EEG to the user's head that can recognize different brain patterns that correspond to different letters, the system can be a keyboard for those who lack almost all voluntary motor function but whose brains work normally.

This neurological condition, often referred to as locked-in syndrome, is different from quadriplegia in that locked-in patients cannot control even the mouth or eye muscles that many quadriplegics use to communicate. There are roughly 25,000 to 50,000 sufferers of locked-in syndrome in the United States. Causes of locked-in syndrome include high spinal cord injury, a massive stroke, and amyotrophic lateral sclerosis (ALS).


Famous patients include physicist Stephen Hawking, whose communication systems are currently linked to his still usable cheek muscles, and The Diving Bell and the Butterfly author Jean-Dominique Bauby, who wrote his memoir through a system of blinks of his left eyelid, the only muscle he could still control. Bauby's blink system is the most common way for locked-in patients to communicate, although such methods are often extremely slow and difficult.

Wilson's adviser, biomedical engineering assistant professor Justin Williams, explained how their new system manages to tell what letter the user is thinking about (there's also a video below illustrating the process):


"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."

The system works well with short messages - Wilson says the fastest users can "type" about eight characters per minute - which makes it perfect for Twitter, the latest web phenomenon where users post status updates of 140 characters or less. Wilson has been tweeting for the past nine days (the posts using the EEG are in all caps). Williams explained the particular advantages of integrating their technology with Twitter:

"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."

Hopeful that the current popularity of Twitter provides a ready-made launching pad for the system, Williams described how using Twitter with the EEG would be not only helpful but also empowering for locked-in patients:

"So someone could simply tell family and friends how they're feeling today," says Williams. "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. That's why we did these things."

The brain-computer interface technology is still very much in its infancy, although these recent developments represent significant forward progress. Though years away from being commercially available, the technology will soon begin in-home trials in the United States and Germany, and Wilson plans to include Twitter in the trials. The future commercial version of the interface will ideally be essentially a baseball cap with built-in EEG that is wired into the user's computer system. There is also the possibility of a more invasive system where electrodes are implanted beneath the skin, which Williams believes would significantly increase typing speed.

[University of Wisconsin-Madison News]