Neuroscience: Can "locked-in" sufferers tweet, using brain signals alone?

According to a recent (4/20/09) release from the University of Wisconsin-Madison,

In early April, biomedical engineer Adam Wilson posted a status update on the social networking Web site Twitter - just by thinking about it.

Just 23 characters long, his message, "using EEG to send tweet," demonstrates a natural, manageable way in which "locked-in" patients can couple brain-computer interface technologies with modern communication tools.

A "tweet is a Twitter message.

"Locked-in" means that due to a disease, you can't move or speak (except possibly for eye movements) but are fully conscious. Yes, I know, it does sound awful, but it happens, often due to catastrophic accidents. (Note: "Locked-in" syndrome should be distinguished from persistent vegetative state (PVS), in which the person's state of consciousness is not certain. A person in PVS might not benefit from a highly active communication system.)

The interface consists, essentially, of 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 texting 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, as with texting, users improve as they practice using the interface. "I've seen people do up to eight characters per minute," says Wilson.

A free service, Twitter has been called a "micro-blogging" tool. User updates, called tweets, have a 140-character limit — a manageable message length that fits locked-in users' capabilities, says Williams.

Presumably, like other prisoners, locked-in patients have time to spare, so they can sort through the letters.

However, caution, this has - so far as I can see - not yet been tested on actual locked-in sufferers. Still, it remains a viable research project for helping to free them, at least a little bit.

Here's a demo.

Hat tip: Stephanie West Allen at Brains on Purpose