Friday, April 24, 2009

Twittering without hands, using only brain interface, holds possibilities for people with disabilities

From The Telegraph in the UK:

Adam Wilson posted the 17-character message using a brain-computer interface (BCI) that he is helping to build for people whose minds function but whose bodies do not work.

Mr Wilson, a biomedical engineering doctoral student at the University of Wisconsin-Madison, first wrote: "SENT FROM BCI2000", referring to the model number of his machine.

He followed this with "USING EEG TO SEND TWEET". The system works by monitoring electroencephalography – or EEG – which is the electrical activity produced on the scalp by the movement of neurons within the brain.

The user of a BCI wears a cap, which is studded with electrodes and connected to a computer. The electrodes detect the electrical signals caused by thoughts.

Mr Wilson's Twitter set-up contains an onscreen alphabet. The letters flash in turn, and when the letter that the user wants to type flashes, the system detects a spike in their brain activity, and selects that letter.

Justin Williams, an assistant professor who works with Mr Wilson, said: "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."

Mr Wilson likened the process to writing a text message on a mobile phone. "You have to press a button four times to get the character you want," he said of texting. "So this is kind of a slow process at first."

However as with texting, users pick up speed with practice, he said, adding: "I've seen people do up to eight characters per minute."

Mr Wilson and Mr Williams said that they hope the system will become available for people who have disabilities caused by things such as severe strokes or spinal cord injuries.

"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," Mr Williams said.

"Someone could simply tell family and friends how they're feeling today ... 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."