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Mind reading demonstration.

Bin He (center, standing) monitors a "mind reading" trial along with Christopher Wilke (left) and Zhongming Liu. XiaoXiao Bia is the subject.

Reading minds: University research may help those who cannot move

University research may help those who cannot move

By Deane Morrison

From M, winter 2005

You probably wouldn't like it if anyone could read your thoughts. But what if you couldn't move a muscle in your body to communicate?

Two million people in the United States with some advanced diseases or paralyzing injuries lack the ability to move even their eyes to express their thoughts and wishes. For these people, mind reading could be a blessing--and it's already happening in the laboratory of Bin He, a professor of biomedical engineering at the University.

The "mind reader" is a computer which analyzes EEG readings from an array of electrodes connected to a headpiece.

Here's how it works: A volunteer, wearing the headpiece, sits at a monitor watching a cursor moving continuously from left to right across the screen. A vertical bar randomly appears near either the upper right corner or the lower right corner. The volunteer's job is to deflect the cursor up or down to hit the bar. The computer is programmed to move the cursor up if the volunteer thinks about moving her left hand and down if she thinks about moving her right hand.

One afternoon in September, a visitor to He's lab watched a medical student hit the target in15 out of 16 attempts.

At this point in the research, the computer only responds to two simple thoughts: left and right. But even getting across only two ideas is enough to establish a binary code for locked-in patients. It could be alphabetic, like Morse code, which uses only dots and dashes to represent letters. Or it could be a series of choices a patient could make until a complete message is delivered. For example, one might ask, "Would you like to watch TV?" ("Yes") Comedy or drama? ("Comedy") Movie or sitcom? ("Sitcom") and so forth. Selecting from choices presented in pairs could even make voting possible.

About 12 laboratories in the country are using electrodes to allow people to move cursors, He says. But He can construct an image of a person's cerebral cortex as the person thinks about moving either the right hand or the left hand. The computer maps the area(s) of the brain that "light up" when the thought is generated. Typically, a highlighted patch in the rear right cortex is associated with thinking about moving the right hand; the rear left cortex lights up when the person thinks about the left hand.

"We can tell with one trial which hand the person is thinking of," says He. "Someday, we hope to have a unique pattern of brain activity for a large number of thoughts."

The National Institutes of Health and the National Science Foundation have endorsed He's work in the form of a total of $2 million in current research grants.

That says something.