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New way for paralyzed people to control movements

Now, researchers have found a way to avoid the wires.

Scientists have developed what they call a noninvasive brain-computer interface (BCI), which allows a person to move a cursor across a computer screen by thinking about it.

BCIs translate electrical signals in the brain into physical outputs, which could help people paralyzed by stroke, spinal cord injury, or Lou Gehrig’s disease.

In the study, Jonathan Wolpaw and Dennis McFarland of the New York State Department of Health and State University of New York found that humans can control two-dimensional movement with a noninvasive BCI that analyzes human brain waves. The brain waves are caused by electrical signals transmitted between brain cells as the thinking process takes place.

In the study, people with and without spinal cord injuries wore a cap of electrodes that transmitted brain wave activity to a computer. The participants learned to use their thoughts to direct a cursor on a computer screen, often by imagining specific actions.

A computer program analyzed the EEGs, selected the brain waves the person was best able to control, and translated them into cursor movement. Individuals with spinal cord injuries actually performed better than uninjured users, possibly reflecting greater motivation or injury-associated brain changes, the researchers said.

They predict that future improvements of this noninvasive BCI will focus on three-dimensional movement. The findings are to be published this week in the early online edition of the research journal Proceedings of the National Academy of Sciences.

—EJL

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