Much like a scene from some sci-fi flick, four epilepsy patients successfully learned how to control a cursor on a video screen using only their minds. This important development from researchers at Washington University at St. Louis could lead to biomedical devices that can control paralyzed or artificial limbs.
First, the researchers placed an electronic grid that records electrocorticographic (ECoG) activity directly on the patients' brains. The grids and the patients were connected to a computer running a program known as BCI2000. The researchers then asked the patients to perform and imagine various motor and speech tasks.
Next, the patients played a simple, one-dimensional computer game where they had to move a cursor up or down toward one of two targets. They also imagined various movements and words without actually performing or saying them. The system recorded all of the corresponding brain activity.
Then, the patients tried to play the game without moving or talking at all. The system translated their brain activity into the appropriate corresponding movement. After a brief training session, the patients achieved between 74% and 100% accuracy in moving the cursor with their minds. One patient even hit 33 out of 33 targets in a row.
The next step, researchers say, is to try games with 2D movements. Also, they want to implant the ECoG grids onto nonhuman primates to determine how long the system can provide reliable data. Using this data, the researchers would develop a brain-machine interface for long-term implantation.
Recently approved by the U.S. Food and Drug Administration, Cyberkinetics Inc. has a similar technology, though it's in the early stages of development (see "Researchers Test Brain Implant For Quadriplegics," June 21, 2004, p. 8).
For more information, go to www.wustl.edu
