Mind Over Matter; November 1999; Scientific American Magazine; by Zucker; 2 Page(s)

The disabling effects of spinal injury or degenerative disease on voluntary movement can be permanent, because damaged nerve cells and their "wiring" fail to regenerate. In many cases, however, motor areas of the brain that normally control body movements are left intact. Could activity of these motor areas actually be used to operate robotic limbs? As far-off as it seems, research suggests that this idea might not be merely science fiction.

In the July issue of Nature Neuroscience, John K. Chapin and his colleagues at MCP Hahnemann Medical College in Philadelphia report how they got rat motor neurons to control a simple device to obtain a food reward. They implanted a rat's brain with a 16-electrode array that could record activity of about 30 neurons at once. Such simultaneous recording is critical, because a neuron's activity is not specific to a particular muscle contraction and so cannot give complete directions for appropriate movements by itself. The team then trained the rat to press a lever for a reward that was delivered by a robotic device.