In a new study, Stanford engineer Krishna Shenoy and a group of researchers at Caltech have shown that at least some links in that chain can be dramatically bypassed. The study is a significant advance in the growing field of neural prosthetics - implanted devices that eventually may help severely paralyzed patients regain some of their lost functions. The results of the study were presented by Daniella Meeker, a Caltech graduate student, at the annual meeting of the Society for Neuroscience in San Diego on Nov. 11.

Planned movements

Shenoy, Meeker and their colleagues showed that electrical signals from the parietal reach region (PRR), the part of the brain responsible for planning arm movements, can be used to control the movement of a cursor on a computer screen. Using signals from an electrode implanted in the PRR of a monkey, the researchers were able to mimic the animal`s arm movements with the movements of a cursor called a prosthetic icon. Eventually, the monkey was able to control the icon by thought alone.

Previous studies have shown that the brain cells responsible for moving an arm also can be used to control robotic arms, computer cursors or other devices. But this study is the first to show that the cells responsible for planning those movements can do the same.

``The key difference between our approach and the approach of several other groups around the country is that we`re looking at neural activity that is present before, or even without, real arm movement,`` says Shenoy, an assistant professor of electrical engineering at Stanford.

The advantage of using planning cells is that they encode a simpler set of parameters
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-3926
Stanford University
28-Nov-2001