The activity of motor cortex (MI) neurons conveys movement intent sufficiently well to be used as a control signal to operate artificial devices^{1, 2, 3}, but until now this has called for extensive training or has been confined to a limited movement repertoire^{2, 3}. Here we show how activity from a few (7–30) MI neurons can be decoded into a signal that a monkey is able to use immediately to move a computer cursor to any new position in its workspace (14° 14° visual angle). Our results, which are based on recordings made by an electrode array that is suitable for human use^{4, 5}, indicate that neurally based control of movement may eventually be feasible in paralysed humans.

1. Department of Neuroscience, Box 1953, Brown University, Providence, Rhode Island 02912, USA
   e-mail: Email: mijail_serruya@brown.edu
2. Present addresses: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637, USA (N.G.H.); Center for Neural Science, New York University, New York, New York 10003, USA (L.P.)