Paralysed patients may benefit from the development of an implantable brain–computer interface device that can bypass damaged motor pathways^{1, 2, 3}. But it is unclear whether chronically de-efferented areas will still be sufficiently excitable to respond to motor attempts^{4, 5} if the motor cortex has been extensively reorganized^{6, 7}, and, if they are, whether this excitability is somatotopically organized^{8, 9}. Here we use functional magnetic resonance imaging to study brain activity in subjects with spinal-cord injuries while they are executing, or attempting to execute, movements of different limbs. We show that their motor-cortical activation closely follows normal somatotopic organization in the primary and non-primary sensorimotor areas. Our results indicate that any reorganization of the motor system that does occur in these patients does not affect attempt-related activation, and that it should be possible to access voluntary control signals by using a cortical neuroprosthetic.

1. Department of Bioengineering, University of Utah, Salt Lake City, Utah 84112, USA
2. Nuclear Magnetic Resonance Center, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA

Correspondence to: Richard A. Normann¹ e-mail: Email: normann@utah.edu