Fig. 1.

A: monkeys (execution) or experimenters (observation) performed the reach, grasp, manipulate task. Blue lights instructed the target object. Hand postures in each of the 4 behavioral epochs (labeled at left) have been redrawn from selected video frames. B: neurons were recorded from floating microelectrode arrays implanted in premotor cortex (PM; open squares) and primary motor cortex (M1; closed squares). In monkey L, all PM arrays were situated in the ventral PM, but in monkey X, the more medial PM array may have been in dorsal PM. AS, arcuate sulcus; C, caudal; CS, central sulcus; M, medial.