Figure 2.

a–i, Movement patterns elicited by long-duration intracortical microstimulation. Movements were classified as either simple, when involving a single forelimb joint, or complex, when involving multiple forelimb joints. Complex movements were classified as elevations involving flexion of the elbow followed by extension of the wrist (a), advances involving forward displacement of the elbow and shoulder with wrist extension and hand opening (b), grasps involving flexion of the wrist and simultaneous digit contraction and hand closure (c), and retractions involving caudal displacement of the elbow and shoulder (d). Simple movements consisted of flexions of the digits (e) or elbow (g), extensions of the elbow (f) or wrist (i), as well as supinations of the forelimb (h).