Figure 4.

a, b, Locations of neurons showing learning-related responses or color sensitivity, across M1 and premotor cortex. Cortical locations of recording sites (a) and microstimulation (b), both from monkey K, are superimposed on a surface map, extracted from MRI analysis (BioSpec 4.7 T; Bruker) and verified by skull endocast analysis. as, Arcuate sulcus; ps, principal sulcus; sd, superior precentral dimple. Dashed lines classify areas as M1, PMd, or PMv. a, Locations of neurons showing learning-related responses (black dots; n = 53 sites), neurons showing color sensitivity after learning (red dots; n = 21), and nondiscriminative neurons (gray dots; n = 41). b, Microstimulation map. Black dots, Locations in which intracortical microstimulation of <20 μA induced movements around the shoulder or elbow (n = 36). c, d, Learning-related responses (c) and color sensitivity (d), recalculated separately for neurons recorded from M1 (n = 60 cells), PMv (n = 63), and PMd (n = 17) of both monkeys. Responses are marked by dashed lines and compared with responses of the entire neuronal population (marked by solid lines; n = 140) (same as Fig. 3a,b). c, Learning-related responses for neurons recorded from the different areas. Notation is as in Figure 3a. d, Color sensitivity for neurons recorded from the different areas. Notation is as in Figure 3b. Note that the learning-related responses and color sensitivity were distributed evenly across M1 and premotor cortex.