A. Display monitor. Location of the two target positions. A 2 × 2 cm square located 10 cm below either one (randomly, 50/50) of the two targets served as starting position (SP) of the hand (in this figure, the left SP is represented). B. Trial events in the choice task. Grey areas correspond to the time of illumination of the starting position (SP) and of the target stimuli. E1 to E6: epochs for analysis. C. Location of task-related cells. Abbreviations: CC, corpus callosum; ArS, rostral extent of the superior branch of the arcuate sulcus; Ars, arcuate sulcus; end of SP, caudal extent of the Sulcus Principalis; SGm, medial superior gyrus; Cgd and Cgv, dorsal and ventral banks of cingulate sulcus; CgG, cingulate gyrus.