Infrared probe geometry positioning. Schematic of probe placement projected on cortical locations specific to the PFC, M1, and SMA. Optodes are placed for maximum coverage over the PFC, M1, and SMA. Red dots indicate infrared sources, blue dots indicate long separation detectors, and textured blue dots indicate short separation detectors. The PFC has three sources (1–3), the M1 has four sources (4–7), and the SMA has one source (8). Each of the sources is connected to their corresponding long and short separation detectors. (Color figure online)