Figure 2: (a) Spatial profiles of fNIRS CHs (left and right side views of the probe arrangements). fNIRS CH orientation is also illustrated. Detectors are shown as gray lozenges, illuminators as gray circles, CHs as black and white numbers (1-44), and ROIs (8 CHs) as yellow circles. CH 11 and CH 34, shown as dotted black squares, were placed over the C3 and C4 positions, respectively, in accordance with the international 10-20 system [26]. (b) CH locations on the brain. Left and right side views are illustrated. Statistically estimated fNIRS CH locations (yellow [ROIs] or blue circles) for all subjects, and their spatial variability associated with the estimation are exhibited in MNI space.