Figure 2From: Increased cerebral blood flow in the right frontal lobe area during sleep precedes self-awakening in humansApproximate positions of the 31 fNIRS channels superimposed on a head model. The 31 measuring channels were produced by optrodes placed equidistantly over the prefrontal cortex (PFC) area. The lower line of the 4 × 5 optrode probe was positioned along the reference curve linking C3, C4, Fz, and FPz. Red denotes source optrodes and blue denotes detector optrodes.Back to article page