NIRS and EEG data for (a) Group 1 and (b) Group 2. The top portions of the figure depict the difference between the left channel (FP1) and right channel (FP2) EEG signals. The bottom portions of the figure show NIRS signals for the blood oxygenation changes. The red line is the HbO2 concentration and the blue line is the HHb concentration. The x-axis is the experimental time and the y-axis is the change in concentration.