Fig. 2.

(a) Experiment setup including two channels of bbNIRS on two lateral sides of the forehead and EEG cap. The electrophysiological data collected by 2-bbNIRS were the focus in this study. (b) The protocol of this study consisted of 5 visits with a 7-min pre-stimulation, an 8-min randomized tPBM or sham, and 7-min post-stimulation period. The bbNIRS data were collected concurrently during pre- and post-stimulation. (c) Illustration of the light source, two spectrometers, 2-channel probe bundle for 2-bbNIRS measurements. (d) Illustration of the delivery location for the right and left tPBM/sham.