Analysis pipeline of the fNIRS data. Raw data from each participant were first preprocessed using the principal component analysis (PCA) and the correlation-based signal improvement method (CBSI). Next, each IER block was segmented into three stages. Based on this, we computed the Fc and IBS matrices for three stages, and then obtained the block-aggregated Fc and IBS matrices by averaging those in three blocks. Eventually, these Fc and IBS matrices were baseline-corrected by subtracting Fc/IBS values of the resting sessions, and submitted to the following statistical tests.