Fig. 3.

The data processing flowchart with five steps. Step 1: $\mathrm{\Delta }[\mathrm{HbO}]$ and $\mathrm{\Delta }[\mathrm{CCO}]$ quantification at each time point and construction of time series (blue boxes); Step 2: amplitude and phase decomposition using the multi-taper method (yellow box); Step 3: determination of four types of coherences for each E/N/M bands (green box). Steps 1 to 3 were repeated for pre- and post-stimulation periods (outlined by the dashed box). Step 4: baseline subtraction for coherence values (purple box). This step was repeated for each of the 26 participants (outlined by the second middle dotted box) and then for each of the five measurements (outlined by the outer dash-dotted box). Step 5 marks a two-step statistical analysis (gray box and solid box): sham subtraction followed by one-sample $t$-tests used to identify group-level, sham-controlled changes for respective coherence parameters in response to tPBM. Note that labels of (a)–(e) correspond to the data shown in Fig. 4 in the Results section.