For each peak voxel in the grand-averaged functional maps, voxel time series were computed for the specific coordinate per participant. Briefly, in each participant, we applied the individual sensor-weighting matrix to the preprocessed signal vector, which yielded a time series for each source vector centered in the voxel of interest. The vector sum of the two orientations was then computed and normalized using the baseline period from the source analysis, ultimately yielding one time series per voxel per participant. For each person, the average over the respective time–frequency windows of interest for theta, alpha, and gamma frequency were computed using these time series, and these values were used in the statistical analysis.
