To image cortical activity in the statistically-determined time–frequency windows of interest, we utilized the dynamic imaging of coherent sources (DICS) beamformer to calculate voxel-wise source power across the entire brain volume for each participant59,60. The resulting images were normalized using a pre-stimulus baseline period of equal duration and bandwidth to the time–frequency window of interest. Such source images are commonly referred to as pseudo-t maps, with the unit (pseudo-t) reflecting noise-normalized power differences (i.e., task vs. baseline) per voxel61. Source images were computed at 4.0 × 4.0 × 4.0 mm resolution and were transformed into standardized space. The resulting images were averaged across all participants (collapsed across group) to identify voxels with the strongest responses per time–frequency bin of interest.
