ERPs were calculated by averaging epochs extracted from − 1000 to 4000 ms of the stimulus event (i.e. memory cue: the appearance of the cue word) in the T and the NT conditions without baseline correction101 (link)–104 (link). After artifact rejection, we obtained a total of 4158 and 4259 epochs for the T and NT conditions respectively.
The significance in the ERPs (and their topographies) between conditions at the population level was calculated in EEGlab by permutation statistics (p < 0.05), corrected for multiple comparisons (ERPs from 64 electrodes) by using the false discovery rate (FDR) method.