The next day, participant received a surprise source retrieval task. This retrieval task also consisted of six experimental runs and included the same number of trials as the encoding task. Trial duration and jittering of the trials was also identical to the encoding task. Retrieval trials consisted of two phases. During the first phase (3000 msec), one of the cue-words from the encoding task was presented again, and participant's indicated the correct encoding source (1 = imagined sound, 2 = heard sound, 3 = imagined image, 4 = observed image). During the second phase (1500 ms), the participants rated the confidence of their judgment (“unsure”/“sure”).
