Effects of emotionally incongruent musical excerpts on memory retrieval

Music's power to trigger memories has rarely been tested; in particular, it is not clear what mechanisms govern memory retrieval elicited by musical cues. Previous research has suggested that memory retrieval is underpinned by two mechanisms: (1) distinctiveness-the probability that a cue will retrieve a memory declines with the number of stimuli previously encoded with that same cue and (2) incongruence-a cue encoded with emotionally incongruent targets triggers more memories of the stimuli associated with it than a cue encoded with emotionally congruent stimuli. Our participants experienced an implicit encoding phase where they were presented with auditory-visual pairs of stimuli (pieces of music and images of facial expressions). In the retrieval phase, participants were asked to remember encoded stimuli triggered by music. As expected, musical cues encoded with emotionally incongruent facial expressions triggered more memories than cues encoded with congruent facial expressions. Contrary to our prediction and to previous findings, music from distinctive pairs of stimuli triggered fewer memories than cue pairs displayed multiple times in the encoding phase. Our finding suggests that the manipulation of stimuli at encoding is crucial when using musical cues to trigger memories.