Musical expertise shapes visual-melodic memory integration

Music can act as a powerful mnemonic device that can elicit vivid episodic memories. However, how musical information is integrated with non-musical information is largely unknown. Here, we investigated whether and how musical expertise modulates binding of melodies and visual information into integrated memory representations. We reasoned that the significant mnemonic demands of musicianship might alter the underlying integration process and reveal mechanisms by which music promotes retrieval of non-musical memories. Professional musicians and musical laypersons learned overlapping pairs of everyday objects and melodies (AB- and BC-pairs, object-melody and melody-object pairs). Participants were then tested for memory of studied pairs (direct trials) and for inferential AC-decisions (indirect trials). Although musicians showed a higher overall performance than non-musicians, both groups performed well above chance level in both trial types. Non-musicians reacted faster in indirect compared to direct trials, whereas the reverse pattern was found in musicians. Differential correlations of trial type performance between groups further suggested that non-musicians efficiently formed integrated ABC-triplets already during the encoding phase of the task, while musicians separately memorized AB- and BC-pairs and recombined them at retrieval for AC-decisions. Our results suggest that integrative encoding is a default mechanism for integration of musical and non-musical stimuli that works with great efficacy even in musically untrained subjects and may contribute to the everyday experience of music-evoked episodic memories. By contrast, recombination at retrieval seems to be an advanced strategy for memory integration that critically depends on an expert ability to maintain and discriminate musical stimuli across extended memory delays.