The Neural Architecture of Music-Evoked Autobiographical Memories
Petr Janata Department of Psychology, Center for Mind and Brain, University of California, Davis, CA 95618, USA
The medial prefrontal cortex (MPFC) is regarded as a region of the brain that supportsself-referential processes, including the integration of sensory information with self-knowledge and the retrieval of autobiographical information. I used functional magnetic resonance imaging and a novel procedure for eliciting autobiographical memories with excerpts of popular music dating to one’s extended childhood to test the hypothesis that music and autobiographical memories are integrated in theMPFC. Dorsal regions of the MPFC (Brodmann area 8/9) were shown to respond parametrically to the degree of autobiographical salience experienced over the course of individual 30 s excerpts. Moreover, the dorsal MPFC also responded on a second, faster timescale corresponding to the signature movements of the musical excerpts through tonal space. These results suggest that the dorsal MPFC associatesmusic and memories when we experience emotionally salient episodic memories that are triggered by familiar songs from our personal past. MPFC acted in concert with lateral prefrontal and posterior cortices both in terms of tonality tracking and overall responsiveness to familiar and autobiographically salient songs. These ﬁndings extend the results of previous autobiographical memory research bydemonstrating the spontaneous activation of an autobiographical memory network in a naturalistic task with low retrieval demands. Keywords: emotion, episodic memory, fMRI, medial prefrontal cortex, tonality
Introduction The evocation of autobiographical memories and associated emotions by music counts among the most poignant experiences associated with music; yet, little is known about how theseprominent facets of the human experience are bound together in the brain. In this study, I test the hypothesis that the medial prefrontal cortex (MPFC) serves as a hub that associates features of the music with autobiographical memories and emotions. I also describe the broader network of brain areas that is recruited during the reliving of music-evoked autobiographical memories (MEAMs). There areseveral reasons to suspect that the MPFC might support the integration of memories, emotions, and music. Meta-analyses of autobiographical memory retrieval tasks indicate MPFC involvement (Gilboa 2004; Svoboda et al. 2006), and more generally, the MPFC is engaged by judgments regarding self-relevance and affect (Ochsner et al. 2004). The reason to suspect that music engages the MPFC is 4-fold.First, the region was observed to track the movement of a melody through the tonal space created by the system of major and minor keys underlying Western tonal music (Janata, Birk, et al. 2002). The trajectory that a piece of music takes in tonal space
serves as a signature of that piece of music. Given that excerpts of music serve as potent retrieval cues for memories (Janata et al. 2007),structural descriptors of such pieces (such as their movements in tonal space) constitute probes with which to identify brain regions that are responding to speciﬁc ethologically valid memory retrieval cues. These time-varying descriptors may complement simpler static descriptors (such as whether the overall excerpt is familiar to the listener) in identifying brain areas that respond to personallyrelevant musical stimulation. Second, emotional responses to music and the perceived pleasantness of music modulate activity in the MPFC. Ventral regions in particular were shown to respond more strongly to short consonant musical passages compared with the same passages rendered increasingly more dissonant (Blood et al. 1999), and the same areas were active while listening to unfamiliar but pleasant...