Brain networks underlying aesthetic appreciation as modulated by interaction of the spectral and temporal organisations of music

Music is organised both spectrally and temporally, determining musical structures such as musical scale, harmony, and sequential rules in chord progressions. A number of human neuroimaging studies investigated neural processes associated with emotional responses to music investigating the influence of musical valence (pleasantness/unpleasantness) comparing the response to music and unpleasantly manipulated counterparts where harmony and sequential rules were varied. Interactions between the previously applied alterations to harmony and sequential rules of the music in terms of emotional experience and corresponding neural activities have not been systematically studied although such interactions are at the core of how music affects the listener. The current study investigates the interaction between such alterations in harmony and sequential rules by using data sets from two functional magnetic resonance imaging (fMRI) experiments. While replicating the previous findings, we found a significant interaction between the spectral and temporal alterations in the fronto-limbic system, including the ventromedial prefrontal cortex (vmPFC), nucleus accumbens, caudate nucleus, and putamen. We further revealed that the functional connectivity between the vmPFC and the right inferior frontal gyrus (IFG) was reduced when listening to excerpts with alterations in both domains compared to the original music. As it has been suggested that the vmPFC operates as a pivotal point that mediates between the limbic system and the frontal cortex in reward-related processing, we propose that this fronto-limbic interaction might be related to the involvement of cognitive processes in the emotional appreciation of music.