Brain correlates of music-evoked emotions

Music is a universal feature of human societies: in all cultures that we know about, humans make (or made) music. Newborn infants show limbic responses to music 1 , and 5-month-old infants enjoy moving in synchrony with music 2 . For adults, the prime motivations for engaging with music are experiencing, and regulating, emotions and moods 3 (a neurobiological definition of emotion is provided in BOX 1). Although researchers still debate the degree of overlap between music-evoked emotions and emotions evoked in everyday life, there is now evidence that music can evoke changes in the major reaction components of emotion, including subjective feeling, physiological arousal (autonomic and endocrine changes), motoric expression of emotion (such as smiling) and action tendencies (for example, dancing, singing, playing an instrument, foot tapping and clapping, even if only covertly). The potential of music to evoke emotions makes music a valuable tool for the investigation of emotions and their neural correlates. During recent years, neuroscientific research on music-evoked emotions has rapidly progressed and increased our knowledge about neural correlates of human emotion in general. Here, I review this research and summarize the findings by providing a meta-analysis of functional neuroimaging studies on music-evoked emotions. Findings to date indicate that the superficial amygdala has a central role in the processing of stimuli with universal socio-affective significance (such as music), that music-evoked pleasure is associated with activity of the dopaminergic mesolimbic reward pathway (including the nucleus accumbens) and that the hippocampal formation is involved in emotions related to social attachments. The power of music to change the neuronal activity within these brain structures has implications for the development of music-based therapies for the treatment of neurological and psychiatric disorders associated with dysfunction and morphological abnormalities in these structures. Phylogenetic origins of sound-evoked emotions The auditory system evolved phylogenetically from the vestibular system. Interestingly, the vestibular nerve contains a substantial number of acoustically responsive fibres. The otolith organs (the saccule and utricle) are sensitive to sounds and vibrations 4 , and the vestibular nuclear complex exerts a major influence on spinal (and ocular) motor neurons in response to loud sounds with low frequencies or with sudden onsets 4,5 Moreover, both the vestibular nuclei and cochlear nuclei project to the reticular formation, and the vestibular nucleus also projects to the parabrachial nucleus, a convergence site for vestibular, visceral and autonomic processing 6,7 . Such projections initiate and support movements and contribute to the arousing effects of music. Thus, subcortical processing of sounds gives rise not only to auditory sensations but also to muscular and autonomic responses, and the stimulation of motor neurons and autonomic neurons by low-frequency beats might contribute to the human impetus to 'move to the beat' (REFS 5,8). Beyond these phylogenetically old brainstem systems, which are in part the basis for visceral reactions to music, several forebrain systems also contribute to music-evoked emotional experiences. Music Structured sounds that are produced by humans as a means of social interaction, expression, diversion or evocation of emotion. Functional neuroimaging Functional neuroimaging methods, such as functional MRI (fMRI) or positron emission tomography (PET), use indirect measures (for example, changes in regional blood flow) to localize neural activity in the brain. Otolith organs The two otolith organs, the saccule and utricle, are vestibular organs that sense linear acceleration (and its gravitational equivalent). Vestibular nuclei Nuclei that are located in the brainstem and receive information from the vestibular nerve. Brain correlates of music-evoked emotions Stefan Koelsch Abstract | Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders