By Jackie Man
Music is an integral part of human experience, involved in our deepest emotions and our most firmly held beliefs. Whether for the enjoyment of listening, for a form of escape or for expressing emotions, many people around the world consider music significant in their lives. Thus, the relationship between music and the brain has emerged as a core research topic in the study of recognition and neuroscience (Graziano, Amy & Julene, 2015). Whilst attempts have been made by psychologists and musicologists to understand the associations between musical creativity and psychopathology, music is yet not fully understood as an emotion system (Michael, T.D. 2020). So why does music influence our brain in such a strong way?
In order to understand why and how music affects human emotion and feelings, the mechanisms behind the way in which music changes the brain’s behaviours must first be understood. In terms of how music is received, according to a research paper written by Silbersweig and Brigham and Women’s Hospital (BWH) psychiatry colleague Samata Sharma, the processes by which we perceive sounds as music is incredibly complex. After sound waves are transformed into electrical signals, it passes the brainstem via sensory nerves for auditory information (Harvard, 2020). It then disperses to activate auditory cortices on both sides of the brain, which involves subcortical structures like cochlear nuclei, the brainstem and the cerebellum. What part of the brain is activated by music relies heavily on multiple factors: whether the person hears, performs, learns, or composes music; plays a key role in explaining this phenomenon.
In fact, listening involves memory centres in the brain, including the hippocampus and lower parts of the frontal lobe; music has been regarded as a right-brain activity because of its reliance on creativity (Levitin, D.J. 2006). However, recent studies into music localization using advanced imaging technologies such as fMRI and PET shows that playing music professionally produces analytical processes in the left brain hemisphere, compared to music amateurs or listeners processing music on the right brain hemisphere. Using in-vivo magnetic resonance morphometry, analyses revealed that the anterior half of the corpus callosum (CC) was significantly larger in musicians than to the controlled group (Schlaug et al., 2020). This research illustrates that the left hemisphere is predominant in perceiving music in musicians compared to amateurs, and that music lateralization towards the right brain hemisphere is achieved through the study of music listeners, in relation to the emotional experience of music brings.
Another topic that came to awareness between the cross-bridge of psychology, musicology and neurology, was the idea of music as an expression of emotions. Several scientific studies have depicted that listening to music can change one’s mood in several different ways (Sharma, Samata & Silbersweig, 2018). For example, a team of Montreal researchers investigated how music evokes and affects human emotions. This group of researchers observed numerous individual’s brain activities using a fMRI and ligand-based positron emission tomography (PET), whilst they were listening to a playlist of their favourite songs. PET results show that music triggers the release of dopamine in both the dorsal and ventral striatum, known to be a response to pleasurable stimuli. The anticipatory phase, set off by temporal cues, was found to trigger expectations of euphoric emotional states and create a sense of wanting and reward prediction (Gottfied, J. 2020). Indeed, a lot of composers and artists also take advantage of this phenomenon and exploit emotional arousal by delaying expectations or manipulating the desired result to maximize the effect before resolution.
However, other studies report an observed decrease in activity in the amygdala and hippocampus regions, accompanying the feeling of pleasure. This phenomenon suggests that the euphoric feeling is mediated with antagonistic withdrawal mechanisms, given the role of the amygdala in negative emotional experiences. These findings suggest that the pleasure of music may be due to both positive engagement of brain areas related to reward, and inhibition of areas related to negative affective states. With findings suggesting how music can also lead to an inhibition effect in addition to the feeling of pleasure, scientists went on to investigate whether music can be a potential method of therapy and a means of accessing and stimulating specific cerebral circuits.
Neuroscientists first investigated possibilities of music therapy through imaging technology. Through peering non-invasively inside individuals’ brains to observe how neural circuits were fired, it was found that patients with sensory amusia lose the ability to perceive or respond to music while those with musical hallucinosis perceive music without it actually being played. These changes in brain circuitry and connectivity suggest the therapeutic opportunities through activating certain regions of the brain can promote healing (Harvard, 2020).
Several other studies have also shown how rhythmic entrainment of motor function can actively facilitate the recovery movement in patients with stroke, Parkinson’s disease, cerebral palsy and traumatic brain injury (Thaut, 2005). It was found that in people with memory disorders, such as Alzheimer’s disease, neuronal memory traces built through music are profoundly rooted and more resilient to neurodegenerative influences. With people with depression, music therapy is found to improve mood disorders. Similar to the effects of music on depression, studies have also shown how epilepsy, a common disorder associated with electroencephalography abnormalities, can be normalised by music in some people. This can be explained by the evidence that music can decrease seizure frequency, stop refractory status epilepticus and decrease electroencephalographic skip frequency in children with epilepsy in both mentally awake and sleep states (Michael, T.D. 2020). These data suggest that the effects of music therapy in patients with neuropsychiatric disorders should be further explored, to explain and show how different components of electroencephalography, or modulation of musical input to stimulus can affect the emotional state of patients, thus produce a healing effect.
Although there is still a lot to discover regarding the neuroscience of music, scientific studies over the years have provided insight into the mechanisms behind how music is transmitted into the brain. Furthermore, researchers are beginning to understand how music can act to heal and affect one’s emotions and feelings. That said, other aspects of the neuroscience of music (e.g. music therapy in patients with neuropsychiatric disorders) will require further exploration and research as cognitive neuroscientists continue to explore the neurological side of music.
References:
Gottfried, J., 2020. Neurobiology Of Sensation And Reward. [online] Ncbi.nlm.nih.gov. Available at: <https://www.ncbi.nlm.nih.gov/books/n/frsenserwd/> [Accessed 7 October 2020].
Graziano, Amy B., and Julene K. Johnson. (2015) “Music, Neurology, and Psychology in the Nineteenth Century.” In Music, Neurology, and Neuroscience: Historical Connections and Perspectives (Progress in brain research 216)
LEVITIN, D. J. (2006). This is your brain on music: the science of a human obsession. New York, N.Y., Dutton.
Michael Trimble, D., 2020. Music And The Brain: The Neuroscience Of Music And Musical Appreciation. [online] PubMed Central (PMC). Available at: <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5618809/> [Accessed 7 October 2020].
Neuro.hms.harvard.edu. 2020. Music And The Brain. [online] Available at: <https://neuro.hms.harvard.edu/harvard-mahoney-neuroscience-institute/brain-newsletter/and-brain/music-and-brain> [Accessed 7 October 2020].
Schlaug, G., Jäncke, L., Huang, Y., Staiger, J. and Steinmetz, H., 2020. Increased Corpus Callosum Size In Musicians.
Sharma, Samata R. and Silbersweig, David, “Setting the Stage: Neurobiological Effects of Music on the Brain” (2018). Crossroads of Music and Medicine. 6. https://remix.berklee.edu/mh-exchange-music-medicine/6
Societyforscience.org. 2020. Neuroscience And Music Are More Related Than You Think | Society For Science & The Public. [online] Available at: <https://www.societyforscience.org/blog/neuroscience-and-music-are-more-related-than-you-think/> [Accessed 7 October 2020].
Thaut, M. H. (2005) The future of music in therapy and medicine. Annals of the New York Academy of Science, 1060, 303–308.
Imperial Bioscience Review 