By Lia Hale
28th January 2022
Music has been an indispensable aspect of human civilisation since our beginnings – and not just for the purpose of communication…whether it is the theme song of your favourite childhood television show, the soundtrack to your favourite film or your most played song of 2021, the strength of emotional response a piece of music can produce is quite remarkable. The use of music purely for pleasure is, as far as we are aware, unique to humans. But what is it that makes us react this way to music? How can vibrations of air at different frequencies bring us to tears?
The answer lies within us, in our brain’s reward system. This system consists of the ventral tegmental area, which is one the brain’s primary dopamine-producing areas, the nucleus accumbens, which is responsible for motivation and reward and the mesolimbic dopamine pathway, which connects the two areas together. Our brain’s reward system is involved in producing feelings of pleasure in response to external stimuli, thereby acting as a reward and motivating us to seek out the same stimuli again. The reward system is therefore heavily implicated in addiction (and other psychiatric conditions such as depression). However, it has also been discovered to be responsible for the strong emotional response produced by music. This means that, technically, the high we get from listening to music is the same as that from drugs such as amphetamines or cocaine. That may help to explain why your Spotify Wrapped told you that you spent hundreds of minutes listening to the same song – maybe you were addicted!
Much of our understanding about the reward system’s involvement in the musical experience comes from a fascinating condition called musical anhedonia. Individuals with musical anhedonia comprise about 5% of the population – essentially, they do not experience any pleasure in response to music. This absence of a pleasure response is specific to musical stimuli, and thus has presented a unique opportunity to identify the exact mechanisms responsible for our infatuation with music as a species.
Rather than activating the auditory cortex alone, it appears that an interaction between the auditory cortex and the reward pathway occurs in response to musical stimuli, and it is this interaction which is absent in those with musical anhedonia. This means that their perception and understanding of music (or any other auditory stimuli) is intact – it just the emotional reaction that is missing.
But if such individuals function completely normally aside from their neutral reaction to music, this emphasises the question of why humans experience such an emotional response to music if it poses no significant survival advantage. Of course, music has served as a key vector for communication in an abundance of species; therefore, the ability to produce and understand musical phrases is critical in nature. However, what appears to be unique to humans is the level of pleasure we experience from music itself and thus the practice of listening to music for no purpose other than pure enjoyment. Whilst a direct survival role for music is still up for debate, its importance and contribution to our lives certainly is not.
Lia is a contributing writer for I, Science. After graduating with a degree in Neuroscience form Cardiff University, she embarked on the MSc in Science Communication at Imperial. She hopes to communicate her passion for science to a wider audience in her future career.