How Music Plays Your Brain
Listening to music can be a euphoric experience. It’s unclear exactly why it should feel so good. Is there some evolutionary advantage to enjoying music? Is it a byproduct of some other important function? Is it just one big accident in our evolutionary history? The debate still rages on these questions, but there is one important fact that we can be confident about: music has some deep-rooted appeal for humans.
There is something special about music even for the youngest listeners. Infants in their first year of life already have a meaningful sense of musical timing and pitch. When listening to samples of Western music, Mafa populations in Cameroon recognize the same basic emotions of happiness, sadness, and fear that Westerners do. Both populations also enjoy a similar sense of musical harmony when they listen to each other’s music. When asked to express different emotions by creating musical or physical movement patterns in a computer program, participants in the USA and a tribal village in Cambodia make very similar choices. There is a fundamental core to musical experience and expression that all humans seem to share.
We can look beyond humans to examine how deep our musical roots really stretch. In addition to the cross-cultural appeal of music, there may be a cross-species appeal. There are ongoing discussions about exactly how much our perception of music overlaps with that of non-human primates. Although there are commonalities in our ability to detect rhythms, it is still unclear whether monkeys can synchronize their movements with music in the way that humans can. Some non-human primates, like Kuni the bonobo, may spontaneously synchronize with audible rhythms when they play with a drum. But we need to wait for more evidence to fully understand whether non-human primates enjoy dancing as much as we do.
Non-human primates, just like humans, do prefer consonant music over atonal or dissonant music. However, researchers have often struggled to find any consistent preference for music over silence when non-human primates can choose between them. In 2014, one research group decided to test this question in a little more detail, by trying a range of different musical styles. They divided a room into four zones, which progressively increased in distance from a music speaker playing either West African akan, North Indian raga, or Japanese taiko instrumental music. As the music played, the researchers measured where a group of chimpanzees spent most of their time. If they spent most of their time in zone 1, closest to the speaker, it would indicate that the chimpanzees enjoyed the music. If they preferred to stay in zone 4, where they could barely hear the music, that would suggest they preferred silence.
When the Japanese music played, the chimpanzees showed no preferences between zones. They seemed to be just as happy close to the speaker as they were far away from it. But when the African or Indian music played, they spent the majority of their time in zone 1, as close to the music as possible. In fact, they spent significantly more time in zone 1 than they did when no music was playing. So the tonal melodies and ambiguous pulses in West African akan and North Indian raga music seem to set a nice mood for chimpanzees.
What exactly is our brain doing when we listen to music? Instead of processing individual sounds, the brain processes patterns of sound as it implicitly develops expectancies about what is coming next. The auditory parts of our brain analyze several core features of music including pitch and duration, and interact with frontal brain areas as we use our working memory to pull together the information into higher level abstract representations. Many of us have experienced the intense chills that come with listening to deeply moving parts of our favorite music. As this happens, the reward centers of our brain, especially subcortical areas including the ventral striatum that sit deep within the brain, adjust their activity: the more chills we feel, the more activity they show. In fact, when we experience those moments of musical euphoria, the striatum releases dopamine, one of the brain’s reward-related neurotransmitters.
Experts who play musical instruments probably experience music differently to non-musicians. A recent study looked for this difference in the brain. The researchers put beatboxers and guitarists in a brain scanner and measured the levels of activity in their brain as they listened to music involving beatboxing or guitars. When looking at parts of the brain involved in translating sensory information into motor actions (sensorimotor areas), they found an interesting pattern. Guitarists showed increased sensorimotor activity when listening to guitar music, and beatboxers showed increased sensorimotor activity when listening to beatboxing music. So their prior musical experiences in physically playing instruments changed how their brains reacted when listening to those instruments.
The researchers drilled down a little further to examine the finer details of the sensorimotor activity for each group. The primary sensorimotor areas of our brains are organized somewhat topographically: different sections of their structure represent different parts of the body (you can map out and illustrate these maps with “cortical homunculi”). This means you can compare “hand” activity to “mouth” activity in those brain areas. If musicians’ sensorimotor activity during listening represents the actions involved in playing the music, then you would expect to see hand areas activated for the guitarists and mouth areas activated for the beatboxers. After all, those are the body parts they use when making their music. This is precisely what the researchers found. Guitarists activated their hand areas when listening to guitar music, while beatboxers activated their mouth areas for beatboxing music. Their brains automatically recruited relevant sensorimotor regions in processing the musical audio, almost as though they were actually playing the music on some level. In other words, the musicians’ passive listening became a little more active when listening to their own type of music.
Music is one of those real-life miracles that practically all of us can connect to. It brings us together at festivals, bars, and other social events, and can give us a dramatic emotional lift when we most need it. The question of why it has these magical effects continues to elude us, but this mystery makes our musical experiences all the more impressive. Whether you’re a metalhead or an opera enthusiast, don’t forget to fully appreciate and enjoy your next musical fix. If you’re lucky, it might inspire a creative spark or moment of ecstasy. But at the very least, you’ll be tapping into an experience that you share with many of your fellow primates.