Why Does Your Favourite Song Stuck in Your Head?

The image of “music brain”. Retrieved from https://www.redbubble.com/people/enjoy riot/works/21210285-music-brain?p=poster

Music isn’t music until your brain makes it so. Sounds can be noise in one context and music in another. We can determine whether one person is speaking or singing. According to the “speech-to-song illusion“, if you pull out a phrase from a spoken sentence and repeats it over and over again, our brain will interpret them in a way that makes it sounds musical. Then, if you listen to the entire sentence again, it will sound as if the person suddenly start to sing when he/she gets to the repeated part, but the sounds reaching the ear are the same in all those cases. So, what is changed in our brain?

The vast majority of people love some kind of music. This characteristic of music, the fact that it’s universally loved but highly subjective, has ensured that it continues to baffle us.

Do we actually need music in our life?

We all need certain things to survive and reproduce: food, water, sex, etc. Human brains have evolved in such a way that when we don’t have those things, we seek them out. They become enjoyable, and we define them as “biological reinforcers.” However, music is just a bunch of sounds strung together, it doesn’t provide us with the essential nutrients; it doesn’t bind to our neurons the way drugs do; nor it doesn’t ensure that our genes live on although that might be debatable. So why have we chosen to devote our valuable energy and resources to its production and possession? A research study by Honning et al., suggest three theories regarding the musical sound evolution:

1. Music as sexual display: human music, as in birds and other animals, is an effective display of intelligence and/or strength that can be used to attract a mate.
2. Music to soothe infants: some parents communicate in a musical way with their babies, cooing at them in lullaby speech and singing them to sleep. It could help forge parent-child bonds and allowed us to teach our helpless young in the time before they could speak.
3. Music for the group: music is a useful tool for social communication between adults and helped strengthen group identities.

Although music is not directly important for our survival but instead, it plays a mediating role as a technological advancement that served many useful purposes and positive impacts that we kept it close to us which make us feel good and pleasurable.

What happens to our brain when we listen to music?

When people listen to the music they enjoy, our brain generates similar patterns of activity and would likely enhance the creative ability regardless of one’s genre preference. A study conducted by Wilkins et al., evaluated brain networks from 21 young adults with the functional magnetic resonance imaging (fMRI) while listening to iconic musical selections on their favourite song, the music genre they like and dislike. As a result, the researchers found that a person’s preferred musical piece would likely enhance the connection across the default mode network (DMN) between different regions of the brains.

An fMRI image of brain activity when people listen to the type of music they like, dislike and their favourite. Retrieved from https://www.nature.com/articles/srep06130/figures/2

The DMN is associated with support of inner functional brain states, such as the introspection, self-awareness, mind-wandering and possibly imagination. When the DMN is activated, the brain region involved in goal-oriented activity, called the cognitive-executive network (CEN), is shut down. Contrary to DMN, the cognitive-executive network is most active during cognitive tasks including attention and working memory. With that being said, the enhancement of connection across DMN causes the release of dopamine, a type of neurotransmitter that released when we feel pleasure that associated with rewards such as food, drugs and sex. Due to the release of dopamine,  our brain encourages us to keep listening to music. Surprisingly, in other word, it is basically the brain telling us whether or not we should listen to music.

Another study by Halassa et al. studied how to switch between these two modes of brain network on mice. As a result, patients suffer from certain brain disorders found to involve trouble with either activating one of the mode or switching between the two. Moreover, the researchers suggest that people with autism that have difficulties with DMN activity could possibly be treated with music therapy.

Image of “music therapy”. Retrieved from https://www.mskcc.org/experience/patient-support/activities/music-therapy

There are still many ambiguous questions on the connection between music and mental states. Using the information from current and future studies, we can address issues that individuals have regarding the mechanism of music in our brain and the therapeutic elements beneficial to mental health. Furthermore, scientifically designed music and neurotechnology can facilitate positive changes in brain chemistry, function and structure through the simple practice of listening.

By Sammi Lu