Music. The very word itself evokes something solid yet abstract at the same time. Music, at its core, is a collection of sounds but it is precisely the way the human brain processes and interprets these sounds that has fascinated researchers. The Canadian Institute for Advanced Research (CIFAR) recently gave a presentation at Koerner Hall in Toronto titled Our Musical Brain, which presented new research on how the brain processes music. Certain parts of the lecture that fascinated me was how the brain works in following and predicting rhythm, how this affects movement and, consequently, how movement influences social relations.
How does the brain decode music? Neuroscientist Laurel Trainor from McMaster University explains that as the “messengers” of the brain, known as neurons, depolarize and fire, they create electrical signals and form an electrical field. This field can then be measured using an electroencephalogram (EEG). The resulting image shows the electrical signals as oscillations (or waves). If there is a rhythm the neurons naturally synchronize their firing to it.
Our brain creates oscillations that change with the speed of the rhythm. The faster the rhythm, the higher and denser the brain waves become. What is interesting to note is that the brain is always in a state of anticipation. The brain does more than just listen to and follow a rhythm; it tries to predict the next beat. It is this anticipation of the next beat that helps the neurons synchronize to the rhythm.
Curiously, though music is a collection of sounds, it affects not only the parts of the brain that decode sound, but also those that dictate movement. The regions of the brain that entrains or synchronizes to the beat are the auditory cortex, the supplementary motor area (SMA), and the cerebellum. The auditory cortex decodes sounds entering the brain while the other two areas are focused on movement. Though technically having nothing to do with hearing, the SMA and cerebellum also entrain to the beat and that is why we sometimes get the urge to move or dance.
And it is precisely the prediction of rhythm and movement that helps with social bonding and survival. Being able to predict rhythm is a useful asset, though most of us do it unconsciously. Laurel Trainor explains further that our ancestors used the ability to recognize patterns as a means to avoid the impending attack of a lion. Sports players notice patterns to try and foresee where their teammates will be in a few moments from now in order to score, or prevent the scoring of, a goal.
Additionally, moving in the same rhythm promotes common emotions and encourages social connections. This is one reason why we have music at weddings, funerals, parties or chants at sports events, during frosh week at universities, and even in the military. Music has the ability to influence a group of people to feel one emotion, which in turn promotes cooperation, trust, and most importantly, likeability.
The ability to move in sync to a rhythm develops early in a person’s life. One experiment that the presenter did was bounce 14-month old babies, who were strapped to an experimenter, to a beat opposite a stranger who either bounced in sync or out of sync with them. Afterwards, the babies were involved in helping the stranger with a task. The results were eye opening. The babies were more likely to help the stranger that bounced in sync with them than the stranger who did not. Another experiment saw the babies bouncing to the same beat with a stranger and then having the stranger interact with a friend. Because the stranger bounced in sync with them, the babies were more likely to help the stranger and the stranger’s friend. The opposite is also true. The babies were more likely to refuse to help the strangers or their friends if they had not bounced in sync with them!
Rhythm in music affects human behaviour in extraordinary ways. From dancing, to survival, to being more cooperative, music has a powerful sway over the human condition. Next time a situation arises where no one seems to be cooperating, try playing some music and bouncing along with the rhythm. It just might convince everyone to follow your beat.