Why music makes our brain sing
Music is not tangible. You can’t eat it, drink it or mate with it. It doesn't protect against the rain, wind or cold. It doesn't vanquish predators or mend broken bones. And yet humans have always prized music.
People have always invested significant time and effort to create music, as the discovery of flutes carved from animal bones would suggest.
More than a decade ago, our research team used brain imaging to show that music that people described as highly emotional engaged the reward system deep in their brains. Subsequently we found that listening to what might be called “peak emotional moments” in music causes the release of the neurotransmitter dopamine, an essential signalling molecule in the brain.
Most interesting here is when this neurotransmitter is released: not only when the music rises to a peak emotional moment, but also several seconds before, during what we might call the anticipation phase.
The idea that reward is partly related to anticipation (or the prediction of a desired outcome) has a long history in neuroscience. Making good predictions about the outcome of one’s actions would seem to be essential in the context of survival, after all.
To dig deeper into how music engages the brain’s reward system, we designed a study to mimic online music purchasing. Our goal was to determine what goes on in the brain when someone hears a new piece of music and decides he likes it enough to buy it.
We found that neural activity within the striatum — the reward-related structure — was directly proportional to the amount of money people were willing to spend. Also, the cross talk between this structure and the auditory cortex, which also increased for songs that were ultimately purchased compared with those that were not.
So each act of listening to music may be thought of as both recapitulating the past and predicting the future. When we listen to music, these brain networks actively create expectations based on our stored knowledge.
Robert J. Zatorre is a professor of neuroscience at the Montreal Neurological Institute and Hospital at McGill University. Valorie N. Salimpoor is a post-doctoral neuroscientist at the Baycrest Health Sciences’ Rotman Research Institute in Toronto.