’m hungry. I eat a ham and cheese sandwich. I feel good. Not just physically sated, but in a state of emotional wellbeing. This is the work of brain’s reward pathway, known as the mesolimbic system. Food keeps us kicking. For the brain, rewarding this behavior makes evolutionary sense.
Even worms and flies, which evolved more than a billion years ago, use the same reward molecule as humans — dopamine — to modulate behavioral responses to natural stimuli. It’s not just food, either. The brain rewards us for sex and certain social interactions.
It also rewards us for listening to music.
But why we listen to music, and why the brain rewards this behavior, is less clear than the impulse for food or sex. Music is abstract. It serves no evident biological or survival purpose. Yet it triggers the same kind of response — the brain releases dopamine — as more concrete and survival-related stimuli. As researchers continue probing the “why,” they’re beginning to work out some of the “how.”
At both molecular and anatomical levels, science beautifully explains what we know intuitively: music makes us feel. To track the effects of music, scientists developed an objective measure of emotional arousal based on changes in the nervous system, including increased heart rate and respiration. This is called the “chills” or “musical frisson” response.
Researchers at Canada’s McGill University wanted to better understand the relationship between music and pleasure. In a study, they found that when people heard what they defined as pleasurable music, the “chills” response increased. Examining the process, they found that music caused the release of dopamine — the pleasure molecule — but in a temporally specific way. The researchers zeroed in on two points in time during the music listening experience — what they called “peak pleasure” and “anticipation.” Think of peak pleasure as your favorite part of a song, the part that, no matter how many times you listen to it, sends chills down your spine. The anticipatory phase comes just before the moment of intense emotion, when you’re on the edge of your seat, waiting to be swept away. The researchers specifically defined the anticipation phase as the 15 seconds prior to peak pleasure.
During moments of peak pleasure, dopamine levels were highest in the brain’s right nucleus accumbens, the same brain region implicated in the euphoric response to cocaine, and the region that mediates strong emotional responses. During the anticipatory phase, dopamine was highest in the right caudate region. The right caudate is thought to help us learn stimulus-response associations and to regulate the reinforcing characteristics of things like food.
In short: the theory is that composers use tactics such as slowing down or suddenly speeding up tempo to awaken anticipation of a peak moment. This in turn arouses the region of the brain the helps us learn response patterns. We learn to like this music. Then, the actual peak pleasure generates emotions.
But we don’t respond to all music at all times. Emotional responses and reward pathways are far more active for familiar than unfamiliar music.
A study conducted at Portugal’s University of Porto found that when people listened to four kinds of music — songs they classified as “familiar and liked,” “familiar and unliked,” “unfamiliar and liked,” and “unfamiliar and unliked” — it was the familiar music that got the brain’s attention. This was true even when the music fell into the “familiar and unliked” category. The results suggest our response to music is very much a learned one.
Music may not help us survive in biological terms, but it does make elicit emotions, love, hatred, peace, conflict, joy, sorrow — based on the music itself. Maybe this emotional response is also part of survival, but survival of a different sort.