Listening to music in and of itself is undeniably pleasurable. Unlike food or sex, music is not intrinsically valuable to the humankind; regardless of what Shakespeare may have lead you to believe, moonlight serenades are not required for survival of our species. Yet, how is music – something so intangible, so “useless”- capable of triggering such profound feelings of euphoria across cultures and generations since prehistoric times?
A few years ago, in an attempt to unravel the mystery, researchers from Montreal monitored the brain’s reward system of volunteers as they listened to music that gave them the “chills”. To visualize changes in the brain, researchers injected the volunteers with a radioactive ligand that binds to receptors of dopamine, a neurotransmitter that mediates the pleasurable effects of natural and drug rewards. As music gradually built up, edging closer and closer to the climax, dopamine flooded the right caudate nucleus, correlating with the listener’s experience of anticipation. At the moment of the “chills”, dopamine rushed out from the synapses of neurons in the right nucleus accumbens (NAc). This intangible mental “high” accompanied a measurable physical response – increased heart rate and sweating, rapid breathing, and a drop in skin temperature – all physical signs of emotional arousal.
It seems rather clear-cut that music feels good because it triggers a dopamine rush. Yet the story, like most of science, is not so simple. Dopamine is released during presentation of the reward, or (as learning occurs) in anticipation of reward. For a familiar piece of music, the theory fits our understanding of pleasure – we squirm at the edge of our seats, anticipating the chills; but how can dopamine release explain our appreciation for previously unheard music?
In a new series of experiments, the same researchers studied how the brain values a newly encountered piece of music. Using an iTunes-like interface, they first played for the volunteers a short clip of an unfamiliar song, and then asked them how much they’re willing to pay ($0, $0.99, $1.29, or $2) to buy the entire tune. Compared to relying on subjective rating, this design allowed researchers to put an objective number on the “value” of music.