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What is happening in the brain when you hear a song you like for the first time? A new imaging study is one step closer to explaining the neural roots of your latest music mix.
Over the last decade I’ve spent an embarrassing amount of time discovering new music, then selecting and compiling my favorite songs of a given moment into personally prized packages of audio bliss (aka mixtapes). Not everyone stays up to 4 am scouring the blogosphere for the best new talent, but it’s safe to say most people enjoy music. And yet, music doesn’t serve any obvious evolutionary advantage. Why would abstract sequences of tones and rhythms be so universally cherished?
While the question of the evolutionary impetus continues to puzzle neuroscientists, they have begun to understand how the brain processes music, revealing in part why it’s so pleasurable. For instance, a 2011 study found that the neurotransmitter dopamine is released into the reward center of the brain during and just prior to favorite moments in a piece of music. Here, much of the pleasure is linked to anticipation of key musical features, and outcomes that are either expected or unexpected, such as the resolution of a dissonant chord. The specific timing of dopamine release is consistent with many individual experiences of music as well as many aspects of music theory. Most experiments, however, have focused on music that people already know and love, leaving it unclear if similar mechanisms act during that sometimes-magical first listen, or whether they are only the result of a pre-established emotional connection with particular songs.
To answer this question, a group of Canadian neuroscientists recruited 19 volunteers to have their brains imaged by functional MRI (fMRI) while they listened to teaser clips of 60 songs. Right after listening, the volunteers were asked to evaluate how much they liked each song by stating how much of their own money they were willing to shell out for the track—$0.99, $1.29, or $2—if any (at the end they went home with their purchased music). The scientists were then able to correlate brain activity, indicated by changes in blood flow, with how much a person enjoyed the music.
According to results published last week in the journal Science, the researchers found that multiple areas of the brain, including portions of the striatum and the cerebellum, among others, were more active during desirable songs, but that the best predictor of how much a person was willing to spend was activity within the nucleus accumbens, a cluster of neurons deep in the brain commonly referred to as the ‘pleasure center.’ The authors conclude that the reward circuits in the brain can also be activated by music that has never been heard before.
Interestingly, other regions of the brain, such as those involved with auditory processing and higher-order thinking, were more likely to interact with the nucleus accumbens during play of the most desirable songs. Together, these results suggest that the brain draws on past musical experience and knowledge to inform its evaluation of a given song. This type of connectivity might be one explanation for how musical taste can transform—radically, in some cases, from metal to classical, for example—or stay relatively static, perhaps depending on the level of exposure to different types of sounds.
As a perennial mix-maker always on the look out for new songs, I’ve noticed that I do enjoy a lot of songs right off the bat, so I’m not surprised there’s now solid experimental evidence for how this pleasure happens. At the same time, for every song that’s a no-brainer addition to a mix after the first listen—say, The Dirty Projectors’ “Gun Has No Trigger,” with its slightly dissonant harmonies and bursting chorus, or Cat Power’s “Ruins,” with its climactic lead guitar line—there are tracks that turn out to be real ‘growers.’ The latest example of this for me is the Atoms for Peace song, “Ingenue,” which required repeated listens before I found the delightfully layered rhythms and chords intoxicating. I’ve often wondered what accounts for the difference in preference from the outset, and I’d love to have an fMRI machine of own to check this phenomenon out. Until then, I’ll keep adding to my mixtape library, and see where it takes me.