Brain scans solve an enduring mystery about our love of music

Why do we love music? Why is sometimes music so good that the hair on our arms pricks up and we shiver — despite there being no obvious biological benefits to enjoying music?

These are the questions that researchers from McGill University in Canada have been studying for years. Now, they believe they’ve definitively proved what’s happening in the brain when we listen to a piece of music we love.

Their findings were published Monday in the Journal of Neuroscience.

The background — In their previous research, Robert Zatorre and Ernest Mas Herrero established a correlation between a subject listening to music they loved and activity in a part of the brain’s reward system called the striatum.

That was interesting because activity in that area is usually associated with pleasure as it relates to survival, Zatorre tells Inverse.

“We’ve known for 67 years, that if you take a rat and it’s really hungry and you give it food and you measure the activity in the brain, the striatum responds very strongly to the highly pleasurable substance that it needs to survive,” he says.

The pleasure the rat feels stems from the feel-good neurotransmitter dopamine, released by the stratum when it consumes the thing it needs to survive.

The striatum, Zatorre says, is also there to respond to biological stimuli. It’s the striatum that helps identify if you’re too cold and you need to get warm or vice versa. It responds to sexual stimulation and essentially all things Zatorre says are “very biologically driven.”

And yet music isn’t one of the things we’ve traditionally considered necessary for survival. The researchers’ previous research had shown a correlation between music and striatum, but the researchers wanted to see if they could prove causation.

What they did — In a controlled study with 17 participants, Zatorre and Mas Herrero used a technique called Transcranial Magnetic Stimulation (TSM) to stimulate or inhibit the striatum while subjects listened to pop music.

During TSM, a magnetic coil is placed over a specific area of the brain and a technician sends bursts of electromagnetic pulses to that area of the brain, stimulating activity. Depending on the frequency of bursts, TSM can also inhibit activity in the targeted area of the brain.

After listening to music while undergoing the TSM, the subjects were moved to an fMRI machine where the researchers could observe exactly what was happening in the subjects’ striatum and auditory complex (the area of the brain that processes music).

The thought process, Zatorre explains, was “if we do [TSM] to stimulate the striatum and measure brain activity at the same time, we ought to see that stimulation influences the striatum and the activity the striatum, in turn, causes the differences in the way people feel about a piece of music.”

The researchers also included a value component into the study: at various levels of excitatory TSM stimulation — the kind designed to activate the striatum to release dopamine — they asked the subjects how much they would pay to purchase the music they were listening to. Part of the brain’s reward system is designed to evaluate how much value you place on something.

What they found — The results of the study confirmed the team’s hypothesis: the striatum and the auditory complex were talking to each other.

“The auditory parts of the brain were more correlated with the striatum when the stimulation was positive than when the stimulation was negative,” Zatorre says.

This is important, he says, because “it's telling us that when you really like the music you’re hearing, your striatum is communicating back and forth with the auditory cortex — the part of the brain that’s actually perceiving all the different sound patterns, the rhythms of chord relationships, and melodic expectancy patterns.” Previous research suggests communication between different areas of the brain can have powerful influences on our feelings and behavior.

“Chills are a sign of arousal.”

This conclusively demonstrates that the pleasure we do (or don’t) derive from music is the result of our communication between our auditory complex and striatum — and how excited or inhibited our striatum is as a result, the researchers say.

How stimulated the striatum was not only correlated with how high the subjects rated the piece of music but also corresponded with how much money they said they’d be willing to pay for it. (Anyone who has shelled out an absurd amount of money on concert tickets is likely familiar with this process.)

The big takeaway — Zatorre and Mas Herrero also found that the chills we experience during a particularly moving piece of music are also directly related to the brain’s survival system.

“Chills are a sign of arousal,” Zatorre says.

It doesn’t have to be good arousal, he adds. If you feel someone walking behind you in a dark alley, you’re also going to feel chills; it’s your autonomic nervous system responding. Your heart rate and respiration go up, the hair on your skin goes up. The blood vessels on the surface of the skin constrict because the body is trying to conserve heat, in case it has to run away from danger.

“We see all those same patterns, [are various states of arousal–-both good and bad] even if chills aren't occurring,” Zattore says. When people get chills from a piece of music, their arousal is “simply at the maximum,” he explains. The same fundamental process is at work when you listen to non-chills-inducing music too, just at a much lower level.

What’s next — The researchers aren’t done with their research. The team is now collaborating with a group in Tel-Aviv to develop “a music feedback idea to enhance the motivation and pleasure of people who have disorders of the reward system, like Parkinson’s Disease,” Zattore says.

They haven’t tested on anything on patients yet — for now, it’s all very experimental. But, he adds, it’s worth a shot even if it doesn’t work the way they hope.

“Either way, we’ll learn something,” he says. “And that’s the goal of science — learning.”

In the meantime, whether you’ve got the pandemic blues or are just having a bad day, take some time to listen to some of your favorite music. Science says it may help you survive.

Abstract: Music's ability to induce feelings of pleasure has been the subject of intense neuroscientific research lately. Prior neuroimaging studies have shown that music-induced pleasure engages cortico-striatal circuits related to the anticipation and receipt of biologically relevant rewards/incentives, but these reports are necessarily correlational. Here, we studied both the causal role of this circuitry and its temporal dynamics by applying Transcranial Magnetic Stimulation (TMS) over the left dorsolateral prefrontal cortex combined with functional Magnetic Resonance Imaging(fMRI) in 17 male and female participants. Behaviorally, we found that, in accord with previous findings, excitation of fronto-striatal pathways enhanced subjective reports of music-induced pleasure and motivation; whereas inhibition of the same circuitry led to the reduction of both. fMRI activity patterns indicated that these behavioral changes were driven by bidirectional TMS-induced alteration of fronto-striatal function. Specifically, changes in activity in the nucleus accumbens (NAcc) predicted modulation of both hedonic and motivational responses, with a dissociation between pre49 experiential vs. experiential components of musical reward. In addition, TMS-induced changes in the fMRI functional connectivity between the NAcc and frontal and auditory cortices predicted the degree of modulation of hedonic responses. These results indicate that the engagement of cortico-striatal pathways and the NAcc, in particular, is indispensable to experience rewarding feelings from music.