A disconnect between brain regions explains why 5% of people don't enjoy music.

They're among us. They're those people who don't dance in clubs, who don't go to concerts. They ask you to turn the music down in the car, they don't obsess over one song every summer, and if you asked them, they wouldn't be able to name a favorite singer. They're musical anhedonics, people who don't connect at all with music. Ten years ago, a group of researchers discovered that approximately 5% of the population could be included in this group. People who, despite having normal hearing and the ability to enjoy other experiences or stimuli, don't enjoy music.

It's a simple matter of taste, but it's reflected in our brains. Researchers found that in musical anhedonic patients, there was a disconnect between the brain's auditory and reward networks. In an article published a few days ago in the journal Trends in Cognitive Science , this same team reviewed all of their scientific research. They describe the brain mechanisms behind the condition and assert that understanding it could help us understand how pleasure and addiction work.

“There are individual differences in responses to rewarding stimuli,” says Josep Marco-Pallarés , professor of psychology at the University of Barcelona and one of the authors of the study. “And these are determined not by deficiencies in the reward circuit, but by the way in which the perceptual areas connect to it.” To demonstrate this idea, his team gave participants a test (which can be taken here ) and then classified them according to their score as anhedonic, hedonistic, and musical hyperhedonistic. The participants were then subjected to a brain scan and their responses to a monetary reward and a musical stimulus were observed.

The circuit lit up in both cases in almost all participants. However, those who had scored very low on the test showed little activity in the nucleus accumbens with music, but did so with money. "This shows that there are specific sensitivities to different types of stimuli determined by how the perceptual areas interact with the reward circuit," explains Marco-Pallarés.

Sex, drugs, and rock and roll . The components of this famous triad impact different regions of the brain, but all of them then connect with the reward circuit to transform the stimulus into pleasure. The studies of Marco-Pallarés and his colleagues can help us understand not only how we understand and enjoy music, but also how we relate to pleasure and addictions. Why are some people more hedonistic or more enjoyers, if we are born with a predisposition to fall into addiction or find it more difficult to enjoy what others find pleasurable?

When Ozempic and other weight-loss drugs became popular , many patients reported less desire to smoke or drink . Improvements were reported in patients addicted to shopping or gambling . Over time, various studies have explained that this is because the drug disrupts not so much how we perceive food (which maintains its flavor) but how those flavors are translated into pleasure. The drug had disrupted the reward circuit, and this would have reduced all kinds of addictive behaviors. Pleasurable stimuli have different entry pathways into the brain, but ultimately they all end up in the same place. That's why research on specific musical anhedonia transcends music.

“We propose using our methodology to study other types of rewards. This could lead to the discovery of other specific anhedonias,” says Marco-Pallarés. People who are unable to enjoy food, or those for whom sex brings no pleasure, may also have two brain areas that are barely connected.

It's still not clear exactly why specific musical anhedonia develops, but both genetics and environment could play a role. A study this year, conducted on twin brothers and published in Nature , explained that genetic variability can explain up to 54% of the difference in appreciation or pleasurable response to music.

“I think it's a very interesting study,” says Noelia Martínez , a neuroscientist at Pompeu Fabra University and a participant in some of the studies cited in the Trends in Cognitive Science review. “In addition to providing a first glimpse into the underlying genetic basis, it raises other questions, such as whether this genetic variability is something that can change over time.” Whether musical-specific anhedonia can somehow be reversed.

Another of the aforementioned studies was conducted with children under three years old, and it was already evident that there was a wide variety in the way they responded to musical stimuli. Children danced to lively music, even before they could walk. They calmed down with a lullaby, even before they understood its words. Several of Marco-Pallarés's colleagues are currently collaborating with geneticists to identify specific genes that could be involved in musical anhedonia.

Music can be the gateway to understanding how we process pleasure in our brains. And it's curious, Martínez points out, because we're not talking about an instinct, but rather a social construct, a human creation. "Music is an artistic, cultural, aesthetic stimulus... That's why I'm fascinated by the fact that it's capable of producing that release of hormones that usually occurs with primary reinforcers like food or sex," the expert reflects. This is perhaps what has made it common to all the world's cultures. That other animals, such as birds, cetaceans, and dogs, also have a certain musical sense. And that, for 95% of humans, listening to music produces a tremendous dopamine release.