“Music produces a kind of pleasure which human nature cannot do without,” the Chinese philosopher Confucius is said to have proclaimed more than 2,500 years ago.

Well, Confucius may have overstated his point. A small but intriguing study published in the journal Current Biology last week reports that a small but significant number of people — individuals who are otherwise perfectly healthy, psychologically speaking — do not get pleasure from music.

The Spanish and Canadian researchers who conducted the study call this trait specific musical anhedonia. It should not to be confused, they stress, with general anhedonia, which is an inability to experience pleasure from just about everything (including music) and a common symptom of depression and other psychological illnesses.

Nor is specific musical anhedonia simply a reflection of narrow musical tastes.

“What our findings reveal is not a particular preference for one class of stimuli over another (one person may enjoy opera, while another may find it boring), but an inability to derive pleasure from an entire domain, music, which the vast majority of human populations do find pleasurable,” the researchers explain.

These findings have implications that go beyond figuring out why certain patterns of musical tones evoke emotions (or don’t, as the case may be).

“Studying this particular and rather encapsulated aspect of anhedonia may help shed light more generally on why the link between perception and pleasure can sometimes be broken,” say the researchers.

Why and how the study was done

The impetus for the current study began when its authors were developing a questionnaire designed to measure the sense of reward (pleasure) that different individuals receive when listening to music. The researchers soon noticed that a small percentage of people (less than 5 percent) had a low sensitivity to music, but an average sensitivity to other rewards.

To figure out what was going on, the researchers decided to study some of those people in more depth. They selected three separate groups of 10 individuals who, according to the questionnaire, responded to music with a high, average or low level of pleasure.

Two experiments were conducted. In the first, the participants were asked to rate the amount of pleasure they were experiencing while listening to excerpts of soothing pieces of music. The specific musical works were chosen both by the researchers and by the participants, although, interestingly, the group with a low sensitivity to music had difficulty coming up with their own selections.

“Some of them asked family and friends to give them music,” one of the study’s co-authors, neuroscientist Josep Marco-Pallares of the Bellvitge Biomedical Research Institute in Barcelona, told Los Angeles Times reporter Geoffrey Mohan.

In the second experiment, the participants were asked to perform a quick monetary task in which they could win — or lose — real money.  Both of these experiments are known to engage reward-related neural circuits in the brain.

Two physiological measurements of emotional response — heart rate and skin conductivity — were also tracked for each of the participants during the experiments.

Findings

The study found that the people who had said on the questionnaire that they didn’t find pleasure in music were telling the truth. They didn’t exhibit the same physiological responses to the music as the other two groups.

No chills. No thrills.

Their responses when experiencing rewards during the monetary task were similar to those of the other groups, however. In other words, they found winning money pleasurable. That finding demonstrates, say Marco-Pallares and his colleagues, that people who are otherwise psychologically healthy can have an anhedonia specific to music.

To make sure the people with a low emotional response to the music did not have amusia — a difficulty processing and understanding music, particularly the pitch of different notes (tone-deafness) — the researchers asked them to rate several different excerpts of music as either happy, sad, scary or peaceful. They were able to do that just fine. Amusia, therefore, wasn’t the reason they didn’t enjoy music.

Beyond music

The study’s findings have implications that go beyond helping scientists better understand the neural processes by which music evokes emotions, according to its authors. The results may also lead to a deeper understanding of conditions in which the brain’s reward system goes awry, such as addiction and depression.

“The idea that people can be sensitive to one type of reward and not to another suggests that there might be different ways to access the reward system and that, for each person, some ways might be more effective than others,” said Marco-Pallares in a statement released with the study.

How music-sensitive are you?

Want to know where you fall on the music-reward spectrum? Marco-Pallares and his colleagues have put their questionnaire online.

At the same site, curious readers will also find a list of the self-selected musical selections used in the study. FYI: “ANH” refers to the anhedonic, or low-sensitivity, group of participants; “HDN” to the hedonic, or average-sensitivity, group; and “H-HDN” to the hyperhedonic, or high-sensitivity, group.