Music is popular in almost all human societies, but there are people who just can’t seem to be into it, no matter how exciting. Studying those who don’t like music can provide insight into why the rest of us do, and more general insights into human behavior.
Previous neuroimaging studies showed that music-induced pleasure may arise from the interaction between auditory neural networks and the brain’s reward networks. A recent study published in PNAS shows that people who don’t like music have lower brain activity in both systems when they listen to tunes.
The study in question used functional MRI scans to monitor brain activity in three groups of 15 participants. One group was indifferent to music, the other group reacted normally to it, and the last group experienced intense pleasure from music. Musicians were excluded from the sample to reduce bias that could be introduced by including participants trained in music production.
Each subject was asked to provide two pieces of instrumental music that they found emotionally pleasing (this was a particularly difficult task for those participants who dislike music). To complement the music provided by the participants, the researcher used music recommended by Spotify’s music-matching algorithm. The subjects’ brains were imaged via fMRI while they listened to music and while they participated in other traditionally rewarding activities, such as gambling.
The imaging showed that people who enjoyed music less had relatively lower blood flow to areas involved in the brain’s reward system when listening to music (particularly around a structure called the nucleus accumbens). There were no significant differences in blood flow to the reward areas of the brain when the participants engaged in gambling activities. This means that there is no fundamental problem in the reward system of the people who don’t like music – music just doesn’t get it going.
The authors suspected that this difference could be due to reduced connectivity between the parts of the brain that interpret the music and the parts that process reward. They tested this hypothesis by seeing if there was a strong correlation between activity in reward and auditory regions. The results indicate that people who dislike music have less functional connectivity, particularly between brain regions related to auditory processing and areas related to reward. “Functional connectivity” is measured by looking at which parts of the brain are activated simultaneously or in rapid succession in response to a stimulus. This finding thus means that subjects who disliked music showed less interaction in their superior temporal gyrus, their ventral striatum and their nucleus accumbens in response to listening to music. The fMRI findings of this study allowed the authors to clearly demonstrate that people who do not enjoy music have impaired communication between their auditory cortex and the mesolimbic reward system.
This work does not address cause and effect – it is not clear whether the reduced communication between these regions causes people to appreciate music less or whether their lack of appreciation leads to reduced communication. Still, these findings could help neuroscientists examine reward responses in general, including the responses that make the experiment’s control activity, gambling, so problematic for some.
PNAS2016. DOI: 10.1073/pnas.1611211113 (About DOIs).