Did you know that 3 to 5 percent of the population can't find joy in music? This is because they have a condition known as specific musical anhedonia.
In a study published in the Proceedings of the National Academy of Sciences, researchers from the University of Barcelona and McGill University's Montreal Neurological Institute and Hospital showed that people with the condition have reduced functional connectivity between regions of the brain responsible for sound processing and reward.
The rsearchers worked with 45 healthy individuals, who filled out a questionnaire to measure their level of music sensitivity. The study participants were then grouped into three depending on their responses and were made to listen to music excerpts while inside a functional MRI machine and rated their pleasure levels in real-time. As control for brain responses related to other types of reward, the participants also did some gambling where it was possible to win or lose actual money.
Music And Brain Connections
Based on fMRI data, the researchers observed that those with specific musical anhedonia had low activity within the Nucleus Accumbens, a crucial subcortical structure in the brain's reward network. Additionally, this drop in activity cannot be attributed to the Nucleus Accumbens improperly functioning because it activated during the gambling task when money was won.
However, specific musical anhedonics did show lower functional connectivity between the Nucleus Accumbens and brain regions linked to auditory processing. On the contrary, those who happened to enjoy music showed instead enhanced connectivity.
According to the researchers, the fact that study participants could not be sensitive to music but still respond to another type of stimulus shows that there are different reward pathways for different kinds of stimuli. The results of the study also offer a look at how music was awarded reward value, as observed from an evolutionary perspective.
Brain Connectivity And Cognitive Problems
Brain connectivity issues have been proven to be the cause of other problems related to cognitive ability. For instance, studies exploring autism spectrum disorder in children have shown that a child's inability to find pleasure in the human voice may be attributed to reduced connections between the reward system's distributed nodes, such as the Nucleus Accumbens, and the bilateral posterior superior temporal sulcus.
Funded by the Canadian Institutes of Health Research and the Governments of Spain and Catalonia, what the current study reinforces is that brain connections are important to how people respond to reward. Its results can also be used to help guide treatment development for disorders related to reward, such as addiction, depression and apathy.
Researchers for the study include: Josep Marco-Pallarés, Robert J. Zatorre, Antoni Rodriguez-Fornells, Ernest Mas-Herrero, and Noella Martinez-Molina.
The Brain And Rewarding Experiences
According to another study, the same brain reward circuits activated by music also light up when an individual experiences spiritual and religious feelings. Specifically, the Nucleus Accumbens was mentioned in the research, the same portion of the brain's reward network that showed a drop in activity in those with specific musical anhedonia.