Enjoying Sad Music: What’s Going On In the Brain?

Post by Anastasia Sares

What's the science?

There are many components to an emotional response, such as whether it is pleasant or unpleasant, the intensity of an emotion, and our aesthetic enjoyment of the experience. This can lead to situations where we experience a “negative” emotion (like in response to a sad piece of music) but enjoy it at the same time. In addition, emotions are dynamic, but many carefully controlled studies focus on short stimuli and static responses. This week in NeuroImage, Sachs and colleagues dynamically tracked the neural responses of people listening to a sad (but enjoyable) piece of music in order to separate out different aspects of emotional cognition.

How did they do it?

Thirty-six participants first listened to three musical pieces passively in an MRI scanner. The pieces were unfamiliar, wordless, and validated for emotional content by prior testing. After the MRI, they were asked to complete a rating task, using a sliding scale to continuously track their emotional states while listening to the same pieces again. They listened to each song twice, separately evaluating their enjoyment of the song and its emotional quality/intensity (how happy/sad it was). Participants also completed questionnaires about musicality, empathy, anxiety, and depression.

One sad piece, in particular, was chosen for the fMRI analysis: Discovery of the Camp by Michael Kamen. It clocks in at 11 minutes, which gave ample opportunity to examine emotions unfolding over time. The idea of the analysis was to find parts of the brain that acted in synchrony across individuals—meaning that they were probably responding to some aspect of the stimulus. The authors did this by recording the brain activity at many points in the brain (voxels) and calculating the correlation of the signals between participants at each voxel using a process called inter-subject correlation. They also looked for brain regions where inter-subject correlations were predicted by changes in the emotion and enjoyment ratings.

What did they find?

Signals from auditory brain regions and some motor brain regions were correlated across participants while listening to the music. Most of these were likely driven by the auditory signal itself. However, signals were also correlated in the insula, which is involved in processing the body’s own internal changes and the emotional states of other people. Both sadness and enjoyment involved synchronization in striatal regions. The intensity of sadness ratings was additionally related to dynamic synchronization in the limbic network, while enjoyment ratings were related to auditory, orbitofrontal, and default mode networks. This shows the separation between the emotion communicated by the piece (processed in the limbic system) and the participant’s enjoyment (aesthetic evaluation and reward, processed in other regions).

One subcategory of the empathy questionnaire, fantasy, measures how transported a person is by a story or narrative and has previously been associated with the enjoyment of sad music. The authors, therefore, divided the participants into a high-fantasy and low-fantasy group to see whether their brain synchronization differed as a function of empathy. The high-fantasy group demonstrated more correlated activity in the left auditory cortex, extending to the middle temporal gyrus, frontal areas, and some visual areas. The low-fantasy group had more correlated activity in posterior auditory and parietal areas as well as the insula and caudate. The authors interpret the group differences in the following manner: high-fantasy participants may focus on reflecting, understanding, and visualizing emotions during music listening, and thus may enjoy sad music, while low-fantasy participants may have a more intense emotional response.

What's the impact?

This study separates the emotions communicated by a piece of music from the enjoyment of that music, showing that different brain networks are involved in processing various aspects of our emotional experience. Individual differences in empathy also play a role in our reaction to emotional stimuli. This is a step forward, but we are still only scratching the surface of the rich and complex nature of human emotion.

Sachs et al. Dynamic intersubject neural synchronization reflects affective responses to sad music. NeuroImage (2019). Access the original scientific publication here.