Music study links attenuation of emotional reactions in anhedonia to prolonged activity in the brain’s attentional networks

Anhedonia is associated with abnormally sustained activity in the brain areas responsible for attention. Researchers from the IoPPN Department of Neuroimaging used music to study the relationship between anhedonia and emotion-related brain activity. Anhedonia is a key symptom of depressive disorders, characterized by an inability to experience pleasure typically associated with pleasant stimuli and life events.

Previous studies on the effect of anhedonia have used single emotional cues (pictures) and single subjective ratings (self-report). This study followed the course of individuals’ emotional experiences across several longer cues (happy, sad, and neutral musical excerpts).

The study involved 31 healthy individuals aged 18 to 30, with varying degrees of anhedonia, who listened to pieces of classical music categorized into negative, neutral, and positive emotions (10 pieces in total, 30 seconds per piece). The researchers examined how the individuals’ brains responded and transitioned between the alternating pieces. The results are published in the journal Scientific reports.

Participants’ emotional responses were recorded continuously during the MRI (magnetic resonance imaging) brain scan.

The researchers observed that individuals with greater anhedonia showed less intense emotional responses and increased activity in brain areas involved in paying attention to the external environment. Furthermore, this increased brain activity during listening to emotional music decreased more slowly and was still present during subsequent listening to emotionally neutral music.

“Our study is the first to characterize the dynamic time course of emotional reactivity related to anhedonia using a real-world stimulus in the scanner. We also demonstrate abnormally persistent recruitment of brain networks, related to outwardly focused attention, evoked by emotional music,” said Dr Owen O’Daly, Senior Lecturer at IoPPN and lead author of the study.

“Whether such exaggerated brain activity reduces a person’s ability to regulate emotional states or simply disrupts the processing of important emotional signals is an exciting question that requires further study.

“Importantly, this study builds on previous research in anhedonia and demonstrates the value of combining functional MRI with experience sampling and more engaging and behaviorally relevant naturalistic tasks, which we believe hold great potential for psychiatric neuroimaging.”

“What we found in this study is that people with anhedonia still experience emotions of sadness and joy when asked to engage in a task, but these emotions are not as intense,” said Dr. Marie-Stephanie Cahart, a postdoctoral researcher at IoPPN and first author of the study.

“What we observed looks like a form of emotional disengagement accompanied by prolonged activity in brain regions related to attention, particularly during more neutral pieces of music. We would like to further investigate these neutral moments, as they may be more important than previously thought in anhedonia and depression.”