Fronto-striatal activity predicts anhedonia and positive empathy subtypes

Abstract

The dorsolateral prefrontal cortex, globus pallidus, and nucleus accumbens are important components of the reward circuit in the brain; and prior research suggests individuals with damage to these regions feel less pleasure (i.e., are anhedonic). However, little is known about how these brain regions relate to vicarious pleasure. Pilot fMRI data were collected from 20 participants (M_age = 22, SD = 7.0, 63% female) during a validated empathy induction paradigm that utilized video clips extracted from the television show "Extreme Makeover: Home Edition" to elicit empathic happiness (i.e. vicarious happiness) when targets display positive affect, and either empathic cheerfulness (i.e. the tendency to want to cheer someone up) or empathic concern (i.e. vicarious sadness) when targets display negative affect. Participants also completed the novel "Happy Faces" task-a behavioral measure of anhedonia-while fMRI was collected. fMRI data during task completion were used to predict trait empathy measured via self-report outside of the scanner, and accuracy on the "Happy Faces" task. Results indicate that globus pallidus activity during empathic concern-eliciting video clips significantly predicted self-reported trait empathic cheerfulness (R² = 26%, p = 0.045). Furthermore, greater dorsolateral prefrontal cortex (DLPFC) activity during the Happy Faces task predicted accurate performance on the task (R² = 34%, p < .05); and greater nucleus accumbens shell activity during the Happy Faces task predicted greater trait empathic happiness (R² = 38%, p < .05). These results suggest that fronto-striatal circuitry contributes to our experience of anhedonia, empathic happiness, and empathic cheerfulness.

Keywords: Anhedonia; Positive empathy; fMRI.