Abnormal processing of social feedback is an important contributor to social dysfunction in depression, however the exact mechanisms remain unclear. One important factor may be the extent to which social processing depends on expectations, in particular whether social feedback confirms or violates expectations.
To answer this question, we studied behavioral and brain responses during the evaluative processing of social feedback in 25 individuals with subthreshold depression (SD) and 25 healthy controls (HCs). Participants completed a Social Judgment Task in which they first indicated expectation about whether a peer would like them or not, and then received peer's feedback indicating acceptance or rejection.
Individuals with SD who reported greater depressive symptoms gave fewer positive expectations. Compared to HCs, individuals with SD showed reduced activation in the medial prefrontal cortex when expecting positive feedback. They also exhibited increased dorsal anterior cingulate cortex after receipt of unexpected social rejection, and reduced ventral striatum activity after receipt of unexpected social acceptance.
The observed alternations are specific to unexpected social feedback processing and highlight an important role of expectancy violation in the brain dysfunction of social feedback perception and evaluation in individuals at risk for depression.