Background: Social feedback, i.e., receiving social rewards like approval, acceptance, interest, or praise or conversely, receiving social punishments like being excluded, rejected or criticised in social interactions, is a critical source of social information. There is abundant evidence suggesting that, compared to healthy controls, individuals with depression show more negative experience of social feedback, have a more negative expectation of social feedback, and potentially show dysregulation of negative emotions evoked by negative social feedback. The brain structural and functional alterations associated with changes in anticipation and response to social feedback in these groups is however unclear. The aims of this PhD thesis were to address multiple aspects of social feedback processing in depression: (1) Anticipating and consuming social feedbacks; (2) Processing the expectancy violation of social feedbacks. (3) Emotion regulation of social feedbacks. Methods: Multi-modal approaches, including fMRI, non-invasive brain stimulation, EEG, eye-tracker recording and cognitive testing were employed as research tools for my project. The large-scale MRI analysis of the existing neuroimaging data such as UK biobank were also used. Paper one. This study provides evidence that depression is characterized by distinct neural alteration in processing monetary and social incentives. Paper two. This study highlights an important role of expectancy violation in the brain dysfunction of social feedback perception and evaluation in depression. Paper three. This study suggests a causal role for rVLPFC in down-regulation of negative emotions produced by social exclusion. Paper four. This study highlights a more specific causal relationship between rVLPFC rTMS and reappraisal success of social pain compared to physical pain. Paper five. This study found that the tDCS-activated rVLPFC could improve emotion regulation capacity on social exclusion. However the findings do not suggest that individuals with high depressive mood benefit from a single-tDCS session on the emotion regulation of social exclusion. Paper six. This study demonstrates cultural differences in emotional reaction to and emotion regulation of social exclusion. Paper seven. This study provides evidence linking loneliness to grey matter volume changes in ACC and VLPFC in depression. Conclusions: Taken together these papers show neural deficits contributing to abnormal social feedback processing (anticipation, experience, expectancy violation, and emotion regulation) in individuals with depression. These results may have potential implications for clinical practice on how abnormal brain could be normalized in certain targeted interventions, and highlight the importance of protecting individuals with depression from specific social risk factors such as the negative social feedback.
|Date of Award||31 Dec 2020|
- The University of Manchester
|Supervisor||Rebecca Elliott (Supervisor) & Nils Muhlert (Supervisor)|