NEUROCOGNITIVE MECHANISMS OF REGRET AND ITS DYSFUNCTIONS IN DEPRESSION

Abstract

This thesis examines the behavioral and neural correlates of regret in depression. In study 1, a meta-analysis of regret-related fMRI studies (N=19) over a range of tasks showed that the experience of regret led to activations in the rostral anterior cingulate cortex (rACC), the medial orbitofrontal cortex (mOFC), and the striatum. In study 2, I used task-based fMRI to examine alternations in regret-anticipation, experience, and regret-based decision making to show that high levels of depressive-symptoms lead to a blunted experience of regret and a diminished ability to make choices that avoid the potential experience of regret, coupled with diminished activity in the rACC, mOFC, and striatum in anticipation of regret. In study 3, I used a multi-strategy learning game and fMRI to show that the depressed group were less sensitive to history of received-payoff in decisions and showed hypoactivation in the ventral striatum (VS) – suggesting diminished reinforcement learning.