Neuroeconomic approaches to emotion-related influences on decision-making

Abstract

Decades of classic economic research have neglected the role of incidental and integral emotional factors in human decision-making. Standard economic models assume that decision-making is consequentialist in nature: Decision-making is postulated to be guided by the decision maker’s rational assessment of desirability and likelihood of alternative outcomes, i.e., by his strive to maximize utility (Rick & Loewenstein, 2008). However, advances in psychology and behavioral economics led to the gradual acceptance of incidental and integral emotion-related forces on decision-making. Still, we particularly lack detailed insight into the neurobiological mechanisms of the interaction between emotion and decision-making. The purpose of this dissertation was to gain a more detailed understanding of these neurobiological substrates of the modulatory effects of different emotion-related factors on decision-making. To this end, four studies investigated different aspects of this interaction with behavioral, neuroimaging and neurostimulation tools. Study A employed transcranial magnetic stimulation in order to investigate the neurobiological mechanisms causally underlying the framing effect, a decision-making bias hypothesized to be based on the influence of integral emotion on the decision-making process. This study shows that temporal disruption of activity in unilateral dorsolateral prefrontal cortex, a brain region known for its involvement in cognitive control, does not lead to changes in framing susceptibility, and casts doubt on the essential role of this brain region in the framing effect. In Study B, the effects of incidental anticipatory anxiety on risky decision-making in a non-social context were investigated. The results demonstrate that induced anxiety leads to significant changes in neural value coding (especially in insula, ventral striatum and ventromedial prefrontal cortex), without changes in observable behavior (i.e., choices). Study C focused on the effects of incidental anticipatory anxiety on social decisionmaking. Anticipatory anxiety caused a breakdown in trusting behavior, which was correlated with activity and connectivity changes in neural social cognition networks (e.g., temporoparietal junction, posterior superior temporal sulcus). The results of Studies B and C highlight the task- and context-specific effects of anxiety on behavioral and neural aspects of non-social and social risky decision-making. Study D addressed the neuroanatomical substrate of emotion-related traits (i.e., personality and emotion-related traits) consistently found to influence daily decisionmaking.I found unique and specific associations between distinct affective and personality features such as impulsivity, sensation seeking, and negative emotionality and brain morphometry. Importantly, the identified brain regions have been shown to be (functionally and structurally) involved in decision-making and valuation. This finding emphasizes the association between affective and personality traits and variation in individual decisionmaking styles. In sum, this dissertation contributes to a detailed understanding of the modulatory influence of emotion on decision-making. I present different neurofunctional and neurostructural correlates of emotion-decision-making interactions, which are highly taskdependent. Notably, these findings might offer a neurobiological account for deviant decision-making observed in numerous psychiatric disorders such as anxiety and affective disorders.