The Influence of Stress on the Intrinsic Cost of Self-Control

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Project Summary The use of self-control in everyday life is critical to healthy, adaptive functioning but is often compromised by stress. Neurophysiological responses to stress are thought to alter decision-making circuits in the brain, leading to impaired emotional and behavioral control, and suboptimal decisions that can have deleterious consequences to both psychological and physical health. Exposure to stress is widely considered to be a major predictive factor to the development, maintenance and relapse of a range of mental disorders, including anxiety, depression, and those marked by pathological choice, such as such as obesity, gambling, and substance use. However, a mechanistic account of how stress influences the use of self-control during value- based decision-making is lacking. Recent research has proposed that since the exertion of self-control utilizes cognitive resources, it imposes costs on an individual that may lead them to deviate from goal-directed strategies to control behavior, relying instead on strategies that are less computationally costly but may lead to suboptimal outcomes. The current proposal aims to advance our understanding of how stress might influence decisions to use self-control strategies by measuring the costs individuals assign to self-control use. We will characterize the specific effects of stress on decisions to use self-control using behavioral measures, neuroendocrine measures of stress response, neuroeconomics, functional neuroimaging and computational modeling. Specifically, we will examine how individuals construct the cost of self-control after pre-exposure to stress using a validated neuroeconomic approach (Aim 1). Further, we will characterize the neural mechanisms underlying how self-control decisions are made under stress using model-based fMRI (Aim2). We predict that (1) self-control will be perceived as more costly under stress than under non-stress conditions, (2) the interaction between value-encoding brain regions (i.e., striatum, ventromedial prefrontal cortex (PFC)) and regions that support different aspects of cognitive control (i.e, dorsolateral PFC, anterior cingulate cortex) will register self-control costs in dissociable ways, and (3) that stress will selectively alter patterns of brain activity related to computing self-control costs in these regions. The knowledge obtained from this proposal will advance our understanding of the neurocomputational mechanisms that guide self-control decisions and how these mechanisms are altered under stress. These aims will facilitate the training goals of this proposal by offering training in behavioral economic theory, advanced functional imaging, and computational modeling. The proposed research will have direct implications both for stress-related anxiety and mood disorders and those that are marked by pathological choice, such as obesity, gambling alcoholism and drug addiction.