Project Summary Self-control failures are a universal challenge for healthy and clinical populations. Recent theoretical and empirical work suggests these failures may arise from excessive cognitive costs associated with exercising control. However, traditional self-control paradigms do not provide a methodological platform to quantify these costs. Further, we know little about the neural basis of self-control costs nor how these representations change under different classes of psychological stress, which is a major risk factor for self-control failure. To address this, we developed a novel decision-making task that measures how much individuals will pay to restrict access to tempting rewards that may derail their long-term goals and lead to self-control failure (precommitment). Here, we aim to use an expanded and refined version of this newly validated tool to examine neurocomputational and affective mechanisms underlying prospective self-control costs and how they relate to real-world self-control failures. In Aim 1, we seek to identify the computational, motivational and cognitive mechanism that gives rise to self-control costs. We will model the cost function for self-control, test how this metric relates to cognitive constructs typically implicated in self-control in the literature and disentangle the motivational mechanism underlying the use of precommitment. In Aim 2 we seek to characterize the neural correlates of self-control costs, track how activity within these regions dynamically fluctuate depending on the feature of food stimuli participants focus on and identify neural mediators and connectivity patterns stemming from these costs. In Aim 3, we seek to examine how different classes of stressor type (physiological, social, or lifetime stress) shapes the behavioral and neural representations of self-control costs. Characterizing individuals’ self-control cost function and how these costs are represented in the brain will allow for a more direct test of how stress exposure affects decisions to use self-control and may lead to potential interventions that can buffer individuals from the effects of stress on such decisions.