The Role of Stress Neuromodulators in Decision Making Under Risk

Affective states like acute stress can influence cognition, i.e., memory processes. Physiologically, acute stress elicits an array of autonomic and endocrine responses, including a fast release of norepinephrine from the locus coeruleus noradrenergic (LC NA) system. Compelling evidence shows that in healthy humans, stimulation of the noradrenergic system increases memory performance whereas noradrenergic blockade reduces memory performance. Functional magnetic resonance imaging (fMRI) studies have shown that manipulations of the noradrenergic system affects responsiveness and connectivity within networks that are important for autonomic-neuroendocrine control and temporal and spatial attention orientation. So far, no study investigated the neural underpinnings of memory processes after a pharmacologically induced noradrenergic blockade. The aim of the proposed project is to combine precise pharmacological manipulation of the noradrenergic system with behavioral modeling of distinct memory processes, and fMRI methods to study the effect of a pharmacologically induced blockade of the noradrenergic system on two distinct memory processes. Behaviorally, the investigators will focus on the effect of the noradrenergic blockade on working memory performance, and recognition memory. Participants are randomly assigned to one of two groups: (A) clonidine, or (B) placebo.