Role of the Noradrenergic System in the Regulation of Learning Dynamics: Evaluation of the Effect of a Low-dose Selective Noradrenaline Reuptake Inhibitor (NOISYXETINE)

Administration of low-dose selective noradrenaline reuptake inhibitor (sNRI) (e.g. atomoxetine) to healthy subjects is a validated model of increasing cortical noradrenaline levels which, combined with computational modelling of behaviour, allows fine-grained analysis of the impact on learning processes of noradrenaline's fluctuations in the human cortex. The study goal is to characterize the modifications of certain cognitive processes and associated brain circuits under low-dose sNRI using validated computational learning models. The study will be interested in how subjects will modify their learning under the effect of the drug across two separate investigations; one utilizing in a stable evidence accumulation task and one utilising a changing evidence accumulation task. This approach will help to better understand the link between noradrenaline and accumulation of evidence in healthy subjects, and indirectly in some neuropsychiatric pathologies. The study is a single centre, double-blinded, randomized, placebo-controlled, cross-over study involving evaluable healthy adults separated in 2 cohorts: A for participants having the stable task and B for those having the changing one. Participants will then be randomized in a 1:1 ratio to one of the following treatment sequences: * Atomoxetine 40 mg - Placebo (Subgroups A1 or B1); * Placebo - Atomoxetine 40 mg (Subgroups A2 or B2).