Making decisions immediately post-stress: Evidence for dorsolateral prefrontal cortex involvement with an fMRI study

Identifying neural markers might help to investigate the specific effects of stress on risky decision-making and to understand the behavioral interventions for risk adjustment. It is proposed that stress makes decision-making less deliberate. We employ fMRI to investigate this, with stress and post-stress decision-making occurring during the same fMRI session with a minimal stress-to-decision-making latency and concurrent electrodermal activity (EDA) measurement. In this within-subject study (40 participants, 18 males, M_age = 24.6 ± 3.9 years), participants performed the "decision-making under risk" task twice: immediately following stress induction, and after a control condition. The order of the stress and control conditions was counterbalanced. Stress was induced by asking participants to solve mental arithmetic tasks under time pressure while receiving negative feedback. During the decision-making task, participants chose between a safe and a risky option with monetary incentives. Behavioral and EDA (n = 34; due to technical issues) data confirmed that stress induction was successfully implemented. Participants took less risky decisions post-stress than post-control. An fMRI contrast analysis revealed that the right fronto-opercular and the left anterior part of the dorsolateral prefrontal cortex (dlPFC) exhibited significantly lower activation during decisions post-stress than decisions post-control. The results indicate that decisions taken immediately after exposure to the acute stressor are less risky. Furthermore, decisions post-stress are associated with reduced activation in the regions of the dlPFC, possibly leading to lower cognitive control and less deliberate decision-making post-stress. Interventions to increase dlPFC activation might be suitable to improve the decision-making post-stress.