Stressed individuals exhibit pessimistic bursting beliefs and a lower risk preference in the balloon analogue risk task.

Stress alters decision-making by usually promoting risk-taking and reward-seeking, which could be advantageous in a context where risk is rewarded, such as the Balloon Analogue Risk Task (BART). However, previous studies addressing this issue showed inconsistencies which could emerge from assessing decision-making as a single dimension. Our aim is to study through computational modelling how stress influences cognitive subprocesses of the decision-making during the BART. For this purpose, 94 healthy participants were submitted to BART, but only half were exposed to the virtual Trier Social Stress Test (TSST-VR). The Experimental-Weight Mean-Variance (EWMV) model was used to gain insight into the subprocesses involved in risk-taking during BART. Rather than reward-seeking, our results showed a pessimistic prior belief about the balloons bursting likelihood, and a lower risk preference in the stressed participants. This cautious attitude could be attributable to an alertness state promoted by stress. Yet, since risk is rewarded in BART, it could also evidence a maladaptive decision-making derived from learning difficulties and altered feedback-processing under stress.