Mini-Review The Impact of Stress in Decision Making in the Context of Uncertainty P. Morgado, N. Sousa, and J.J. Cerqueira* Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal and ICVS-3Bs PT Government Associate Laboratory, Braga/Guimar ~ aes, Portugal For a number of decades, different fields of knowledge, including psychology, economics, and neurosciences, have focused their research efforts on a better understand- ing of the decision-making process. Making decisions based on the probability of future events is routine in every- day life; it occurs whenever individuals select an option from several alternatives, each one associated with a spe- cific value. Sometimes subjects decide knowing the pre- cise outcomes of each option, but commonly they have to decide without knowing the consequences (because either ambiguity or risk is involved). Stress has a broad impact on animal behaviors, affects brain regions involved in decision-making processes, and, when maladaptive, is a trigger for neuropsychiatric disorders. This Mini-Review provides a comprehensive overview on how stress impacts decision-making processes, particularly under uncertain conditions. Understanding this can prove to be useful for intervention related to impairments to decision-making processes that present in several stress-triggered neuro- psychiatric disorders. V C 2014 Wiley Periodicals, Inc. Key words: stress; decision making; uncertainty During the past decades, different fields of knowl- edge, including psychology, economics, and neuroscien- ces, have focused on the decision-making process, highlighting its broad impact and huge complexity and contributing to the rise of a new area devoted to the study of brain computations implicated in valued decisions (Rangel et al., 2008). Making decisions based on the probability of future events is routine in everyday life; it occurs whenever individuals select an option from several alternatives, each one associated with a specific value. To manage limited resources, living organisms have to make critical decisions that have survival value, which means that being a good decider has selective and evolutionary impact (Kalenscher and van Wingerden, 2011). Con- versely, impaired/poor decision making can have cata- strophic consequences and constitutes an important feature of several neuropsychiatric disorders, such as schiz- ophrenia, anxiety disorders, substance abuse disorders, obsessive compulsive disorder, and pathological gambling (for review see Ernst and Paulus, 2005). Decisions are driven by values, subjective attributes tagged to the different options at the beginning of the decision-making process and representing the benefits/ gains expected from each. This valuation process and the following decisions are modulated by several variables, including uncertainty, cost and effort, delay, and social modulators, the contribution of which will be briefly reviewed. Sometimes individuals decide knowing the precise outcomes of each option, but more often they have to bet without an exact knowledge of the consequences (Hsu et al., 2005). “Uncertainty” refers to this lack of knowl- edge concerning the outcomes of a specific choice (Hsu et al., 2005). Uncertain events can be categorized by the confidence in the probability assignment to each out- come. “Ambiguity” refers to situations in which the out- comes cannot be fully specified and/or their probability is completely unknown, and “risk” refers to situations in which the distribution (or probability) of each possible outcome is (at least partially) known, with a continuum between both extremes. It is believed that the processing of ambiguity and risk is supported by distinct neural mechanisms involving different brain regions (activation within the lateral prefrontal cortex is related to ambiguity, whereas activation of the posterior parietal cortex is pre- dicted by risk preference; Huettel et al., 2006). In con- trast, whether value and uncertainty share common neuronal circuits/mechanisms is still an open question. Uncertainty about an outcome is thought to modu- late our choices according to a simple linear model in which its probability weighs the utility of the outcome (the expected-utility model, devised by Bernoulli in Contract grant sponsor: Foundation for Science and Technology; Con- tract grant numbers: SFRH/SINTD/60129/2009; PTDC/SAU-NSC/ 111814/2009; Contract grant sponsor: Programa Operacional Factores de Competitividade (COMPETE)]. *Correspondence to: Joao J Cerqueira, Life and Health Sciences Research Institute, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal. E-mail: jcerqueira@ecsaude.uminho.pt Received 22 July 2014; Revised 16 September 2014; Accepted 29 October 2014 Published online 6 December 2014 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jnr.23521 V C 2014 Wiley Periodicals, Inc. Journal of Neuroscience Research 93:839–847 (2015)