The neurobiological and cognitive processes underpinning stress-induced impact on decision-making

Abstract

Research evidence shows that acute stress and the effect of cortisol could alter decision-making performance, with individual cortisol responsiveness as mediating factor. Men have been consistently reported to make disadvantageous decisions due to their higher risk-taking or reward-seeking behaviours, while women show the reverse trend. However, a certain degree of risk-taking is necessary in many important decisions in real life, yet relatively few research studies have used a decision-making task that requires a risk-taking tendency for advantageous outcomes (i.e. risk-seeking decision-making). In addition, the specific mechanisms underlying the cortisol effect on this type of decision-making are not fully known. Study 1 was an experimental study using the Balloon Analogue Risk Task (BART) as the risk-seeking decision-making task. The effect of cortisol responsiveness and gender on decision-making and its underlying cognitive components was examined in a healthy university sample (42 men and 42 women). Stress was induced by the Trier Social Stress Test (TSST) in the experimental condition. Three cognitive tasks (Tower of London test, Stroop test, and a masked emotional Stroop task) and the BART were then administered. The data showed that when under stress, the men had better risk-seeking decision-making performance than the women. The interaction between gender and cortisol responsiveness was not significant. Descriptively, the male cortisol responders tended to be more risk-taking while the female responders showed less consistent risk-taking behaviours. The relationship between risk-taking behaviours and cortisol reactivity was negative among the male cortisol responders, while the results for the female responders showed a quadratic relationship with risk-taking behaviours that increased with cortisol reactivity but then declined. Study 2 extended the experimental design of Study 1 to 16 male law enforcement officers and used a simulated crisis intervention as an effective stress induction. The cortisol responders appeared to be more risk-avoidance when compared with the non-responders. Cortisol reactivity in the police officers was associated with the personality tendencies of lower openness, higher sensitivity to somatic symptoms, and higher interpersonal suspiciousness, which might have been shaped by the law enforcement culture and altered their decision-making behaviours when under stress. Study 3 was a small exploratory study to investigate cortisol responsiveness and risk-seeking decision-making in a subgroup of the sample from Study 1 (17 men and 24 women) with different types of psychopathic personality traits as classified by the factor scores of the Psychopathic Personality Inventory – Revised (PPI-R). Compared with those with low psychopathic traits, the participants with high traits in global psychopathic personality, Fearless Dominance (FD), and Self-centred Impulsivity (SCI) generally displayed the tendency of increased cortisol reactivity to the TSST and more risk-taking behaviours in decision-making. However, the individuals with high Cold-heartedness (CH) traits appeared to show the profile of a “successful psychopath,” namely the lack of a risk-taking tendency and better executive planning ability. The cognitive components underlying the risk-seeking decision-making could not be directly identified from the data, yet the possible underlying mechanisms in cortisol responders and non-responders implied from the present findings were discussed.published_or_final_versionPsychologyDoctoralDoctor of Philosoph