Acute Stress Weakens The Effect Of Coping Styles In Unfair Decision-making: Behavior And Brain Mechanisms

People often need to make choices under stress.When people facing or have just experienced a psychosocial stress event,their body(especially the brain)is under the turbulence of the strong physiological.How will this turbulence affect specific decision-making functions? It is still a relatively new research question.More importantly,whether it is stress response or decision-making style,there is a strong personal imprint,that is,individual differences are likely to play a relatively important direct or indirect role in this process.Among these individual differences,whether to adopt a positive or a negative coping style in the face of stress is more likely to directly affect people’s interpretation of the stressor and the choice of fighting or fleeing in the face of stress.Current studies have shown that acute stress affects unfairness decisionmaking,but will coping styles affect unfairness decision-making,and Will different coping styles under acute stress have different impacts on unfairness decisionmaking?These problems currently lack corresponding experimental research.This study explored the relationship between coping styles,acute stress and unfairness decision-making through two experiments,and used functional near-infrared spectroscopy imaging technology(f NIRS)in the second study to deeply study its internal brain mechanisms.The experimental procedures of the two studies were roughly the same.Both used the Trait Coping Style Questionnaires(TCSQ)to measure the trait coping styles of the subjects,and then the subjects entered the stress or nonstress induction process,and finally completed the unfairness decision-making task.Study 1 was mainly about whether coping styles affected unfairness decisionmaking,and the relationship between coping styles,acute stress and unfairness decision-making.Using the Maastricht Acute Stress Test(the Maastricht Acute Stress Test,MAST)to induce 60 subjects’ acute stress,and during this period,a physiological recorder was used to record the Electrodermal activity(EDA)and electrocardiogram(ECG)of the subjects in order to assess the peripheral physiological response of acute stress.Unfairness decision-making was studied by the classic moral decision-making task related to unfairness adapted by the research team.Saliva samples were collected4 times during the entire experiment to detect saliva cortisol concentration.The experiment uses a mixed design of 2(group: stress group,control group)× 2(classification of classic moral distress situation: impersonal,personal)× 2(unfairness:primitive classic moral dilemma,classic moral dilemma related to unfairness),the dependent variable is the proportion of utilitarian choices of subjects under different conditions.The results of the analysis of moral decision-making found that the proportion of utilitarian choices in moral dilemma decisions related to unfairness was significantly higher than that in the original moral dilemma.Cortisol concentration under the curve and the proportion of utilitarian choices in classic moral dilemmas related to unfairness were Negative correlation.Under control condition,positive coping was negative related with the proportion of utilitarian choices in the unfairness moral decision-making.But the correlation is not significant under acute stress condition.It can be seen from the results of study 1 that acute stress and coping styles will affect unfairness decision-making,and acute stress weakens the influence of coping styles on unfairness decision-making.Study 1 verified the impact of coping styles on unfairness decision-making,and found that acute stress weakened the role of coping styles in unfairness decision-making.In the second study,the Ultimatum Game(the Ultimatum Game,UG)paradigm was used to study unfairness decision-making.To study the internal brain mechanism,f NIRS was used to measure the changes in blood oxygen concentration of the subjects’ cerebral cortex during the UG task.The Trier Social Stress Test(TSST)was used to induce acute stress.A total of 52 subjects participated in the experiment.The experiment used a mixed design of 2(group: stress group,Control group)× 2(distribution method: fairness,low unfairness,high unfairness).The results of behavioral studies found that only under control condition,positive coping was positively correlated with the acceptance rate of low unfair distribution;negative coping and low unfair distribution acceptance rates were negatively correlated.But the correlation was also not significant under stress condition.The results f NIRS analysis revealed a significant interaction between group and fairness in the frontopolar cortex.During fair allocation,there was a significant difference in the activation of the frontal polar cortex between the stress group and the control group.But activation in the frontopolar cortex was both inhibited in unfair conditions.Correlation analysis of f NIRS data and coping styles found that in the low and high unfair distributions,positive coping and frontopolar cortex were positively correlated in the control group,but was not associated with frontopolar cortex activation in the stress group.Study 2provided a supplement to the behavioral and brain mechanisms of the weakening effect of acute stress on active coping.Combining the results of Research 1 and 2 showed that coping styles would affect unfairness decision-making,and the influence of coping styles on unfairness decisionmaking would be weakened by acute stress.Based on the f NIR results in Study 2,we hypothesized that the brain mechanism may be that individuals who were positive coping with stress,have higher activation of the frontopolar cortex in the face of unfairness,and the top-down cognitive control pathways are better able to function,and therefore were less emotional and were resistant to the effects of unfairness in decision making.But acute stress inhibited the activation of the frontal polar cortex,so the role of active coping in unfair decision-making is weakened.The study of the weakening of the response to acute stress and its brain mechanism would help to further reveal the impact of stress on individual differences,discover more stress susceptibility factors,so as to do in-depth research on the pathogenesis of stress-related psychological diseases and targeted psychological intervention methods.