Cardiovascular Reactivity And4 Other Factors Are Associated With Reward-Seeking and Loss-Avoidance in an MTBI- and Stress-Stratified Student Sample

Decision making deficits are often present in individuals with mild traumatic brain injury (mTBI), including impulsivity. Stress can situationally increase impulsive decision-making. The Iowa Gambling Task (IGT) is a common test for impulsive decision making when outcomes have consequences. MTBI, induced stress, and bio-psycho-socio characteristics that determine how stress is managed (stress appraisal and cardiovascular reactivity) may exert an influence on aspects of impulsivity, reward-seeking and loss-avoidance. Participants were stratified by history of mTBI. Participants were block-assigned to stress or control conditions. The IGT was administered, and a series of questionnaires was used to capture stress appraisal; a biometric monitor recorded cardiovascular reactivity. A 2 x 2 factorial (no-TBI/mTBI; stress/ control) ANOVA was used to evaluate reward-seeking, operationalized using CD-AB. A similar 2 x 2 factorial ANOVA was used to analyze loss-avoidance, operationalizing this behavior using average dollar amount won during the task (Net Gain). Multiple linear regression models evaluated the combined influence of stress appraisal and cardiovascular reactivity on reward-seeking and loss-avoidance. ANOVA did not reveal significant differences between groups for either CD-AB score or New Gain. Multiple regression modeling accounted for 20% of shared variance in CD-AB score and 18% of shared variance in Net Gain. Modeling revealed that reward-seeking was associated with time of day and cardiovascular activity; and loss-avoidance was associated with stress appraisal, cardiovascular activity at different phases of the study, and smoking. Reward-seeking and loss-avoidance in this sample are distinct concepts with distinct influences.