Brain, Body, and Behavior: A Multidimensional Approach to Stress and Resilience

This dissertation investigates the dynamic interplay of psychological, physiological, and behavioral responses to stress, as well as the relationship between stress and resilience. Across three empirical studies, using both virtual reality and real-life acute stress induction paradigms, stress responses were examined using multiple measures, including self-report, heart rate, cortisol, and facial expressions. Study 1 evaluated a virtual reality-based Stroop paradigm and demonstrated that it reliably elicits cognitive interference and a mild stress response. Study 3 introduced and validated the German adaptation of the Short Stress State Questionnaire, showing that self-reported stress states sensitively capture distinct cognitive, motivational, and affective changes across challenge- and threat-based stressors. Study 4 examined multimodal stress responses in a within-subjects comparison of the Trier Social Stress Test and its friendly variant. Findings revealed that stress responses unfold across psychological, physiological, and behavioral domains, with heart rate and cortisol increases corresponding to higher subjective stress. Facial expressions showed condition-specific modulation but did not reliably map onto standard emotion categories. A fourth publication, Study 2, contributed a complementary structured review examining associations between resilience and stress biomarkers, particularly regarding inflammatory markers and cortisol, identifying potential protective patterns across differing conceptualizations of resilience. Collectively, the publications presented in this dissertation underscore the value of integrating psychological, physiological, and behavioral indicators to conceptualize stress—and resilience—as dynamic, multisystem processes. Together, all four studies inform the integrative model of stress and resilience developed in this dissertation and highlight methodological and theoretical directions for advancing stress research and interventions, specifically targeting the brain, the body, and behavior.