1 - (OP20) Pupil-based Indices of Arousal Flexibility as Markers of Resilience and Prevention Under Stress

In a world increasingly shaped by chronic and complex health conditions, prevention has become a key strategy for mitigating the development of stress-related psychopathology. From a cognitive-behavioral perspective, resilience can be understood as the capacity to flexibly regulate arousal, emotions, and coping responses in the face of stress. The present study investigated resilience-related regulatory processes in a vulnerable group—medical students during their first clinical placement—a developmental phase characterized by both potentially traumatic and chronic stressors that may increase risk for PTSD and other stress-related disorders.
We present longitudinal data from 102 medical students followed across this critical phase of training. The study focused on neurobiological and everyday emotion regulation processes relevant to CBT models of stress adaptation, with particular emphasis on pupil-based regulatory flexibility as an index of a flexible arousal system. Adaptive pupil responses—reflecting flexible arousal regulation—were innovatively assessed under controlled high- and low-stress conditions prior to the onset of the clinical internship, allowing examination of regulatory capacity before prolonged real-world stress exposure.
Results indicated that higher regulatory flexibility, reflected in adaptive pupil responses, was associated with greater resilience during clinical placement. Students showing greater arousal flexibility demonstrated more effective stress coping and a reduced emergence of PTSD symptoms and other stress-related complaints over time. These findings align with CBT models linking physiological regulation to cognitive appraisal and behavioral coping processes.
Importantly, pupil-based markers of regulatory flexibility emerged as a promising target for early identification and prevention, as well as a potential mechanistic target for CBT-informed interventions aimed at strengthening emotion regulation, stress tolerance, and adaptive coping in high-stress environments. Together, these findings provide new insights into the neurobiological mechanisms underlying resilience and highlight pupil-based measures of arousal flexibility as a translational bridge between basic neuroscience and CBT-oriented prevention and intervention development. By advancing our understanding of flexible regulation under stress, this work supports the development of targeted CBT-based strategies to enhance resilience and reduce the long-term risk of stress-related psychopathology.