The Leiden Stroop-like Stress Task: A tool to reveal physiological dynamics using graded stress induction.

Stress evokes a complex repertoire of psychological and physiological responses. This paper introduces the Leiden Stroop-like Stress Task (LSST), a paradigm designed to induce progressively increasing levels of stress by manipulating task difficulty and social-evaluative threat across four 10-minute blocks. Fifty-four healthy adults (35 females; mean age = 21 ± 3 years) completed the LSST, with repeated assessments of self-reported stress and challenge-threat appraisal, as well as continuous cardiovascular recordings. Results confirmed the LSST's effectiveness in eliciting gradual increases in self-reported stress, negative affect, and heart rate, along with gradual decreases in positive affect. Blood pressure and pre-ejection period also showed moderate, but more discrete, changes over time. Challenge-threat appraisals gradually shifted from challenge to threat but, on average, remained on the challenge side of the bipolar continuum. Vascular resistance, as measured by total peripheral resistance, exhibited a continuous increase. This vascular effect was accompanied by (slightly) increased ventricular contractility and heart rate as well as stable cardiac output, thus reflecting a classic physiological threat pattern. Exploratory within-subject correlations revealed consistent alignment between self-reported stress and physiological measures. Our findings demonstrate that the LSST enables the graded induction of mild-to-moderate stress and effectively captures stress dynamics across psychological and physiological levels. We discuss the potential of this paradigm to provide insights into stress dynamics and its vascular hemodynamic profile, as well as interventions aimed at increasing stress resilience.