Heart rate variability reveals graded task difficulty effects and sensitization dynamics in anticipatory psychological stress via time-domain analysis

This study provides preliminary evidence supporting the use of SDNN as a complementary physiological indicator of anticipatory psychological stress responses. The findings suggest that task difficulty not only modulates individuals' anticipatory psychological responses on a cognitive level but also significantly shapes the dynamic trajectory of the SDNN during stress development. The observed sensitization effect indicates that higher-difficulty tasks can lead to enhanced anticipatory psychological stress responses in subsequent tasks. These results have potential implications for optimizing psychological stress response intervention strategies and for the development of standardized and replicable paradigms for anticipatory psychological stress research. Future studies should incorporate a larger and more diverse sample to further investigate how individual differences influence anticipatory psychological stress responses.