Distinct dimensions of interoception modulate the link between cardiovascular reactivity and perceived stress

Perceived stress, even when the stressor is the same, varies across individuals. Interoception-the ability to perceive and process internal bodily states-plays a crucial role in shaping the relationship between perceived stress and physiological changes in the body. We aimed to determine how interoception modulates the translation of cardiovascular reactivity into perceived stress during various stress situations. To examine this effect under varying degrees of external pressure, participants performed a speech task under two different themes: a higher-stress condition, in which they were informed that their content about social and political issues would be evaluated by professionals, and a lower-stress condition, in which they could speak freely about their personal experiences. During the tasks, we measured cardiovascular reactivity by using the hemodynamic profile (HP), which reflects the qualitative nature of blood pressure responses (i.e., myocardial-dominant vs. vascular-dominant). Following each task, participants reported subjective emotional states. To assess individual differences in interoception, we employed a Heartbeat Counting Task (HCT) and the Multidimensional Assessment of Interoceptive Awareness (MAIA). The results revealed that, in the higher-stress condition, excitement was negatively associated with HP among individuals with higher HCT scores, whereas it was positively associated with HP among those with lower HCT scores. In contrast, in the lower-stress condition, MAIA scores interacted with HP to affect excitement, which was negatively associated with HP among individuals with higher MAIA scores, and positively associated with HP among those with lower MAIA scores. We show that the interplay between interoception and cardiovascular reactivity substantially influences the perception of excitement as a subjectively positive aspect. These results provide important insights into the quality of perceived stress, highlighting its dependence on context and individual traits. Our findings offer a physiological anthropological insight into the mind-body connection, suggesting that interpreting cardiovascular reactivity as allostasis demonstrates how individuals utilize multidimensional interoceptive cues to adapt to environmental demands and reshape their physiological states into qualitative emotional experiences.