Comparison of interoceptive abilities across the respiratory, esophageal and cardiac domain: A pilot study.

Interoception, the processing and perception of internal bodily signals, regulates a wide range of psychological and somatic functions, including emotional experiences, bodily symptom perception, self-awareness and decision-making, highlighting its important role in the maintenance of bodily and mental homeostasis. Traditionally, interoception has been studied within single organ domains, with findings often generalized to interoception as a whole. However, evidence suggests interoceptive abilities may be domain-specific rather than a general ability. This pilot study investigated how perceptual and affective dimensions of interoception relate across organ systems. Thirty-three healthy adults completed comparable magnitude estimation and sustained stimulation tasks, allowing for comparisons across the respiratory, esophageal, and cardiac domain in a within-subjects design. Respiratory sensations were evoked through inspiratory resistive loads, esophageal sensations through balloon inflations, and cardiac sensations via graded cycle ergometer exercise. Interoceptive sensitivity, the ability to perceptually discriminate between stimulation levels, was quantified as the slope of intensity ratings relative to stimulation intensity. Acute affective responses were assessed through unpleasantness ratings during sustained stimulation. Results revealed no significant correlations in interoceptive sensitivity across domains, with Bayesian analyses providing anecdotal support for the null hypothesis. In contrast, acute affective responses showed partial convergence: respiratory unpleasantness ratings correlated significantly with both esophageal and cardiac ratings, whereas esophageal and cardiac ratings were not significantly correlated. These findings support a multidimensional model of interoceptive processing, where interoceptive sensitivity appears domain-specific, while acute affective responses show partial generalization across organ systems. The results caution against generalizing findings from single-organ paradigms to overall interoceptive functioning.