The respiratory occlusion discrimination task: A new paradigm to measure respiratory interoceptive accuracy

Interoception, or the sense of the internal state of the body, is hypothesized to be essential for a wide range of psychobiological processes and the development and perpetuation of several (mental) health problems. However, the study of interoceptive accuracy, the objectively measured capacity to detect or discriminate conscious bodily signals, has been hampered by the use of tasks with questionable construct validity and is often limited to studying interoception solely in the cardiac domain. We developed a novel task to measure interoceptive accuracy in the respiratory domain, the respiratory occlusion discrimination (ROD) task. In this task, interoceptive accuracy is defined as an individual's ability to detect small differences in lengths of short respiratory occlusions, assessed by means of an adaptive staircase procedure. This article describes a validation study (N = 97) aimed at investigating the internal consistency, test-retest reliability, and discriminant validity of the ROD task. The average just noticeable difference of lengths of respiratory occlusion was 74.22 ms, with large inter-individual variability (SD = 37.1 ms). The results of the validation study indicate acceptable internal consistency (Cronbach's alpha = 0.70), 1-week test-retest reliability (r = 0.53), and discriminant validity, as indicated by a lack of correlation between the ROD task and an auditory discrimination task with identical design (r = 0.18), and a weak correlation with breathing behavior (r = -0.27). The ROD task is a promising novel paradigm to study interoceptive accuracy and its role in various psychobiological processes and disorders.