Operationalisation of interoceptive expectations: A novel paradigm to measure detection and Adjustment to Interoceptive Discrepancy

Interoception is a bidirectional process, with both descending predictions and ascending sensation playing a role in the regulation and perception of homeostatic states. Mistuning of both streams has been associated with psychopathology in mental disorders, including hyperprecise prior beliefs and altered sensory representations. However, empirical research has typically focused on associations between self-report scales and objective physiology during rest or bodily perturbations, without manipulating or measuring descending. Therefore, we developed the novel Adjustment to Interoceptive Discrepancy (AID) paradigm, that builds and then violates interoceptive beliefs to measure expectations and adjustment of expectations over subsequent trials following an unexpected stimulus. We validated this paradigm in the nociceptive domain in a total of 57 university-aged participants. The AID paradigm successfully induced interoceptive discrepancy (i.e., a difference between expectation and perception ratings) that was resolved as participants adjusted expectations appropriately across subsequent trials. This adjustment was more rapid for stimuli that were perceived as more versus less intense than expected. Notably, there were individual differences in the pattern of this adjustment, revealing different strategies in how individuals adjust to unexpected interoceptive sensations, although these were unrelated to interoceptive sensibility scores. Overall, the AID paradigm provides a useful method to assess interoception across expected versus unexpected stimuli, to probe interindividual differences of interoceptive predictions, and ultimately to enable research on the bidirectional processing of internal stimuli in mental health.