Background: Interoceptive signals related to changes in heartbeat, respiration, and gastric functioning continuously feedback to the brain. The interpretation of these signals influences several cognitive, affective, and motoric functions. Previous research has highlighted the distinction between the ability to accurately detect interoceptive information (i.e., interoceptive accuracy) and an individual's beliefs about his or her interoceptive abilities (i.e., interoceptive sensibility). Although numerous studies have delineated the neural substrates of interoceptive accuracy, less is known about the brain areas involved with interoceptive sensibility. Materials and Methods: In the current study, 28 healthy participants completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), a self-report measure of interoceptive sensibility, before undergoing a 7-min resting-state functional magnetic resonance imaging scan. IRB ethics approval was obtained prior to data collection. Results: Overall MAIA scores, as well as scores on its eight subscales, were entered as covariates in subsequent region-of-interest and independent-component analyses. These analyses yielded three key results. First, interoceptive sensibility was negatively correlated with the functional connectivity of visual regions. Second, the cerebellar resting-state network showed positive correlations with two MAIA subscales, suggesting that this structure plays a role in interoceptive functions. Finally, the functional connectivity of the insula, a structure critical for interoceptive accuracy, was not correlated with any of the MAIA scores. Conclusion: These results demonstrate that the brain areas associated with individual differences in interoceptive sensibility show relatively little overlap with those involved with the accurate detection of interoceptive information. Impact statement The current research demonstrates that individual differences in interoceptive sensibility (i.e., self-reported sensitivity to interoceptive information) are related to differences in resting-state functional connectivity. These data also indicate that the brain areas related to interoceptive sensibility are different than the brain areas involved with interoceptive accuracy (i.e., the objective detection of interoceptive signals). This latter finding suggests that although the insula is critical for many interoceptive processes, our subjective beliefs about our interoceptive abilities involve other neural structures, particularly visual regions and the cerebellum.
Keywords: Multidimensional Assessment of Interoceptive Awareness; functional connectivity; interoception; interoceptive sensibility; resting-state fMRI.