Salience network connectivity in the insula is associated with individual differences in interoceptive accuracy

The insula and the anterior cingulate cortex are core brain regions that anchor the salience network, one of several large-scale intrinsic functional connectivity networks that have been derived consistently using resting-state functional magnetic resonance imaging (fMRI). While several studies have shown that the insula and anterior cingulate cortex play important roles in interoceptive awareness, no study to date has examined the association between intrinsic salience network connectivity and interoceptive awareness. In this study, we sought to test this idea in 26 healthy young participants who underwent a resting-state fMRI scan and a heartbeat counting task outside the scanner in the same session. Greater salience network connectivity in the posterior insula (but not the anterior cingulate cortex) using independent component analysis correlated with higher accuracy in the heartbeat counting task. Furthermore, using seed-based approach, greater interoceptive accuracy was associated with greater intrinsic connectivity of all insular functional subdivisions to salience network regions, including the anterior insula, orbitofrontal cortex, ventral striatum and midbrain. These associations remained after correcting for voxel-wise grey matter volumes. The findings underscore the critical role of insular salience network intrinsic connectivity in interoceptive awareness and pave the way for future investigations into how salience network dysconnectivity affects interoceptive awareness in brain disorders.