Effect of Interoception on Intra- and Inter-Network Connectivity of Human Brain - An Independent Component Analysis of fMRI Data

Most stimuli in the viscera do not reach conscious perception, although they may activate some cortical structures. However, recent evidences suggest that various forms of subliminal interoceptive inputs may influence brain function. In this study, we used spatial independent component analysis (ICA) as a multivariate method to investigate the effect of interoception on the intra- and inter-network connectivity of the human brain. 15 healthy participants were scanned during the resting-state and a visceral stimulation task. Following a recently suggested ICA framework, we applied a high model order ICA of 75 to the fMRI data, and identified 34 components as non-artifactual intrinsic connectivity networks (ICNs). Results demonstrate significant intra-network connectivity difference within the salience network (SN) and the default mode network (p < 0.05, family-wise error corrected). Significant inter-network connectivity differences were also found for several ICN pairs, most notably between the SN and the frontoparietal central executive network, and between the SN and the limbic association network (p < 0.05, false discovery rate corrected for multiple comparisons). Taken together, these observations suggest significant effect of interoception on the network connectivity architecture of the human brain especially involving the SN when compared to the resting-state baseline.