Structural-functional connectivity mapping of the insular cortex system: A combined data-driven and meta-analytic topic mapping approach

The insular cortex is an important anatomical integration hub and can serve as a suitable model for exploring structural-functional relationships. In this study, we examined structural and functional magnetic resonance correspondence via the diffusion tensor imaging (DTI) and resting-state functional connectivity (RSFC) profiles of the insular cortex and its mapping with functional networks (FNs) across the brain. We explored these associations primarily by using a data-driven method to independently estimate the structural-functional connectivity in the human insular cortex system. Data were obtained from the Human Connectome Project comprising 108 resting-state functional magnetic resonance neuroimaging (fMRI) and DTI. Brain networks were acquired and defined according to the seven Yeo FNs. In general, we observed moderate to high association between the structural and functional mapping results of three distinct insular subregions: the posterior insula (sensorimotor: RSFC, DTI = 50%, 72%, respectively), dorsal anterior insula (ventral attention: RSFC, DTI = 83%, 83%, respectively), and ventral anterior insula (frontoparietal: RSFC, DTI = 42%, 89%, respectively). We also examined the cognitive and behavioral domains associated with these three insular subregions using meta-analytic topic mapping and found cognitive and behavioral relations to affective processes, reflecting the core properties of the cytoarchitecture. In sum, given the core role of the insula in the human brain, our findings on the correspondence of the insular cortex system between DTI and RSFC mappings provide a novel approach and insight for clinical researchers to detect dysfunctional brain organization in various neurological disorders.