Figure 4. Dysfunctional connectivity and aberrant structural covariation across networks.

Depicts the significant increase (red lines) or decrease (blue lines) in functional connectivity (A) or in structural co-occurrence (B) comparing schizophrenic to healthy subjects in the across-network RSFC analyses (cf. SFig. 1). Circles represent regions of interest in the default mode network (DMN, orange), the “DMN proper” (yellow), the saliency network (SN, purple) and the dorsal attention network (DAN, light green). The left column shows the differences within each network, while the right column displays differences between two networks. The connectivity findings show that the dysfunctional connectivities within the DMN include several subnodes that are not part of the “DMN proper”. While the functional coupling between the DMN and the SN is partly disrupted, the functional connectivity between the DMN and the DAN is particularly disturbed. Furthermore, the connectivities within and between the SN and the DAN remain largely intact. The covariance findings show that the deviant structural covariations within the DMN involve several subnodes not part of the “DMN proper”. The volumetric relationships between the DMN and the SN are also more disrupted than between any other network pair. Collectively, the findings emphasize inter-network dysregulation rather than exclusive disturbance of the DMN core parts. Flat brains were generated using PyCortex (Gao et al., 2015).