title: Estimates of segregation and overlap of functional connectivity networks in the human cerebral cortex.
abstract: The organization of the human cerebral cortex has recently been explored using techniques for parcellating the cortex into distinct functionally coupled networks. The divergent and convergent nature of cortico-cortical anatomic connections suggests the need to consider the possibility of regions belonging to multiple networks and hierarchies among networks. Here we applied the Latent Dirichlet Allocation (LDA) model and spatial independent component analysis (ICA) to solve for functionally coupled cerebral networks without assuming that cortical regions belong to a single network. Data analyzed included 1000 subjects from the Brain Genomics Superstruct Project (GSP) and 12 high quality individual subjects from the Human Connectome Project (HCP). The organization of the cerebral cortex was similar regardless of whether a winner-take-all approach or the more relaxed constraints of LDA (or ICA) were imposed. This suggests that large-scale networks may function as partially isolated modules. Several notable interactions among networks were uncovered by the LDA analysis. Many association regions belong to at least two networks, while somatomotor and early visual cortices are especially isolated. As examples of interaction, the precuneus, lateral temporal cortex, medial prefrontal cortex and posterior parietal cortex participate in multiple paralimbic networks that together comprise subsystems of the default network. In addition, regions at or near the frontal eye field and human lateral intraparietal area homologue participate in multiple hierarchically organized networks. These observations were replicated in both datasets and could be detected (and replicated) in individual subjects from the HCP.
authors.affiliation: Center for Cognitive Neuroscience, Duke-NUS Graduate Medical School, Singapore; Department of Electrical and Computer Engineering, National University of Singapore, Singapore.
authors.forename: B T Thomas
authors.initials: BT
authors.lastname: Yeo
authors.affiliation: Department of Psychology, Center for Brain Science, Harvard University, Cambridge, USA; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, USA.
authors.forename: Fenna M
authors.initials: FM
authors.lastname: Krienen
authors.affiliation: Center for Cognitive Neuroscience, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Michael W L
authors.initials: MW
authors.lastname: Chee
authors.affiliation: Department of Psychology, Center for Brain Science, Harvard University, Cambridge, USA; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, USA; Department of Psychiatry, Massachusetts General Hospital, Boston, USA.
authors.forename: Randy L
authors.initials: RL
authors.lastname: Buckner
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000502:physiology*; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult
keywords: Default network; Dorsal attention; Human Connectome Project; Intrinsic connectivity; MRI; Resting-state fMRI