Flatmap_Template

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Harvard_Precision_Neuroimaging_Group.scene

FULL TITLE:
Organization of the Human Cerebral Cortex Estimated Within Individuals: Networks, Global Topography, and Function

SPECIES:
Human

DESCRIPTION:
Network parcellation, temporal signal-to-noise ratio (tSNR), and task contrast maps (in relation to network borders) for participants P1-P15 are made available here. Lateral and medial views of the left hemisphere are shown on an inflated and flattened cortical surface. Data on the right hemisphere can be visualized by opening the scenes. Figures were originally created using Connectome Workbench v1.3.2 and are compatible with v1.5.0. More information about each contrast map can be found in the README file uploaded on Harvard Dataverse (https://doi.org/10.7910/DVN/AVB4BW), along with detailed descriptions, code, and stimuli for each task.

ABSTRACT:
The cerebral cortex is populated by specialized regions that are organized into networks. Here we estimated networks from functional MRI (fMRI) data in intensively sampled participants. The procedure was developed in two participants (scanned 31 times) and then prospectively applied to 15 participants (scanned 8-11 times). Analysis of the networks revealed a global organization. Locally organized first-order sensory and motor networks were surrounded by spatially adjacent second-order networks that linked to distant regions. Third-order networks possessed regions distributed widely throughout association cortex. Regions of distinct third-order networks displayed side-by-side juxtapositions with a pattern that repeated across multiple cortical zones. We refer to these as Supra-Areal Association Megaclusters (SAAMs). Within each SAAM, two candidate control regions were adjacent to three separate domain-specialized regions. Response properties were explored with task data. The somatomotor and visual networks responded to body movements and visual stimulation, respectively. Second-order networks responded to transients in an oddball detection task, consistent with a role in orienting to salient events. The third-order networks, including distinct regions within each SAAM, showed two levels of functional specialization. Regions linked to candidate control networks responded to working memory load across multiple stimulus domains. The remaining regions dissociated across language, social, and spatial / episodic processing domains. These results suggest progressively higher-order networks nest outwards from primary sensory and motor cortices. Within the apex zones of association cortex, there is specialization that repeatedly divides domain-flexible from domain-specialized regions. We discuss implications of these findings including how repeating organizational motifs may emerge during development.

PUBLICATION:
Journal of Neurophysiology - DOI: 10.1152/jn.00308.2023