Heritability and cross-species comparisons of human cortical functional organization asymmetry.
The human cerebral cortex is symmetrically organized along large-scale axes but also presents inter-hemispheric differences in structure and function. The quantified contralateral homologous difference, that is asymmetry, is a key feature of the human brain left-right axis supporting functional processes, such as language. Here, we assessed whether the asymmetry of cortical functional organization is heritable and phylogenetically conserved between humans and macaques. Our findings indicate asymmetric organization along an axis describing a functional trajectory from perceptual/action to abstract cognition. Whereas language network showed leftward asymmetric organization, frontoparietal network showed rightward asymmetric organization in humans. These asymmetries were heritable in humans and showed a similar spatial distribution with macaques, in the case of intra-hemispheric asymmetry of functional hierarchy. This suggests (phylo)genetic conservation. However, both language and frontoparietal networks showed a qualitatively larger asymmetry in humans relative to macaques. Overall, our findings suggest a genetic basis for asymmetry in intrinsic functional organization, linked to higher order cognitive functions uniquely developed in humans.
Funder: Max-Planck-Gesellschaft; FundRef: http://dx.doi.org/10.13039/501100004189
Funder: Azrieli Center for Autism Research
Funder: Canada First Research Excellence Fund; FundRef: http://dx.doi.org/10.13039/501100010785
Funder: International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity
Natural Sciences and Engineering Research Council of Canada (Discovery-1304413)
Canadian Institutes of Health Research (FDN154298)