A core organizing axis of the human cerebral cortex
Julia M. Huntenburg · Universitätsbibliothek der FU Berlin Hochschulschriftenstelle u. Dokumentenserver · 2018
Classical work in neuroanatomy suggests that the spatial arrangement of cortical areas in overarching gradients is a key organizational feature of the cerebral cortex. While studies performed in experimental animals provide strong evidence for spatial gradients in cortical microstructure and connectivity, similar research in humans has been obstructed by methodological challenges. In consequence, the significance of structural gradients for human cortical function remains unaddressed. The work presented in this dissertation capitalizes on recent advances in magnetic resonance imaging and novel analytic strategies to investigate spatial gradients in the human cerebral cortex in vivo. We first introduce a set of relevant tools and proceed to demonstrate a global gradient in cortical features that spans between sensorimotor and transmodal areas. This gradient is reflected in the distribution of intracortical myelin and captures the main axis of variance in functional connectivity patterns. It is spatially embedded in the intrinsic geometry of the cortex and tracks a functional spectrum of increasing abstraction. Finally, we propose that this gradient constitutes a core organizing axis of the human cerebral cortex, and describe an intrinsic cortical coordinate system on its basis. Studying the cortex with respect to its intrinsic dimensions can inform our understanding of how the spectrum of cortical function emerges from structural constraints.