How does the brain's structure enable and constrain our cognitive abilities? Historically, cognitive neuroscience has focused on describing discrete, mutually exclusive modules or networks; however, current network-level descriptions of brain organization fail to account for integrated features of cognition. Building on recent work describing a principal gradient in cortical connectivity that reflects how activity from primary sensory/motor areas is integrated into transmodal regions of the default-mode network, we hypothesize that coherent aspects of cognition are an emergent property of a whole brain architecture consisting of multiple zones of integration. In particular, this project investigates the hypothesis that each region of transmodal cortex is the apex of a ‘zone’ of integration that is anchored by multiple unimodal cortical regions.
To investigate the mechanism that allows abstract representations to form in transmodal systems, we implement structural studies to investigate covariance in zone geometry across healthy adults, how zones have emerged through evolution and how they change across the lifespan. We then explore the functional consequence of zones of integration for higher-order human cognition. Studies address the ways in which individual differences in cognition emerge from variation in the architecture of different zones, and how brain activity is altered based on information that needs to converge across multiple zones. Finally, we examine how the absence of input from a sensory modality (through congenital deafness or blindness) alters the structure and function of transmodal regions in a zone-specific manner.
By describing how the spatial layout of the cortex shapes its functions, this research aims to provide a novel framework for understanding the structural constraints that underpin the integrated nature of human cognition.
