Individual Variability in the Innate Functional Organization of the Human Brain

Abstract

The adult brain is organized into distinct functional networks, forming the basis of information processing and determining individual differences in behavior. Is this network organization genetically determined and present at birth? Here, we use unsupervised learning to uncover intrinsic functional brain organization using resting-state connectivity from a large cohort of neonates (Developing Human Connectome Project). We identified a set of symmetric, hierarchical, and replicable networks: sensorimotor, visual, default mode, ventral attention, and high-level vision. We also quantified neonate individual variability, finding low variability for sensorimotor, but high for ventral attention networks. These neonate networks resembled adult networks (Yeo et al., 2011), but frontoparietal and limbic networks found in adults were indiscernible in neonates. Finally, differential gene expression provided a potential explanation for the emergence of these distinct networks. Our results reveal the basic proto-organization of cortex at birth, but indicate a role for maturation and experience in developing adult-like functional brain organization.

The Role of Visual Experience in Individual Differences of Brain Connectivity

“…A lack of a shared experience may lead to increased interindividual variability in the blind as (likely already variable) nondominant inputs may be strengthened by small environmental experiences, genetic predispositions, or random noise. This would lead to strengthening individual connectivity variance present already in neonates ( Molloy and Saygin, 2021 ) and driving different individuals to strengthening connectivity with different systems.…”

Generalization and Idiosyncrasy: Two Sides of the Same Brain

“…A lack of the shared (visual) experience to constrain connectivity may lead to increased variability in the blind population. Indeed, individual variability in brain connectivity in newborns is greater than in adults (Molloy and Saygin, 2021). Therefore, the lack of a common visual experience could play a crucial role in maintaining and even increasing the amount of variability in the connectivity profile of V1 among blind individuals.…”