A subset of brain regions within adult functional connectivity networks demonstrate high reliability across early development

The human cerebral cortex contains groups of areas that support sensory, motor, cognitive, and affective functions, often categorized as functional networks. These areas show stronger internal and weaker external functional connectivity (FC) and exhibit similar FC profiles within rather than between networks. Previous studies have demonstrated the development of these networks from nascent forms present before birth to their mature, adult-like topography in childhood. However, analyses often still use definitions based on adult functional networks. We aim to assess how this might lead to the misidentification of functional networks and explore potential consequences and solutions.

Our findings suggest that even though adult networks provide only a marginally better than-chance description of the infant FC organization, misidentification was largely driven by specific areas. By restricting functional networks to areas showing adult-like network clustering, we observed consistent within-network FC both within and across scans and throughout development. Additionally, these areas were spatially closer to locations with low variability in network identity among adults. Our analysis aids in understanding the potential consequences of using adult networks “as is” and provides guidance for future research on selecting and utilizing functional network models based on the research question and scenario.

Highlights

• Specialized functional networks in the human cerebral cortex, evident in resting-state fMRI, support sensory, motor, cognitive, and affective functions and evolve throughout the lifespan.

• Existing studies have focused on age-specific networks for infants, but less on to what extent adult networks can describe infant functional connectivity (FC).

• Analysis revealed a subset of areas in infants showing adult-like network organization, with within-network FC exhibiting less variation across age and higher reliability across scans.

• These areas are posited near locations with low variability in functional network identity in adults, suggestive of the relationship between developmental sequence and interindividual variability in functional network organization.