Functional connectivity development along the sensorimotor-association axis enhances the cortical hierarchy.

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Human brain maturation is theorized to follow a hierarchical sensorimotor-association axis.
• This axis ranges from unimodal sensorimotor cortices to transmodal association cortices.

Purpose of the Study:

• To investigate if functional connectivity development during childhood and adolescence aligns with the sensorimotor-association cortical hierarchy.
• To test this hypothesis across multiple large-scale, independent neuroimaging datasets.

Main Methods:

• Utilized four large, independent datasets (total n=3355, ages 5-23 years).
• Included the Philadelphia Neurodevelopmental Cohort, Nathan Kline Institute-Rockland Sample, Human Connectome Project: Development, and Healthy Brain Network.
• Analyzed the development of functional connectivity across the sensorimotor-association axis.

Main Results:

• Functional connectivity development systematically varied along the sensorimotor-association axis across all datasets.
• Connectivity increased in sensorimotor regions.
• Connectivity decreased in association cortices, reinforcing the cortical hierarchy.

Conclusions:

• The sensorimotor-association axis represents a dominant organizational principle for functional connectivity development.
• Findings support and refine the hierarchical model of cortical organization during human development.