Structural and Cognitive Measures Across Childhood, Adolescence, and Adulthood: Associations with Education and Brain Morphometry

Background: The organization of the human brain shows key characteristics through its cortical thickness and brain volume distribution across different regions, and the way both brain hemispheres display their distinct functions. However, age-stratified neuroimaging data that jointly consider structural asymmetry, education, and cognition within a single population remain limited, especially for South Asian groups.
Methods: The study involved 200 neurologically healthy people from South India who ranged in age from 3 to 90 years. The researchers divided participants into five distinct age groups, which included childhood, adolescence, early adulthood, mid-adulthood, and late adulthood. The research team used a 3.0 Tesla scanner to capture high-resolution T1-weighted MRI scans, which FreeSurfer (v7.3.2) software used to calculate regional cortical thickness and volumetric measures for predefined cortical regions. The researchers measured hemispheric asymmetry through a standardized laterality index. The researchers used the Montreal Cognitive Assessment (MoCA) to measure cognitive performance. The researchers conducted statistical analyses through paired-sample t-tests, which compared hemispheric differences and used Pearson correlation analyses and general linear models that included age, sex, and years of education as covariates.
Results: Across all age groups, significant hemispheric asymmetry was observed in the examined cortical regions (p < 0.001). The frontal regions showed permanent leftward volumetric asymmetry, which reached its peak in the rostral anterior cingulate cortex (laterality index = 0.252), inferior frontal gyrus (0.065), and superior frontal gyrus (0.029). The posterior regions exhibited rightward volumetric asymmetry, which reached its peak in the inferior parietal lobule (−0.143) and middle temporal gyrus (−0.089) areas. The researchers found that cortical thickness showed asymmetry, which reached statistical significance, although it produced smaller results than volumetric asymmetry. Age-group comparisons revealed relative stability of regional volumes and cortical thickness across developmental and adult stages. The researchers found that years of education, together with MoCA scores, produced positive effects on cortical thickness and volume in frontal, parietal, and temporal regions.
Conclusions: The age-stratified study shows that regional hemispheric asymmetry remains consistent throughout childhood, adolescence, and adulthood. The study found that volumetric measurements showed stronger lateralization than cortical thickness measurements. The research results show how educational background and cognitive abilities impact brain structure through their effects on cortical development. The research results establish normative reference data for South Indian populations based on age group measurements of cortical asymmetry and morphometric data.