Building brains; What can we conclude about children's educational success by looking at their brain structure, cognitive abilities, and socioeconomic background?

Recognizing individual differences is essential for creating inclusive and effective educational settings that support all children's learning and school success and that are considerate of their varying needs. The primary aim of this work was to help uncover some of the influencing factors and underlying dynamics that affect children’s individual educational attainment. Through brain imaging and behavioral data from the large-scale, multisite Adolescent Cognitive Brain Development (ABCD) study, this thesis explores links between brain structure, socioeconomic variables, cognitive abilities, and success in school. In Study I, we investigated associations between T1w/T2w ratio as an index of cortical myelin and cognitive abilities. Despite using a large sample, we did not find any robust correlations between the two, confirming reservations against using this metric to study interindividual differences in behavior. Similarly, using voxel-based morphometry to study variations in language performance, resulted in a complex picture in Study II. We demonstrated replicable associations between language performance and regional grey matter in medial cortical regions and subcortical structures, including the right occipital fusiform and lingual cortex, the right amygdala, anterior parahippocampal gyrus, medial orbitofrontal cortex, and the temporal pole. However, factoring in additional covariates indicated that grey matter volume is not a suitable metric to reliably differentiate between typically developing children with varying language abilities. In Study III, we explored academic resilience by investigating whether children’s cognitive abilities affect the association between socioeconomic status (SES) and attainment in school. While not providing evidence for a safeguarding influence of cognitive performance, the results indicate a small but robust effect of SES on school performance across time and levels of cognitive ability. In the age of big data and continuing enthusiasm for magnetic resonance imaging (MRI) as a research tool in cognitive neuroscience, this work illustrates limitations of the two when it comes to explaining complex and often subtle behavioral differences.