PT  - JOURNAL ARTICLE
AU  - John D. Lewis
AU  - Vladimir S. Fonov
AU  - D. Louis Collins
AU  - Alan C. Evans
AU  - Jussi Tohka
AU  - for the Brain Development Cooperative Group, and the Pediatric Imaging, Neurocognition, and Genetics Study
TI  - Cortical and subcortical T1 white/gray contrast, chronological age, and cognitive performance
AID  - 10.1101/537043
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 537043
4099  - http://biorxiv.org/content/early/2019/01/31/537043.short
4100  - http://biorxiv.org/content/early/2019/01/31/537043.full
AB  - The maturational schedule of typical brain development is tightly constrained; deviations from it are associated with cognitive atypicalities, and are potentially predictive of developmental disorders. Previously, we have shown that the white/gray contrast at the inner border of the cortex is a good predictor of chronological age, and is sensitive to aspects of brain development that reflect cognitive performance. Here we extend that work to include the contrast at the white/gray border of subcortical structures. We show that cortical and subcortical contrast together yield better age-predictions than any non-kernel-based method based on a single image-type, and that the residuals of the improved predictions provide new insight into unevenness in cognitive performance. We demonstrate the improvement in age predictions in two large datasets: the NIH Pediatric Data, with 831 scans of typically developing individuals between 4 and 22 years of age; and the Pediatric Imaging, Neurocognition, and Genetics data, with 909 scans of individuals in a similar age-range. Assessment of the relation of the residuals of these age predictions to verbal and performance IQ revealed correlations in opposing directions, and a principal component analysis of the residuals of the model that best fit the contrast data produced components related to either performance IQ or verbal IQ. Performance IQ was associated with the first principle component, reflecting increased cortical contrast, broadly, with almost no subcortical presence; verbal IQ was associated with the second principle component, reflecting reduced contrast in the basal ganglia and increased contrast in the bilateral arcuate fasciculi.