Cognitive ability changes and dynamics of cortical thickness development in healthy children and adolescents

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2014-01, Vol.84, p.810-819
• Main Authors: Burgaleta, Miguel, Johnson, Wendy, Waber, Deborah P., Colom, Roberto, Karama, Sherif
• Format: Article
• Language: English
• Subjects: Adolescence; Adolescent; Age; Biological and medical sciences; Brain development; Brain plasticity; Brain research; Cerebral Cortex - anatomy & histology; Child; Cognition; Cognition & reasoning; Cognitive ability; Cortical thickness; Female; Fundamental and applied biological sciences. Psychology; Humans; Image Processing, Computer-Assisted; Intelligence; Magnetic Resonance Imaging; Male; Mental health; Performance IQ; Quality control; Studies; Teenagers; Verbal IQ; Vertebrates: nervous system and sense organs
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2013.09.038

Intelligence quotient (IQ) scores tend to remain stable across the lifespan. Nevertheless, in some healthy individuals, significant decreases or increases in IQ have been observed over time. It is unclear whether such changes reflect true functional change or merely measurement error. Here, we applied surface-based corticometry to investigate vertex-wise cortical surface area and thickness correlates of changes in Full Scale IQ (FSIQ), Performance IQ (PIQ) and Verbal IQ (VIQ) in a representative sample of children and adolescents (n=188, mean age=11.59years) assessed two years apart as part of the NIH Study of Normal Brain Development. No significant associations between changes in IQ measures and changes in cortical surface area were observed, whereas changes in FSIQ, PIQ, and VIQ were related to rates of cortical thinning, mainly in left frontal areas. Participants who showed reliable gains in FSIQ showed no significant changes in cortical thickness on average, whereas those who exhibited no significant FSIQ change showed moderate declines in cortical thickness. Importantly, individuals who showed large decreases in FSIQ displayed the steepest and most significant reductions in cortical thickness. Results support the view that there can be meaningful cognitive ability changes that impact IQ within relatively short developmental periods and show that such changes are associated with the dynamics of cortical thickness development. •Intelligence quotient (IQ) scores tend to remain stable across the lifespan.•Despite high stability, some individuals display strong longitudinal changes in IQ.•These have been frequently interpreted as measurement error.•Here, changes in IQ were associated with local rates of cortical thinning.•Some IQ changes are therefore genuine and have a neuroanatomical substrate.