Journal Article

Is bigger always better? The importance of cortical configuration with respect to cognitive ability

Vuoksimaa, Eero, Franz, Carol E., Neale, Michael C., Rinker, Daniel A., Thompson, Wesley K., Kremen, William S., Lyons, Michael J., Eyler, Lisa T., Panizzon, Matthew S., Chen, Chi-Hua, Fiecas, Mark, Jak, Amy J., Dale, Anders M., Tsuang, Ming T., Fennema-Notestine, Christine, Hagler, Donald J.

2016

Overview

General cognitive ability (GCA) has substantial explanatory power for behavioral and health outcomes, but its cortical substrate is still not fully established. GCA is highly polygenic and research to date strongly suggests that its cortical substrate is highly polyregional. We show in map-based and region-of-interest-based analyses of adult twins that a complex cortical configuration underlies GCA. Having relatively greater surface area in evolutionary and developmentally high-expanded prefrontal, lateral temporal, and inferior parietal regions is positively correlated with GCA, whereas relatively greater surface area in low-expanded occipital, medial temporal, and motor cortices is negatively correlated with GCA. Essentially the opposite pattern holds for relative cortical thickness. The phenotypic positive-to-negative gradients in our cortical-GCA association maps were largely driven by a similar pattern of genetic associations. The patterns are consistent with regional cortical stretching whereby relatively greater surface area is related to relatively thinner cortex in high-expanded regions. Thus, the typical “bigger is better” view does not adequately capture cortical-GCA associations. Rather, cognitive ability is influenced by complex configurations of cortical development patterns that are strongly influenced by genetic factors. Optimal cognitive ability appears to be driven both by the absolute size and the polyregional configuration of the entire cortex rather than by small, circumscribed regions. •Cortical surface area (SA)/thickness (CT)-cognition associations are positive.•Scaling for total SA and mean CT yields a different pattern.•Genetically driven gradients of positive-to-negative associations are observed.•SA gradients parallel to high/low-expanding regions in evolution/human development•CT gradients are largely orthogonal to SA gradients.

• Publisher: Elsevier Inc,Elsevier Limited
• Subject: Animal cognition / Behavior / Brain Mapping / Brain research / Cerebral Cortex - anatomy & histology / Cognition - physiology / Cognitive ability / Confidence intervals / Cortical surface area / Cortical thickness / General cognitive ability / Humans / Image Processing, Computer-Assisted / Intelligence - genetics / Magnetic Resonance Imaging / Male / Middle Aged / Neurodevelopment / Studies / Twin research / Twins