title: Reversed hierarchy in the brain for general and specific cognitive abilities: a morphometric analysis.
abstract: Intelligence is composed of a set of cognitive abilities hierarchically organized. General and specific abilities capture distinguishable, but related, facets of the intelligence construct. Here, we analyze gray matter with three morphometric indices (volume, cortical surface area, and cortical thickness) at three levels of the intelligence hierarchy (tests, first-order factors, and a higher-order general factor, g). A group of one hundred and four healthy young adults completed a cognitive battery and underwent high-resolution structural MRI. Latent scores were computed for the intelligence factors and tests were also analyzed. The key finding reveals substantial variability in gray matter correlates at the test level, which is substantially reduced for the first-order and the higher-order factors. This supports a reversed hierarchy in the brain with respect to cognitive abilities at different psychometric levels: the greater the generality, the smaller the number of relevant gray matter clusters accounting for individual differences in intelligent performance.
authors.affiliation: Facultad de Psicología, Universidad Autónoma de Madrid, 28049, Madrid, Spain; Fundación CIEN - Fundación Reina Sofía, 28031, Madrid, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Román
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Abad
authors.forename: Sergio
authors.initials: S
authors.lastname: Escorial
authors.forename: Miguel
authors.initials: M
authors.lastname: Burgaleta
authors.forename: Kenia
authors.initials: K
authors.lastname: Martínez
authors.forename: Juan
authors.initials: J
authors.lastname: Álvarez-Linera
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Quiroga
authors.forename: Sherif
authors.initials: S
authors.lastname: Karama
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Haier
authors.forename: Roberto
authors.initials: R
authors.lastname: Colom
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D003071:Cognition; D005163:Factor Analysis, Statistical; D005260:Female; D066128:Gray Matter / Q000033:anatomy & histology*; D006801:Humans; D007206:Individuality; D007360:Intelligence; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008960:Models, Psychological; D009483:Neuropsychological Tests; D009929:Organ Size; D011594:Psychometrics; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: Voxel-based Morphometry (VBM); cortical surface area; cortical thickness; intelligence; surface-based morphometry