title: Regional Variations in Brain Gyrification Are Associated with General Cognitive Ability in Humans.
abstract: Searching for a neurobiological understanding of human intellectual capabilities has long occupied those very capabilities. Brain gyrification, or folding of the cortex, is as highly evolved and variable a characteristic in humans as is intelligence. Indeed, gyrification scales with brain size, and relationships between brain size and intelligence have been demonstrated in humans [1-3]. However, gyrification shows a large degree of variability that is independent from brain size [4-6], suggesting that the former may independently contribute to cognitive abilities and thus supporting a direct investigation of this parameter in the context of intelligence. Moreover, uncovering the regional pattern of such an association could offer insights into evolutionary and neural mechanisms. We tested for this brain-behavior relationship in two separate, independently collected, large cohorts-440 healthy adults and 662 healthy children-using high-resolution structural neuroimaging and comprehensive neuropsychometric batteries. In both samples, general cognitive ability was significantly associated (pFDR < 0.01) with increasing gyrification in a network of neocortical regions, including large portions of the prefrontal cortex, inferior parietal lobule, and temporoparietal junction, as well as the insula, cingulate cortex, and fusiform gyrus, a regional distribution that was nearly identical in both samples (Dice similarity coefficient = 0.80). This neuroanatomical pattern is consistent with an existing, well-known proposal, the Parieto-Frontal Integration Theory of intelligence [7], and is also consistent with research in comparative evolutionary biology showing rapid neocortical expansion of these regions in humans relative to other species. These data provide a framework for understanding the neurobiology of human cognitive abilities and suggest a potential neurocellular association.
authors.affiliation: Section on Integrative Neuroimaging, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: gregorymd@mail.nih.gov.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Gregory
authors.affiliation: Section on Integrative Neuroimaging, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: J Shane
authors.initials: JS
authors.lastname: Kippenhan
authors.affiliation: Psychosis and Cognitive Studies Section, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Dwight
authors.initials: D
authors.lastname: Dickinson
authors.affiliation: Section on Integrative Neuroimaging, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Carrasco
authors.affiliation: Lieber Institute for Brain Development, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Venkata S
authors.initials: VS
authors.lastname: Mattay
authors.affiliation: Lieber Institute for Brain Development, Baltimore, MD 21205, USA; Departments of Psychiatry and Neuroscience and the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Weinberger
authors.affiliation: Section on Integrative Neuroimaging, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA; Psychosis and Cognitive Studies Section, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: karen.berman@nih.gov.
authors.forename: Karen F
authors.initials: KF
authors.lastname: Berman
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D003071:Cognition; D005260:Female; D006801:Humans; D007206:Individuality; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D055815:Young Adult