title: The functional connectome of cognitive reserve.
abstract: Cognitive Reserve (CR) designates the brain's capacity to actively cope with insults through a more efficient use of its resources/networks. It was proposed in order to explain the discrepancies between the observed cognitive ability and the expected capacity for an individual. Typical proxies of CR include education and Intelligence Quotient but none totally account for the variability of CR and no study has shown if the brain's greater efficiency associated with CR can be measured. We used a validated model to estimate CR from the residual variance in memory and general executive functioning, accounting for both brain anatomical (i.e., gray matter and white matter signal abnormalities volume) and demographic variables (i.e., years of formal education and sex). Functional connectivity (FC) networks and topological properties were explored for associations with CR. Demographic characteristics, mainly accounted by years of formal education, were associated with higher FC, clustering, local efficiency and strength in parietal and occipital regions and greater network transitivity. Higher CR was associated with a greater FC, local efficiency and clustering of occipital regions, strength and centrality of the inferior temporal gyrus and higher global efficiency. Altogether, these findings suggest that education may facilitate the brain's ability to form segregated functional groups, reinforcing the view that higher education level triggers more specialized use of neural processing. Additionally, this study demonstrated for the first time that CR is associated with more efficient processing of information in the human brain and reinforces the existence of a fine balance between segregation and integration. Hum Brain Mapp 37:3310-3322, 2016.. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Marques
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Moreira
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Magalhães
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Patrício
authors.initials: P
authors.lastname: Costa
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Nadine
authors.initials: N
authors.lastname: Santos
authors.affiliation: Department of Psychology, LMU University of Munich, Munich, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Zihl
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: José
authors.initials: J
authors.lastname: Soares
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center, Braga, Braga, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Sousa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D058245:Cognitive Reserve / Q000502:physiology*; D063132:Connectome; D004522:Educational Status; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*
keywords: brain reserve; cognitive reserve; connectome