title: Differential age-related gray and white matter impact mediates educational influence on elders' cognition.
abstract: High education, as a proxy of cognitive reserve (CR), has been associated with cognitive advantage amongst old adults and may operate through neuroprotective and/or compensation mechanisms. In neuromaging studies, indirect evidences of neuroprotection can be inferred from positive relationships between CR and brain integrity measures. In contrast, compensation allows high CR elders to sustain greater brain damage. We included 100 cognitively normal old-adults and investigated the associations and interactions between education, speed of processing (SP), memory and two brain integrity measures: cortical thickness (CTh) of gray matter (GM) and fractional anisotropy (FA) in the white matter (WM). High education was associated with better cognitive performance, enlarged CTh in frontal lobe areas and reduced measures of FA in several areas. Better SP performance in higher educated subjects was related to more preserved GM and WM, while memory status amongst high educated elders was better explained by a putative compensatory mechanism and independently from cerebrovascular risk indicators. Moreover, we analyzed the direct effect of age on measures of brain integrity and found a stronger negative effect on WM than in CTh, which was accentuated amongst the high CR sample. Our study suggests that the cognitive advantage associated to high education among healthy aging is related to the coexistence of both neuroprotective and compensatory mechanisms. In particular, high educated elders seem to have greater capacity to counteract a more abrupt age impact on WM integrity.
authors.affiliation: Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, C/ Casanova 143, 08036, Barcelona, Spain.|Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: Lídia
authors.initials: L
authors.lastname: Vaqué-Alcázar
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Oslo, Norway.
authors.forename: Roser
authors.initials: R
authors.lastname: Sala-Llonch
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.|Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y nutrición (CIBEROBN), Insituto de Salud Carlos III, Madrid, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Valls-Pedret
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Oslo, Norway.
authors.forename: Dídac
authors.initials: D
authors.lastname: Vidal-Piñeiro
authors.affiliation: Department of Psychology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.|Center for Neurocognitive Research, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Sara
authors.initials: S
authors.lastname: Fernández-Cabello
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.|Neuroradiology Section, Radiology Service, Centre de Diagnòstic per la Imatge, Hospital Clínic, Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Bargalló
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.|Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y nutrición (CIBEROBN), Insituto de Salud Carlos III, Madrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ros
authors.affiliation: Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, C/ Casanova 143, 08036, Barcelona, Spain. dbartres@ub.edu.|Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. dbartres@ub.edu.|Institute of Neurosciences, University of Barcelona, Barcelona, Spain. dbartres@ub.edu.
authors.forename: David
authors.initials: D
authors.lastname: Bartrés-Faz
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004522:Educational Status; D005260:Female; D066128:Gray Matter / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012016:Reference Values; D066127:White Matter / Q000033:anatomy & histology* / Q000502:physiology
keywords: Aging; Cognitive reserve; Compensation; Education; Memory; Neuroprotection; Speed of processing; Structural changes