Associations between education and brain structure at age 73 years, adjusted for age 11 IQ.
OBJECTIVE
To investigate how associations between education and brain structure in older age were affected by adjusting for IQ measured at age 11.


METHODS
We analyzed years of full-time education and measures from an MRI brain scan at age 73 in 617 community-dwelling adults born in 1936. In addition to average and vertex-wise cortical thickness, we measured total brain atrophy and white matter tract fractional anisotropy. Associations between brain structure and education were tested, covarying for sex and vascular health; a second model also covaried for age 11 IQ.


RESULTS
The significant relationship between education and average cortical thickness (β = 0.124, p = 0.004) was reduced by 23% when age 11 IQ was included (β = 0.096, p = 0.041). Initial associations between longer education and greater vertex-wise cortical thickness were significant in bilateral temporal, medial-frontal, parietal, sensory, and motor cortices. Accounting for childhood intelligence reduced the number of significant vertices by >90%; only bilateral anterior temporal associations remained. Neither education nor age 11 IQ was significantly associated with total brain atrophy or tract-averaged fractional anisotropy.


CONCLUSIONS
The association between years of education and brain structure ≈60 years later was restricted to cortical thickness in this sample; however, the previously reported associations between longer education and a thicker cortex are likely to be overestimates in terms of both magnitude and distribution. This finding has implications for understanding, and possibly ameliorating, life-course brain health.
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria. simon.cox@ed.ac.uk.
Simon R
SR
Cox
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
David Alexander
DA
Dickie
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Stuart J
SJ
Ritchie
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Sherif
S
Karama
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Alison
A
Pattie
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Natalie A
NA
Royle
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Janie
J
Corley
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Benjamin S
BS
Aribisala
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Maria
M
Valdés Hernández
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Susana
S
Muñoz Maniega
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
John M
JM
Starr
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Mark E
ME
Bastin
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Alan C
AC
Evans
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Joanna M
JM
Wardlaw
From the Centre for Cognitive Ageing and Cognitive Epidemiology (S.R.C., S.J.R., A.P., N.A.R., B.S.A., M.V.H., S.M.M., J.M.S., M.E.B., J.M.W., I.J.D.), Department of Psychology (S.R.C., S.J.R., A.P., J.C., I.J.D.), Brain Research Imaging Centre (D.A.D.,N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), Neuroimaging Sciences, Centre for Clinical Brain Sciences, and Alzheimer Scotland Dementia Research Centre (J.M.S.), University of Edinburgh; Scottish Imaging Network (S.R.C., D.A.D., N.A.R., B.S.A., M.V.H., S.M.M., M.E.B., J.M.W.), a Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK; Department of Neurology and Neurosurgery (S.K., A.C.E.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal; Department of Psychiatry (S.K.), Douglas Mental Health University Institute, McGill University, Verdun, Quebec, Canada; and Department of Computer Science (B.S.A.), Lagos State University, Lagos, Nigeria.
Ian J
IJ
Deary
D000368:Aged; D016880:Anisotropy; D001244:Association; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D057187:Independent Living; D008607:Intellectual Disability / Q000473:pathology*; D007360:Intelligence; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male
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