Associations between education and brain structure at age 73 years, adjusted for age 11 IQ

Neurology. 2016 Oct 25;87(17):1820-1826. doi: 10.1212/WNL.0000000000003247. Epub 2016 Sep 24.


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.

MeSH terms

  • Aged
  • Anisotropy
  • Association*
  • Atrophy / pathology
  • Brain / diagnostic imaging
  • Brain / pathology*
  • Cohort Studies
  • Educational Status*
  • Female
  • Humans
  • Independent Living
  • Intellectual Disability / pathology*
  • Intelligence
  • Intelligence Tests
  • Magnetic Resonance Imaging
  • Male