ABSTRACT
Higher educational attainment and larger brain size generally have been viewed as protective factors that increase brain reserve and therefore delay the appearance of dementia symptoms in individuals with brain pathology. It is likely that brain reserve is a multifactorial concept, related to the number of neurons, the density of their interconnections, and the number and sophistication of cognitive strategies for solving problems (Mortimer, 1997). In this regard, larger brain size and higher educational attainment may be expected to act synergistically, with those possessing the combination of a large brain and an extensive education deriving the greatest benefit. We tested this hypothesis by examining the reduction in risk of prevalent dementia resulting from having a larger brain, a higher education, or both.
