Nature or nurture

What factors can mitigate the decline of memory and cognitive function with advancing age, or reduce the chance of developing Alzheimer disease (AD)? Besides “choosing one’s parents wisely”—or settling for a short happy life—a number of experiences that may decrease the rate of cognitive decline have been evaluated, especially education and mental activities. Does more extensive exercise of the mind alter the course of changes in cognitive function, brain structure, neurodegenerative changes, or the risk of AD with advancing age? To what extent is the rate of decline fixed in our genes, or modified by our experiences? How closely is cognitive function in the elderly linked to the structural and neuropathologic appearance of the brain (the “hardware”), or to a lifetime of learning and experience (the “software”)?

In this issue of Neurology®, Koepsell et al.¹ report examining a large, multicenter clinical and neuropathologic database of patients with AD, to evaluate the degree to which higher education may modulate the severity of cognitive impairment produced by increasing severity of AD neuropathology. The authors tested the conflicting proposals that, as the neuropathologic changes of AD increase in severity,^2–4 the difference in cognitive function (measured by the Mini-Mental State Examination [MMSE]) between patients with higher and lower education would …