Cognitive Reserve in Healthy Aging and Alzheimer's Disease: A Meta-Analysis of fMRI Studies.

Cognitive reserve (CR) has been defined as the ability to optimize or maximize performance through differential recruitment of brain networks. In the present study, we aimed at providing evidence for a consistent brain network underpinning CR in healthy and pathological aging. To pursue this aim, we performed a coordinate-based meta-analysis of 17 functional magnetic resonance imaging studies on CR proxies in healthy aging, Alzheimer's disease (AD), and mild cognitive impairment (MCI). We found that different brain areas were associated with CR proxies in healthy and pathological aging. A wide network of areas, including medial and lateral frontal areas, that is, anterior cingulate cortex and dorsolateral prefrontal cortex, as well as precuneus, was associated with proxies of CR in healthy elderly patients. The CR proxies in patients with AD and amnesic-MCI were associated with activation in the anterior cingulate cortex. These results were discussed hypothesizing the existence of possible compensatory mechanisms in healthy and pathological aging.