Revue de neuropsychologie


Individual variability in episodic memory functioning in normal and pathological aging: the role of cognitive reserve Volume 5, issue 4, Octobre-Novembre-Décembre 2013


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Université de Liège, centre de recherches du Cyclotron, allée du 6 août, B30, 4000 Liège, Belgique, Université de Liège, département psychologie, cognition et comportement, Belgique, CHU Liège, clinique de la mémoire, Belgique

Cognitive reserve refers to the moderating effect of some person-specific variables that attenuate or delay the clinical manifestations of age- or pathology-related brain changes. This notion can at least partly explain the large heterogeneity in memory performance and cognitive decline observed in old age. So, individuals with high cognitive reserve would maintain a good cognitive functioning for longer than people with low cognitive reserve. Several neuroimaging studies examining the role of cognitive reserve on memory-related cerebral activations in older participants have shown that individuals with high cognitive reserve need less cerebral activation to reach equivalent level of performance (neural efficiency), have a greater brain capacity to respond to increasing task demands, and can implement alternative neurocognitive mechanisms (compensation). There is also evidence of better functional connectivity at rest in the brain of older adults with high cognitive reserve. However, it is still unclear when these different cerebral instantiations of reserve come into play and whether they interact. The most widely used method to characterize cognitive reserve is to quantify the individual's characteristics that were found to protect against the negative effect of aging and pathology. Those proxy measures include education, occupational attainment, intellectual ability, and leisure activities. These variables, which very likely interact, would contribute to build a reserve throughout the life. An alternative measurement method, based on the statistical decomposition of the variance of a specific cognitive function, aims at capturing the discrepancy between brain changes and their clinical consequences. Although the concept is theoretically and methodologically complex, there is a great interest in understanding the mechanisms underlying cognitive reserve as this can lead to interventions to slow cognitive aging or reduce the risk of dementia.