Abstract
Alzheimer's disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed.
Original language | English |
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Pages (from-to) | 9-15 |
Number of pages | 7 |
Journal | Behavioural Brain Research |
Volume | 281 |
DOIs | |
State | Published - Mar 5 2015 |
Bibliographical note
Funding Information:I thank Dr. Fergus Craik for helpful comments on a previous version of this manuscript. I also gratefully acknowledge my valued colleagues at the Sanders-Brown Center on Aging and the Magnetic Resonance Imaging and Spectroscopy Center for their contributions to several studies described in this review. This work was supported in part by a grant from the National Institutes of Health Institute of Aging ( R01-AG033036 ). The content is solely the responsibility of the author and does not necessarily represent the official views of the NIH.
Publisher Copyright:
© 2014 Elsevier B.V.
Keywords
- Aging
- Alzheimer's disease
- Bilingualism
- Cognitive reserve
- Neural reserve
ASJC Scopus subject areas
- Behavioral Neuroscience