Neural Correlates of Cognitive Reserve Based on EEG Signals: A Systematic Review

• Published in: Psychology & Neuroscience 2023-12, Vol.16 (4), p.317-338
• Main Authors: Pereira da Silva, Sayonara, da Silva-Sauer, Leandro, Karoline Gonçalves da Fonsêca, Égina, Basso Garcia, Ricardo, Fernández-Calvo, Bernardino
• Format: Article
• Language: English
• Subjects: Biological Markers; Cognitive Reserve; Electroencephalography; Evoked Potentials; Human; Physiological Correlates
• ISSN: 1984-3054; 1983-3288
• DOI: 10.1037/pne0000327

Background: Cognitive reserve (CR) is a construct for explaining cognitive and functional differences among individuals with similar levels of brain aging or pathology. Objective: We systematically reviewed studies that investigated the neural basis of CR by analyzing electrophysiological signals (EEG), as frequency bands and event-related potentials (ERP) to analyze whether CR would have any effect on the EEG. Method: Study protocol was registered in PROSPERO (CRD42020186722). The search was conducted on Pubmed/Medline, Scopus, and IEEE Xplore databases with combinations of the following terms in titles, abstracts, and keywords: "event-related potential," "evoked potential," "ERP," "electroencephalography," "brain rhythms," and "cognitive reserve." Results: We found 1,390 articles, 15 of which met the inclusion criteria. Information regarding sample characteristics, EEG equipment, and methods (channels, potentials, and tasks), CR proxies, studies main objectives, and results summary were systematized. Overall, 13 studies showed that higher CR levels were related to greater synchronization in frequency bands or to large amplitudes and faster latencies in ERPs. Conclusion: Even considering the great disparity between methods and samples of the analyzed studies, the results suggest that CR is related to the EEG. We discussed the evidence that CR may influence EEG signals and may be considered a promising technique to provide physiological biomarkers to estimate CR. Further implications regard the potential confounding effects of CR on studies of biomarkers or neural correlates of dementia or other brain pathology. Public Significance Statement This study proposes an up-to-date review of brain biomarkers of cognitive reserve, a rapidly growing research topic in the field of cognitive neuroscience. This is relevant because cognitive reserve, if not controlled, may be a confounding factor in studies aimed at identifying brain biomarkers or neural correlates of dementia or other brain pathologies. Here, we summarized the characteristics of cognitive reserve biomarkers that should be considered in electroencephalographic (EEG) studies.