Electroencephalography, Magnetoencephalography, and Cognitive Reserve: A Systematic Review

Area of Science:

• Neuroscience
• Cognitive Psychology
• Biomedical Engineering

Background:

• Cognitive reserve (CR) represents the brain's capacity to withstand neuropathology with minimal clinical symptoms, yet its underlying neuroplastic mechanisms are not fully understood.
• Techniques like electroencephalography (EEG) and magnetoencephalography (MEG) offer potential insights into how the brain efficiently utilizes resources, which is theorized to be central to CR.

Purpose of the Study:

• To systematically review and synthesize existing research on the neural correlates of cognitive reserve (CR) estimates.
• To evaluate findings from electroencephalography (EEG) and magnetoencephalography (MEG) studies investigating the relationship between brain activity and CR.

Main Methods:

• A systematic review of cross-sectional studies published since the first standardized definition of CR.
• Inclusion criteria focused on original research using (M)EEG in humans with validated CR estimates; 11 EEG and 5 MEG studies met criteria.
• Quality assessment was performed using an adapted Newcastle-Ottawa scale; no electrocorticography (ECOG) studies were included.

Main Results:

• The review encompassed 1383 participants across heterogeneous groups (patients, young and older healthy individuals).
• Studies employed various (M)EEG methodologies, including event-related potentials/fields, resting-state oscillations, and brain connectivity analyses.
• Several associations were observed between different (M)EEG measures and various CR estimates across the included studies.

Conclusions:

• Findings suggest that (M)EEG measures are indeed related to cognitive reserve (CR) estimates, especially in healthy populations.
• The specific nature of the (M)EEG-CR relationship is influenced by the studied population and cognitive tasks.
• Further research is warranted to fully elucidate these complex associations across different contexts.