EEG biomarkers distinguish good and poor learners

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Benjamin Falkenburg¹ (benfalken@g.ucla.edu), Michael Kahana; ¹University of Pennsylvania

Background/Objective: Individual differences in learning ability – particularly episodic memory – are well-documented, yet the neural mechanisms underlying these differences remain unclear. Electroencephalographic (EEG) biomarkers have been shown to differentiate successful from unsuccessful encoding events within individuals; this study aims to determine whether EEG spectral patterns can reliably distinguish high and low recall performers, thereby advancing cognitive assessments with neural biomarkers. Design: We analyzed data from three independent studies involving over 1,000 subjects and 5,000 hours of memory testing. Subjects completed word-list learning tasks with free recall, while high-density EEG recorded neural activity during encoding. Spectral decomposition isolated theta (3–5 Hz), alpha (8–10 Hz), and gamma (80–90 Hz) power across anterior and posterior regions. The subsequent memory effect (SME) was computed by comparing spectral power for words later recalled versus forgotten, and participants were grouped by recall performance. Results: Consistent with previous findings, successful encoding was marked by increased anterior theta and decreased posterior alpha power. However, high performers exhibited significantly reduced anterior theta activity compared to low performers, suggesting a reduced reliance on effortful encoding processes. Multivariate analyses identified anterior theta suppression during encoding as the strongest predictor of recall ability (p ≤ 0.05). Conclusion: These results challenge the view of theta as a uniform marker of successful encoding. Instead, reduced anterior theta in high performers may reflect a shift toward more automatic, efficient encoding. Incorporating EEG biomarkers into cognitive assessments could enhance memory performance predictions and guide personalized clinical interventions.

Topic Area: LONG-TERM MEMORY: Episodic