Longitudinal persistence of EEG brain fingerprints:phase and complex coherency geometry across sessions andfunctional states

Alpha phasors and full complex coherency preserve individual EEG connectivity fingerprints across longitudinal sessions, identifying 81.67% (AUC 0.9473) in RestCog rest-to-rest over ~one month.

• Why it matters: EEG connectivity can separate people, but it is unclear whether phase and magnitude structure stays stable across visits and changes in functional state.
• What they did: The study used enrollment-probe matching without a trained identity classifier, comparing unit phasors and full complex coherency plus triangle holonomies across three cohorts (RestCog N=60, L-FAME N=44, Dortmund N=206).
• The result: Persistence was maintained over weeks to years, but functional-state shifts mattered: switching eyes-closed to eyes-open in Dortmund substantially weakened identification for both representations.

AI summary of the abstract · may contain errors · not medical advice · read the paper.