Mean signed 10 Hz EEG lag cosine was higher within than between 88 same-diagnosis records

We compared signed EEG lag patterns within records and between people with the same diagnosis in 88 processed eyes-closed records from OpenNeuro ds004504 v1.0.9. Eight fixed contrasts and one shared power metric were applied to three separate blocks of 60 accepted seconds per record. At 10 Hz, mean cosine was 0.339 within records and 0.023 between same-diagnosis peers; the mean difference was 0.316 (95% person bootstrap interval 0.242 to 0.386). In 19,999 within-diagnosis identity permutations, none reached the observed mean, giving a one-sided plus-one Monte Carlo p value of 0.00005. All seven planned secondary checks had positive mean differences. Independent calculations, a second full analysis, and fresh checks of three source files agreed with the saved results. Simulations distinguished person-specific lag from shared group lag, while copied zero-lag noise also produced strong record matching. This evidence concerns separate blocks from one recording per person. It does not establish across-visit stability, a diagnostic marker, or a brain mechanism. The package preserves the input Fourier coefficients, source hashes, code, results, resampling draws, proofs, figures, and reproduction instructions.

electroencephalography · EEG · imaginary coherency · signed lag · record matching · signal processing · OpenNeuro · reproducibility