Mean 2–30 Hz O1 distance was lower at 10-second spacing than under random order within parts of 88 ds004504 v1.0.9 records with 19-channel mean referencing

We tested spectral shape and time order in 88 public EEG records from ds004504 version 1.0.9. Each record supplied 20 five-second O1 windows. The primary measure used a 19-channel mean reference and normalized 2–30 Hz power. We scored 1,502 pairs with start times 10 seconds apart. Random orders kept the same spectra within separate early and late parts. Mean Jensen-Shannon divergence was 0.207155 nats in time order and 0.210740 nats under random order. The reduction was 1.70%. Its 95% record bootstrap interval was 0.70% to 2.73%. A two-sided test with 19,999 random orders gave p = 0.0016. The supplied-reference check and coarse-band check had intervals that included zero. The early-part interval also included zero. We provide an exact random-order mean and variance for fixed graphs with missing edges. Small exhaustive tests checked these moments. Fresh source retrieval reproduced all 88 saved records exactly. The package includes signals, source hashes, boundary times, code, results, and replay instructions. The result applies to these processed records and this measure. It does not establish a neural cause, nonstationarity, or a clinical marker.

EEG · spectral shape · Jensen-Shannon divergence · time order · permutation reference · exact moments · bootstrap · OpenNeuro