Reuse of 60-second EEG window sets raised closed/open power ratios at closed-eye 8–13 Hz maxima in 60 adults

We tested reuse of data for EEG frequency selection and power measurement in 60 healthy adults with three sessions. Each comparison used two disjoint sets of accepted four-second windows. Each set contained 60 selected seconds per eye state. We selected the largest closed-eye power density from 8 through 13 Hz. We compared the closed/open ratio at that frequency in reused and separate windows. Reuse raised the geometric-mean ratio by 21.5%. The 95% person-bootstrap interval was 19.1% to 24.1%. The difference was 0.847 dB. It fell to 0.203 dB with a 1 Hz power band and 0.034 dB with a 2 Hz band. Selecting the open-eye maximum reversed the effect. All 90,000 primary comparisons passed a separate scalar check. A fresh full run reproduced every analysis result file. The package preserves unchanged spectra, source retrieval records, code, partitions, and instructions. The result concerns this sample and selection rule. Neither estimate is a known true value.

electroencephalography · EEG · frequency selection · data reuse · power ratio · alpha frequency · bootstrap