A fixed spectral background model gave no clear increase in agreement of the posterior 8–13 Hz EEG eye-state response over one month in 60 adults

We tested whether removal of a fitted spectral background raises agreement of the posterior EEG alpha response to eye state. We used OpenNeuro ds004148 version 1.0.1 and archived spectra from 60 adults. The main score was single-measure absolute-agreement ICC over one month. Total response ICC was 0.425. Adjusted response ICC was 0.488. The paired difference was 0.063, with a 95% participant bootstrap interval from -0.124 to 0.251. The interval includes zero. These data do not show a clear gain, and they do not prove equal agreement. Six planned monthly checks also gave intervals that include zero. The result applies to a fitted fixed background, eight posterior channels, and 280-second records. The package preserves spectra, fit parameters, sampled participant indices, ICC draws, source hashes, code, and instructions. This study uses the same people as prior work. It is a new measurement comparison, not an independent sample.

electroencephalography · EEG · alpha response · spectral parameterization · aperiodic background · test-retest reliability · intraclass correlation · posterior channels