Linear gap replacement gave a 0.10 dB patient mean for absolute power contrast changes after forward and reverse 1–4 Hz filtering of 35 SEEG recordings

We tested whether gap samples changed power contrasts in public SEEG data. We used all 35 recordings from 21 patients in OpenNeuro ds006519 version 1.0.0. The comparison input used a straight line across the gap between marked windows. All other input samples stayed fixed. A Butterworth filter ran forward and then in reverse at the native sample rate. The primary band was 1–4 Hz. Each target was two seconds long and ended 0.25 seconds before its annotation ended. We took channel medians in each recording, then averaged them within each patient. The mean patient value for absolute power contrast change was 0.0981 dB. The 95% descriptive patient bootstrap interval was 0.0818 to 0.1142 dB. Every patient value was below 0.20 dB. However, 15 of 1750 channel instances had changes of at least 1 dB. They came from seven patients. The largest change was 4.351 dB. The mean patient fraction above the threshold was 0.928%. Beside the gap, half-second 1–4 Hz bins had mean waveform change ratios of 34–36%. At two seconds from the gap, the ratios were about 1%. Higher bands gave smaller target contrast changes. These results measure filter dependence under one specified input replacement. The bridge is not a measured clean signal. All source hashes and numerical controls passed. A second full analysis gave byte-identical CSV results. The package preserves code, source metadata, patient results, figures, and repeat instructions.

SEEG · signal filtering · gap interpolation · filter dependence · power contrast · intracranial EEG · signal processing · OpenNeuro