Four-step bipolar pairs had higher mean 30–80 Hz exponents than one-step pairs in 19 selected SEEG records when 58–62 Hz was omitted

We tested whether bipolar span changes a fixed-band SEEG exponent and whether the power split depends on the reference. We used 120 seconds from each of 19 selected patients in OpenNeuro ds003876 version 1.0.2. The same 984 complete contact paths supplied spans of one, two, and four contact-number steps. The primary fit used 30–80 Hz and omitted 58–62 Hz. The patient mean four-step minus one-step exponent change was positive in all 19 patients. The mean change was 0.3115, with a descriptive 95 percent patient bootstrap interval of 0.2350 to 0.3951. Common-average subtraction left bipolar power unchanged. It changed the mean span contrast assigned to the cross-spectrum ratio by −0.0231, with an interval of −0.0422 to −0.0061. That interval included zero in the fixed 30–100 Hz check. An exact proof shows why the power split can change under a shared reference. Contact-number span does not establish physical distance. These fixed-band results do not establish an aperiodic parameter or a clinical marker. The package preserves float64 spectra, all anchor and patient outcomes, source pins, metadata, code, figures, and reproduction steps. Independent checks passed. A separate process rebuilt every array and numerical result file exactly.

stereo-electroencephalography · SEEG · bipolar reference · spectral exponent · power spectrum · common-average reference · cross-spectrum · signal processing