Spectral curvature in fixed models gave a mean onset label AUC gain of 0.027 in 16 SEEG test patients, with an interval that included zero

We tested whether spectral curvature improves seizure onset zone ranking beyond mean log power, spectral slope, and contact order. We used public SEEG from OpenNeuro ds004100 version 1.1.3. We fitted fixed ranking models on file 01 from 15 patients. We tested file 02 from 16 other patients. Comparisons used positive and negative bipolar pairs on the same electrode shaft. Each patient had equal weight. Mean AUC was 0.921213 for the base model and 0.948461 with curvature. The mean gain was 0.027247. Its patient bootstrap 95 percent interval was -0.001821 to 0.061713, conditional on the fitted models. The exact sign-flip probability was 0.126953 under sign symmetry. The main test did not establish a positive gain. Seven fixed checks gave mean gains from -0.006540 to 0.092415. We preserved the exact spectra, both source label tables, fitted models, pair scores, code, a saved plan, and raw retrieval recipes. Independent calculations and two spectrum reconstructions pass for all 72 raw files. The target is a clinical onset flag. This test does not measure surgery benefit or a neural cause of curvature.

stereoelectroencephalography · seizure onset zone · spectral curvature · AUC · patient-level evaluation · epilepsy