Under patient independence and sign symmetry, the fixed alpha contrast test did not detect a mean change in 17 SEEG patients with negative motor responses

We tested a fixed alpha spectral contrast in public SEEG data after stimulation with negative motor responses. The source was OpenNeuro ds006519, version 1.0.0. We fixed the measure from a prior visual study before we computed the motor outcome. We used native samples without new filtering or resampling. The analysis retained 30 records from 17 patients. It gave each patient equal weight. The contrast removes a local change that is linear in log frequency. It does not isolate an alpha oscillation. The mean was -0.334 dB. The 95 percent patient bootstrap interval was -0.971 to +0.132 dB. The exact two-sided sign-flip test gave p = 0.317. This test requires independent patient effects and sign symmetry under the zero null. It did not detect a mean change at the planned 0.05 level. All 15 planned secondary intervals included zero. The wide interval permits a decrease and does not show that responses are absent. Patient overlap with the visual export is unknown. We did not test a difference between conditions. All 355 source objects passed fixed hash checks. All 30 native spectrum files were rebuilt byte for byte. An offline repeat gave all 12 numerical result files byte for byte. The package preserves code, metadata, source pins, spectra, tables, bootstrap draws, the exact sign null, and repeat instructions.

stereoelectroencephalography · negative motor response · alpha spectral contrast · intracranial EEG · sign-flip test · patient bootstrap