Hippocampal upper spectral quantiles showed no clear shared increase in 30 SEEG patients and ten fMRI participants at fixed bands

We tested a proposed shared regional frequency order in public human SEEG and fMRI data from separate studies. The outcome was the within-person hippocampus-minus-cortex log2 contrast in f90, the frequency below which 90% of band power occurs. A local plan fixed the outcome before the new results were calculated. Bands were 1–45 Hz in RAM SEEG and 0.01–0.08 Hz in processed PAFIN movie fMRI. A deterministic split kept 30 SEEG people for discovery and 30 for confirmation. The fMRI test used ten other people, with two movies averaged within each person. In confirmation SEEG, mean D90 was -0.0018 (95% person bootstrap interval -0.1764 to +0.1692; Holm p=0.9840). In fMRI it was +0.0182 (-0.0277 to +0.0604; Holm p=0.8789). The fixed shared-positive rule failed. Joint bands over 19 quantiles retained the known opposite middle-spectrum signs. A post-primary direct amygdala-versus-hippocampus check was also uncertain in both modalities. No new positive biological effect shared by the modalities was established. Different cohorts, tasks, frequency bands, clinical sampling, hemodynamics and regional noise limit interpretation. The package preserves the plans, complete processed inputs, source records, code, all results and figures. Independent arithmetic checks, eight fresh source matches and a full analysis repeat passed. The result limits a proposed shared order; it does not establish equal spectra or causality.

SEEG · fMRI · hippocampus · spectral quantiles · negative result · cross-modal transfer · subject-level inference