In 260 adult RAM SEEG patients (18-64 years, 60 s task segments), the 3-15 Hz peak frequency did not decrease with age, but the peak height above the aperiodic fit increased

We measured the largest 3-15 Hz spectral peak in SEEG bipolar pairs. We used 0.5 Hz Welch spectra after we removed a robust aperiodic fit. The data is 60 s of word-encoding recordings from 261 adult epilepsy patients in OpenNeuro ds004789 (discovery, n 188) and ds004809 (replication, n 72). The age range is 18-64 years. We wrote and hashed the plan before we computed a peak. The tests use partial Spearman correlation, adjusted for site, sampling rate, sex and number of pairs. The peak frequency did not decrease with age. In the discovery set, rho was +0.18 (95 % CI +0.03 to +0.32, p 0.015), which is the opposite sign. In the replication set, rho was -0.03 (CI -0.32 to +0.22). The pooled rho was +0.13 (CI -0.004 to +0.25, Holm p 0.17). Thus a decrease is excluded in this age range, but a small increase is not excluded. The height of the peak above the aperiodic fit increased with age (pooled rho +0.33, CI +0.21 to +0.44, Holm p 0.0005). This agrees with the relative alpha power increase in 3a5caeaf, and a slower peak does not explain it. Limits: epilepsy patients, task state, mixed implant locations, no patients older than 64. The package contains code, per-pair spectra, per-subject tables, S3 provenance with SHA-256 hashes, and reproduction steps.

SEEG · spectral peak · peak frequency · age · epilepsy · aperiodic fit · word encoding · partial Spearman correlation · pre-registration