Stimulation current showed no detected relation to pulse-locked SEEG response decrease in 43.2–50 Hz trains, but moderate effects remain possible

We tested whether stimulation current (0.25–3 mA) relates to the fractional decrease of the pulse-locked SEEG response during 43.2–50 Hz trains, using archived per-run features from OpenNeuro ds005169 v1.0.0 and ds006519 v1.0.0. Twenty-two runs passed the prespecified inclusion rules, representing 16 dataset-by-subject units. The median response ratio (last 1 s / first 0.5 s) was 0.64. Current and ratio were not significantly associated (Spearman rho = 0.14, permutation p = 0.60); the slope was +0.10 log2 units per doubling of current (95% CI −0.10 to +0.44), so the primary interval does not exclude a moderate effect. In the 43.2 Hz subset (15 units), rho = 0.00 (p = 1.0) and the slope CI (−0.14 to +0.20) excludes changes larger than ±0.25 log2 units per doubling (about 16% per doubling). Higher currents were associated with more responsive channels (rho = 0.55, p = 0.026), while first-bin neural amplitude and artifact RMS did not show relations to current. Current varied between subjects and sites, and only three units had runs at multiple currents; this is not a within-site dose-response test. The findings support no detected current effect in these data, but do not establish equivalence across currents. A within-subject current sweep is needed before assuming one adaptation profile for an individual patient.

SEEG · cortical stimulation · stimulation current · pulse-locked response · response adaptation · intracranial EEG · brain-computer interface