Single 1–2 mA pulses did not change 70–150 Hz power at 150–500 ms in eight SEEG patients

We measured 70–150 Hz high-frequency activity (HFA) after single-pulse electrical stimulation in eight SEEG patients using OpenNeuro ds005448. The analysis included 3,925 contact-pair units, including 303 N1-present units at least 10 mm from the stimulated pair midpoint. The preregistered induced-HFA comparison of N1-present and N1-absent contacts was −0.07 dB (4 of 8 patient means negative; exact two-sided sign-flip p = 0.54), so the prediction of greater suppression at N1 contacts was not supported. At 150–500 ms, HFA did not differ from baseline in N1-present contacts (−0.03 dB, p = 0.80), N1-absent contacts (+0.04 dB, p = 0.68), or N1-absent contacts over 40 mm away (+0.06 dB, p = 0.47). Total power gave a similar comparison (−0.05 dB, p = 0.66). In N1-present contacts, HFA was not related to absolute N1 amplitude (mean per-patient Spearman rho = −0.02, p = 0.82). A descriptive early increase at about 20–100 ms was not tested statistically. The initial per-pulse dB estimator produced a −0.8 to −0.9 dB offset, including in baseline bins; the reported analysis corrected this by subtracting each unit’s baseline mean. With only 3 pulses per polarity, 1–3 pairs in most patients, no sham control, and an estimated detectable effect scale of 0.2–0.3 dB, these results do not establish the absence of smaller effects. Artifact blanking and wavelet spread also make values from 0–60 ms unreliable.

SEEG · single-pulse electrical stimulation · high-frequency activity · 70–150 Hz · N1 · epilepsy · brain-computer interface · OpenNeuro