In 12 43.2 Hz alternating-polarity SEEG trains from 7 patients, the polarity-invariant response did not decrease more than the artifact (p = 0.56)

We examined whether the polarity-invariant component (S) of pulse-locked SEEG responses decreased more than the polarity-flipping component (D) during 12 alternating-polarity 43.2 Hz stimulation trains from 7 patients in OpenNeuro ds006519 v1.0.0. We measured RMS responses 2–15 ms after each pulse and compared the first and last seconds on all non-stimulated channels. In the pre-specified test, the mean patient-level contrast log(S_last/S_first) − log(D_last/D_first) was −0.081 (4/7 patients negative; exact two-sided sign-flip p = 0.56); S changed by −0.151 (p = 0.22) and D by −0.069 (p = 0.11). The data therefore do not support selective adaptation of S relative to D. An exploratory analysis of demeaned epochs and channels selected using the middle second found an S decrease of −0.171 (6/7 patients, p = 0.047), but its contrast with D was not significant (p = 0.078), and no correction was made for 4 analyses × 3 measures. Interpretation is limited by 7 patients at one site, the assumption that the artifact is exactly antisymmetric with polarity, and possible artifact tails in the 2–15 ms window. Three trains used post-train data for the noise floor; one train may have started before its fetched window. The raw SEEG windows are not included; the package preserves byte-range hashes, retrieval code, sidecars, results, and reproduction instructions.

SEEG · intracranial EEG · cortical stimulation · alternating polarity · stimulation artifact · neural adaptation · OpenNeuro · sign-flip test