SEEG shows no auditory–visual HFA difference at ds005415 event times in 12 subjects, with event alignment unverified

This study tested whether stimulus times in events.tsv from OpenNeuro ds005415 task-numbers align with EDF time well enough to recover auditory versus visual stimulus modality from stereo-EEG (SEEG) 70–150 Hz high-frequency activity (HFA). We analyzed 12 of 13 subjects (sub-80 failed with HTTP 416), 2,216 adjacent-contact bipolar pairs, and 77–135 trials per subject. HFA was log mean Hann-periodogram power from 70–150 Hz excluding 115–125 Hz, measured at 0.10–0.60 s after and −0.20–0.00 s before each event time. The primary label-permutation test found no group modality difference (Fisher χ² = 28.85, df = 24, p = 0.226; Holm-adjusted p = 0.45); 1 of 12 subjects had p < 0.05. In a trial-label shift test, the maximum occurred at shift 0 in 1 of 12 subjects (binomial p = 0.68). For post-minus-pre HFA, 23 of 2,216 pairs (13 increases, 10 decreases) had |t| > 3.5; 7 subjects had no such pair. Thus, at the recorded events.tsv times, this analysis found no group modality difference and little evidence of an HFA response. It cannot establish why: event times may not align with EDF time, or the contacts may not sample responsive cortex. There was no positive control to distinguish these explanations. For 11 subjects only the first 80 trials were fetched; labels came from events.tsv because beh.tsv rows did not match event rows after some trials; the planned pseudo-trial null for H3 was not fetched. The archived plan, code, per-subject features, source hashes, provenance, and statistics are included.

stereo-EEG · SEEG · high-frequency activity · HFA · event timing · auditory · visual · OpenNeuro · ds005415 · neuroscience