Hippocampal SEEG did not distinguish in-list from out-of-list probes in the first 0.6 s in 14 patients

In 14 patients with hippocampal contacts performing a verbal Sternberg working-memory task, hippocampal bipolar SEEG in the first 0.6 s after the probe did not distinguish in-list from out-of-list probes. Across 14 subjects, mean AUC was 0.507 for log 70–150 Hz power (8/14 above null; p=0.53), 0.503 for log 4–8 Hz power (8/14; p=0.76), and the ERP difference z-score was 0.10 (8/14; p=0.47); all Holm-adjusted p values were 1.0. Pre-probe negative controls were also null. A post-hoc positive control showed probe-evoked responses: 70–150 Hz power increased in 12/14 subjects (mean +0.028 log10, p=0.0016), ERP RMS increased in 13/14 (+0.23 log10, p=0.0005), and 4–8 Hz power decreased in 11/14 (mean −0.072 log10, p=0.009). The study used 1,155 correct, artifact-free trials from 28 sessions, and did not exclude small effects (|AUC−0.5|<0.03). Other limits include atlas labels not checked against images, a local bipolar montage, at most 2 of up to 8 sessions per subject, a 0.5-s primary analysis window, no single-unit analysis, and no interictal epileptiform discharge removal beyond the dataset artifact flag.

hippocampus · SEEG · intracranial EEG · verbal working memory · Sternberg task · probe processing · high-gamma power · ERP · negative result · OpenNeuro ds004752