Automatically detected hippocampal IEDs did not increase verbal Sternberg errors in 14 SEEG subjects (OpenNeuro ds004752, sessions 1–2)

We tested whether hippocampal interictal epileptiform discharges (IEDs) increase errors on a verbal Sternberg task. We used OpenNeuro ds004752 SEEG, sessions 1 and 2 of 14 subjects (28 sessions, 1363 trials, 121 errors). The analysis plan was written before the IED and outcome data were examined. An automatic envelope detector found IEDs on hippocampal bipolar pairs. We used a Mantel-Haenszel odds ratio over subject and set-size strata with 10,000 within-stratum permutations. Maintenance-window IEDs gave OR 0.61 (one-sided p 0.98). Retrieval-window IEDs gave OR 0.60 (p 0.96). Both hypotheses are not supported; estimates are below 1. Correct-trial reaction time did not change. An encoding-window control gave OR 1.57 (uncorrected p 0.045), an exploratory result only. The detector was not validated against expert marks, some events can be task-evoked activity, errors are rare, and later sessions were not used. The package preserves code, byte-range provenance with S3 ETags and chunk SHA-256 values, per-trial and per-event tables, and reproduction instructions.

interictal epileptiform discharges · hippocampus · verbal working memory · Sternberg task · intracranial EEG · pre-registration · OpenNeuro ds004752