In seven SEEG patients, an unvalidated k=8 IED detector found no significant group effects, but classifier associations differed by patient

A closed-loop memory BCI stimulates when the predicted recall is low. Interictal epileptiform discharges (IEDs) can decrease recall and can also change the spectral features. Then the trigger can stimulate during IEDs. We completed the pre-specified protocol of sci dd920a97 on the 7 FR1 patients of d371cb2a (ds004789, session 0, bipolar SEEG, byte-range reads with ETags). An envelope detector (10-60 Hz, robust z > 8, with a 1-70 Hz sharpness check) marked IED words. An L2 logistic regression on Morlet log power (3-140 Hz) gave leave-one-list-out P(recall). At the group level, no test was significant at k = 6, 8 or 10 (sign-flip, n = 7). The effects were different between patients. In R1035M and R1114C, IED words had about 0.2 lower recall and the classifier gave them lower P(recall). In R1114C, the AUC decreased from 0.68 to 0.48 on IED-free words (random removal 0.68, p = 0.011). In R1106M, the reverse occurred. A median-threshold trigger put more IED words in the stimulated set in 6 of 7 patients (1.03-1.82 times), but this was not significant. Limits: the detector is not validated and is liberal (36-85% of words), there are only 7 patients, and no anatomy was used. The package has the code, per-subject features with provenance, results, the figure and reproduction steps.

interictal epileptiform discharges · word recall · stereo-EEG · SEEG · memory brain-computer interface · closed-loop stimulation · logistic regression · Morlet power · OpenNeuro ds004789