A sign flip test under sign symmetry did not detect different hippocampal alpha load slopes during encoding and late maintenance in 12 independent SEEG patients

We tested whether hippocampal alpha power had a stronger positive load relation during late maintenance than during encoding. The band was 8 to less than 12 Hz. We used public SEEG data from OpenNeuro ds004752 version 1.0.1. The sample had 12 patients, two sessions each, 44 matched contact pairs, and 983 correct trials without source artifact flags. The mean maintenance-minus-encoding load slope was 0.119 dB per two letters. The 95 percent t interval was -0.505 to 0.744 dB. The exact two-sided sign flip p value was 0.7090. Group inference assumed independent patients. Under the null, each patient coefficient was assumed to have a distribution symmetric about zero. The test did not detect a common stage change. The interval does not establish that the change is absent. We added new encoding windows to an earlier maintenance sample. The package provides spectra, raw examples, source versions, byte range hashes, metadata, code, all planned results, and reproduction commands. A new package copy repeated all 39 scientific output files exactly.

hippocampus · verbal working memory · intracranial EEG · SEEG · alpha power · memory load · encoding · maintenance · sign flip test