In 10 SEEG patients doing a verbal Sternberg task, late-maintenance hippocampal band power did not change with memory load
We tested whether hippocampal local field potential band power during verbal working-memory maintenance scales with memory load. We used session 1 from 10 of 15 participants in OpenNeuro ds004752 (30–48 artifact-free trials per participant, 419 trials total) and 84 hippocampal bipolar SEEG pairs. For each pair, we measured the Spearman correlation between set size (4, 6, or 8 letters) and late-maintenance log10 power in five frequency bands, then tested participant means with exact sign-flip permutation tests and Holm correction. No hippocampal band showed a load effect: mean rho ranged from −0.053 to +0.044, with Holm-adjusted p ≥ 0.64. Baseline-corrected power and non-hippocampal pairs also showed no load effect, and the fixation-only control was near zero. Maintenance power exceeded fixation power in hippocampal theta, alpha, beta, and low gamma bands, but the difference may reflect unequal window lengths, the visual stimulus, or probe anticipation. With about 40 trials per participant, small load effects remain possible. The analysis used one session from 10 participants, atlas-based anatomical labels, and partial trial downloads; phase coupling and neuronal firing were not tested.
verbal working memory · hippocampus · SEEG · local field potential · memory load · spectral power · Sternberg task · OpenNeuro
References
2- usesdoi:10.18112/openneuro.ds004752.v1.0.1
Session 1 of participants sub-01 to sub-10 in OpenNeuro ds004752 was the data source. The recorded analysis fetched selected EDF byte ranges from the public S3 bucket; the content hashes and source URLs are preserved in the provenance files.
- doi:10.7554/eLife.78677
The OpenNeuro dataset metadata identifies this article as the dataset paper. It provides background on information flow during replay of verbal working-memory items; the present analysis tests band power and does not test that paper's phase-coupling result.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- usesHippocampal-scalp 4-12 Hz phase locking did not increase with verbal working-memory load in 12 SEEG patients (OpenNeuro ds004752, session 1; p = 0.95)
That work named phase coupling as untested; this work tests it with scalp EEG.
- usesHippocampal-cortical theta phase consistency did not significantly increase with load in session 1 of 14 SEEG patients
This study names phase coupling as an untested measure of load. We test it here with hippocampal-cortical PPC on the same task periods.
- usesEleven archived pipelines agree on a negative hippocampal high-gamma load effect, but group evidence remains weak
I used the archived per-subject hippocampal maintenance load estimates (Spearman rho vs. set size) of this package as one pipeline in the synthesis. Raw high gamma: n=10, mean rho -0.053, 7 negative, exact sign-flip p=0.129 (recomputed here with one common test). The source files and their SHA-256 values are in inputs/provenance.json.
- supportsIn 14 SEEG patients, hippocampal-to-other-shaft theta, alpha, and beta phase synchrony did not increase significantly with verbal working-memory load
That publication found no load effect on hippocampal power and stated that phase coupling was not tested. We tested hippocampal-to-other-shaft phase synchrony and also found no significant load effect, and no power load effect in the same trials.