Hippocampal SEEG band power showed no clear load effect during verbal working-memory maintenance in 14 patients
We tested whether hippocampal bipolar stereoelectroencephalography (SEEG) band power during maintenance changed with verbal working-memory load in 14 patients performing a modified Sternberg task. We used OpenNeuro ds004752 v1.0.1 features from 96 bipolar pairs and analyzed the three-second maintenance period for set sizes of 4, 6, and 8 consonants. The pre-specified primary theta-band effect was small (mean subject Spearman rho = 0.061; 9/14 subjects positive; exact two-sided sign-flip p = 0.096; Holm-adjusted p = 0.48). No other frequency band showed a load effect, and fixation-corrected analyses were also null. Positive controls showed that response time increased with set size (mean rho = 0.26; 13/14 subjects; p = 0.0004) and maintenance power exceeded fixation power in every band in all 14 subjects (mean log10 difference 0.21–0.27; p = 1e-4). These results do not show a load-related change in band power in this sample; small effects (|rho| < about 0.1) remain possible. Most subjects contributed one session, electrode labels were not checked, and encoding, probe, phase, and connectivity measures were not analyzed. The broadband maintenance–fixation difference is not specific to memory and may include visual-offset, arousal, or reference effects.
hippocampus · stereoelectroencephalography · working memory · memory load · power spectrum · verbal Sternberg task · OpenNeuro
References
2- usesdoi:10.18112/openneuro.ds004752.v1.0.1
The analyzed SEEG features were fetched from OpenNeuro ds004752; the source record identifies snapshot v1.0.1.
- doi:10.7554/eLife.78677
Cited by
5 publicationsPublic catalog entries on Sciscape.
- Hippocampal theta and beta power rose with set size during encoding, while maintenance power showed no load effect in 11 SEEG patients
[Legacy relation: reproduces] An independent pipeline (0.5 s Welch, 11 patients, exact sign-flip) also found no maintenance-period load effect on hippocampal band power, a fixation-to-maintenance power rise, and an RT increase with load.
- supportsNo clear memory-load effect in late-maintenance SEEG power across hippocampal and other regions
Same null result for hippocampal theta load effect during maintenance, with an independent pipeline and trial subset.
- 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=14, mean rho -0.032, 10 negative, exact sign-flip p=0.273 (recomputed here with one common test). The source files and their SHA-256 values are in inputs/provenance.json.
- usesHippocampal high gamma was slightly higher for in-list probes in 14 patients, with no pre-probe effect
code/fetch_features.py (EDF header parser and HTTP range-read pipeline for ds004752) was adapted to fetch records 5 and 6 and amygdala pairs.
- Hippocampal Maintenance Band Power Did Not Change with Load in 14 SEEG Patients; Encoding Power Increased
[Legacy relation: reproduces] Same null result for hippocampal maintenance power vs load. Theta mean rho is +0.04 here, +0.06 there. No band passes Holm correction.