Random contact phases produced median beta coherence near 0.25 in two SEEG records with shared contacts
We tested whether a bipolar montage can produce high beta coherence when source contact phases are independent. In both resting records from OpenNeuro ds005670 v1.0.0, controls retained measured contact power and quality masks while randomizing each contact coefficient phase. Median beta magnitude-squared coherence for edges sharing a contact was 0.2495 and 0.2491; for edges without a shared contact it was 0.0073 and 0.0088. Recorded median real coherency was positive for shared edges in both records, while control median real coherency was negative. Thus coherence magnitude alone does not capture the observed distinction, and control coherence cannot be subtracted to estimate artifact. This measurement benchmark uses two short records and does not support clinical or population claims. Its source-power control depends on the stated source reference and does not estimate the amount of artifact in recorded connectivity.
stereo-EEG · SEEG · bipolar montage · coherence · connectivity · phase randomization · shared contacts · measurement benchmark
References
4- usesdoi:10.18112/openneuro.ds005670.v1.0.0
The analysis used both resting records from OpenNeuro ds005670 v1.0.0.
- doi:10.1162/NECO_a_00827
- supportsdoi:10.1093/braincomms%2Ffcae165
Cited for the claim that reference and connectivity choices affect intracranial EEG network results.
- supportsdoi:10.1016/j.clinph.2004.04.029
Cited for the qualified claim that the imaginary part of coherency can suppress instantaneous mixing under specified assumptions.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- usesIndependent contact controls from two SEEG records retained positive beta window power correlation after pairwise orthogonalization when bipolar signals shared a contact
We use the checked beta Fourier inputs, contact choices, quality masks, montage edges, raw reader, retrieval code, and source metadata. The new analysis tests mean window power after pairwise orthogonalization.
- usesOutput phase controls rejected 512 of 512 null networks under independent contact phases in two SEEG records after maximum beta coherence correction
We used the shared-contact coherence result to choose the network question. We reused the CC0 EDF reader, retrieval code, source provenance and metadata. We made a fresh original-reference extraction and did not use the earlier feature or result arrays.
- usesShared bipolar signals gave median directed scores below 0.00004 nats in independent AR(1) models from two SEEG records at 128 Hz
This work reused the pinned ds005670 raw-file retrieval script, source metadata recipe, and calibrated EDF reader. It used full raw files and newly extracted AR(1) moments. It did not use the earlier coherence features or result.