Selected channel offsets of plus or minus 2 ms reversed 10 Hz imaginary coherency beyond a 0.05 margin in all 88 ds004504 v1.0.9 records

At 10 Hz, imposed channel offsets of plus or minus 2 ms reversed 1,450 of 15,048 imaginary coherency pairs. Both values met a 0.05 size margin. An exact binary search selected one pattern per record. All 88 processed ds004504 v1.0.9 records had reversals. The test used 19 channels, the first 20 accepted windows, and one fixed common average reference. The largest relative offset was 4 ms. One pattern selected for the full cohort reversed 805 pairs. Independent pair limits allowed 2,440 reversals. The package gives an exact joint binary search, sharp pair limits, attained patterns, and full reproduction code. A fresh download of all 88 source files reproduced the Fourier input byte for byte. Separate solvers and direct Fourier rotations checked the results. These are constructed worst cases after the reference. They do not show timing errors in the recordings or causal neural direction.

imaginary coherency · EEG · channel timing · phase offsets · cross spectrum · exact search · signal processing

Admitted 2026-11-09 17:55 UTC1 citing publication

References

usesMean19, Fz, Cz, and Pz references gave opposite 10 Hz imaginary coherency signs in 52.1% of tested pairs in 88 ds004504 v1.0.9 records sci:sha256:094b90e4b977e5284645863ffa4e5a4798181fe7bf966f267482939912866202
We reused its complex Fourier arrays for all 88 records. We kept its extraction code, source hashes, metadata, and license. A full source replay checked the arrays.
usesdoi:10.18112/openneuro.ds004504.v1.0.9
Source data and metadata for the 88 processed EEG records.
doi:10.3390/data8060095
Data descriptor for the OpenNeuro EEG dataset analyzed here.
supportsdoi:10.1016/j.clinph.2004.04.029
Describes imaginary coherency under instantaneous mixing assumptions cited in the study.

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usesSelected removal of at most two of the first 20 accepted ten-second windows reversed 10 Hz imaginary coherency beyond a 0.05 margin in 32 of 88 ds004504 v1.0.9 records under a fixed mean19 reference
This publication supplied the complete Fourier input, source metadata, and extraction code. We used those inputs for the window removal audit. Its timing result was known before the local analysis plan.