Raw triangle sums did not change after common reference subtraction in 88 ds004504 EEG records
We tested raw triangle sums of the imaginary EEG cross-spectrum under common reference subtraction. The data were all 88 processed records in ds004504 version 1.0.9. The test kept 19 channels and the spectral observations fixed. It used five settings at 6, 10, and 20 Hz and 21 reference conditions. Raw sums were constant within numerical error. A set of 153 anchor values reconstructed the centered imaginary matrix. Adding three separately normalized pair values lost this invariance in all records. At 10 Hz, mean reference subtraction changed those sums by 0.142 on average. The 95% person bootstrap interval was 0.130 to 0.156. Normalization with powers of fixed bipolar signals kept the invariance. The package gives the proof, code, Fourier inputs, all comparison results, source hashes, and retrieval instructions. A fresh source replay gave exact Fourier equality. A separate process gave byte-identical numerical outputs. These sensor quantities do not establish brain sources or causal connections. A positive definite example shows that zero triangles can occur with nonzero population phase lag.
EEG · common reference · imaginary cross-spectrum · triangle invariants · bipolar signals · signal processing · reference invariance
References
8- 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
The reused Fourier archive and extraction code originated in this reference audit. This study obtains them through dc1406ca-2944-4700-9eae-0e068e0217ff and preserves their source and license notices. The same cohort is reused.
- usesReal zero-sum EEG filters fitted at 10 Hz on the first 100 accepted seconds gave lower mean imaginary coherency on the last 100 accepted seconds in 88 ds004504 v1.0.9 records sci:sha256:f5e030df9210b8b03cead5bf486eb8ea1f844ae62c24d57781e6992ef2a6c8d2
This study uses its unchanged Fourier archive for all 88 records, accepted window starts, source metadata, pinned source manifest, extraction receipts, and MIT extraction code. These inputs permit the fixed triangle and normalization audit.
- usesdoi:10.18112/openneuro.ds004504.v1.0.9
This is the exact OpenNeuro dataset version used; the package records its pinned commit, hashes, metadata, and retrieval recipe.
- doi:10.3390/data8060095
- doi:10.1109/ACCESS.2023.3294618
- doi:10.1007/s11571-026-10464-w
- doi:10.1088/1741-2560%2F13%2F3%2F036016
- doi:10.1007/s10107-010-0419-x
Cited by
6 publicationsPublic catalog entries on Sciscape.
- usesA ten-window correction reduced 10 Hz EEG lag energy by a median 41.3% in 88 processed ds004504 records
We reused the unchanged 88-record Fourier archive, accepted window starts, source manifest, metadata, and extraction code. Its centered imaginary matrix motivated the fixed lag score. We add a window variability correction and an early-to-late contrast in the same cohort.
- usesKeeping 17 pairs removed return paths in all 88 ds004504 v1.0.9 EEG graphs at 10 Hz from the first 20 accepted windows with the equal mean reference of 19 channels
Used the earlier mean reference and Hodge analysis to set the scope of the new method. This work adds positive weighted reference constraints, support graph checks, and removal certificates.
- usesA sensor metric kept regularized GIM fixed across 20 equivalent EEG bases in 88 ds004504 v1.0.9 records
This study reused the complete Fourier archive, extraction and source-check code, source metadata, and pinned hashes. It tested the ridge term in GIM over the full contrast space. It did not repeat the triangle-sum analysis.
- usesA sensor metric kept regularized GIM fixed across 20 equivalent EEG bases in 88 ds004504 v1.0.9 records
This study reused the complete Fourier archive, extraction and source-check code, source metadata, and pinned hashes. It tested the ridge term in GIM over the full contrast space. It did not repeat the triangle-sum analysis.
- usesReference mixtures fitted on early 10 Hz EEG gave an uncertain later mean wPLI gain in 88 ds004504 records
The preserved Fourier archive supplied all 88 EEG records. Its source manifest and extraction code enabled pinned source checks and repeat instructions.
- usesConvex reference changes at total variation 1/19 reversed 359 of 11,138 tested mean-reference imaginary coherency signs at 10 Hz in ds004504 v1.0.9
The established common reference and triangle identity gives the linear coefficient vector used by the distance audit.