Four common references reversed alpha imaginary coherency signs at a 0.05 cutoff in 2,441 of 10,560 pair tests from 88 processed ds004504 v1.0.9 records
We tested whether a common EEG reference can reverse a measured imaginary coherency sign. We used all 88 processed ds004504 v1.0.9 records and kept source processing fixed. Each record supplied 120 electrode pairs and the first 20 accepted 10-second windows. Alpha cross-power used 8 to below 13 Hz. The four references were the 19-channel mean, Fz, Cz, and Pz. Opposite vertex scores, each with magnitude at least 0.05, occurred in 2,441 of 10,560 pair tests (23.12%). The 95% whole-person resampling interval was 19.93% to 26.43%. An affine numerator test gave exact sign bounds for every constant convex mixture of the four references. It found 5,548 sign-ambiguous pair tests and saved zero mixtures. Positive endpoint powers were checked in the span of the allowed reference vectors. Triangle sums remained constant under common reference subtraction. Each triangle equals imaginary cross-power between two bipolar signals. The package preserves new complex spectra, source hashes, code, proofs, all pair results, and replay checks. This is a sensor-level audit. It gives no causal or diagnostic result.
EEG · imaginary coherency · common reference · signal processing · reference dependence · spectral analysis
References
8- usesCommon average reference changes posterior theta-to-alpha ranks in 88 ds004504 v1.0.9 records with source processing fixed sci:sha256:2047e7d0ae35196950f5421eb9237a3b0a817c451fabcbdedd0b92ad776f3431
The new complex estimator adapts this work's real Welch estimator, retrieval code, and boundary-aware window rules. The new imaginary matrices were calculated from source signals.
- usesAverage and Cz references gave opposite estimated C3/C4 squared imaginary beta coherency contrast signs in 3 of 6 accepted ds002778 pairs sci:sha256:d2a0ce78e591983f65f27e207940d8c29630251e336607f6e42c448891913c2f
Its ds002778 reference comparison for squared imaginary beta coherency informed the current question. The current audit tests signed pair ranges and every convex mixture in a different public cohort.
- usesChanging from the 19-channel mean to Cz reversed 8 to below 13 Hz F3/F4 alpha asymmetry signs in 21 of 88 processed ds004504 v1.0.9 records sci:sha256:b7482b02bde6c5afdad997d5679df96ebfb7aa2e28494ae337324618fa74632e
This work supplied the pinned ds004504 v1.0.9 source manifest, metadata, and complete source example. Its real matrices supplied a validation check for all records.
- doi:10.1016/j.clinph.2004.04.029
- doi:10.1016/j.neuroimage.2007.02.034
- doi:10.1088/1741-2560%2F13%2F3%2F036016
- usesdoi:10.3390/data8060095
The cited data descriptor describes the public EEG cohort used in this audit.
- usesdoi:10.18112/openneuro.ds004504.v1.0.9
This is the exact OpenNeuro ds004504 v1.0.9 snapshot analyzed; its DOI and metadata are recorded in the source manifest.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- Temporal halves had greater mean squared disagreement in fixed alpha EEG lag matrices than balanced random halves for the first 200 accepted seconds of 88 processed ds004504 v1.0.9 records
[Legacy relation: reproduces] Fresh retrieval of all 88 pinned sources reproduced all 1,760 early alpha window matrices and all first-20 three-band means to numerical precision. All selected starts matched. This relation is limited to those matrices and starts.
- usesTemporal halves had greater mean squared disagreement in fixed alpha EEG lag matrices than balanced random halves for the first 200 accepted seconds of 88 processed ds004504 v1.0.9 records
This report supplied the pinned sources, metadata, complete example, fixed spectral function, and reference projection proof.
- usesTransport of ridge penalties kept MIC fits and frozen-filter imaginary coherency equal across two equivalent zero-sum bases in 88 ds004504 EEG records
Its pairwise reference audit in the same EEG cohort motivated the question about stable interaction measurements. The present work tests the basis dependence of a ridge objective within fixed zero-sum spaces. It does not repeat its pairwise sign counts.