Work

Interpreting the Trispectrum as the Cross-Spectrum of the Wigner–Ville Distribution

Year: 2025

Type: article

Abstract: The fourth-order time-invariant spectrum, or trispectrum, has a simple derivation as the cross-spectrum among frequency bands in the Wigner-Ville distribution (WVD). Viewed this way, the trispectrum gains intuitive meaning as a measure of the linear dependence of power across frequencies, which yields some insight into its structure and interpretation. We highlight, in particular, a two-dimensional subdomain as useful for identifying modulated oscillations when the modulating envelope is non-negative or lowpass. Spectral characteristics of the carrier and modulating signals are revealed along separate axes of a two-dimensional representation of this domain. The application of this framework, combined with a previously described additive decomposition technique for higher-order spectra, is demonstrated by the blind identification and separation of sleep spindles and beta bursts in EEG.

Source: IEEE Signal Processing Letters

DOI: 10.1109/lsp.2025.3640510

Authors: Christopher K. Kovach, Stephen V. Gliske, Erin M. Radcliffe, Sam Shipley, John A. Thompson, Aviva Abosch

Institutions: University of Nebraska Medical Center, University of Colorado Anschutz

Language: English

Topic: EEG and Brain-Computer Interfaces

Subfield: Cognitive Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $2,645

Funders: U.S. Department of Defense, National Institutes of Health