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arXiv · 2406.05073

Reconstruction of phase-amplitude dynamics from electrophysiological signals

Azamat Yeldesbay·Gemma Huguet·Silvia Daun
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Abstract

We present a novel method of reconstructing the phase-amplitude dynamics directly from measured electrophysiological signals to estimate the coupling between brain regions. For this purpose, we use the recent advances in the field of phase-amplitude reduction of oscillatory systems, which allow the representation of an uncoupled oscillatory system as a phase-amplitude oscillator in a unique form using transformations (parameterizations) related to the eigenfunctions of the Koopman operator. By combining the parameterization method and the Fourier-Laplace averaging method for finding the eigenfunctions of the Koopman operator, we developed a method of assessing the transformation functions from the signals of the interacting oscillatory systems. The resulting reconstructed dynamical system is a network of phase-amplitude oscillators with the interactions between them represented as coupling functions in phase and amplitude coordinates.

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Azamat Yeldesbay, Gemma Huguet, Silvia Daun. 2024-06-07. Reconstruction of phase-amplitude dynamics from electrophysiological signals. https://doi.org/10.1063/5.0251072

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