Learning Cortico-Muscular Dependence through Orthonormal Decomposition of Density Ratios

Shihan Ma, Bo Hu, Tianyu Jia, Alexander Kenneth Clarke, Blanka Zicher, Arnault H. Caillet, Dario Farina, Jose C Principe

Keywords: EEG-EMG fusion, statistical dependence, orthonormal decomposition, cortico-muscular connectivity

Abstract: The cortico-spinal neural pathway is fundamental for motor control and movement execution, and in humans it is typically studied using concurrent electroencephalography (EEG) and electromyography (EMG) recordings. However, current approaches for capturing high-level and contextual connectivity between these recordings have important limitations. Here, we present a novel application of statistical dependence estimators based on orthonormal decomposition of density ratios to model the relationship between cortical and muscle oscillations. Our method extends from traditional scalar-valued measures by learning eigenvalues, eigenfunctions, and projection spaces of density ratios from realizations of the signal, addressing the interpretability, scalability, and local temporal dependence of cortico-muscular connectivity. We experimentally demonstrate that eigenfunctions learned from cortico-muscular connectivity can accurately classify movements and subjects. Moreover, they reveal channel and temporal dependencies that confirm the activation of specific EEG channels during movement.

Primary Area: Neuroscience and cognitive science (neural coding, brain-computer interfaces)

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Submission Number: 6942