Enhancing Brain Source Reconstruction by Initializing 3D Neural Networks with Physical Inverse Solutions.

Journal: IEEE transactions on medical imaging
Published Date:

Abstract

Reconstructing brain sources is a fundamental challenge in neuroscience, crucial for understanding brain function and dysfunction. Electroencephalography (EEG) signals have a high temporal resolution. However, identifying the correct spatial location of brain sources from these signals remains difficult due to the ill-posed structure of the problem. Traditional methods predominantly rely on manually crafted priors, missing the flexibility of data-driven learning, while recent deep learning approaches focus on end-to-end learning, typically using the physical information of the forward model only for generating training data. We propose the novel hybrid method 3D-PIUNet for EEG source localization that effectively integrates the strengths of traditional and deep learning techniques. 3D-PIUNet starts from an initial physics-informed estimate by using the pseudo inverse to map from measurements to source space. Secondly, by viewing the brain as a 3D volume, we use a 3D convolutional U-Net to capture spatial dependencies and refine the solution according to the learned data prior. Training the model relies on simulated pseudo-realistic brain source data, covering different source distributions. Trained on this data, our model significantly improves spatial accuracy, demonstrating superior performance over both traditional and end-to-end data-driven methods. Additionally, we validate our findings with real EEG data from a visual task, where 3D-PIUNet successfully identifies the visual cortex and reconstructs the expected temporal behavior, thereby showcasing its practical applicability.

Authors

  • Marco Morik
  • Ali Hashemi
  • Klaus-Robert Müller
    Berlin Institute for the Foundations of Learning and Data (BIFOLD), Berlin, Deutschland.
  • Stefan Haufe
    Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Klinik für Neurologie mit Experimenteller Neurologie, Berlin, Germany.
  • Shinichi Nakajima
    Machine Learning Group, Technische Universität Berlin, 10587 Berlin, Germany; BIFOLD - Berlin Institute for the Foundations of Learning and Data, Germany; RIKEN AIP, 1-4-1 Nihonbashi, Chuo-ku, Tokyo 103-0027, Japan. Electronic address: nakajima@tu-berlin.de.

Keywords

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