The electroencephalogram (EEG) is a cornerstone of neurophysiological research and clinical neurology. Historically, the classification of EEG as showing normal physiological or abnormal pathological activity has been performed by expert visual review. The potential value of unbiased, automated EEG classification has long been recognized, and in recent years the application of machine learning methods has received significant attention. A variety of solutions using convolutional neural networks (CNN) for EEG classification have emerged with impressive results. However, interpretation of CNN results and their connection with underlying basic electrophysiology has been unclear. This paper proposes a CNN architecture, which enables interpretation of intracranial EEG (iEEG) transients driving classification of brain activity as normal, pathological or artifactual. The goal is accomplished using CNN with long short-term memory (LSTM). We show that the method allows the visualization of iEEG graphoelements with the highest contribution to the final classification result using a classification heatmap and thus enables review of the raw iEEG data and interpret the decision of the model by electrophysiology means.

Department of Neurology St Anne's University Hospital Brno Czech Republic

Mayo Systems Electrophysiology Laboratory Department of Neurology Mayo Clinic Rochester MN 55905 USA Department of Physiology and Biomedical Engineering Mayo Clinic Rochester MN 55905 USA

Mayo Systems Electrophysiology Laboratory Department of Neurology Mayo Clinic Rochester MN 55905 USA Department of Physiology and Biomedical Engineering Mayo Clinic Rochester MN 55905 USA Czech Institute of Informatics Robotics and Cybernetics Czech Technical University Prague Prague Czech Republic

Mayo Systems Electrophysiology Laboratory Department of Neurology Mayo Clinic Rochester MN 55905 USA International Clinical Research Center St Anne's University Hospital Brno Brno Czech Republic

Mayo Systems Electrophysiology Laboratory Department of Neurology Mayo Clinic Rochester MN 55905 USA The Czech Academy of Sciences Institute of Scientific Instruments Brno Czech Republic International Clinical Research Center St Anne's University Hospital Brno Brno Czech Republic

The Czech Academy of Sciences Institute of Scientific Instruments Brno Czech Republic

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