Journal of Guangxi Normal University(Natural Science Edition) ›› 2025, Vol. 43 ›› Issue (3): 43-56.doi: 10.16088/j.issn.1001-6600.2024092401

• Intelligence Information Processing • Previous Articles     Next Articles

Complex-value Covariance-based Convolutional Neural Network for Decoding Motor Imagery-based EEG Signals

HUANG Renhui, ZHANG Ruifeng, WEN Xiaohao, BI Jinjie, HUANG Shoulin*, LI Tinghui   

  1. School of Electronics and Information Engineering/School of Integrated Circuits, Guangxi Normal University, Guilin Guangxi 541004, China
  • Received:2024-09-24 Revised:2024-10-31 Online:2025-05-05 Published:2025-05-14

Abstract: To improve the classification performance of motor imagery (MI) tasks by deeply mining and using the characteristic information of electroencephalogram (EEG) signals has always been the focus of brain-computer interfaces (BCI) research. Because EEG feature space is highly dimensional and directly related to both amplitude and phase of EEG signals, how to simultaneously represent and utilize the information contained in amplitude and phase has become a difficult issue. To address this issue, a three-dimensional complex convolutional neural network based on complex-value covariance features is proposed. Firstly, complex-value covariance matrices related to different frequencies as MI-based EEG features is constructed. As a result, complex value can combine the amplitude and phase information of EEG signals together. Moreover, the covariance matrices can preserve multivariate information such as amplitude, phase, spatial locations, frequency, etc. required for classification. Secondly, a full complex convolutional neural network is designed for learning the covariance features and thus achieving high performance classification. Experimental results on two publicly available datasets show that the proposed method can achieve mean accuracies that are at least 2.49 and 1.85 percentage points higher than state-of-the-art methods.

Key words: electroencephalogram, brain-computer interface, fusion of amplitude and phase information, complex covariance features, complex-valued convolutional neural network, information interactive

CLC Number:  TN911.7
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