A Lightweight EEG Signal Classification Model Based on Riemannian Manifold
(School of Mathematics and Computer Science, Yan'an University, Yan'an 716000, China)
Abstract
To improve the accuracy and robustness of Motor Imagery EEG (MI-EEG) decoding, this paper proposes a Dense Riemannian Attention Network. The model integrates efficient feature encoding, second-order statistical modeling, and a hierarchical Attention Mechanism. Firstly, temporal-spatial features are extracted using one-dimensional convolution along with spatial-spectral attention. Then, a stackable hierarchical Riemannian attention block is introduced to perform deep modeling on covariance features, while dense connections are employed to enhance feature reuse. Finally, a multi-scale structure is utilized to capture information across different temporal scales. Experimental results demonstrate that the proposed method achieves an average classification accuracy of 82.79% on the BCI Competition IV-2a dataset, significantly outperforming EEGNet (71.95%) and FBCNet (76.52%). These results verify the effectiveness and generalization capability of the proposed model for MI-EEG decoding tasks.
Keywords
EEG signal; motor imagery; Attention Mechanism; Deep Learning; brain-computer interface
References
- [1] VAFAEI E,HOSSEINI M. Transformers in EEG Analysis:A Review of Architectures and Applications in Motor Imagery,Seizure,and Emotion Classification [J/OL].Sensors,2025,25(5):1293(2025-02-20).https://doi.org/10.3390/s25051293.
- [2] YANG X,JIA Z. Spatial-Temporal Mamba Network for EEG-Based Motor Imagery Classification [C]//International Conference on Advanced Data Mining and Applications.Singapore:Springer,2024:418-432.
- [3] WANG J,YE W,HE J,et al. Integrating Biological and Machine Intelligence: Attention Mechanisms in Brain Computer Interfaces [J/OL].Information Fusion,2025:103417(2025-07-02).https://doi.org/10.1016/j.inffus.2025.103417.
- [4] LIU H,YANG S,ZHANG Y,et al. LIBEER: A Comprehensive Benchmark and Algorithm Library for EEG-Based Emotion Recognition [J].IEEE Transactions on Affective Computing,2025,16(4):3596-3613.
- [5] MA X,CHEN W,PEI Z,et al. A Temporal Dependency Learning CNN With Attention Mechanism for MI-EEG Decoding [J].IEEE Transactions on Neural Systems and Rehabilitation Engineering,2023,31:3188-3200.
- [6] JIN M,DU C,HE H,et al. PGCN:Pyramidal Graph Convolutional Network for EEG Emotion Recognition [J].IEEE Transactions on Multimedia,2024,26:9070-9082.
- [7] LI C,WANG F,ZHAO Z,et al. Attention-Based Temporal Graph Representation Learning for EEG-Based Emotion Recognition [J].IEEE Journal of Biomedical and Health Informatics,2024,28(10):5755-5767.
- [8] XU B,ZHANG X,ZHANG X,et al. DDNet: A Hybrid Network Based on Deep Adaptive Multi-Head Attention and Dynamic Graph Convolution for EEG Emotion Recognition [J/OL].Signal,Image and Video Processing,2025,19(4):293(2025-01-26).https://doi.org/10.1007/s11760-025-03876-4.
- [9] MIAO Z,ZHAO M,ZHANG X,et al. LMDA-Net:A Lightweight Multi-Dimensional Attention Network for General EEG-Based Brain-Computer Interfaces and Interpretability [J/OL].NeuroImage,2023,276:120209(2023-06-06).https://doi.org/10.1016/j.neuroimage.2023.120209.
- [10] ZHU X,LIU C,ZHAO L,et al. EEG Emotion Recognition Network Based on Attention and Spatiotemporal Convolution [J/OL].Sensors,2024,24(11):3464(2024-05-27).https://doi.org/10.3390/s24113464.
- [11] MA X,CHEN W,PEI Z,et al. Attention-Based Convolutional Neural Network With Multi-Modal Temporal Information Fusion for Motor Imagery EEG Decoding [J/OL].Computers in Biology and Medicine,2024,175:108504(2024-06-01).https://doi.org/10.1016/j.compbiomed.2024.108504.
- [12] DING Y,LI Y,SUN H,et al. EEG-Deformer:A Dense Convolutional Transformer for Brain-Computer Interfaces [J].IEEE Journal of Biomedical and Health Informatics,2025,29(3):1909-1918.
- [13] DEVARAJAN K,PONNAN S,PERUMAL S. Hybrid CNN-Transformer Architecture for Enhanced EEG-Based Emotion Recognition:Capturing Local and Global Dependencies With Self-Attention Mechanisms [J/OL].Discover Computing,2025,28(1):87(2025-05-22).https://link.springer.com/article/10.1007/s10791-025-09596-0.
- [14] LUO J,WANG Y,XIA S,et al. A Shallow Mirror Transformer for Subject-Independent Motor Imagery BCI [J/OL].Computers in Biology and Medicine,2023,164:107254(2023-07-25).https://doi.org/10.1016/j.compbiomed.2023.107254.
- [15] HAN C,LIU C,WANG J,et al. A Spatial–Spectral and Temporal Dual Prototype Network for Motor Imagery Brain–Computer Interface [J/OL].Knowledge-Based Systems,2025,315:113315(2025-03-18).https://doi.org/10.1016/j.knosys.2025.113315.
- [16] LIANG W,ALLISON B Z,XU R,et al. SecNet:A Second Order Neural Network for MI-EEG [J/OL].Information Processing & Management,2025,62(3):104012(2024-12-06).https://doi.org/10.1016/j.ipm.2024.104012.
Funding
Shaanxi Provincial Science and Technology Plan Project (2023-JC-QN-0744); Research Plan Project of Shaanxi Provincial Department of Education (23JK0738); Horizontal Project (YDYZH20241231)
About the authors
Wang Long (1999-), male, Han ethnicity, from Yan'an, Shaanxi Province, is currently pursuing a master's degree. His research interests include deep learning and EEG signals; Corresponding author: Yang Zhanhai (1973-), male, Han ethnicity, born in Jingyang, Shaanxi, associate professor, master's student, research direction: software engineering, network control.