EEGM2: An Efficient Mamba-2-Based Self-Supervised Framework for Long-Sequence EEG Modeling

Deep learning has achieved significant progress in the development of electroencephalogram (EEG) foundation models, with Transformer-based architectures excelling at capturing long-range dependencies. However, their quadratic computational complexity presents challenges in memory efficiency, training, and inference speed, limiting their scalability and generalizability as a foundation model. In this paper, we propose EEGM2, a self-supervised framework based on structured state space duality (SSD) that overcomes these limitations. EEGM2 introduces three key innovations: (1) a reconstruction-based framework that captures both local and global EEG features through Mamba-2 structured state space models, (2) a spatiotemporal-aware loss function that enhances robustness to noise and preserves spectral information, and (3) a multi-branch receptive field input embedding strategy that improves cross-subject generalization and stability for EEG sequences of varying lengths. In comparison to traditional pretraining methods, on raw EEG or latent representation spaces, EEGM2 shows superior performance on long-sequence tasks, where conventional models struggle. Our experimental results on six EEG datasets validate that EEGM2 not only achieves state-of-the-art cross-domain accuracy but also reduces computational overhead, making it a more efficient solution for deployment on resource-constrained BCI devices.