Ugan: Uncertainty-Guided Graph Augmentation Network for EEG Emotion Recognition

The underlying time-variant and subject-specific brain dynamics lead to statistical uncertainty in electroencephalogram (EEG) representations and connectivities under diverse individual biases. Current works primarily augment statisticallike EEG data based on deterministic modes without comprehensively considering uncertain statistical discrepancies in representations and connectivities. This results in insufficient domain diversity to cover more domain variations for a generalized model independent of individuals. This article proposes an uncertainty-guided graph augmentation network (Ugan) to generalize EEG emotion recognition across subjects by comprehensively mimicking and constraining the uncertain statistical shifts across individuals. Specifically, an uncertainty-guided graph augmentation module is employed to augment both connectivities and features of EEG graph by manipulating domain statistical characteristics. With the original and augmented EEG graph covering diverse domain variations, the model can mimic the uncertain domain shifts to achieve better generalizability against potential subject variability. To extract discriminative characteristics and preserve emotional semantics after augmentation, a graph coteaching learning module is designed to facilitate coteaching knowledge learning between the original and augmented views. Moreover, a coteaching regularization module is developed to constrain semantic domain invariance and consistency, thereby rendering the model invariant to uncertain statistical shifts. Extensive experiments on three public EEG emotion datasets, i.e., Shanghai Jiao Tong University emotion EEG dataset (SEED), SEED-IV, and SEED-V, validate the superior generalizability of Ugan compared to the state-of-the-art methods.