Biomedical Engineering Research Laboratory,
Department of Biomedical Genius, Faculty of Technology,
University Aboubekr Belkaid,
University Aboubekr Belkaid, P.O. Box 230, Chetouane, Tlemcen 13000, Algeria

Abstract: Electroencephalography (EEG)-based eye state classification is a key task in neuroscience and biomedical engineering, widely employed in cognitive monitoring and brain computer interface systems. While many studies report high classification accuracy within a single dataset, performance often deteriorates across different subjects or databases due to inter-subject variability and heterogeneous acquisition conditions. In this study, we introduce a subject-invariant and interpretable approach for EEG eye state classification that explicitly addresses cross-database generalisation. Our approach combines multi-domain EEG features with correlation alignment (CORAL) for domain adaptation and integrates neurophysiological constraints grounded in established EEG principles, including alpha-band reactivity, functional connectivity, and signal complexity. We evaluated the proposed method on three real-world universal EEG databases: PhysioNet, SPIS, and MNNIT. In cross-database evaluations, conventional models achieved accuracies of 63.4–66.1%, revealing limited generalisation. Incorporating CORAL improved performance to 72.1–74.8%, and the addition of neurophysiological constraints further increased accuracy to 81.5–83.2%. Notably, interpretability was maintained through SHAP-based feature importance analysis, identifying alpha-band power, occipital-parietal coherence, and entropy as the most influential features. These findings demonstrate that combining domain adaptation with physiologically informed constraints substantially enhances cross-database EEG eye-state classification, providing a robust and clinically interpretable solution for real-world EEG applications.


Keywords: Electroencephalography (EEG); Eye-state classification; CORAL; Neurophysiological constraints; Model interpretability.

VOLUME 10 ISSUE 04 2026: 1-13