Day 9 of the BCI & Neurorehabilitation Spring School was dedicated to exploring the multifaceted applications of brain-computer interfaces (BCIs) in brain assessment, communication, and rehabilitation. Expert speakers from around the world discussed topics ranging from BCI-based assessment and prediction for patients with disorders of consciousness to the use of hemodynamic BCIs for functional brain assessment and neurotherapy. Attendees gained insights into diagnostic research on Locked-in Syndrome, assessment techniques for comatose patients, and the significance of resting-state EEG alpha rhythms. The day also featured discussions on real-time assessment of concentration performance, the role of neurotechnology in clinical care, and cognition assessment and management in patients with Disorders of Consciousness. Additionally, practical sessions on mindBEAGLE assessment and offline analysis of ERPs provided attendees with valuable hands-on experience and tools for further research and application.