The deployment of Brain-Computer Interfaces (BCI) for non-responsive patients will provide access to modern information and communication technology such as internet, personal computer or home appliances when only a single response of a person is available. In this extreme case, no current assistive technology can help the patient interact with the environment. This situation poses serious ethical issues, since medical treatment can prolong the patients' life, but leave them in a state of unacceptable quality of life.DECODER will develop a BCI into single-switch based systems to practically enhance inclusion of patients who are otherwise only little or not at all able to interact with their environment and share ICT. This achievement will move on from the improvement of three components of state-of-the-art BCIs, i.e. signal acquisition (input), signal classification and signal translation (output) and adapt them to the specificities of non-responsive patients such as low arousal, short attention span, and altered electrical activity of the brain. A forth component is the application; existing assistive technology will be adapted to a single-switch control. Besides classic EEG paradigms near-infrared spectroscopy will be used for signal acquisition due to its higher spatial resolution. Potential and automated software will identify the best signal for each user and will optimize signal translation.Prior to providing such patients with ICT an unequivocal diagnosis is of utmost importance to define the most appropriate rehabilitation strategy and most suitable supportive technology for interaction. A hierarchical diagnostic approach starting with simple presentation of stimuli to intentional control of BCI will be developed, validated and disseminated.By implementing existing well-established and currently developed tools at all levels of the BCI and bringing together a multidisciplinary team we can ensure the achievement of the goals of DECODER.