Degenerative diseases of the muscular or neural system and brain injury can leave humans without any means of communication which makes diagnosis and the determination of the level of consciousness extremely difficult. The electrophysiological responses of the brain to specific sensory stimulation are related to the level of information processing. It can be distinguished between precursors, basics and indicators of consciousness. While precursors and basics can be elicited with passive, indicators require active stimulation paradigms in which the subject is actively responding albeit without motor action. The activity of the brain to such paradigms can be recorded with electroencephalography (EEG) and functional imaging technology such as magnetic resonance imaging (fMRI) or near-infrared spectroscopy (fNIRS). These characteristic responses of the brain can be detected or “read” by specific algorithms and then interpreted with regards to the level of consciousness. Provided consciousness is detected, these patterns of the brain can be used for active communication. A locked-in individual is required to produce these specific activation patterns which then in turn correspond to Yes and No for basic communication.