EEG oscillatory states as neuro-phenomenology of consciousness as revealed from patients in vegetative and minimally conscious states

► Decreased number of EEG spectra (SP) types was related to altered consciousness. ► Unawareness was associated with the lack of diversity of alpha-rhythmic SP types. ► Occurrence probability of delta-, theta-rhythmic SPs was associated with unawareness. ► Occurrence probability of fast-alpha-rhythmic SPs was associated with consciousness. ► Number, duration and type of EEG microstates related to consciousness expression.