Consciousness is one of the most significant scientific problems today. Renewed interest in the nature of consciousness - a phenomenon long considered not to be scientifically explorable, as well as increasingly widespread availability of multimodal functional brain imaging techniques (EEG, ERP, MEG, fMRI and PET), now offer the possibility of detailed, integrated exploration of the neural, behavioral, and computational correlates of consciousness. The present volume aims to confront the latest theoretical insights in the scientific study of human consciousness with the most recent behavioral, neuroimaging, electrophysiological, pharmacological and neuropathological data on brain function in altered states of consciousness such as: brain death, coma, vegetative state, minimally conscious state, locked-in syndrome, dementia, epilepsy, schizophrenia, hysteria, general anesthesia, sleep, hypnosis, and hallucinations. The interest of this is threefold. First, patients with altered states of consciousness continue to represent a major clinical problem in terms of clinical assessment of consciousness and daily management. Second, the exploration of brain function in altered states of consciousness represents a unique lesional approach to the scientific study of consciousness and adds to the worldwide effort to identify the 'neural correlate of consciousness'. Third, new scientific insights in this field have major ethical and social implications regarding our care for these patients.