title: Experimental and theoretical approaches to conscious processing.
abstract: Recent experimental studies and theoretical models have begun to address the challenge of establishing a causal link between subjective conscious experience and measurable neuronal activity. The present review focuses on the well-delimited issue of how an external or internal piece of information goes beyond nonconscious processing and gains access to conscious processing, a transition characterized by the existence of a reportable subjective experience. Converging neuroimaging and neurophysiological data, acquired during minimal experimental contrasts between conscious and nonconscious processing, point to objective neural measures of conscious access: late amplification of relevant sensory activity, long-distance cortico-cortical synchronization at beta and gamma frequencies, and "ignition" of a large-scale prefronto-parietal network. We compare these findings to current theoretical models of conscious processing, including the Global Neuronal Workspace (GNW) model according to which conscious access occurs when incoming information is made globally available to multiple brain systems through a network of neurons with long-range axons densely distributed in prefrontal, parieto-temporal, and cingulate cortices. The clinical implications of these results for general anesthesia, coma, vegetative state, and schizophrenia are discussed.
authors.affiliation: INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette, 91191 France. stanislas.dehaene@gmail.com
authors.forename: Stanislas
authors.initials: S
authors.lastname: Dehaene
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Changeux
mesh_terms: D000818:Animals; D001288:Attention / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000166:cytology / Q000502:physiology*; D001931:Brain Mapping; D003243:Consciousness; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008954:Models, Biological; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*