Consciousness: a neurobiological approach.

Consciousness and the disorders of consciousness can be more fully understood once they are integrated with the neurobiology of mental events. After a review of animal and human research, we found several anatomical structures in the central nervous system are required for consciousness. Identification of the critical structures, however, depends on what is meant by consciousness. In the general sense of mental responsivity, the reticular activating system must be intact. Consciousness has also been defined as the awareness of the sights, sounds, and feelings of everyday experience. In this sense, the system of sensory inputs and outputs of the anterior temporal cortex, amygdala, and the hippocampus must be functional. There is no neural evidence for "higher" consciousness.