Consciousness, schizophrenia and scientific theory

The positive symptoms of acute schizophrenia are, of their very nature, aberrations of conscious experience. A recent theory of the mechanisms underlying their occurrence spans four levels: neuroanatomical, neurochemical, cognitive and the symptoms themselves. The theory is capable of being tested in animals and human subjects, and it has passed a number of experimental tests at both levels with success. Implications of the theory for the scientific treatment of consciousness are considered. Although the theory permits useful questions relating to consciousness to be put and even to some extent to be answered, it leaves the most basic issue--the theoretical link between the occurrence of conscious experience and the neural substrate of the brain--unresolved, as do all similar theories so far.