Global Workspace theory proposes that conscious experience arises when specialized unconscious processors in the brain compete for access to a global broadcasting capability; the winning processor disseminates its information widely, enabling integration across separate modules. This architecture, also used in computer systems, accounts for phenomena from perceptual consciousness to problem-solving, voluntary action, and directed attention. The theory is consistent with limited-capacity mechanisms but not reducible to them. It requires competition for input to a neural global workspace and global distribution of output, functions carried out by brain structures necessary for normal conscious experience. The theory generates testable predictions for high-speed brain imaging.
Schizophrenia is diagnosed through standardized interviews that reliably assess subjective psychological symptoms, particularly Schneider's first-rank symptoms: specific auditory hallucinations, ego-boundary disturbances (intrusions into consciousness attributed to external forces), and delusional perception. Amphetamine-like drugs can induce similar symptoms in non-schizophrenic individuals, and both those symptoms and schizophrenia symptoms are reduced by neuroleptic drugs. Amphetamines increase dopamine-mediated neural transmission while neuroleptics decrease it. Post-mortem studies of schizophrenia patients found no increase in dopamine release, but some cases showed evidence of increased dopamine receptor sensitivity.