Professor Tim Crow believes that the difference in the development of the human brain from the primate brain - which allows us to process thought and speech - is linked to why psychotic illnesses occur. The human brain has developed to have a strong regional bias, so each side of the brain performs certain roles - for example, speech is controlled by the left side of the brain. Professor Crow of the mental health charity Sane's Prince of Wales International Centre in Oxford, suggests the division boundaries between certain areas of the brain, particularly those which are concerned with language...