Schizophrenia verbal task. Coloured Positron Emission Tomography (PET) brain scans of a schizo- phrenic versus normal patient speaking. External views of the brain are seen. Areas highlighted in red/yellow are active during a verbal fluency task in which the patient's were asked to generate words. At top the normal brain shows much activity in prefrontal and motor areas, less in parietal area on the left side. In the schizophrenic brain, these areas are active, with the added area of the middle temporal gyrus (lower centre of brain) not seen in normal subjects. Schizophrenia leads to deluded thinking, hallucination and depression.