There are also consistent reductions in the size of the medial temporal lobe and the left neocortical superior temporal gyrus in patients with schizophrenia; those areas are responsible for declarative memory and auditory processing, respectively. Some studies have also found that the total volume of grey matter is decreased in schizophrenic individuals compared to normal subjects, though this is most pronounced in the frontal and temporal lobes.2
Structural brain changes don't always correlate to alterations in brain function, however, so scientists often combine the two by looking at functional MRI (fMRI). Structural MRI scans detect only differences in tissue type, but fMRI also reveals changes in blood oxygenation levels, a correlate of localized neural activity. "The reason that functional imaging has become very important is that it provides us with an ability to get insights into the psychology of schizophrenia, including the nature of the cognitive impairments that are present," ...