Computerized EEG in schizophrenic patients.

We undertook a study of electroencephalograms (EEGs) in 30 right-handed, untreated patients (27.3 +/- 10.0 years; hebephrenic, 16; paranoid, 12; residual, 2) who fulfilled ICD-9 criteria for schizophrenia and compared them with sex- and age-matched controls by using the percentage of power in six EEG frequency bands calculated as a fraction of total power. T-statistic significance probability mapping (t-SPM) showed that, compared with normal controls, schizophrenics had more slow activity (delta, theta, and alpha 1) in the parieto-occipital regions, and more fast activity (beta 1) in the occipital regions. In contrast, alpha 2 activity decreased strikingly in the occipital regions and this decreased activity extended over much of the head. These findings were thought to indicate both cerebral hypofunction and excitability in acute untreated schizophrenia.