Modified activity of the human auditory cortex during auditory hallucinations.

Previous reports have shown abnormalities in brain metabolism and evoked responses of schizophrenic patients with hallucinations. The authors recorded electric and magnetic auditory responses during transitory auditory hallucinations in two patients. Small but replicable response delays occurred during hallucinations. The results suggest that the effect of hallucinations on auditory cortex activity is similar to the effect of real sounds.