The auditory evoked response was studied in normal volunteers and patients with schizophrenia. The 100 msec (N100) response is thought to be processed in primary auditory cortex. Magnetoencephalograhy (MEG) was used to determine the source of the N100m (magnetic field associated with the N100). This work was accomplished under protocol 88-N-119 and involved collaboration between two branches, one in NINCDS and on in NIMH.