AUDITORY MISMATCH NEGATIVITY IN SCHIZOPHRENIA - TOPOGRAPHIC EVALUATION WITH A HIGH-DENSITY RECORDING MONTAGE

Objective: The mismatch negativity, a negative component in the audito ry event-related potential, is thought to index automatic processes in volved in sensory or echoic memory. The authors' goal in this study wa s to examine the topography of auditory mismatch negativity in schizop hrenia with a high-density, 64-channel recording montage. Method: Mism atch negativity topography was evaluated in 23 right-handed male patie nts with schizophrenia who were receiving medication and in 23 nonschi zophrenic comparison subjects who were matched in age, handedness, and parental socioeconomic status. The Positive and Negative Syndrome Sca le was used to measure psychiatric symptoms. Results: Mismatch negativ ity amplitude was reduced in the patients with schizophrenia. They sho wed a greater left-less-than-right asymmetry than comparison subjects at homotopic electrode pairs near the parietotemporal junction. There were correlations between mismatch negativity amplitude and hallucinat ions at left frontal electrodes and between mismatch negativity amplit ude and passive-apathetic social withdrawal at left and right frontal electrodes. Conclusions: Mismatch negativity was reduced in schizophre nia, especially in the left hemisphere. This finding is consistent wit h abnormalities of primary or adjacent auditory cortex involved in aud itory sensory or echoic memory.