PM503. Spatial components of magnetic mismatch negativity and the cortical thickness of its structural correlates in schizophrenia

The automatic auditory change detection response observed through the mismatch negativity (MMN) component of event-related potentials has been methodically studied in schizophrenia. MMN amplitude attenuation is a consistent finding in this population, and its generators are said to be localized in temporal, contributing to auditory perception and discrimination, and frontal, attention-switching, cortices. Studies of brain structure in schizophrenia have reported abnormalities in several areas, including those that are thought to be involved in the MMN response. However, the potential relationship between MMN and the characteristics of related brain areas is unclear and warrant further exploration. We conducted a magnetoencephalography study of MMN in 16 schizophrenia patients and 18 healthy control subjects. Through source reconstruction, we extracted whole-brain current source density (CSD) strengths using minimum norm estimation, and focused on areas previously reported as potential generators of MMN. We also went on to examine structural MRI data for cortical thickness. In comparison to healthy control subjects, patients with schizophrenia showed significantly decreased CSD strengths in both temporal and frontal areas of interest. The CSD strengths of both temporal and frontal areas showed positive correlations with cortical thickness in the control group. On the other hand, we observed a negative relationship between CSD and thickness in the patient group. Our findings may provide insight on the complex relationship between functional and structural abnormalities observed in schizophrenia.