Differential relationship between mismatch negativity and cortical thickness of frontal cortices in schizophrenia

Abstract

Introduction: Mismatch negativity (MMN) is thought to reflect pre-attentive, automatic auditory processing. Reduced MMN amplitude is among the most robust findings in schizophrenia research. MMN generators have been shown to be located in the temporal and frontal cortices, which are key areas in the pathophysiology of schizophrenia. This study investigated whether fronto-temporal cortical thickness was associated with reduced MMN current source density (CSD) strength in patients with schizophrenia. Methods: In total, 16 schizophrenia patients and 18 healthy controls (HCs) were examined using magnetoencephalography while they performed a passive auditory oddball paradigm. All participants underwent a T1 structural magnetic resonance imaging scan in a separate session. We evaluated fronto-temporal MMN CSD and cortical thickness, as well as their associations with each other and with clinical symptoms, and explored their utility as classifiers. Results: Patients exhibited significantly reduced CSD strength in all temporal and frontal areas of interest relative to HCs. There was a positive correlation between CSD strength and cortical thickness in both the temporal and frontal areas in HCs. However, schizophrenia patients showed negative correlations between CSD strength and cortical thickness in the bilateral inferior frontal gyri. Additionally, we found positive correlations between frontal cortical thickness and negative and total scores on the Positive and Negative Syndrome Scale (PANSS). Conclusions: Our findings provide evidence for deficient temporal and frontal MMN generators in schizophrenia patients, suggesting disruption of the structure-function relationship in this illness.