Facial Affect Perception and Event-Related Potential N170 in Schizophrenia:

Objective：N170, a component of event-related potentials (ERPs), is reportedly an index of facial perception. Recent studies have also suggested that N170 reflects emotional processing of human facial expressions. This study was designed to clarify how patients with schizophrenia process facial expressions using N170. Methods：We tested 11 patients who met the DSM-IV criteria for schizophrenia and 10 healthy normal controls. Participants were scored using the Positive and Negative Syndrome Scale (PANSS). ERPs were recorded using 64 channels while participants were presented with pictures of faces showing three different emotional states (happy, neutral, fearful). Results：No statistically significant differences appeared in N170 amplitudes between patients and normal controls in any of the three conditions. However, within-group analyses revealed greater N170 amplitudes in both the happy and fearful condition than the neutral condition. Furthermore, patients with schizophrenia exhibited marginally significant shorter N170 latency compared with normal controls, and latency was correlated with total PANSS scores in both the happy and neutral conditions. Amplitudes were not correlated with PANSS scores. Conclusions：The processing of facial expressions showing emotions (happy and fearful) differs from the processing of facial expressions showing a neutral state. In addition, N170 latency could be a good biomarker of the perception of human facial expressions in patients with schizophrenia.