A combined stimuli presentation for assessing facial emotion related N170, N250 and visual mismatch negativity in neuropsychiatric disorders.

Abstract

Event-related potential (ERP) is a useful approach to assess the neurophysiological correlates of facial emotion processing. Previous studies examined the facial emotion recognition (FER) related ERPs (N170, N250, visual MisMatch Negativity) individually using ERP specific paradigms. This approach can be time-consuming and may not resemble real-life scenarios where an individual must process multiple stimuli simultaneously. The aim of the study was to assess the utility of a combined paradigm when compared to individual paradigms to measure N170, N250 and visual MisMatch Negativity (vMMN) in healthy controls (HC), utilizing emotion stimuli standardized in the Indian population. Further, the combined paradigm was examined in patients with schizophrenia (SCZ) to detect the differences in ERPs compared to HC. Within paradigms, ERPs showed higher amplitudes for emotion compared to neutral stimuli suggesting that the paradigms were able to detect valence associated with emotional stimuli. The combined paradigm was able to elicit decipherable peaks of N170, N250 and vMMN similar to individual paradigms. ERP data quality as assessed by analytic Standardized Measurement Error (aSME) showed a satisfactory aggregate score of above 2 for all the three paradigms. Combined paradigm approaches to record ERPs in neuropsychiatric conditions has the advantage of reducing the time required for task administration, avoiding practice effects, better subject cooperation and participation.