The development of neural responses to emotional faces: A review of evidence from event-related potentials during early and middle childhood.

Facial emotion processing (FEP) develops throughout childhood and provides crucial social information necessary for the interpretation and prediction of others' behaviour. This systematic review, which includes a meta-regression component, sought to explore the development of FEP event-related potentials (P100, N170, and late positive potential [LPP]) in children aged three to twelve years. Thirty-four studies, representing data from 1511 children, were included in the review. The combination of meta-regression and systematic review suggest that P100 amplitude decreases with increasing age in response to emotional facial stimuli. P100 latency may show a gradual decrease around the age of ten. In terms of the N170, it is suggested that amplitude follows a non-linear trend with age, and latency may decrease in early childhood before plateauing during middle childhood. Of note, review of the literature indicates that substantial methodological differences and high levels of heterogeneity exist. We suggest future research considers these results within the context of emotion-specific development, whilst also acknowledging how this may relate to individual social functioning skills across early-to-middle childhood.