Age-group differences in the N170 response during Chinese character processing in children aged 7–11 years: a cross-sectional event-related potential study
Background: Research on age-related changes in early electrophysiological responses to Chinese print across primary-school years is limited. This study examined age-group differences in the N170 response during Chinese character processing in children aged 7–11 years. Methods: A total of 103 children aged 7–11 years completed a semantic priming and pseudocharacter judgment task during electroencephalographic recording. Mean N170 voltage was measured from 130 to 240 ms at P7 and P8, the posterior occipitotemporal electrodes. A linear mixed-effects model was used to examine the effects of age group, stimulus type, and hemisphere, as well as their interactions, with sex and the sex-by-hemisphere interaction included as additional fixed effects. A generalized estimating equation (GEE) model was used for the sensitivity analysis. Results: Mean voltage in the N170 window differed across age groups [Wald χ2(4) =20.75, P<0.001]. Values were lower in 7-year-olds than in 10- and 11-year-olds (both Holm-adjusted P<0.001). Stimulus type (P=0.082) and hemisphere (P=0.152) were not significant, and neither showed a reliable interaction with age group. The three-way interaction, sex effect, and sex-by-hemisphere interaction were also nonsignificant. The sensitivity analysis yielded comparable results. Conclusions: N170-window mean voltage differed by age group, with the clearest differences between the 7-year-old group and the 10- and 11-year-old groups. No evidence of discrete transition windows or an age-related hemispheric shift was found. Longitudinal studies are needed to determine how these responses develop across childhood.