Reward positivity and affective functioning in early childhood: evidence from temporospatial principal components...

Reward-related Positivity (RewP) indexes neural sensitivity to reward feedback and has been widely studied in adolescents and adults. However, little is known about how individual differences in RewP are associated with emotional functioning during early childhood, a critical period for affective development. Interpretation of feedback-related ERPs in children is further complicated by temporally overlapping components. This study examined whether a principal component analysis (PCA)-derived RewP is associated with affective functioning in children aged 4-7 years. Electroencephalography was recorded from 140 children during an age-appropriate reward task. Temporospatial PCA was performed on the full EEG sample (n = 140), and primary regression analyses were conducted in the subset with complete covariate data (n = 48). Temporospatial PCA was applied to isolate a RewP component differentiating gain from loss feedback. Positive and negative affect were assessed using the child version of the Positive and Negative Affect Schedule. Regression analyses examined whether PCA-derived RewP- and gain-related P200 amplitudes were associated with affective functioning while controlling for age, sex, ethnicity, income-to-need ratio, child depressive symptoms, and parental depressive symptoms. At the group level, boys showed greater PCA-derived gain-related P200 amplitudes than girls. At the individual level, higher child positive affect was associated with larger PCA-derived RewP amplitudes in the primary covariate-adjusted regression model. In sensitivity analyses conducted in the larger sample without the income-to-needs covariate, negative affect, rather than positive affect, was significantly associated with PCA-derived RewP amplitude. These findings provide novel evidence that RewP may serve as an early neural marker of affective functioning. By extending RewP research to an understudied developmental period and emphasizing normative emotional functioning, this study advances understanding of early reward processing and highlights the utility of PCA for isolating meaningful ERP components in children.