Draft: Development of the Late Positive Potential from Late Childhood to Early Adulthood: Emotion Reactivity, Spatial Dynamics, and Internalizing Symptoms

The late positive potential (LPP) is a neural index of sustained processing of emotionally salient stimuli. Cross-sectional research suggests the LPP decreases across childhood and adolescence, but few longitudinal studies have characterized within-person change. This study examined developmental trajectories of the LPP from late childhood through early adulthood and tested associations with internalizing symptoms. Participants were 297 females (ages 8-14 at baseline) who were majority White and completed four visits spaced 2-3 years apart. Electroencephalography recorded the LPP while participants viewed neutral, pleasant, and unpleasant images. Multilevel modeling tested the impact of age, emotion condition, and electrode site, as well as links to internalizing symptoms. Results showed that emotion modulation of the LPP decreased with age at Oz and Pz but not Cz, most rapidly in late childhood and early adolescence. Age effects were strongest at Oz, while emotion effects were strongest at Pz at younger ages and both Pz and Cz at later ages. Higher internalizing symptoms were associated with a blunted LPP to pleasant images in childhood and early adolescence. Findings indicate the LPP declines rapidly through early adolescence before relative stabilization. Reduced occipital activity may reflect redistribution of emotion-attention networks toward greater frontal dominance during later adolescence.