Electrocortical reactivity to emotional images and faces in middle childhood to early adolescence.

The late positive potential (LPP) is an event-related potential (ERP) component that indexes sustained attention toward motivationally salient information. The LPP has been observed in children and adults, however little is known about its development from childhood into adolescence. In addition, whereas LPP studies examine responses to images from the International Affective Picture System (IAPS; Lang et al., 2008) or emotional faces, no previous studies have compared responses in youth across stimuli. To examine how emotion interacts with attention across development, the current study used an emotional-interrupt task to measure LPP and behavioral responses in 8- to 13-year-olds using unpleasant, pleasant, and neutral IAPS images, as well as sad, happy, and neutral faces. Compared to older youth, younger children exhibited enhanced LPPs over occipital sites. In addition, sad but not happy faces elicited a larger LPP than neutral faces; behavioral measures did not vary across facial expressions. Both unpleasant and pleasant IAPS images were associated with increased LPPs and behavioral interference compared to neutral images. Results suggest that there may be developmental differences in the scalp distribution of the LPP, and compared to faces, IAPS elicit more robust behavioral and electrocortical measures of attention to emotional stimuli.