Semantic processing in children and adults: incongruity and the N400.

Semantic processing in 10-year-old children and adults was examined using event related potentials (ERPs). The N400 component, an index of semantic processing, was studied in relation to sentences that ended with congruent, moderately incongruent, or strongly incongruent words. N400 amplitude in adults corresponded to levels of semantic incongruity with the greatest amplitude occurring to strongly incongruent sentences at all midline electrodes. In contrast, children's N400s were greater for both moderately and strongly incongruent sentences but did not differ between these levels of incongruity. This finding suggests that semantic processing may differ in adults and children.