N400 responses of children with primary language disorder: intervention effects.

Event-related brain potentials were examined in 6 to 8-year-old children with primary language disorder before and after a 5-week narrative-based language intervention. Participants listened to sentences ending with semantically congruous or incongruous words. By comparison with typical controls, the children with primary language disorder exhibited no pretreatment differences in their N400 responses to congruous and incongruous sentence-final words. After intervention, the typical incongruous-congruous difference was observable owing to a dramatic reduction in the amplitude of the N400 response to congruous words. These characteristic changes in brain responses may reflect a positive effect of the language intervention on the lexical-semantic processing skills in children with language impairment.