VISUAL AND AUDITORY SENTENCE PROCESSING - A DEVELOPMENTAL ANALYSIS USING EVENT-RELATED BRAIN POTENTIALS

Subjects aged 5 to 26 years listened to and read (7 to 26 years) sentences that ended either with a highly expected (best completion) or a semantically inappropriate (anomalous completion) word. Event-related potentials (ERPs) to sentence final words displayed effects of contextual priming in both modalities in all age groups. Early and late ERP components displayed large decreases in amplitude and latency with age. These changes necessitated normalization procedures so that overall changes in amplitude with age could be assessed separately from changes in the amplitude of the differences between best-completion and anomalous-completion words. There were significant reductions in the contextual priming effects with age. Moreover, these age-related changes were different for the auditory and visual modalities, and for the early and later phases of the priming effect. These results suggest that nonidentical systems, with different developmental time courses, generate the early and late priming effects in the two modalities.