Development of the N400 in infancy

In this longitudinal EEG study, we examined the developmental trajectory of the N400 component using a word-picture mismatch-paradigm in 18 infants at 10 and 12 months of age. Event-related potentials (ERPs) were recorded and analyzed in three consecutive time windows (400-600 ms, 600-800 ms, 800-1000 ms post-stimulus). At 10 months, a significant N400-like effect occurred (400-600 ms) but diminished by 12 months, potentially due to developmental changes or increased stimuli familiarity. No significant correlation emerged between N400 amplitude and parental reports of receptive vocabulary. These results imply that the N400 effect is present already in infancy.