In parallel with studies of the factors affecting adult word recognition is a growing literature harnessing the power of ERPs to study language learning and development. The neural architecture necessary to support N400 processing seems to be available quite early, as N400 effects have been reported in children as young as 9 months viewing unexpected events in action sequences (Reid et al 2009). In the domain of language, picture/word congruity N400 effects have been seen by 12–14 months of age, and vary with (productive) vocabulary (Friedrich & Friederici in press). Semantic congruity effects in sentences have been reported by 19 months, and are predictive of language skill at 30 months (Friedrich & Friederici 2006).
