The Effects of Semantic Priming and Word Repetition on Event‐Related Potentials

ABSTRACT Event‐related potentials (ERPs) were recorded during the performance of a lexical decision task, in which a proportion of the words were either semantic associates or repetitions of the preceding word. Reaction times were faster to both the second member of associated pairs (targets) and repeated words, with the latter facilitatory effect being more than twice that of the former. ERPs to the semantic primes were more negative‐going than those to targets. This difference peaked around 400–450 ms after stimulus onset. Comparison of unrepeated and repeated words revealed a larger and temporally more extended difference, with a similar scalp topography. The prime‐target differences are interpreted as a further example of the sensitivity of the ‘N400’ component of the ERP to semantic relationships between words. The differences between the repetition and priming effects in ERPs are considered equivocal with respect to the view that the associated behavioural effects are caused by different cognitive mechanisms.