Word repetition effect and the influence of modality, stimulus quality,and lexicality : an ERP approach

Abstract

Repetition effect is known as the improved behavioural performance and reduced neural activation in response to a stimulus when it had been presented previously. In this study, event-related potentials (ERPs) were used to measure repetition effect at P100, P200, and N400; and the influence of modality, stimulus quality, and lexicality on repetition effect. 24 adults participated in an animal judgment task. The visual- and auditory-presented stimuli consisted of real words and pseudo words at different levels of stimulus quality. The stimuli were repeated immediately or after a delay of one to four trials. There was a significant reduction at P200 and N400 at repetition of stimulus, where repetition effect at N400 lasted longer than that at P200. Modality had a significant interaction effect with repetition at N400, indicating larger repetition effect in auditory than that in visual modality. The findings suggest that learning through repetition produce a longer effect for later stage of semantic processing than early pre-lexical processing, while auditory modality benefits more from repetition than visual modality.