Abstract: Not all the knowledge or behaviors of human beings and animals are acquired from the first exposure. Repetitive study, as a more common learning approach, plays an important role in getting new information into long term memory. When stimulus presented repeatedly, repetition effect arises as a sign of learning and memory. Previous researches have found that inter-item lag is one of the most important determining factors of the effect. However, it is still not clear what kind of repetition effect can be produced when it comes to phonological materials. Thus, repetition effect of Chinese spoken word was investigated in this study.
Using a continuous recognition paradigm, 180 bi-syllable spoken words were repeated after 0, 1 or 8~10 intervening items (lags). Electroencephalogram was recorded when 16 right-handed participants were required to judge whether a spoken word had been heard before in the experiment.
The behavior results show that as inter-item lags increase, reaction time facilitation of repeated words decreased gradually till even disappeared. The ERP data show that compared to their first presentation, repeated words elicit widespread positive waveforms. And the ERP repetition effects occur later as lags increase: the old-new effect begins from about 200ms at Lag0, 300ms at Lag1 and 400ms at Lag8.
These results show that the repetition effects of spoken word at different lags are modulated at least by three different neural mechanisms, which reflect facilitation of phonological process, semantic process and episodic information retrieving respectively.

Key words: spoken word, repetition effect, lag, ERP