不同延迟条件下语音词的重复效应

Effect of Inter-Item Lag on Spoken Word Repetition:An Event-Related Potential Study

采用连续再认范式,考察了不同延迟条件下,汉语口语词的重复效应。结果发现,立即重复产生了最大的反应时的易化,随着延迟的增加,易化作用逐渐减小甚至消失。在ERP上,与首次呈现相比,重复呈现的词会诱发广泛分布的更正的波形;并且随着延迟的增加,重复效应出现的时间越来越晚:立即重复条件从200ms左右开始,间隔一个词重复条件从300ms左右开始,间隔8～10个词时,重复效应从400ms左右开始。三种条件下的重复效应分别反映了对再次呈现的词的声学语音特征加工的易化、语义加工的易化和情景信息的提取。

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 Lagl and 400ms at LagS. 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.