State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
Neuroscience. 2011 Oct 13;193:217-28. doi: 10.1016/j.neuroscience.2011.07.010. Epub 2011 Jul 20.
In the present study, the ERP (event-related brain potentials) technique was used to investigate how accentuation influences the semantic short-term memory representations during on-line speech processing, and how this accentuation effect interacts with the distance of accentuation in the speech signal. Chinese spoken sentences were used as stimuli. The sentences included two critical words: Noun1 and Noun2, with the ERP time-locked to Noun2. During sentence comprehension, when the listener hears Noun2, he needs to retrieve Noun1 from the working memory and integrate it with Noun2. We manipulated the (de-)accentuation of Noun1 and the semantic relationship between Noun1 and Noun2 by changing Noun1 in the sentence context. Moreover, we manipulated the distance of accentuation (distance between Noun1 and Noun2) by changing the syntactic structure of the sentences. The results revealed a significant main effect of semantic relatedness, indicating that the low semantic relatedness condition elicited a larger N400 than the high semantic relatedness condition. Importantly, there was a significant two-way interaction between semantic relatedness and accentuation and a significant three-way interaction between semantic relatedness, accentuation, and distance. Further analysis demonstrated that, the semantic relatedness effect was modulated by accentuation in the long-distance sentences, but not in the short-distance sentences. That is, in the long-distance sentences, the semantic relatedness effect reached significance only when the to-be-integrated expression in the preceding sentence context was accented; however, in the short-distance sentences, the semantic relatedness effects reached significance regardless of the presence or absence of accentuation. The results indicated that, during on-line speech processing, accentuation can enhance the corresponding information's semantic short-term memory representation, and that the effect of accentuation on semantic short-term memory is somewhat flexible and shows up only when the words in the speech signal were far apart.
在本研究中，我们使用 ERP（事件相关电位）技术来研究重音如何影响在线言语处理过程中语义短时记忆的表示，以及这种重音效应如何与言语信号中的重音距离相互作用。我们使用汉语口语句子作为刺激。句子包括两个关键词：名词 1 和名词 2，ERP 与名词 2 时间锁定。在句子理解过程中，当听者听到名词 2 时，他需要从工作记忆中检索名词 1 并将其与名词 2 整合。我们通过改变句子语境中的名词 1 来操纵名词 1 的（去）重音和名词 1 与名词 2 之间的语义关系。此外，我们通过改变句子的句法结构来操纵重音的距离（名词 1 和名词 2 之间的距离）。结果显示语义相关性有显著的主效应，表明低语义相关性条件比高语义相关性条件诱发更大的 N400。重要的是，语义相关性和重音之间存在显著的双向交互作用，语义相关性、重音和距离之间存在显著的三向交互作用。进一步分析表明，在远距离句子中，重音对语义相关性的影响受到调节，但在近距离句子中则不受调节。也就是说，在远距离句子中，只有在前句语境中被重读的待整合表达时，语义相关性效应才显著；然而，在近距离句子中，无论是否存在重读，语义相关性效应都达到了显著水平。结果表明，在在线言语处理过程中，重音可以增强相应信息的语义短时记忆表示，并且重音对语义短时记忆的影响具有一定的灵活性，仅在言语信号中的单词相隔较远时才会出现。
