Boudewyn Megan A, Long Debra L, Traxler Matthew J, Lesh Tyler A, Dave Shruti, Mangun George R, Carter Cameron S, Swaab Tamara Y
University of California, Davis.
J Cogn Neurosci. 2015 Dec;27(12):2309-23. doi: 10.1162/jocn_a_00837. Epub 2015 Sep 24.
The establishment of reference is essential to language comprehension. The goal of this study was to examine listeners' sensitivity to referential ambiguity as a function of individual variation in attention, working memory capacity, and verbal ability. Participants listened to stories in which two entities were introduced that were either very similar (e.g., two oaks) or less similar (e.g., one oak and one elm). The manipulation rendered an anaphor in a subsequent sentence (e.g., oak) ambiguous or unambiguous. EEG was recorded as listeners comprehended the story, after which participants completed tasks to assess working memory, verbal ability, and the ability to use context in task performance. Power in the alpha and theta frequency bands when listeners received critical information about the discourse entities (e.g., oaks) was used to index attention and the involvement of the working memory system in processing the entities. These measures were then used to predict an ERP component that is sensitive to referential ambiguity, the Nref, which was recorded when listeners received the anaphor. Nref amplitude at the anaphor was predicted by alpha power during the earlier critical sentence: Individuals with increased alpha power in ambiguous compared with unambiguous stories were less sensitive to the anaphor's ambiguity. Verbal ability was also predictive of greater sensitivity to referential ambiguity. Finally, increased theta power in the ambiguous compared with unambiguous condition was associated with higher working-memory span. These results highlight the role of attention and working memory in referential processing during listening comprehension.
建立指称对于语言理解至关重要。本研究的目的是考察听众对指称歧义的敏感度，作为注意力、工作记忆容量和语言能力个体差异的函数。参与者听故事，故事中引入了两个实体，它们要么非常相似（例如，两棵橡树），要么不太相似（例如，一棵橡树和一棵榆树）。这种操作使得后续句子中的回指（例如，橡树）具有歧义或无歧义。当听众理解故事时记录脑电图，之后参与者完成任务以评估工作记忆、语言能力以及在任务表现中使用语境的能力。当听众接收到关于话语实体（例如，橡树）的关键信息时，阿尔法和西塔频段的功率被用于指示注意力以及工作记忆系统在处理这些实体时的参与情况。然后使用这些测量来预测对指称歧义敏感的ERP成分，即Nref，它是在听众接收到回指时记录的。回指处的Nref振幅由早期关键句子期间的阿尔法功率预测：与无歧义故事相比，在歧义故事中阿尔法功率增加的个体对回指的歧义不太敏感。语言能力也预示着对指称歧义更敏感。最后，与无歧义条件相比，歧义条件下西塔功率的增加与更高的工作记忆广度相关。这些结果突出了注意力和工作记忆在听力理解过程中指称处理中的作用。
