Doctoral dissertation research: The Effects of Syntactic Complexity on Native and Nonnative Agreement Processing: An Event-Related Potentials Investigation

世界上许多语言都表现出某种形式的语法一致性，一种语言成分的语法特征在另一种相关成分上是可见的。最近的心理语言学研究发现了一些影响我们在语言产生过程中计算一致性的语义和句法因素，尽管关于这些因素在语言理解过程中如何相互作用的了解要少得多。在第二语言习得领域，理解一致的过程也是至关重要的，因为人们经常观察到，尽管第二语言学习者接受了多年的正式语言教学，并沉浸在第二语言环境中，但他们在语法一致方面表现出相当大的困难。许多二语习得学者提出二语学习者的一致性问题是加工问题的结果，但很少有研究直接对此进行研究。本论文的研究项目考察了来自不同语言背景的英语本族语者和高级第二语言学习者在实时句子理解过程中如何计算主谓一致性，特别是句子的句法复杂性如何影响一致性处理。本实验利用语法一致现象进一步研究了最近的假设，即二语学习者不能习得非母语语法对比，以及二语学习者的语言处理系统与母语系统有很大的不同。这些问题将通过记录受试者阅读英语句子时的事件相关脑电位(ERPs)来解决。尽管还没有研究发现句法复杂性如何影响协议计算，但事件相关电位对母语协议加工的许多方面都高度敏感。此外，事件相关电位最近才被用来研究二语加工。因此，关于二语协议加工的神经基础，或协议、句法和一语经验在二语加工过程中如何相互作用的知识十分匮乏。因此，将现代心理语言学和神经生理学技术应用于二语习得和加工的研究，将是对已有的丰富的二语语法表征理论语言学文献的补充。这项研究的结果将会引起对语言感兴趣的认知神经学家、理论语言学家和心理语言学家的兴趣，他们研究协议及其与句法结构的关系，以及协议如何与句法分析系统相互作用。这一结果将会引起二语习得理论和应用研究者的兴趣，并可能对语言习得理论和语言教育学产生重大影响。

Many languages of the world show grammatical agreement of some sort, where the grammatical features of a linguistic constituent are visible on another associated constituent. Recent psycholinguistic research has uncovered a number of semantic and syntactic factors that influence how we compute agreement during language production, though much less is known about how these factors interact during language comprehension. Understanding the processing of agreement is also of critical importance in the field of second language acquisition (SLA), as it is frequently observed that second language (L2) learners show considerable trouble with grammatical agreement, often despite many years of formal language instruction and immersion in an L2 environment. Many SLA scholars have proposed that L2 learners' problems with agreement are the result of processing problems, though little research has directly investigated this.This dissertation research project investigates how subject-verb agreement is computed during real-time sentence comprehension by native speakers of English and by advanced second language learners of English from different linguistic backgrounds, specifically focusing on how a sentence's syntactic complexity influences agreement processing. The experiment uses grammatical agreement phenomena to additionally investigate recent hypotheses that nonnative grammatical contrasts are unacquirable by L2 learners and that L2 learners' language processing systems are radically different from native language systems. These questions will be addressed by recording event-related brain potentials (ERPs) while participants read sentences in English. ERPs have been shown to be highly sensitive to many facets of native language agreement processing, though no studies have investigated how syntactic complexity affects agreement computation. Additionally, ERPs have only recently been used to study L2 processing. There is thus a paucity of knowledge about the neural substrates underlying L2 agreement processing or how agreement, syntax, and L1 experience interact during L2 processing. The inclusion of modern psycholinguistic and neurophysiological techniques in studying L2 acquisition and processing will therefore complement the existing rich theoretical linguistic literature on L2 grammatical representation. The outcomes of this research will be of interest to cognitive neuroscientists interested in language and to theoretical linguists and psycholinguists studying agreement, its relationship to syntactic structure, and how agreement interacts with syntactic parsing systems. The results will additionally be of interest to theoretical and applied SLA researchers, having potentially significant implications for language acquisition theory and language pedagogy.