Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC, USA.
Department of Linguistics, University of Maryland, College Park, MD, USA.
Neuropsychologia. 2019 Mar 4;125:116-128. doi: 10.1016/j.neuropsychologia.2019.01.019. Epub 2019 Feb 5.
In fMRI, increased activation for combinatorial syntactic and semantic processing is typically observed in a set of left hemisphere brain areas: the angular gyrus (AG), the anterior temporal lobe (ATL), the posterior superior temporal sulcus (pSTS), and the inferior frontal gyrus (IFG). Recent work has suggested that semantic combination is supported by the ATL and the AG, with a division of labor in which AG is involved in event concepts and ATL is involved in encoding conceptual features of entities and/or more general forms of semantic combination. The current fMRI study was designed to refine hypotheses about the angular gyrus processes in question. In particular, we ask whether the AG supports the computation of argument structure (a linguistic notion that depends on a verb taking other phrases as arguments) or the computation of event concepts more broadly. To distinguish these possibilities we used a novel, lexically-matched contrast: noun phrases (NP) (the frightened boy) and verb phrases (VP) (frightened the boy), where VPs contained argument structure, denoting an event and assigning a thematic role to its argument, and NPs did not, denoting only a semantically enriched entity. Results showed that while many regions showed increased activity for NPs and VPs relative to unstructured word lists (AG, ATL, pSTS, anterior IFG), replicating evidence of their involvement in combinatorial processing, neither AG or ATL showed differences in activation between the VP and NP conditions. These results suggest that increased AG activity does not reflect the computation of argument structure per se, but are compatible with a view in which the AG represents event information denoted by words such as frightened independent of their grammatical context. By contrast, pSTS and posterior IFG did show increased activation for the VPs relative to NPs. We suggest that these effects may reflect differences in syntactic processing and working memory engaged by different structural relations.
在 fMRI 中，通常在一组左半球脑区观察到组合句法和语义处理的激活增加：角回（AG）、前颞叶（ATL）、后上颞沟（pSTS）和下额回（IFG）。最近的研究表明，语义组合由 ATL 和 AG 支持，分工明确，AG 参与事件概念，ATL 参与实体的概念特征编码和/或更一般形式的语义组合。本 fMRI 研究旨在完善有关角回处理的假设。特别是，我们询问 AG 是否支持论元结构的计算（一种依赖于动词将其他短语作为论元的语言概念）或更广泛的事件概念的计算。为了区分这些可能性，我们使用了一种新颖的、词汇匹配的对比：名词短语（NP）（受惊的男孩）和动词短语（VP）（惊吓男孩），其中 VP 包含论元结构，表示一个事件，并为其论元指定一个主题角色，而 NP 则没有，仅表示一个语义丰富的实体。结果表明，虽然许多区域相对于非结构化单词列表（AG、ATL、pSTS、前 IFG）显示出 NP 和 VP 的活性增加，这证明了它们参与组合处理的证据，但 AG 或 ATL 均未显示 VP 和 NP 条件之间的激活差异。这些结果表明，AG 活性的增加并不反映论元结构的计算本身，而是与 AG 表示单词（如 frightened）表示的事件信息的观点一致，而与它们的语法上下文无关。相比之下，pSTS 和后 IFG 确实显示出 VP 相对于 NP 的激活增加。我们认为这些效应可能反映了不同结构关系所涉及的句法处理和工作记忆的差异。
