Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Belgium.
Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Belgium; Neurology Department, University Hospitals Leuven, Leuven, Belgium.
Neuroimage. 2020 Aug 15;217:116892. doi: 10.1016/j.neuroimage.2020.116892. Epub 2020 May 1.
The examination of semantic cognition has traditionally identified word concreteness as well as valence as two of the principal dimensions in the representation of conceptual knowledge. More recently, corpus-based vector space models as well as graph-theoretical analysis of large-scale task-related behavioural responses have revolutionized our insight into how the meaning of words is structured. In this fMRI study, we apply representational similarity analysis to investigate the conceptual representation of abstract words. Brain activity patterns were related to a cued-association based graph as well as to a vector-based co-occurrence model of word meaning. Twenty-six subjects (19 females and 7 males) performed an overt repetition task during fMRI. First, we performed a searchlight classification procedure to identify regions where activity is discriminable between abstract and concrete words. These regions were left inferior frontal gyrus, the upper and lower bank of the superior temporal sulcus bilaterally, posterior middle temporal gyrus and left fusiform gyrus. Representational Similarity Analysis demonstrated that for abstract words, the similarity of activity patterns in the cortex surrounding the superior temporal sulcus bilaterally and in the left anterior superior temporal gyrus reflects the similarity in word meaning. These effects were strongest for semantic similarity derived from the cued association-based graph and for affective similarity derived from either of the two models. The latter effect was mainly driven by positive valence words. This research highlights the close neurobiological link between the information structure of abstract and affective word content and the similarity in activity pattern in the lateral and anterior temporal language system.
语义认知的研究通常将词的具体性和情感性作为概念知识表示的两个主要维度。最近，基于语料库的向量空间模型以及对大规模与任务相关的行为反应的图论分析，极大地改变了我们对单词意义结构的理解。在这项 fMRI 研究中，我们应用表示相似性分析来研究抽象词的概念表示。脑活动模式与基于提示联想的图以及基于词意义共现的向量模型相关联。26 名受试者（19 名女性和 7 名男性）在 fMRI 期间执行了显性重复任务。首先，我们进行了搜索灯分类程序，以识别在抽象词和具体词之间可区分的活动区域。这些区域位于左侧下额回、双侧上颞叶下回和上回、后颞中叶和左侧梭状回。表示相似性分析表明，对于抽象词，双侧上颞叶周围皮层和左侧前上颞叶的活动模式的相似性反映了词意义的相似性。这些影响在上文提示联想图的语义相似性和两个模型中任意一个的情感相似性中最强。后一个效应主要是由正价词驱动的。这项研究强调了抽象和情感词内容的信息结构以及外侧和前颞叶语言系统中的活动模式相似性之间的密切神经生物学联系。
