Representational Similarity Mapping of Distributional Semantics in Left Inferior Frontal, Middle Temporal, and Motor Cortex
Representational Similarity Mapping of Distributional Semantics in Left Inferior Frontal, Middle Temporal, and Motor Cortex
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DOI：
10.1093/cercor/bhw379
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发表时间：
2017-01-01
期刊：
影响因子：
3.7
通讯作者：
Pulvermuller, Friedemann
中科院分区：
文献类型：
--
作者：
Carota, Francesca;Kriegeskorte, Nikolaus;Pulvermuller, Friedemann
语言理解涉及额颞区、顶叶区和感觉运动区的分布式网络，但目前尚不清楚单词的含义及其语义关系在这些区域内是如何被表示和处理的，以及词汇语义表示在区域和语义类型之间的差异程度。我们使用功能磁共振成像和表征相似性分析，涉及到词引起的多体素模式之间的语义相似性动作和对象的话。在左下额叶（BA 44-45-47），左后中颞叶和左中央前皮层，大脑反应模式的相似性反映了动作相关动词之间的语义相似性，以及跨词汇类之间的动作动词和工具相关名词，并在一定程度上，动作动词和食物名词，但不是动作动词和动物名词。相反，后下颞叶皮层表现出相反的反应模式，这反映了物体相关名词之间的语义相似性，但不是动作相关的话。这些结果表明，语义相似性是由一系列皮层区域编码的，包括多模态关联（例如，前下额叶，后中颞）和模态优先（运动前）皮层，在这些地区的代表性的几何形状是部分依赖于语义类型，语义相似性与动作相关的词跨越词汇语义类别的边界。
Language comprehension engages a distributed network of frontotemporal, parietal, and sensorimotor regions, but it is still unclear how meaning of words and their semantic relationships are represented and processed within these regions and to which degrees lexico-semantic representations differ between regions and semantic types. We used fMRI and representational similarity analysis to relate word-elicited multivoxel patterns to semantic similarity between action and object words. In left inferior frontal (BA 44-45-47), left posterior middle temporal and left precentral cortex, the similarity of brain response patterns reflected semantic similarity among action-related verbs, as well as across lexical classes-between action verbs and tool-related nouns and, to a degree, between action verbs and food nouns, but not between action verbs and animal nouns. Instead, posterior inferior temporal cortex exhibited a reverse response pattern, which reflected the semantic similarity among object-related nouns, but not action-related words. These results show that semantic similarity is encoded by a range of cortical areas, including multimodal association (e.g., anterior inferior frontal, posterior middle temporal) and modality-preferential (premotor) cortex and that the representational geometries in these regions are partly dependent on semantic type, with semantic similarity among action-related words crossing lexical-semantic category boundaries.