Similarity of fMRI Activity Patterns in Left Perirhinal Cortex Reflects Semantic Similarity between Words
Similarity of fMRI Activity Patterns in Left Perirhinal Cortex Reflects Semantic Similarity between Words
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DOI：
10.1523/jneurosci.1548-13.2013
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发表时间：
2013-11-20
影响因子：
5.3
通讯作者：
Vandenberghe, Rik
中科院分区：
文献类型：
--
作者：
Bruffaerts, Rose;Dupont, Patrick;Vandenberghe, Rik
语言和非语言的视觉概念输入如何与语义知识相联系是视觉和认知神经科学的核心问题，具有重要的临床意义。在事件相关功能磁共振成像(FMRI)实验中，我们确定了fMRI反应模式与具体单词和图片之间的余弦相似性如何反映单个类别中表示的实体之间的语义聚类和语义距离。语义聚类和24个动画实体之间的语义距离来自概念-特征矩阵，该矩阵基于>；1000受试者的特征生成。在主要的fMRI研究中，19名人类受试者执行了一项文字和图片的属性验证任务，以及一项低水平控制任务。语义任务和对照任务之间的单变量对比产生了从后扣带回到前内侧颞叶皮质的广泛的双侧枕颞叶激活。属于同一语义簇的实体在左侧枕颞叶皮质引发了更相似的fMRI活动模式。当文字和图片分开分析时，只有文字的效果才达到显著水平。词汇的语义相似性效应局限于左侧大脑皮质。根据对左侧周边反应的代表性相似性分析，实体之间的语义距离与书面单词的fMRI反应模式之间的余弦相似性呈负相关。一项对16名新受试者进行的独立复制研究证实了这些新发现。语义相似性通过左侧大脑皮质细粒水平上的功能地形图相似性来反映。专一性这个词排除了知觉驱动，作为一种解释令人困惑，而且很可能与任务有关。
Howverbal and nonverbal visuoperceptual input connects to semantic knowledge is a core question in visual and cognitive neuroscience, with significant clinical ramifications. In an event-related functional magnetic resonance imaging (fMRI) experiment we determined how cosine similarity between fMRI response patterns to concrete words and pictures reflects semantic clustering and semantic distances between the represented entities within a single category. Semantic clustering and semantic distances between 24 animate entities were derived from a concept-feature matrix based on feature generation by >1000 subjects. In the main fMRI study, 19 human subjects performed a property verification task with written words and pictures and a low-level control task. The univariate contrast between the semantic and the control task yielded extensive bilateral occipitotemporal activation from posterior cingulate to anteromedial temporal cortex. Entities belonging to a same semantic cluster elicited more similar fMRI activity patterns in left occipitotemporal cortex. When words and pictures were analyzed separately, the effect reached significance only for words. The semantic similarity effect for words was localized to left perirhinal cortex. According to a representational similarity analysis of left perirhinal responses, semantic distances between entities correlated inversely with cosine similarities between fMRI response patterns to written words. An independent replication study in 16 novel subjects confirmed these novel findings. Semantic similarity is reflected by similarity of functional topography at a fine-grained level in left perirhinal cortex. The word specificity excludes perceptually driven confounds as an explanation and is likely to be task dependent.