Right fusiform response patterns reflect visual object identity rather than semantic similarity
Right fusiform response patterns reflect visual object identity rather than semantic similarity
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DOI：
10.1016/j.neuroimage.2013.05.128
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发表时间：
2013-12-01
期刊：
影响因子：
5.7
通讯作者：
Vandenberghe, Rik
中科院分区：
文献类型：
--
作者：
Bruffaerts, Rose;Dupont, Patrick;Vandenberghe, Rik
我们之前报道了右侧梭状回中部和后部病变（病例JA）的神经心理学后果，导致在缺乏类别选择性（有生命的与无生命的）的情况下，对具体实体的视觉属性的部分知识丧失。我们在两步模型的背景下解释了这一点，该模型区分了结构描述知识和联想语义处理，并在前一个过程中暗示了受损区域。为了在完整的大脑中验证这一假设，对46名健康受试者进行了一系列事件相关的功能磁共振成像研究，采用了多体素模式分析。我们预测，该区域的活动模式将由具体实体之间的身份而不是概念相似性决定。在先前的行为实验中，1000多名受试者为每个实体生成特征。基于层次聚类分析，这些实体被组织成3个语义类（乐器、车辆、工具）。实体以文字或图片的形式呈现。在图像中央凹呈现时，右侧梭状皮质fMRI反应模式之间的余弦相似性似乎反映了实体的身份和实体之间的语义相似性。这个区域的单词没有这种影响。物体同一性对位置、缩放、方向轴和颜色（灰度vs彩色）的影响是不变的。它也适用于引用同一具体实体的不同范例。然而，表观语义相似效应并非不变。本研究为结构描述知识和语义关系加工之间的神经生物学区分提供了进一步的支持，并证实了右中后梭状皮质在前者过程中的作用，与先前的病变证据一致。(C) 2013爱思唯尔公司版权所有。
We previously reported the neuropsychological consequences of a lesion confined to the middle and posterior part of the right fusiform gyrus (case JA) causing a partial loss of knowledge of visual attributes of concrete entities in the absence of category-selectivity (animate versus inanimate). We interpreted this in the context of a two-step model that distinguishes structural description knowledge from associative-semantic processing and implicated the lesioned area in the former process. To test this hypothesis in the intact brain, multi-voxel pattern analysis was used in a series of event-related fMRI studies in a total of 46 healthy subjects. We predicted that activity patterns in this region would be determined by the identity of rather than the conceptual similarity between concrete entities. In a prior behavioral experiment features were generated for each entity by more than 1000 subjects. Based on a hierarchical clustering analysis the entities were organised into 3 semantic clusters (musical instruments, vehicles, tools). Entities were presented as words or pictures. With foveal presentation of pictures, cosine similarity between fMRI response patterns in right fusiform cortex appeared to reflect both the identity of and the semantic similarity between the entities. No such effects were found for words in this region. The effect of object identity was invariant for location, scaling, orientation axis and color (grayscale versus color). It also persisted for different exemplars referring to a same concrete entity. The apparent semantic similarity effect however was not invariant. This study provides further support for a neurobiological distinction between structural description knowledge and processing of semantic relationships and confirms the role of right mid-posterior fusiform cortex in the former process, in accordance with previous lesion evidence. (C) 2013 Elsevier Inc. All rights reserved.