fMRI data for word-pair presentation

There are two general views regarding the organization of object knowledge. The featurebased view assumes that object knowledge is grounded in a widely distributed neural network in terms of sensory/function features (e.g., Warrington & Shallice, 1984), while the category-based view assumes in addition that object knowledge is organized by taxonomic and thematic categories (e.g., Schwartz et al., 2011). Using an fMRI adaptation paradigm, we compare predictions from the feature- and category-based views by examining the neural substrates recruited as subjects read word pairs that are identical, taxonomically related, thematically related or unrelated while controlling for the function features involved across the two categories. The feature-based view predicts that adaptation in function regions (i.e., left posterior middle temporal lobe, left premotor cortex) should be observed for related word pairs regardless of the taxonomic/thematic categories. In contrast, the category-based view generates the prediction that adaptation in the bilateral anterior temporal lobes should be observed for taxonomically related word pairs and adaptation in the left temporo-parietal junction should be observed for thematically related word pairs. By improving upon previous study designs and employing the fMRI adaptation task, this study has the potential to clarify the role of semantic categories and features in the organization of object knowledge.

关于客体知识的组织架构，目前存在两种主流观点。基于特征的视角（feature-based view）认为，客体知识以感官与功能特征为基础，锚定在广泛分布的神经网络中（如Warrington与Shallice，1984）；而基于类别的视角（category-based view）则进一步提出，客体知识还可通过分类学范畴与主题范畴实现组织（如Schwartz等人，2011）。本研究采用功能磁共振适应范式（fMRI adaptation paradigm），通过控制两类范畴所涉及的功能特征，让被试阅读完全相同、分类学相关、主题相关或无关的词对，同时记录被激活的神经底物，以此对比基于特征与基于类别的视角所提出的预测。基于特征的视角预测：无论词对属于分类学还是主题范畴，只要词对相关，功能相关脑区（即左侧后颞中回、左侧前运动皮层）均应出现适应效应。与之相对，基于类别的视角则提出：分类学相关的词对应在双侧前颞叶出现适应效应，而主题相关的词对应在左侧颞顶联合区出现适应效应。本研究通过优化既往研究设计并采用功能磁共振适应任务，有望阐明语义范畴与特征在客体知识组织架构中的作用。