When we read a word or see an object, conceptual meaning is automatically accessed. However, previous research investigating non-perceptual sensitivity to semantic class has employed active tasks. In this fMRI study, we tested whether conceptual representations in regions constituting the semantic network are invoked during passive semantic access and whether these representations are modulated by the need to access deeper knowledge. Seventeen healthy subjects performed a semantically active typicality judgment task and a semantically passive phonetic decision task, in both the written and the spoken input-modalities. Stimuli consisted of one hundred forty-four concepts drawn from six semantic categories. Multivariate Pattern Analysis (MVPA) revealed that the left posterior middle temporal gyrus (pMTG), posterior ventral temporal cortex (pVTC) and pars triangularis of the left inferior frontal gyrus (IFG) showed a stronger sensitivity to semantic category when active rather than passive semantic access is required. Using a cross-task training/testing classifier, we determined that conceptual representations were not only active in these regions during passive semantic access but that the neural representation of these categories was common to both active and passive access. Collectively, these results show that while representations in the pMTG, pVTC and IFG are strongly modulated by active conceptual access, consistent representational patterns are present during active and passive conceptual access in these same regions.

当我们读到一个词或看到一个物体时，概念意义就自动被访问了。然而，先前研究对语义类的非感知敏感性的研究采用了主动任务。在这项 fMRI 研究中，我们测试了在被动语义访问期间是否调用了构成语义网络的区域中的概念表示，以及这些表示是否受到访问更深知识的需要的调节。17 名健康受试者在书面和口头输入模式中执行语义主动典型性判断任务和语义被动语音决策任务。刺激由来自六个语义类别的一百四十四个概念组成。多变量模式分析 (MVPA) 显示，左侧后颞中回 (pMTG)、当需要主动而不是被动的语义访问时，后腹侧颞叶皮层（pVTC）和左额下回（IFG）的三角肌对语义类别表现出更强的敏感性。使用跨任务训练/测试分类器，我们确定概念表示不仅在被动语义访问期间在这些区域中是活跃的，而且这些类别的神经表示对于主动和被动访问都是通用的。总的来说，这些结果表明，虽然 pMTG、pVTC 和 IFG 中的表征受到主动概念访问的强烈调节，但在这些相同区域的主动和被动概念访问期间存在一致的表征模式。使用跨任务训练/测试分类器，我们确定概念表示不仅在被动语义访问期间在这些区域中是活跃的，而且这些类别的神经表示对于主动和被动访问都是通用的。总的来说，这些结果表明，虽然 pMTG、pVTC 和 IFG 中的表征受到主动概念访问的强烈调节，但在这些相同区域的主动和被动概念访问期间存在一致的表征模式。使用跨任务训练/测试分类器，我们确定概念表示不仅在被动语义访问期间在这些区域中是活跃的，而且这些类别的神经表示对于主动和被动访问都是通用的。总的来说，这些结果表明，虽然 pMTG、pVTC 和 IFG 中的表征受到主动概念访问的强烈调节，但在这些相同区域的主动和被动概念访问期间存在一致的表征模式。