Department of Psychology, New York University, 6 Washington Place, New York, NY, USA.
Department of Neuroscience, Max-Planck-Institute (MPIEA), Grüneburgweg, Frankfurt, Germany.
Cereb Cortex. 2019 Jun 1;29(6):2470-2481. doi: 10.1093/cercor/bhy118.
Recent studies of semantic memory have focused on dissociating the neural bases of two foundational components of human thought: taxonomic categories, which group similar objects like dogs and seals based on features, and thematic categories, which group dissimilar objects like dogs and leashes based on events. While there is emerging consensus that taxonomic concepts are represented in the anterior temporal lobe, there is disagreement over whether thematic concepts are represented in the angular gyrus (AG). We previously found AG sensitivity to both kinds of concepts; however, some accounts suggest that such activity reflects inhibition of irrelevant information rather than thematic activation. To test these possibilities, an fMRI experiment investigated both types of conceptual relations in the AG during two semantic judgment tasks. Each task trained participants to give negative responses (inhibition) or positive responses (activation) to word pairs based on taxonomic and thematic criteria of relatedness. Results showed AG engagement during both negative judgments and thematic judgments, but not during positive judgments about taxonomic pairs. Together, the results suggest that activity in the AG reflects functions that include both thematic (but not taxonomic) processing and inhibiting irrelevant semantic information.
分类范畴，它基于特征将相似的物体（如狗和海豹）分组，主题范畴，它基于事件将不相似的物体（如狗和皮带）分组。虽然人们越来越一致地认为分类概念在前颞叶中得到了体现，但对于主题概念是否在角回（AG）中得到体现存在分歧。我们之前发现 AG 对这两种概念都有敏感性；然而，一些解释表明，这种活动反映的是对不相关信息的抑制，而不是主题激活。为了检验这些可能性，一项 fMRI 实验在两个语义判断任务中研究了 AG 中的这两种概念关系。每个任务都训练参与者根据分类和主题相关标准对单词对做出否定（抑制）或肯定（激活）的反应。结果表明，AG 在负判断和主题判断期间都有活动，但在对分类对进行肯定判断时没有活动。总的来说，这些结果表明，AG 的活动反映了包括主题（但不包括分类）处理和抑制不相关语义信息的功能。
