Role of left inferior prefrontal cortex in retrieval of semantic knowledge: A reevaluation
Role of left inferior prefrontal cortex in retrieval of semantic knowledge: A reevaluation
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DOI：
10.1073/pnas.94.26.14792
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发表时间：
1997-12-23
影响因子：
11.1
通讯作者：
Farah, MJ
中科院分区：
文献类型：
--
作者：
Thompson-Schill, SL;D'Esposito, M;Farah, MJ
许多神经影像学研究结果被解释为左额下回（IFG）有助于语义知识提取的证据。我们提供了一个从根本上不同的解释，这是不是检索语义知识本身，是与左IFG活动，而是从语义记忆中的竞争替代品之间的信息选择。在一组受试者中，三个语义任务的选择要求各不相同。功能性磁共振成像信号在重叠区域的左IFG依赖于选择要求在所有三个任务。此外，语义处理的程度是不同的独立的选择要求的任务之一。左IFG活动的情况下，这一比较反驳的论点，选择的影响可以完全归因于语义检索程度的变化。我们的研究结果表明，这是选择，而不是检索，语义知识，驱动活动的左IFG。
A number of neuroimaging findings have been interpreted as evidence that the left inferior frontal gyrus (IFG) subserves retrieval of semantic knowledge. We provide a fundamentally different interpretation, that it is not retrieval of semantic knowledge per se that is associated with left IFG activity but rather selection of information among competing alternatives from semantic memory. Selection demands were varied across three semantic tasks in a single group of subjects. Functional magnetic resonance imaging signal in overlapping regions of left IFG was dependent on selection demands in all three tasks. In addition, the degree of semantic processing was varied independently of selection demands in one of the tasks. The absence of left IFG activity for this comparison counters the argument that the effects of selection can be attributed solely to variations in degree of semantic retrieval. Our findings suggest that it is selection, not retrieval, of semantic knowledge that drives activity in the left IFG.