An Event-Related fMRI Investigation of Implicit Semantic Priming
An Event-Related fMRI Investigation of Implicit Semantic Priming
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DOI：
10.1162/089892903322598120
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发表时间：
2003-11
影响因子：
3.2
通讯作者：
Jesse Rissman;J. Eliassen;S. Blumstein
中科院分区：
文献类型：
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作者：
Jesse Rissman;J. Eliassen;S. Blumstein
使用事件相关功能磁共振成像研究了隐式语义启动的神经基础。听觉上呈现素数-目标对，以对目标刺激进行词汇决策（LD），目标刺激要么在语义上与素数相关，要么与素数无关，或者是非单词。还进行了音调任务作为对照。在行为上，所有参与者都在 LD 任务中表现出语义启动。 fMRI 结果显示，对于 LD 任务的所有三种情况，颞上回 (STG)、颞中回 (MTG) 和顶下叶都有激活，在不相关和非单词条件下的激活程度高于相关条件。相关和不相关条件的直接比较揭示了左侧 STG、左侧中央前回、左侧和右侧 MTG 以及右侧尾状核的病灶，在相关条件下表现出显着较低的激活水平。颞叶活动的减少表明，对主词的感知激活了与目标词共享共同元素的词汇语义网络，因此，可以通过增强的神经效率来识别目标。额叶的减少很可能反映了监测颞叶词汇表征激活、做出决定和规划适当运动反应的效率提高。
The neural basis underlying implicit semantic priming was investigated using event-related fMRI. Prime-target pairs were presented auditorily for lexical decision (LD) on the target stimulus, which was either semantically related or unrelated to the prime, or was a nonword. A tone task was also administered as a control. Behaviorally, all participants demonstrated semantic priming in the LD task. fMRI results showed that for all three conditions of the LD task, activation was seen in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the inferior parietal lobe, with greater activation in the unrelated and nonword conditions than in the related condition. Direct comparisons of the related and unrelated conditions revealed foci in the left STG, left precentral gyrus, left and right MTGs, and right caudate, exhibiting significantly lower activation levels in the related condition. The reduced activity in the temporal lobe suggests that the perception of the prime word activates a lexical semantic network that shares common elements with the target word, and, thus, the target can be recognized with enhanced neural efficiency. The frontal lobe reductions most likely reflect the increased efficiency in monitoring the activation of lexical representations in the temporal lobe, making a decision, and planning the appropriate motor response.