Linking semantic priming effect in functional MRI and event-related potentials
Linking semantic priming effect in functional MRI and event-related potentials
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DOI：
10.1016/j.neuroimage.2004.09.008
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发表时间：
2005-02-01
期刊：
影响因子：
5.7
通讯作者：
Sadato, N
中科院分区：
文献类型：
--
作者：
Matsumoto, A;Iidaka, T;Sadato, N
本研究的目的是利用事件相关功能磁共振成像（fMRI）和事件相关电位（ERP）相结合的研究方法来研究涉及语义启动的神经基质。12名受试者被要求判断所呈现的目标词是真词还是非词。在相关条件下，目标词前面有一个语义相关的启动词。另一方面，在不相关条件下，启动词与目标词没有语义相关性。不相关条件下达到判断的反应时间比相关条件下更长，说明相关条件下语义启动促进了目标词的识别。在fMRI结果中，我们发现在相关和不相关的条件下（即重复抑制效应），左侧额下回背侧和腹侧、前扣带和左侧颞上叶皮层的活动减少。ERP分析显示，与非相关条件（即N400启动效应）相比，相关条件下N400分量的振幅减小。通过独立分量分析（ICA）对BOLD重复抑制效应与N400启动效应进行跨受试者相关性分析，发现左侧颞上回具有显著相关性。这一发现与最近的MEG数据一致，表明N400的来源被判断为双侧颞上叶。我们在此讨论了这一发现与由语义启动引起的语音表征获取的调节有关。(C) 2004爱思唯尔公司版权所有。
The aim of this study is to examine the neural substrates involved in semantic priming using a combined event-related functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) study. Twelve subjects were instructed to judge whether the presented target word was a real word or a nonword. Under the related condition, target words were preceded by a semantically related prime word. On the other hand, under the unrelated condition, prime words did not have semantic relatedness with the target word. The reaction time for reaching a judgment was longer under the unrelated condition than under the related condition, indicating that the recognition of target words is promoted by semantic priming under the related condition. In the fMRI results, we found reduced activity in the dorsal and ventral left inferior frontal gyrus, the anterior cingulate, and left superior temporal cortex for related versus unrelated conditions (i.e., the repetition suppression effect). ERP analysis revealed that the amplitude of the N400 component was reduced under the related condition compared with the unrelated condition (i.e., the N400 priming effect). Correlation analysis between the BOLD repetition suppression effect and the N400 priming effect decomposed by independent component analysis (ICA) across subjects showed significant correlation in the left superior temporal gyrus. This finding is consistent with the recent MEG data suggesting that the source of N400 is judged to be the bilateral superior temporal lobe. We discussed this finding herein in relation to the modulation of access to the phonological representation caused by semantic priming. (C) 2004 Elsevier Inc. All rights reserved.