Neural systems supporting lexical search guided by letter and semantic category cues: a self-paced overt response fMRI study of verbal fluency.
Neural systems supporting lexical search guided by letter and semantic category cues: a self-paced overt response fMRI study of verbal fluency.
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DOI：
10.1016/j.neuroimage.2009.07.036
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发表时间：
2010-01-01
期刊：
影响因子：
5.7
通讯作者：
Martin, Alex
中科院分区：
文献类型：
--
作者：
Birn, Rasmus M.;Kenworthy, Lauren;Case, Laura;Caravella, Rachel;Jones, Tyler B.;Bandettin, Peter A.;Martin, Alex
语言流畅性任务已被广泛用于评估人脑中的语言和执行控制过程。然而，功能性磁共振成像（fMRI）对语言流畅性的研究要么使用无声单词生成（无法提供行为测量），要么使用线索引导的单个单词生成，以应对与言语相关的运动伪影。在这项研究中，我们使用一种近期开发的范式设计来研究在显性、自由回忆的单词生成过程中语言流畅性的神经相关性，以便在更接近标准行为测试要求的条件下评估表现和大脑活动。我们研究了对字母和类别线索的语言流畅性，以便根据先前的神经心理学和神经影像学研究的建议，评估特定额叶和颞叶部位因检索线索类型不同而产生的不同参与情况。此外，我们纳入了任务转换操作和自动言语条件，以调节对执行功能的要求。我们发现，在类别和字母流畅性任务中，左半球的激活更强，而在自动言语过程中，右半球的激活更强。我们还发现，字母和类别流畅性任务与额叶和颞叶特定区域的不同参与有关。这些发现提供了一致的证据，表明字母和类别流畅性表现依赖于部分不同的神经回路。它们也提供了有力的证据，表明在磁共振环境中使用显性、自我节奏的反应可以成功地评估语言流畅性。
Verbal fluency tasks have been widely used to evaluate language and executive control processes in the human brain. FMRI studies of verbal fluency, however, have used either silent word generation (which provides no behavioral measure) or cued generation of single words in order to contend with speech-related motion artifacts. In this study, we use a recently developed paradigm design to investigate the neural correlates of verbal fluency during overt, free recall, word generation so that performance and brain activity could be evaluated under conditions that more closely mirror standard behavioral test demands. We investigated verbal fluency to both letter and category cues in order to evaluate differential involvement of specific frontal and temporal lobe sites as a function of retrieval cue type, as suggested by previous neuropsychological and neuroimaging investigations. In addition, we incorporated both a task switching manipulation and an automatic speech condition in order to modulate the demand placed on executive functions. We found greater activation in the left hemisphere during category and letter fluency tasks, and greater right hemisphere activation during automatic speech. We also found that letter and category fluency tasks were associated with differential involvement of specific regions of the frontal and temporal lobes. These findings provide converging evidence that letter and category fluency performance is dependent on partially distinct neural circuitry. They also provide strong evidence that verbal fluency can be successfully evaluated in the MR environment using overt, self-paced, responses.
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影响因子：
2.4
作者：
Baldo, JV;Shimamura, AP
通讯作者：
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影响因子：
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作者：
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DOI：
10.1017/s1355617705051015
发表时间：
2005-11-01
影响因子：
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