Functional Heterogeneity within the Default Network during Semantic Processing and Speech Production.
Functional Heterogeneity within the Default Network during Semantic Processing and Speech Production.
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DOI：
10.3389/fpsyg.2012.00281
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发表时间：
2012
影响因子：
3.8
通讯作者：
Price CJ
中科院分区：
文献类型：
--
作者：
Seghier ML;Price CJ
本研究采用功能磁共振成像（fMRI）研究了默认模式网络（DMN）核心节点在语言加工过程中的功能异质性。DMN的核心节点被定义为94名健康受试者在多个任务中的任务诱导的失活。我们使用析因设计，操纵不同的任务（语义匹配或言语产生）和刺激（熟悉的单词和物体或不熟悉的刺激），交替固定/休息的时间。我们的研究结果揭示了几个一致的影响DMN，即在左下顶叶语义匹配过程中的失活比知觉匹配平行与更大的失活在语义匹配过程中的前分区的后扣带皮层（PCC）和腹内侧前额叶皮层（MPFC）。这表明，当大脑从事费力的语义任务时，左角回中的DMN的一部分被较少地去激活，而DMN的其他五个节点被更多地去激活。这五个DMN区域，其中失活更大的语义比感知匹配，进一步区分，因为失活更大的（i）后腹侧MPFC的语音生产相对于语义匹配，（ii）后楔前叶和PCC的感知处理相对于语音生产，（iii）右下顶叶皮层的图片的对象相对于书面文字在命名和语义的决定。因此，我们的研究结果强调，任务难度本身不能完全解释任务引起的失活的功能变异。总之，这些结果强调，核心节点内的DMN功能异质性和差异敏感的语言处理类型。
This fMRI study investigated the functional heterogeneity of the core nodes of the default mode network (DMN) during language processing. The core nodes of the DMN were defined as task-induced deactivations over multiple tasks in 94 healthy subjects. We used a factorial design that manipulated different tasks (semantic matching or speech production) and stimuli (familiar words and objects or unfamiliar stimuli), alternating with periods of fixation/rest. Our findings revealed several consistent effects in the DMN, namely less deactivations in the left inferior parietal lobule during semantic than perceptual matching in parallel with greater deactivations during semantic matching in anterior subdivisions of the posterior cingulate cortex (PCC) and the ventromedial prefrontal cortex (MPFC). This suggests that, when the brain is engaged in effortful semantic tasks, a part of the DMN in the left angular gyrus was less deactivated as five other nodes of the DMN were more deactivated. These five DMN areas, where deactivation was greater for semantic than perceptual matching, were further differentiated because deactivation was greater in (i) posterior ventral MPFC for speech production relative to semantic matching, (ii) posterior precuneus and PCC for perceptual processing relative to speech production, and (iii) right inferior parietal cortex for pictures of objects relative to written words during both naming and semantic decisions. Our results thus highlight that task difficulty alone cannot fully explain the functional variability in task-induced deactivations. Together these results emphasize that core nodes within the DMN are functionally heterogeneous and differentially sensitive to the type of language processing.
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DOI：
10.1073/pnas.0504136102
发表时间：
2005-07-05
影响因子：
11.1
作者：
Fox, MD;Snyder, AZ;Raichle, ME
通讯作者：
Raichle, ME
DOI：
10.1177/1073858411403316
发表时间：
2012-06
期刊：
The Neuroscientist : a review journal bringing neurobiology, neurology and psychiatry
影响因子：
--
作者：
Andrews-Hanna JR
通讯作者：
Andrews-Hanna JR
影响因子：
3.1
作者：
Caspers, Svenja;Eickhoff, Simon B.;Amunts, Katrin
通讯作者：
Amunts, Katrin
影响因子：
3.4
作者：
Anderson JS;Ferguson MA;Lopez-Larson M;Yurgelun-Todd D
通讯作者：
Yurgelun-Todd D
影响因子：
2.4
作者：
Behroozmand R;Larson CR
通讯作者：
Larson CR