Dissociation within the Frontoparietal Network in Verbal Working Memory: A Parametric Functional Magnetic Resonance Imaging Study
Dissociation within the Frontoparietal Network in Verbal Working Memory: A Parametric Functional Magnetic Resonance Imaging Study
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DOI：
10.1523/jneurosci.0097-10.2010
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发表时间：
2010-03-10
影响因子：
5.3
通讯作者：
Petrides, Michael
中科院分区：
文献类型：
--
作者：
Champod, Anne Sophie;Petrides, Michael
在大多数关于工作记忆的功能性神经影像学研究中，都观察到中背外侧前额叶皮层（MDLFC）和后顶叶皮层（PPC）的活动同时增加（Collette等人，1999；Gerton等人，2004；Sun等人，2005；Postle等人，2006；Champod和Petrides, 2007； Emery等人，2008）。尽管人们对这两个大脑区域在工作记忆中的重要性达成了广泛共识，但它们的独特贡献，特别是PPC的贡献，仍然是一个激烈争论的问题（Paulesu等人，1993；Smith和Jonides, 1998； Postle等人，1999；Berryhill和Olson， 2008）。本研究的主要目的是验证顶内沟区域皮层参与工作记忆中言语信息的操纵（即重排）的假设，并将该脑区参与工作记忆过程与MDLFC的参与分离。结果表明，在操作和监测工作记忆中线性增加的单词数量时，MDLFC内的活动呈线性增加。与之形成鲜明对比的是，在操纵过程中，PPC内的活动呈线性增加，但在监测线性增加的单词数量时却没有。这项研究首次提供了这两个皮层区域激活的参数解离，表明PPC在工作记忆中信息的操纵中起着至关重要的作用，而MDLFC在监控这一信息方面起着主要作用。
Concomitant increase in activity within the mid-dorsolateral prefrontal cortex (MDLFC) and the posterior parietal cortex (PPC) is observed in most functional neuroimaging studies of working memory (Collette et al., 1999; Gerton et al., 2004; Sun et al., 2005; Postle et al., 2006; Champod and Petrides, 2007; Emery et al., 2008). Despite broad consensus on the importance of these two brain regions in working memory, their unique contribution, especially that of the PPC, remains a matter of heated debate (Paulesu et al., 1993; Smith and Jonides, 1998; Postle et al., 1999; Berryhill and Olson, 2008). The main objective of the present parametric event-related functional magnetic resonance imaging study was to examine the hypothesis that the cortex in the intraparietal sulcus region in the PPC is involved in the manipulation (i.e., rearrangement) of verbal information in working memory and to dissociate the involvement of this brain region from that of the MDLFC in working memory processes. The results demonstrated a linear increase in activity within the MDLFC during the manipulation and monitoring of a linearly increasing number of words in working memory. In sharp contrast, there was a linear increase in activity within the PPC during the manipulation but not the monitoring of a linearly increasing number of words. This study provides the first parametric dissociation of activation in these two cortical regions indicating a crucial role of the PPC in the manipulation of information in working memory, with the MDLFC playing a major role in monitoring this information.