A functional dissociation between language and multiple-demand systems revealed in patterns of BOLD signal fluctuations
A functional dissociation between language and multiple-demand systems revealed in patterns of BOLD signal fluctuations
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DOI：
10.1152/jn.00884.2013
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发表时间：
2014-09-01
影响因子：
2.5
通讯作者：
Fedorenko, Evelina
中科院分区：
文献类型：
--
作者：
Blank, Idan;Kanwisher, Nancy;Fedorenko, Evelina
语言与其他高级认知功能之间有何关系？神经影像学研究已经开始阐明这个问题，揭示出一些大脑区域在语言处理过程中具有相当选择性的参与，而其他“多需求”（MD）区域则广泛地参与不同的认知任务。尽管如此，语言和 MD 系统之间的功能分离仍然存在争议。在这里，我们通过功能 MRI 方法的协同组合来解决这个问题：我们首先在每个受试者中单独定义候选语言特定区域和 MD 区域（使用功能定位器），然后在两种自然条件（“休息”和故事理解）期间测量这些区域中血氧水平依赖性信号波动。在这两种情况下，信号波动在语言区域和 MD 区域之间都具有很强的相关性，但跨系统的相关性很弱或呈负相关。此外，基于这些区域间相关性的数据驱动聚类分析一致地恢复了与语言和 MD 系统相对应的两个聚类。因此，尽管每个系统形成一个内部整合的整体，但这两个系统却彼此严重分离。认知处理过程中语言和 MD 系统的这种独立招募与这两个系统支持不同认知功能的假设是一致的。
What is the relationship between language and other high-level cognitive functions? Neuroimaging studies have begun to illuminate this question, revealing that some brain regions are quite selectively engaged during language processing, whereas other "multiple-demand" (MD) regions are broadly engaged by diverse cognitive tasks. Nonetheless, the functional dissociation between the language and MD systems remains controversial. Here, we tackle this question with a synergistic combination of functional MRI methods: we first define candidate language-specific and MD regions in each subject individually (using functional localizers) and then measure blood oxygen level-dependent signal fluctuations in these regions during two naturalistic conditions ("rest" and story-comprehension). In both conditions, signal fluctuations strongly correlate among language regions as well as among MD regions, but correlations across systems are weak or negative. Moreover, data-driven clustering analyses based on these inter-region correlations consistently recover two clusters corresponding to the language and MD systems. Thus although each system forms an internally integrated whole, the two systems dissociate sharply from each other. This independent recruitment of the language and MD systems during cognitive processing is consistent with the hypothesis that these two systems support distinct cognitive functions.