Task-positive Functional Connectivity of the Default Mode Network Transcends Task Domain
Task-positive Functional Connectivity of the Default Mode Network Transcends Task Domain
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DOI：
10.1162/jocn_a_00859
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发表时间：
2015-12-01
影响因子：
3.2
通讯作者：
Gao, Wei
中科院分区：
文献类型：
--
作者：
Elton, Amanda;Gao, Wei
默认模式网络(DMN)最初被认为是一组大脑区域，在休息时表现出比在一系列任务中始终更活跃的活动。最初，这个网络被认为干扰了目标导向的行为，因为它在许多这样的任务中减少了活动。然而，最近，DMN在目标导向行为中的作用被确立为内部定向任务，在这些任务中，DMN表现出更多的活动。然而，中线DMN区域的中心位置和信息桥接潜力得到了很好的证明，这表明关于它对目标导向任务的功能贡献还有更多需要揭示，这可能基于它的功能相互作用，而不是它的激活水平。在一系列内部和外部任务中，研究DMN功能连接性与任务相关的变化，将为考察DMN在目标定向任务执行中的作用提供必要的研究。在这项研究中，除了静息状态扫描外，20名参与者在执行跨越不同内部和外部域的六项任务时进行了功能磁共振成像。我们假设，与REST相比，DMN将在功能连通性方面表现出任务积极(即对任务绩效有积极贡献)的变化，而不考虑与任务相关的活动变化的方向。事实上，我们的结果表明，在所有六个任务中，DMN与任务促进区域(例如，前脑岛、额下回、额中回)的连接性显著增加。此外，典型相关分析表明，观察到的与任务相关的连接性变化与任务绩效的个体差异显著相关。我们的结果表明，DMN可能不仅支持默认模式，而且可能通过与任务相关脑区的灵活耦合，在内部和外部任务中发挥更大的作用。
The default mode network (DMN) was first recognized as a set of brain regions demonstrating consistently greater activity during rest than during a multitude of tasks. Originally, this network was believed to interfere with goal-directed behavior based on its decreased activity during many such tasks. More recently, however, the role of the DMN during goal-directed behavior was established for internally oriented tasks, in which the DMN demonstrated increased activity. However, the well-documented hub position and information-bridging potential of midline DMN regions indicate that there is more to uncover regarding its functional contributions to goal-directed tasks, which may be based on its functional interactions rather than its level of activation. An investigation of task-related changes in DMN functional connectivity during a series of both internal and external tasks would provide the requisite investigation for examining the role of the DMN during goal-directed task performance. In this study, 20 participants underwent fMRI while performing six tasks spanning diverse internal and external domains in addition to a resting-state scan. We hypothesized that the DMN would demonstrate task-positive (i.e., positively contributing to task performance) changes in functional connectivity relative to rest regardless of the direction of task-related changes in activity. Indeed, our results demonstrate significant increases in DMN connectivity with task-promoting regions (e.g., anterior insula, inferior frontal gyrus, middle frontal gyrus) across all six tasks. Furthermore, canonical correlation analyses indicated that the observed task-related connectivity changes were significantly associated with individual differences in task performance. Our results indicate that the DMN may not only support a default mode but may play a greater role in both internal and external tasks through flexible coupling with task-relevant brain regions.