Recruitment of the default mode network during a demanding act of executive control.
Recruitment of the default mode network during a demanding act of executive control.
复制标题
在执行执行控制苛刻的行为中招募默认模式网络。
DOI：
10.7554/elife.06481
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发表时间：
2015-04-13
期刊：
影响因子：
7.7
通讯作者：
Duncan J
中科院分区：
文献类型：
--
作者：
Crittenden BM;Mitchell DJ;Duncan J
在人类大脑中，默认模式或任务消极网络在许多认知任务中表现出活动减少，并且通常与内部导向的过程有关，例如走神和关于自我的想法。与此相反，这种任务消极的模式，我们表现出增加的活动在一个大的和苛刻的切换任务集。此外，我们采用多体素模式分析，发现在默认模式网络的兴趣区域编码任务相关的信息在任务执行。这个网络中的活动可能是由认知环境的重大修改驱动的，无论是内部还是外部关注的。DOI：http://dx.doi.org/10.7554/eLife.06481.001默认模式网络是大脑中的一个网络，当我们想到自己，回忆过去或只是让我们的思想漫游时，它经常活跃。然而，当我们专注于一项特定的认知任务时，这个涉及大脑许多不同区域的网络通常会变得不活跃。现在，Crittenden等人使用了一种称为功能性MRI的技术来证明，如果我们从一项任务切换到另一项任务，默认模式网络可以再次变得活跃。功能性磁共振成像通过测量大脑中的血流量来工作：大脑中活跃的区域比不活跃的区域有更多的血流量。Crittenden等人研究了人类受试者执行一系列不同任务时的大脑。这些实验表明，当受试者专注于单一任务时，默认模式网络的活动不会改变。当受试者在两个类似的任务之间切换时也是如此。然而，当受试者在两个截然不同的任务之间切换时，网络会变得更加活跃。此外，网络中的活动模式似乎反映了任务的性质。Crittenden等人的工作强烈表明，为了成功地在两个不同的任务之间切换，大脑需要参与默认模式网络，并允许思维漫游。未来的研究将涉及探索这两项任务需要有多大的不同才能激活默认模式网络，并研究网络中的脑损伤如何损害患者在不同任务之间切换的能力。DOI：http://dx.doi.org/10.7554/eLife.06481.002网站
In the human brain, a default mode or task-negative network shows reduced activity during many cognitive tasks and is often associated with internally-directed processes, such as mind wandering and thoughts about the self. In contrast to this task-negative pattern, we show increased activity during a large and demanding switch in task set. Furthermore, we employ multivoxel pattern analysis and find that regions of interest within default mode network are encoding task-relevant information during task performance. Activity in this network may be driven by major revisions of cognitive context, whether internally or externally focused. DOI: http://dx.doi.org/10.7554/eLife.06481.001 The default mode network is a network in the brain that is often active when we think about ourselves, reminiscence about the past or just let our minds wander. However, this network—which involves many different regions of the brain—usually becomes inactive when we focus on a specific cognitive task. Now Crittenden et al. have used a technique called functional MRI to show that the default mode network can become active again if we switch from one task to another. Functional MRI works by measuring the blood flow in the brain: regions of the brain that are active have more blood flow than regions that are not active. Crittenden et al. studied the brains of human subjects as they performed a series of different tasks. These experiments showed that the activity of the default mode network does not change when the subject is focused on a single task. This is also true for when the subject switches between two similar tasks. However, when the subject switches between two very different tasks, the network becomes significantly more active. Moreover, the patterns of activity in the network seem to reflect the nature of the tasks. The work of Crittenden et al. strongly suggests that in order to successfully switch between two different tasks, the brain needs to engage the default mode network and allow the mind to wander. Future studies will involve exploring how different the two tasks need to be in order to activate the default mode network, and studying how brain damage within the network may impair patients ability to switch between different tasks. DOI: http://dx.doi.org/10.7554/eLife.06481.002