Evidence for the Default Network's Role in Spontaneous Cognition
Evidence for the Default Network's Role in Spontaneous Cognition
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DOI：
10.1152/jn.00830.2009
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发表时间：
2010-07-01
影响因子：
2.5
通讯作者：
Buckner, Randy L.
中科院分区：
文献类型：
--
作者：
Andrews-Hanna, Jessica R.;Reidler, Jay S.;Buckner, Randy L.
Andrews-Hanna JR、Reidler JS、Huang C、Buckner RL。默认网络在自发认知中作用的证据。J Neurophysiol 104：322-335，2010.首次发表于2010年5月12日; doi：10.1152/jn.00830.2009。一组被称为默认网络的大脑区域在放松对外部世界的关注时会增加其活动。在这样的时刻，参与者改变他们的外部注意力的焦点，并参与自发的认知过程，包括回忆过去和想象未来。然而，默认网络对外部注意力转移与内部心理状态转移的功能贡献一直难以理清，因为这两个过程在典型情况下是相关的。为了解决这个问题，本研究操纵的因素，促进自发的认知独立于那些改变外部注意力的范围。结果显示，默认网络增加其活动时，自发认知最大化，但不是当参与者增加他们的注意力不可预测的中央凹或周边刺激。为了研究参与者自发思想的性质，第二个实验使用自我报告问卷来量化延长固定时期的自发思想。关于个人过去和未来的想法是自发认知的一个主要焦点，具有相当大的可变性。内侧颞叶和分布在默认网络内的皮质区域之间的活动相关性预测了所观察到的变异性的一小部分，但很重要。总的来说，这些结果表明，在被动状态下，默认网络内的活动反映了自发的，内部导向的认知过程。
Andrews-Hanna JR, Reidler JS, Huang C, Buckner RL. Evidence for the default network's role in spontaneous cognition. J Neurophysiol 104: 322-335, 2010. First published May 12, 2010; doi:10.1152/jn.00830.2009. A set of brain regions known as the default network increases its activity when focus on the external world is relaxed. During such moments, participants change their focus of external attention and engage in spontaneous cognitive processes including remembering the past and imagining the future. However, the functional contributions of the default network to shifts in external attention versus internal mentation have been difficult to disentangle because the two processes are correlated under typical circumstances. To address this issue, the present study manipulated factors that promote spontaneous cognition separately from those that change the scope of external attention. Results revealed that the default network increased its activity when spontaneous cognition was maximized but not when participants increased their attention to unpredictable foveal or peripheral stimuli. To examine the nature of participants' spontaneous thoughts, a second experiment used self-report questionnaires to quantify spontaneous thoughts during extended fixation epochs. Thoughts about one's personal past and future comprised a major focus of spontaneous cognition with considerable variability. Activity correlations between the medial temporal lobe and distributed cortical regions within the default network predicted a small, but significant, portion of the observed variability. Collectively, these results suggest that during passive states, activity within the default network reflects spontaneous, internally directed cognitive processes.