Dissociated patterns of anti-correlations with dorsal and ventral default-mode networks at rest.
Dissociated patterns of anti-correlations with dorsal and ventral default-mode networks at rest.
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DOI：
10.1002/hbm.23532
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发表时间：
2017-05
影响因子：
4.8
通讯作者：
Chang C
中科院分区：
文献类型：
--
作者：
Chen JE;Glover GH;Greicius MD;Chang C
以往的研究表明，静息状态下的功能连接的默认模式网络（DMN）是负相关的一组大脑区域通常在目标导向的任务激活。然而，反相关的位置和程度在不同的研究中是不一致的，这被认为主要是由于全局信号回归（GSR）是否被应用作为预处理步骤的差异。值得注意的是，在后扣带皮层（PCC）/楔前叶（一个经常用于研究DMN功能连接的区域）内定义的种子感兴趣区域的坐标在不同研究中不一致。结合最近的观察，DMN包含功能异质的细分，目前还不清楚这些种子是否映射到不同的DMN子网络，其反相关模式可能不同。如果是这样的话，那么种子位置可能是一个不可忽略的因素，除了预处理步骤的差异，有助于发表的研究报告中关于DMN相关性/反相关性的不一致。在本研究中，我们分别采用基于种子和点过程的分析方法，研究了静息状态下DMN不同子网络的反相关性，发现：（1）DMN腹侧分支（vDMN）的反相关性显著弱于DMN背侧分支（dDMN）的反相关性;（3）早期研究中使用的PCC/楔前叶种子映射到不同的DMN子网络，这可以解释所报道的DMN反相关中的一些不一致性（除了预处理步骤之外）。
Previous studies of resting state functional connectivity have demonstrated that the default-mode network (DMN) is negatively correlated with a set of brain regions commonly activated during goal-directed tasks. However, the location and extent of anti-correlations are inconsistent across different studies, which has been posited to result largely from differences in whether or not global signal regression (GSR) was applied as a pre-processing step. Notably, coordinates of seed regions-of-interest defined within the posterior cingulate cortex (PCC)/precuneus, an area often employed to study functional connectivity of the DMN, have been inconsistent across studies. Taken together with recent observations that the DMN contains functionally heterogeneous subdivisions, it is presently unclear whether these seeds map to different DMN subnetworks, whose patterns of anti-correlation may differ. If so, then seed location may be a non-negligible factor that, in addition to differences in preprocessing steps, contributes to the inconsistencies reported among published studies regarding DMN correlations/anti-correlations. In this study, we examined anti-correlations of different subnetworks within the DMN during rest using both seed-based and point process analyses, and discovered that: (1) the ventral branch of the DMN (vDMN) yielded significantly weaker anti-correlations than that associated with the dorsal branch of the DMN (dDMN); (2) vDMN anti-correlations introduced by GSR were distinct from dDMN anti-correlations; (3) PCC/precuneus seeds employed by earlier studies mapped to different DMN subnetworks, which may explain some of the inconsistency (in addition to preprocessing steps) in the reported DMN anti-correlations.