Anticorrelations in resting state networks without global signal regression.-猫眼课题宝

DOI：

10.1016/j.neuroimage.2011.08.048

发表时间：

2012-01-16

期刊：

NEUROIMAGE

影响因子：

5.7

通讯作者：

中科院分区：

医学1区

文献类型：

作者：

Chai, Xiaoqian J.;Castanon, Alfonso Nieto;Oenguer, Dost;Whitfield-Gabrieli, Susan

关键词：

fMRI Functional connectivity Physiological noise Default mode network Task-positive network Negative correlations

来源链接：

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230748/?report=classic

先前已在静息态功能磁共振成像（fMRI）中观察到自发信号波动的反相关关系。特别是，有人提出，大脑中存在两个系统，它们本质上被组织成反相关网络：默认模式网络，通常表现出与任务相关的失活；以及任务积极网络，通常在需要外部注意的任务期间表现出与任务相关的激活。然而，目前尚有争议的是，在静息态 fMRI 中观察到的反相关性是否有效，或者是通过全局信号回归人为引入的，全局信号回归是一种常见的预处理技术，用于消除静息态 fMRI 信号中的生理和其他噪声。我们使用两种不同的预处理方法检查静息态连接中的正相关性和负相关性：基于分量的降噪方法（CompCor），其中去除了感兴趣的噪声区域的主分量，以及全局信号回归方法。在两种方法下都观察到内侧前额叶皮层中的默认模式网络种子区域与任务正向网络区域之间的鲁棒反相关性。两种方法之间的反相关性的特异性相似。与全局回归方法相比，CompCor 下正相关的特异性和敏感性更高。我们的结果表明，在静息状态连接中观察到的反相关性不是全局信号回归引入的伪影，并且可能具有生物学起源，并且 CompCor 方法可用于检查静息状态下的有效反相关性。

Anticorrelated relationships in spontaneous signal fluctuation have been previously observed in resting-state functional magnetic resonance imaging (fMRI). In particular, it was proposed that there exists two systems in the brain that are intrinsically organized into anticorrelated networks, the default mode network, which usually exhibits task-related deactivations, and the task-positive network, which usually exhibits task-related activations during tasks that demands external attention. However, it is currently under debate whether the anticorrelations observed in resting state fMRI were valid or were instead artificially introduced by global signal regression, a common preprocessing technique to remove physiological and other noise in resting-state fMRI signal. We examined positive and negative correlations in resting-state connectivity using two different preprocessing methods: a component base noise reduction method (CompCor,), in which principal components from noise regions-of-interest were removed, and the global signal regression method. Robust anticorrelations between a default mode network seed region in the medial prefrontal cortex and regions of the task-positive network were observed under both methods. Specificity of the anticorrelations was similar between the two methods. Specificity and sensitivity for positive correlations were higher under CompCor compared to the global regression method. Our results suggest that anticorrelations observed in resting-state connectivity are not an artifact introduced by global signal regression and might have biological origins, and that the CompCor method can be used to examine valid anticorrelations during rest.