An alternative approach towards assessing and accounting for individual motion in fMRI timeseries
An alternative approach towards assessing and accounting for individual motion in fMRI timeseries
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DOI：
10.1016/j.neuroimage.2011.10.043
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发表时间：
2012-02-01
期刊：
影响因子：
5.7
通讯作者：
Wilke, Marko
中科院分区：
文献类型：
--
作者：
Wilke, Marko
运动是功能磁共振成像数据分析的一个重要问题。这份手稿解决了一个问题，是否个性化的评估运动可能是有益的，以及它是否可能是有益的解释运动相关的方差。两个独立的数据集被用来探索和测试这一假设，从总共21个健康的儿童，执行没有外部线索的任务（休息状态）或积极的倾听范式（哔哔声故事）。平移和旋转被组合成一个单一的，个人的总位移的措施，这是证明是显着不同的大脑区域之间的功能，从个人的原点的距离。协变量数量的增加会导致检测功效的损失，但在第一水平上比在第二水平上更严重，并且在不太强大的设计中更严重。计算合成时间序列，从中可以分离运动的直接影响以及运动 *BO影响，从而允许提取反映直接和间接运动影响的个体时间序列。将来自这样的单独导出的“运动指纹”的三个时间过程包括到第一级统计分析中解释了与包括重新对准参数的常用方法相似程度的方差，并且性能在统计上等同于包括第二级上的重新对准参数。因此，根据场景的不同，一种更个性化的方法来解释运动相关的变化可能是有益的。(C)2011 Elsevier Inc. All rights reserved.
Motion is a significant problem for the analysis of functional MRI data. This manuscript addresses the question of whether an individualized assessment of motion may be informative, and whether it may be beneficial with regard to explaining motion-related variance. Two independent datasets are used to explore and test this hypothesis, from a total of 21 healthy children, performing either no externally-cued task (resting state) or an active listening paradigm (beep story). Translations and rotations are combined into one single, individual measure of total displacement, which is demonstrated to be substantially different between brain regions as a function of their distance from the individual origin. An increasing number of covariates leads to a loss of detection power, but more so on the first than on the second level, and more so in less-powerful designs. Synthetic timeseries are calculated from which the direct effects of motion as well as motion*BO effects can be isolated, allowing to extract individual timecourses which reflect both direct and indirect motion effects. Including three timecourses from such an individually-derived "motion fingerprint" into first-level statistical analyses explains variance to a similar degree as the commonly-used approach of including the realignment parameters, and performance is statistically equivalent to including the realignment parameters on the second level. A more individualized approach to explaining motion-related variance may therefore be beneficial, depending on the scenario. (C) 2011 Elsevier Inc. All rights reserved.