Impact of autocorrelation on functional connectivity.
Impact of autocorrelation on functional connectivity.
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DOI：
10.1016/j.neuroimage.2014.07.045
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发表时间：
2014-11-15
期刊：
影响因子：
5.7
通讯作者：
Calhoun VD
中科院分区：
文献类型：
--
作者：
Arbabshirani MR;Damaraju E;Phlypo R;Plis S;Allen E;Ma S;Mathalon D;Preda A;Vaidya JG;Adali T;Calhoun VD
尽管序列相关（自相关）对 fMRI 时间序列一般线性模型残差的影响已被广泛研究，但直到最近，自相关对功能连接研究的影响一直被忽视。最近一些基于经济学结果的研究对功能连接的传统估计提出了质疑，并认为不校正功能磁共振成像时间序列中的自相关会导致“虚假”相关系数。在本文中，我们首先通过理论近似和模拟评估自相关对皮尔逊相关系数的影响。然后我们在真实的功能磁共振成像数据上展示这种效应。据我们所知，这是第一篇全面研究自相关对功能连接估计影响的工作。我们的结果表明，尽管 FC 值发生了变化，但即使在自相关校正之后，FC 值的假设检验结果仍然与校正前非常相似。在实际数据中，我们表明这对于主效应以及健康对照和精神分裂症患者之间的组间差异测试都是正确的。我们进一步讨论自回归过程中的模型阶数选择、频率滤波的影响，并提出用于连通性研究的预处理管道。
Although the impact of serial correlation (autocorrelation) in residuals of general linear models for fMRI time-series has been studied extensively, the effect of autocorrelation on functional connectivity studies has been largely neglected until recently. Some recent studies based on results from economics have questioned the conventional estimation of functional connectivity and argue that not correcting for autocorrelation in fMRI time-series results in “spurious” correlation coefficients. In this paper, first we assess the effect of autocorrelation on Pearson correlation coefficient through theoretical approximation and simulation. Then we present this effect on real fMRI data. To our knowledge this is the first work comprehensively investigating the effect of autocorrelation on functional connectivity estimates. Our results show that although FC values are altered, even following correction for autocorrelation, results of hypothesis testing on FC values remain very similar to those before correction. In real data we show this is true for main effects and also for group difference testing between healthy controls and schizophrenia patients. We further discuss model order selection in the context of autoregressive processes, effects of frequency filtering and propose a preprocessing pipeline for connectivity studies.
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影响因子：
--
作者：
Bartlett, MS
通讯作者：
Bartlett, MS
影响因子：
2.5
作者：
Bianciardi, Marta;Fukunaga, Masaki;van Gelderen, Peter;Horovitz, Silvina G.;de Zwart, Jacco A.;Shmueli, Karin;Duyn, Jeff H.
通讯作者：
Duyn, Jeff H.
影响因子：
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作者：
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通讯作者：
Auer, Dorothee P.
影响因子：
5.7
作者：
FRISTON, KJ;HOLMES, AP;TURNER, R
通讯作者：
TURNER, R
影响因子：
5.7
作者：
Davey, Catherine E.;Grayden, David B.;Johnston, Leigh A.
通讯作者：
Johnston, Leigh A.