独立向量分析(IVA):功能磁共振成像群体研究的多变量方法。
Independent vector analysis (IVA): multivariate approach for fMRI group study.
作者信息
Lee Jong-Hwan, Lee Te-Won, Jolesz Ferenc A, Yoo Seung-Schik
机构信息
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
出版信息
Neuroimage. 2008 Mar 1;40(1):86-109. doi: 10.1016/j.neuroimage.2007.11.019. Epub 2007 Nov 28.
Independent component analysis (ICA) of fMRI data generates session/individual specific brain activation maps without a priori assumptions regarding the timing or pattern of the blood-oxygenation-level-dependent (BOLD) signal responses. However, because of a random permutation among output components, ICA does not offer a straightforward solution for the inference of group-level activation. In this study, we present an independent vector analysis (IVA) method to address the permutation problem during fMRI group data analysis. In comparison to ICA, IVA offers an analysis of additional dependent components, which were assigned for use in the automated grouping of dependent activation patterns across subjects. Upon testing using simulated trial-based fMRI data, our proposed method was applied to real fMRI data employing both a single-trial task-paradigm (right hand motor clenching and internal speech generation tasks) and a three-trial task-paradigm (right hand motor imagery task). A generalized linear model (GLM) and the group ICA of the fMRI toolbox (GIFT) were also applied to the same data set for comparison to IVA. Compared to GLM, IVA successfully captured activation patterns even when the functional areas showed variable hemodynamic responses that deviated from a hypothesized response. We also showed that IVA effectively inferred group-activation patterns of unknown origins without the requirement for a pre-processing stage (such as data concatenation in ICA-based GIFT). IVA can be used as a potential alternative or an adjunct to current ICA-based fMRI group processing methods.
功能磁共振成像(fMRI)数据的独立成分分析(ICA)可生成特定于实验/个体的脑激活图,而无需对血氧水平依赖(BOLD)信号响应的时间或模式做先验假设。然而,由于输出成分之间存在随机排列,ICA并未为推断组水平激活提供直接的解决方案。在本研究中,我们提出一种独立向量分析(IVA)方法,以解决fMRI组数据分析过程中的排列问题。与ICA相比,IVA可对额外的相关成分进行分析,这些成分被用于自动分组跨受试者的相关激活模式。在使用基于模拟试验的fMRI数据进行测试时,我们提出的方法被应用于采用单试验任务范式(右手运动握拳和内部言语生成任务)和三试验任务范式(右手运动想象任务)的真实fMRI数据。广义线性模型(GLM)和fMRI工具箱(GIFT)中的组ICA也被应用于同一数据集,以与IVA进行比较。与GLM相比,即使功能区域显示出偏离假设响应的可变血流动力学响应,IVA仍能成功捕捉激活模式。我们还表明,IVA能够有效推断未知来源的组激活模式,而无需预处理阶段(如基于ICA的GIFT中的数据拼接)。IVA可作为当前基于ICA的fMRI组处理方法的潜在替代方法或辅助方法。