Concurrent EEG/fMRI analysis by multiway Partial Least Squares
Concurrent EEG/fMRI analysis by multiway Partial Least Squares
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DOI：
10.1016/j.neuroimage.2004.03.038
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发表时间：
2004-07-01
期刊：
影响因子：
5.7
通讯作者：
Cohen, MS
中科院分区：
文献类型：
--
作者：
Martínez-Montes, E;Valdés-Sosa, PA;Cohen, MS
使用层析电生理同步成像（SITE）方法，现在可以同时记录EEG和功能性MRI的数据。到目前为止，还没有确定的方法来整合对组合数据集的分析。认识到血流动力学卷积时变脑电图频谱S在空间、频率和时间上本质上是多维的，促使我们使用多向偏最小二乘（N-PLS）分析将脑电图（自变量）和功能磁共振成像（因变量）数据唯一地分解为“原子”的和。每个EEG原子是空间、频谱和时间特征的外部产物，每个fMRI原子是空间和时间特征的外部产物。将分解约束为最大化EEG和fMRI对应时间特征之间的协方差。在所有数据集上，出现了三个谱峰位于θ、α和γ波段的分量；只有α原子与fMRI信号有显著的时间相关性。α带原子的空间分布包括顶枕皮质、丘脑和脑岛，这与Goldman等人使用更传统的分析方法报道的结果非常接近[NeuroReport 13(18)(2002) 2487]。从脑电空间特征重构出的源信号仅显示顶枕源信号。我们解释这些结果表明，一些电源可能本质上对头皮脑电图是不可见的，但可以通过脑电图和功能磁共振成像数据的联合分析来揭示。这些结果也可能揭示了参与控制大脑节律的大脑区域，但这些区域本身可能不是大脑节律的产生者。到目前为止，还没有单一的神经成像方法能够提供空间和时间分辨率的最佳组合；fMRI和EEG的融合有意义地扩展了每种方法的时空分辨率和灵敏度。(C) 2004爱思唯尔公司版权所有。
Data may now be recorded concurrently from EEG and functional MRI, using the Simultaneous Imaging for Tomographic Electrophysiology (SITE) method. As yet, there is no established means to integrate the analysis of the combined data set. Recognizing that the hemodynamically convolved time-varying EEG spectrum, S, is intrinsically multidimensional in space, frequency, and time motivated us to use multiway Partial Least-Squares (N-PLS) analysis to decompose EEG (independent variable) and fMRI (dependent variable) data uniquely as a sum of "atoms". Each EEG atom is the outer product of spatial, spectral, and temporal signatures and each fMRI atom the product of spatial and temporal signatures. The decomposition was constrained to maximize the covariance between corresponding temporal signatures of the EEG and fMRI. On all data sets, three components whose spectral peaks were in the theta, alpha, and gamma bands appeared; only the alpha atom had a significant temporal correlation with the fMRI signal. The spatial distribution of the alpha-band atom included parieto-occipital cortex, thalamus, and insula, and corresponded closely to that reported by Goldman et al. [NeuroReport 13(18) (2002) 2487] using a more conventional analysis. The source reconstruction from EEG spatial signature showed only the parieto-occipital sources. We interpret these results to indicate that some electrical sources may be intrinsically invisible to scalp EEG, yet may be revealed through conjoint analysis of EEG and fMRI data. These results may also expose brain regions that participate in the control of brain rhythms but may not themselves be generators. As of yet, no single neuroimaging method offers the optimal combination of spatial and temporal resolution; fusing fMRI and EEG meaningfully extends the spatio-temporal resolution and sensitivity of each method. (C) 2004 Elsevier Inc. All rights reserved.