Integration of fMRI and simultaneous EEG:: towards a comprehensive understanding of localization and time-course of brain activity in target detection
Integration of fMRI and simultaneous EEG:: towards a comprehensive understanding of localization and time-course of brain activity in target detection
复制标题
DOI：
10.1016/j.neuroimage.2003.10.051
复制
发表时间：
2004-05-01
期刊：
影响因子：
5.7
通讯作者：
Hegerl, U
中科院分区：
文献类型：
--
作者：
Mulert, C;Jäger, L;Hegerl, U
功能磁共振成像和脑电图是分析大脑活动的互补方法，因为每种方法都有其优势，而另一种方法有局限性：因此，功能磁共振成像的空间分辨率在毫米范围内，而脑电图的时间分辨率在毫秒范围内。为了全面了解目标检测中的脑活动，采用听觉怪异范式，对9名健康受试者（24.2 +/- 2.9岁）进行了同时EEG（27个电极）和fMRI的研究。作为第一步，在扫描仪内测量的事件相关电位与扫描仪前直接记录的电位进行了比较。在扫描仪内发现早期N1/P2分量的振幅衰减，而晚期P300分量没有衰减。其次，对低分辨率电磁断层扫描（LORETA）显示的fMRI激活定位和电流源密度进行了独立分析。在大多数区域，包括颞顶叶交界处（TPJ）、辅助运动区(SMA)/前扣带皮层（ACC）、脑岛和额叶中回，BOLD的重心和LORFTA-maxima之间的平均欧氏距离为16.0 +/- 6.6 ram，发现了一致的激活。最后，基于电流源密度最大值进行了时程分析。它揭示了左右半球不同的时间过程模式，右半球额叶和顶叶区域的激活更早。结果表明，脑电图和功能磁共振成像的结合可以提高对大脑活动时空动态的理解。(C) 2004爱思唯尔公司版权所有。
fMRI and EEG are complimentary methods for the analysis of brain activity since each method has its strength where the other one has limits: The spatial resolution is thus in the range of millimeters with fMRI and the time resolution is in the range of milliseconds with EEG. For a comprehensive understanding of brain activity in target detection, nine healthy subjects (age 24.2 +/- 2.9) were investigated with simultaneous EEG (27 electrodes) and fMRI using an auditory oddball paradigm. As a first step, event-related potentials, measured inside the scanner, have been compared with the potentials recorded in a directly preceding session in front of the scanner. Attenuated amplitudes were found inside the scanner for the earlier N1/P2 component but not for the late P300 component. Second, an independent analysis of the localizations of the fMRI activations and the current source density as revealed by low resolution electromagnetic tomography (LORETA) has been done. Concordant activations were found in most regions, including the temporoparietal junction (TPJ), the supplementary motor area (SMA)/anterior cingulate cortex (ACC), the insula, and the middle frontal gyrus, with a mean Euclidean distance of 16.0 +/- 6.6 ram between the BOLD centers of gravity and the LORFTA-maxima. Finally, a time-course analysis based on the current source density maxima was done. It revealed different time-course patterns in the left and right hemisphere with earlier activations in frontal and parietal regions in the right hemisphere. The results suggest that the combination of EEG and fMRI permits an improved understanding of the spatiotemporal dynamics of brain activity. (C) 2004 Elsevier Inc. All rights reserved.