Assessing functional connectivity in the human brain by fMRI
Assessing functional connectivity in the human brain by fMRI
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DOI：
10.1016/j.mri.2007.03.007
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发表时间：
2007-12-01
影响因子：
2.5
通讯作者：
Gore, John C.
中科院分区：
文献类型：
--
作者：
Rogers, Baxter P.;Morgan, Victoria L.;Gore, John C.
功能磁共振成像（fMRI）被广泛用于检测和描绘大脑的区域，这些区域在响应特定的刺激和任务时改变了它们的激活水平。简单的激活图只能描述分布式系统中不同区域的平均参与水平。功能磁共振成像可以潜在地揭示大规模神经系统的组成部分在功能上耦合在一起以完成特定任务的程度。为了更好地理解大脑区域如何促进功能连接回路，有必要记录不同条件、不同时间或不同受试者的激活图。然后可以用各种技术分析在不同条件下获得的数据，以推断网络中节点之间的相关性和耦合性。一些多元统计方法已经适应并应用于分析这些数据中的变化。一种特别有趣的方法适合于研究单个受试者的连通性，它利用在大脑处于所谓的稳定状态（即，没有任何特定的刺激或任务）或处于持续激活状态时获得的MRI图像的运行。MRI信号波动之间的区域间相关性可能揭示功能连接。最近的研究已经证实，在静息状态下，可以检测到视觉、语言、运动和工作记忆系统中每个回路的不同组成部分之间的区域间相关性。在执行连续任务期间，基线上的相关性会发生变化。在这篇综述中，描述和评估了用于评估连通性的各种方法。(c) 2007爱思唯尔公司版权所有。
Functional magnetic resonance imaging (fMRI) is widely used to detect and delineate regions of the brain that change their level of activation in response to specific stimuli and tasks. Simple activation maps depict only the average level of engagement of different regions within distributed systems. FMRI potentially can reveal additional information about the degree to which components of large-scale neural systems are functionally coupled together to achieve specific tasks. In order to better understand how brain regions contribute to functionally connected circuits, it is necessary to record activation maps either as a function of different conditions, at different times or in different subjects. Data obtained under different conditions may then be analyzed by a variety of techniques to infer correlations and couplings between nodes in networks. Several multivariate statistical methods have been adapted and applied to analyze variations within such data. An approach of particular interest that is suited to studies of connectivity within single subjects makes use of acquisitions of runs of MRI images obtained while the brain is in a so-called steady state, either at rest (i.e., without any specific stimulus or task) or in a condition of continuous activation. Interregional correlations between fluctuations of MRI signal potentially reveal functional connectivity. Recent studies have established that interregional correlations between different components of circuits in each of the visual, language, motor and working memory systems can be detected in the resting state. Correlations at baseline are changed during the performance of a continuous task. In this review, various methods available for assessing connectivity are described and evaluated. (c) 2007 Elsevier Inc. All rights reserved.