Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
Magn Reson Med. 2011 Sep;66(3):644-57. doi: 10.1002/mrm.22818. Epub 2011 Mar 10.
Brain functional connectivity (FC) refers to inter-regional synchrony of low frequency fluctuations in blood oxygenation level dependent functional magnetic resonance imaging. FC has been evaluated both during task performance and in the "resting" state, yielding reports of FC differences correlated with behavior and diagnosis. Two methodologies are widely used for evaluating FC from blood oxygenation level dependent functional magnetic resonance imaging data: Temporal correlation with a specified seed voxel or small region of interest; and spatial independent component analysis. While results from seed-based and independent component analysis methodologies are generally similar, they are conceptually different. This study is intended to elucidate and illustrate, qualitatively and quantitatively, the relationship between seed and independent component analysis derived measures of FC. Seed-based FC measures are shown to be the sum of independent component analysis-derived within network connectivities and between network connectivities. We present a simple simulation and an experiment on visuomotor activity that highlight this relationship between the two methods.
脑功能连接（FC）是指血氧水平依赖功能磁共振成像中低频波动的区域间同步。FC 已经在任务执行期间和“休息”状态下进行了评估，报告了与行为和诊断相关的 FC 差异。有两种广泛用于评估血氧水平依赖功能磁共振成像数据 FC 的方法：与指定种子体素或小感兴趣区的时间相关；和空间独立成分分析。虽然基于种子和独立成分分析方法的结果通常相似，但它们在概念上是不同的。本研究旨在定性和定量地阐明种子和独立成分分析衍生的 FC 测量值之间的关系。基于种子的 FC 测量值被证明是独立成分分析衍生的网络内连接和网络间连接的总和。我们提出了一个简单的模拟和一个关于视觉运动活动的实验，突出了这两种方法之间的关系。
