Morgan Victoria L, Price Ronald R
Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232-2675, USA.
Magn Reson Imaging. 2004 Oct;22(8):1069-75. doi: 10.1016/j.mri.2004.07.002.
The correlations in the fluctuations in the blood oxygenation level-dependent (BOLD) MRI signal between anatomically distinct regions of the cortex that are known components of functional systems have been previously studied as possible indicators of functional connectivity. The objective of this study was to examine the effect of sensorimotor brain activity, as assessed by task-based functional magnetic resonance imaging (fMRI), on functional connectivity indices in the same region. Regions of activation for sequential finger motion were determined using a task-based, block-design fMRI study. Functional connectivity measurements based on interregional correlations were acquired at rest and during continuous, sequential finger motion. Connectivity indices were determined using normalized mean correlations within and between three regions of interest activated for the finger motion task. Connectivity indices were also determined for a control region that was not activated for the task. Continuous motor tasks performed during BOLD measurements did not significantly affect the functional connectivity as compared to the connectivity at rest within or between regions known to be activated by the task. However, there appeared to be a trend suggesting a slight reduction in connectivity indices during the motor task. The connectivity within and between those areas not activated for the task remained unchanged between conditions. These results suggest that in the motor system investigated, the recruitment of neurons to perform a specific task may moderately reduce the degree of hemodynamic coupling within and between regions.
血氧水平依赖（BOLD）磁共振成像（MRI）信号在已知为功能系统组成部分的皮质不同解剖区域之间波动的相关性，此前已作为功能连接性的可能指标进行了研究。本研究的目的是通过基于任务的功能磁共振成像（fMRI）评估感觉运动脑活动对同一区域功能连接性指标的影响。使用基于任务的组块设计fMRI研究确定连续手指运动的激活区域。在静息状态和连续手指运动期间获取基于区域间相关性的功能连接性测量值。使用针对手指运动任务激活的三个感兴趣区域内和之间的归一化平均相关性确定连接性指标。还为未因该任务而激活的对照区域确定了连接性指标。与任务激活区域内或之间静息状态下的连接性相比，在BOLD测量期间执行的连续运动任务对功能连接性没有显著影响。然而，似乎有一个趋势表明在运动任务期间连接性指标略有降低。在不同条件下，未因该任务而激活的那些区域内和之间的连接性保持不变。这些结果表明，在所研究的运动系统中，募集神经元执行特定任务可能会适度降低区域内和区域间血流动力学耦合的程度。
