Kasess Christian H, Windischberger Christian, Cunnington Ross, Lanzenberger Rupert, Pezawas Lukas, Moser Ewald
MR Center of Excellence, Medical University of Vienna, Austria; Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria; Division of Biological Psychiatry, Medical University of Vienna, Austria.
MR Center of Excellence, Medical University of Vienna, Austria; Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria.
Neuroimage. 2008 Apr 1;40(2):828-837. doi: 10.1016/j.neuroimage.2007.11.040. Epub 2007 Dec 8.
Although motor imagery is widely used for motor learning in rehabilitation and sports training, the underlying mechanisms are still poorly understood. Based on fMRI data sets acquired with very high temporal resolution (300 ms) under motor execution and imagery conditions, we utilized Dynamic Causal Modeling (DCM) to determine effective connectivity measures between supplementary motor area (SMA) and primary motor cortex (M1). A set of 28 models was tested in a Bayesian framework and the by-far best-performing model revealed a strong suppressive influence of the motor imagery condition on the forward connection between SMA and M1. Our results clearly indicate that the lack of activation in M1 during motor imagery is caused by suppression from the SMA. These results highlight the importance of the SMA not only for the preparation and execution of intended movements, but also for suppressing movements that are represented in the motor system but not to be performed.
尽管运动想象在康复和体育训练中的运动学习中被广泛应用，但其潜在机制仍知之甚少。基于在运动执行和想象条件下以非常高的时间分辨率（300毫秒）获取的功能磁共振成像（fMRI）数据集，我们利用动态因果模型（DCM）来确定辅助运动区（SMA）和初级运动皮层（M1）之间的有效连接测量值。在贝叶斯框架下测试了一组28个模型，迄今为止表现最佳的模型显示运动想象条件对SMA和M1之间的正向连接有强烈的抑制作用。我们的结果清楚地表明，运动想象期间M1缺乏激活是由SMA的抑制引起的。这些结果突出了SMA的重要性，不仅对于预期动作的准备和执行，而且对于抑制在运动系统中表征但不执行的动作。
