Asymmetric directed functional connectivity within the frontoparietal motor network during motor imagery and execution
Asymmetric directed functional connectivity within the frontoparietal motor network during motor imagery and execution
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DOI：
10.1016/j.neuroimage.2021.118794
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发表时间：
2021-12-14
期刊：
影响因子：
5.7
通讯作者：
Kawanabe, Motoaki
中科院分区：
文献类型：
--
作者：
Ogawa, Takeshi;Shimobayashi, Hideki;Kawanabe, Motoaki
想象和执行运动控制都是由神经元网络中的相互作用组成的，包括前额运动相关区域和后顶叶区域。为了揭示额顶运动网络中的神经表征，目前已经提出了两种方法：一种是从大脑活动的空间模式中解码与运动控制相关的动作/模式；另一种是估计定向功能连接(运动区内两个脑区之间的直接联系)。然而，在运动想象(MI)或运动执行(ME)过程中，额顶叶运动网络多个区域之间的直接连接尚未被研究。这里，我们试图刻画代表MI和ME条件的有向功能连通性。我们开发了一种延迟顺序运动和成像任务，以唤起与ME和MI相关的大脑活动，这可以通过功能磁共振成像来记录。我们应用了一种因果发现方法，一个线性的非高斯非循环因果模型，来确定每种情况下额顶运动相关脑区之间的直接功能连接。我们发现ME患者的对侧背侧运动前皮质(DPMC)到初级运动皮质(M1)的直接功能连接高于MI患者。我们进一步发现DPMC和腹侧运动前皮质(VPMC)对顶区有显著的直接影响。特别是，同侧大脑半球DPMC至顶上小叶(SPL)的连通性在所有条件下均表现出显著的正向连通性，而从vPMC到SPL的侧间连通性在所有条件下均表现出显著的负面效应。最后，我们发现从A1到M1，也就是音频-运动通路，在同一半球有正向影响。这些结果表明，起源于d/vPMC的运动指令来源影响了M1和顶区实现ME和MI。此外，连续的声音可能在功能上促进了颞叶运动的过程。
Both imagery and execution of motor control consist of interactions within a neuronal network, including frontal motor-related and posterior parietal regions. To reveal neural representation in the frontoparietal motor network, two approaches have been proposed thus far: one is decoding of actions/modes related to motor control from the spatial pattern of brain activity; and the other is estimating directed functional connectivity (a directed association between two brain regions within motor areas). However, directed connectivity among multiple regions of the frontoparietal motor network during motor imagery (MI) or motor execution (ME) has not been investigated. Here, we attempted to characterize the directed functional connectivity representing the MI and ME conditions. We developed a delayed sequential movement and imagery task to evoke brain activity associated with ME and MI, which can be recorded by functional magnetic resonance imaging. We applied a causal discovery approach, a linear non-Gaussian acyclic causal model, to identify directed functional connectivity among the frontoparietal motor-related brain regions for each condition. We demonstrated higher directed functional connectivity from the contralateral dorsal premotor cortex (dPMC) to the primary motor cortex (M1) in ME than in MI. We further identified significant direct effects of the dPMC and ventral premotor cortex (vPMC) to the parietal regions. In particular, connectivity from the dPMC to the superior parietal lobule (SPL) in the same hemisphere showed significant positive effects across all conditions, while interlateral connectivities from the vPMC to the SPL showed significantly negative effects across all conditions. Finally, we found positive effects from A1 to M1, that is, the audio-motor pathway, in the same hemisphere. These results indicate that the sources of motor command originating in the d/vPMC influenced the M1 and parietal regions for achieving ME and MI. Additionally, sequential sounds may functionally facilitate temporal motor processes.