Makary Meena M, Eun Seulgi, Park Kyungmo
aDepartment of Biomedical Engineering, Kyung Hee University, Yongin, Republic of Korea bDepartment of Systems and Biomedical Engineering, Faculty of Engineering, Cairo University, Giza, Egypt.
Neuroreport. 2017 Jul 5;28(10):610-617. doi: 10.1097/WNR.0000000000000809.
Motor imagery (MI) relies on conscious mental simulation of a motor act without overt motor output and can promote motor skill acquisition and facilitate rehabilitation for patients with stroke or neurological conditions. Although a plethora of neuroimaging studies have investigated the neural network of MI regarding different body parts, exploration of the neural correlates to facial MI remains warranted. Here, we used functional MRI with a large cohort of 41 participants who underwent motor execution (ME) and MI runs of mouth-stretching tasks. Then, we carried out conjunction and contrast analyses to investigate the commonalities and differences between the two conditions. Conjunction analysis, representing the shared neural network between ME and MI, showed activation in the primary motor cortex, primary and secondary somatosensory cortices, premotor cortex, parietal lobe, anterior insula, supplementary motor area (SMA) and pre-SMA, thalamus, putamen, and caudate. Contrast analysis showed greater activation of primary motor cortex, primary and secondary somatosensory cortices, SMA, anterior insula, and the thalamus in response to ME than MI and greater activation of the premotor cortex, pre-SMA, putamen, and caudate in response to MI than ME. Interestingly, we found exclusive activation in the anterior cingulate cortex and left ventrolateral prefrontal cortex in response to MI, reflecting the motor inhibition network responsible for blocking the transmission of motor commands to peripheral effectors during mental rehearsal. Taken together, these findings show that, despite the neural overlap between ME and MI, there are different degrees of activation within this overlap, and that MI normally involves motor command inhibition possibly mediated by the anterior cingulate cortex and ventrolateral prefrontal cortex.
运动想象（MI）依赖于对运动行为的有意识心理模拟，而无需明显的运动输出，并且可以促进运动技能的习得，并有助于中风或神经系统疾病患者的康复。尽管大量的神经影像学研究已经探究了与不同身体部位相关的运动想象神经网络，但对与面部运动想象相关的神经关联进行探索仍然很有必要。在这里，我们对41名参与者组成的大型队列进行了功能性磁共振成像研究，这些参与者进行了嘴巴伸展任务的运动执行（ME）和运动想象测试。然后，我们进行了联合分析和对比分析，以研究这两种情况之间的共性和差异。联合分析代表了运动执行和运动想象之间共享的神经网络，结果显示在初级运动皮层、初级和次级体感皮层、运动前皮层、顶叶、前岛叶、辅助运动区（SMA）和前辅助运动区、丘脑、壳核和尾状核中存在激活。对比分析显示，与运动想象相比，运动执行时初级运动皮层、初级和次级体感皮层、辅助运动区、前岛叶和丘脑的激活程度更高；与运动执行相比，运动想象时运动前皮层、前辅助运动区、壳核和尾状核的激活程度更高。有趣的是，我们发现仅在运动想象时前扣带回皮层和左侧腹外侧前额叶皮层有激活，这反映了在心理演练过程中负责阻止运动指令传递到外周效应器的运动抑制网络。综上所述，这些发现表明，尽管运动执行和运动想象之间存在神经重叠，但在这种重叠范围内存在不同程度的激活，并且运动想象通常涉及可能由前扣带回皮层和腹外侧前额叶皮层介导的运动指令抑制。
