Kraeutner Sarah, Gionfriddo Alicia, Bardouille Timothy, Boe Shaun
Laboratory for Brain Recovery and Function, Dalhousie University, Halifax, NS, Canada; Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.
Laboratory for Brain Recovery and Function, Dalhousie University, Halifax, NS, Canada; School of Physiotherapy, Dalhousie University, Halifax, Nova Scotia, Canada.
Brain Res. 2014 Nov 7;1588:81-91. doi: 10.1016/j.brainres.2014.09.001. Epub 2014 Sep 22.
Motor imagery (MI) is a form of practice in which an individual mentally performs a motor task. Previous research suggests that skill acquisition via MI is facilitated by repetitive activation of brain regions in the sensorimotor network similar to that of motor execution, however this evidence is conflicting. Further, many studies do not control for overt muscle activity and thus the activation patterns reported for MI may be driven in part by actual movement. The purpose of the current research is to further establish MI as a secondary modality of skill acquisition by providing electrophysiological evidence of an overlap between brain areas recruited for motor execution and imagery. Non-disabled participants (N=18; 24.7±3.8 years) performed both execution and imagery of a unilateral sequence button-press task. Magnetoencephalography (MEG) was utilized to capture neural activity, while electromyography used to rigorously monitor muscle activity. Event-related synchronization/desynchronization (ERS/ERD) analysis was conducted in the beta frequency band (15-30 Hz). Whole head dual-state beamformer analysis was applied to MEG data and 3D t-tests were conducted after Talairach normalization. Source-level analysis showed that MI has similar patterns of spatial activity as ME, including activation of contralateral primary motor and somatosensory cortices. However, this activation is significantly less intense during MI (p<0.05). As well, activation during ME was more lateralized (i.e., within the contralateral hemisphere). These results confirm that ME and MI have similar spatial activation patterns. Thus, the current research provides direct electrophysiological evidence to further establish MI as a secondary form of skill acquisition.
运动想象（MI）是一种个体在脑海中执行运动任务的练习形式。先前的研究表明，通过运动想象进行技能习得是由感觉运动网络中与运动执行相似的脑区重复激活所促进的，然而这一证据存在矛盾之处。此外，许多研究并未控制明显的肌肉活动，因此所报告的运动想象激活模式可能部分是由实际运动驱动的。当前研究的目的是通过提供运动执行和想象所募集的脑区之间重叠的电生理证据，进一步将运动想象确立为技能习得的第二种方式。非残疾参与者（N = 18；24.7±3.8岁）执行了单侧序列按键任务的执行和想象。利用脑磁图（MEG）来捕捉神经活动，同时使用肌电图严格监测肌肉活动。在β频段（15 - 30Hz）进行事件相关同步/去同步（ERS/ERD）分析。将全脑双态波束形成器分析应用于MEG数据，并在Talairach标准化后进行三维t检验。源水平分析表明，运动想象与运动执行具有相似的空间活动模式，包括对侧初级运动皮层和体感皮层的激活。然而，在运动想象期间这种激活明显较弱（p<0.05）。同样，运动执行期间的激活更偏向一侧化（即，在对侧半球内）。这些结果证实了运动执行和运动想象具有相似的空间激活模式。因此，当前研究提供了直接的电生理证据，以进一步将运动想象确立为技能习得的第二种形式。
