Centre for Motor Control, Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, ON, Canada.
Centre for Motor Control, Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, ON, Canada.
Neuropsychologia. 2019 Nov;134:107206. doi: 10.1016/j.neuropsychologia.2019.107206. Epub 2019 Sep 26.
Previous behavioural research has revealed that motor imagery (MI) can be an effective technique to generate and enhance motor learning and rehabilitation. This MI-enhanced motor performance may emerge because MI shares overlapping neural networks with movement execution and observation and leads to the activation and neuro-plasticity of the motor system. Neurophysiological studies using transcranial magnetic stimulation (TMS) have shown that physical and observational practice can elicit use-dependent, neuro-plastic changes in the cortical representation of movement. The purpose of the current experiment was to determine if similar changes in cortical representation of thumb movements could be elicited with MI training. Single-pulse TMS was provided over primary motor cortex to generate involuntary thumb movements before and after each of five training blocks. The dominant direction (flexion or extension) of TMS-evoked thumb movements was used as an index of the representation of thumb movements in primary motor cortex. During training, participants either imagined moving (experimental MI group) or physically moved (control PT group) their thumbs in the direction opposite to the dominant direction of their TMS-evoked thumb movements determined in the pre-training assessment. Both PT and MI training resulted in increases in the percentage of TMS-evoked thumb movements in the trained direction. These changes were apparent for the MI group after 900 imagery trials, whereas the changes were detectable in the PT group after 300 trials. These results indicate that MI can induce plastic changes similar to those of physical training, although more trials may be needed for these changes to occur.
先前的行为研究表明，运动想象（MI）可以是一种有效的技术，用于产生和增强运动学习和康复。这种 MI 增强的运动表现可能会出现，因为 MI 与运动执行和观察共享重叠的神经网络，并导致运动系统的激活和神经可塑性。使用经颅磁刺激（TMS）的神经生理学研究表明，物理和观察练习可以引起运动皮层代表中与使用相关的神经可塑性变化。本实验的目的是确定是否可以通过 MI 训练引起拇指运动皮层代表的类似变化。在每个 5 个训练块之前和之后，在初级运动皮层上提供单脉冲 TMS 以产生无意识的拇指运动。TMS 诱发的拇指运动的主导方向（屈曲或伸展）被用作初级运动皮层中拇指运动代表的指标。在训练期间，参与者要么想象移动（实验 MI 组），要么在预训练评估中确定的 TMS 诱发拇指运动的主导方向相反的方向上实际移动（对照 PT 组）拇指。PT 和 MI 训练均导致训练方向上 TMS 诱发的拇指运动的百分比增加。这些变化在 MI 组在进行 900 次想象试验后变得明显，而在 PT 组在进行 300 次试验后变得可检测。这些结果表明，MI 可以诱导类似于物理训练的塑性变化，尽管可能需要更多的试验才能发生这些变化。
