Corticospinal Excitability During Actual and Imaginary Motor Tasks of Varied Difficulty
Corticospinal Excitability During Actual and Imaginary Motor Tasks of Varied Difficulty
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不同难度的实际和想象的运动任务期间皮质脊髓的兴奋性
DOI：
10.1016/j.neuroscience.2018.08.011
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Yoshitake Y.
中科院分区：
文献类型：
--
作者：
Watanabe H;Mizuguchi N;Mayfield DL;Yoshitake Y.
本研究探讨了在实际（ACT）和想象（IMG）不同难度的单手力匹配任务的对侧和同侧半球的皮质脊髓兴奋性。17名年轻男性成人（21.2 ± 2.2岁）实际上和实际上将其左手食指外展力与显示的目标力匹配。通过改变每个平均目标力的可接受力范围（ACT为5和15%MVC，IMG为15%MVC）来操纵任务难度。具体而言，简单（EASY）和困难（DIFF）任务分别分配了目标力±7%和±0%的可接受力范围。单脉冲经颅磁刺激在ACT中应用于两个半球，在IMG中应用于左半球。运动诱发电位（MEP）收集任务期间从第一背侧骨间肌。在ACT中，收缩和静止的手的MEP在DIFF期间显著大于EASY（P< 0.05），当跨目标力水平塌陷时。在IMG中，DIFF时静息右手MEP显著大于EASY时（P< 0.05）。ACT中右手MEP波幅从EASY到DIFF的相对变化与IMG中的相应变化呈正相关（r= 0.63）。这些结果表明，更大的任务难度增加皮质脊髓兴奋性的对侧半球的ACT，并增加皮质脊髓兴奋性的同侧半球的ACT和IMG。随着任务难度的增加，同侧半球皮质脊髓兴奋性的相对变化在ACT和IMG之间相关。
The present study examined corticospinal excitability of the contralateral and ipsilateral hemispheres during actual (ACT) and imaginary (IMG) unilateral hand force-matching tasks of different difficulty. Seventeen young male adults (21.2 ± 2.2 yrs) actually and imaginarily matched their left index finger abduction force to a displayed target force. Task difficulty was manipulated by varying the acceptable force range about each mean target force (5 and 15% MVC for ACT, 15% MVC for IMG). Specifically, easy (EASY) and difficult (DIFF) tasks were assigned an acceptable force range of ±7% and ±0% of target force, respectively. Single pulse transcranial magnetic stimulation was applied to the both hemispheres in ACT and over the left hemisphere in IMG. Motor evoked potentials (MEPs) were collected from the first dorsal interosseous muscle during tasks. In ACT, MEPs in both the contracting and resting hands were significantly larger (P< 0.05) during DIFF than EASY when collapsed across target force levels. In IMG, MEPs in the resting right hand were significantly larger (P< 0.05) during DIFF than during EASY. The relative change in MEP amplitude in the right hand from EASY to DIFF in ACT was positively correlated (r= 0.63) with that in IMG. These results indicate that greater task difficulty increases corticospinal excitability of the contralateral hemisphere in ACT, and increases corticospinal excitability of the ipsilateral hemisphere in both ACT and IMG. The relative changes in corticospinal excitability of the ipsilateral hemisphere with increasing task difficulty are correlated between ACT and IMG.