Takagi Atsushi, Honda Kazuaki
Communication Science Laboratories, NTT, Inc., 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
iScience. 2025 Jul 18;28(8):113146. doi: 10.1016/j.isci.2025.113146. eCollection 2025 Aug 15.
The brain activity during bimanual movements exhibits a unique pattern not seen when either arm is moved alone. Existing theories suggest that the distinct pattern may come from the integration of motor timing between the hemispheres, but specifically how they combine remains unclear. Here, we measured the muscle activation timing of the left and right shoulders during a unimanual and bimanual periodic force control task and compared the empirical results with the predictions from three competing models of motor timing integration. Our results are most consistent with the view that the motor timing of the dominant hemisphere can be shared to improve the non-dominant arm's motor timing by up to 20%. However, the sharing of motor timing occurs more readily during symmetric bimanual movements relative to antisymmetric movements. Our results highlight the unique neural processes underlying symmetric coordination and clarify the circumstances in which motor timing can be shared between the limbs.
双手运动期间的大脑活动呈现出一种独特模式，单臂单独运动时并未出现这种模式。现有理论表明，这种独特模式可能源于半球之间运动时间的整合，但它们具体如何结合尚不清楚。在此，我们在单手和双手周期性力控制任务中测量了左右肩部的肌肉激活时间，并将实验结果与三种相互竞争的运动时间整合模型的预测进行了比较。我们的结果最符合以下观点：优势半球的运动时间可以共享，从而将非优势手臂的运动时间提高多达20%。然而，相对于非对称运动，运动时间的共享在对称双手运动期间更容易发生。我们的结果突出了对称协调背后独特的神经过程，并阐明了肢体之间可以共享运动时间的情况。
