Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka 565-0871, Japan; The Japan Society for the Promotion of Science, Tokyo 102-0083, Japan.
Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka 565-0871, Japan; Graduate School of Medicine and Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan.
Brain Res. 2019 Nov 1;1722:146365. doi: 10.1016/j.brainres.2019.146365. Epub 2019 Aug 7.
In this study, we demonstrate the involvement of left frontoparietal cortices in neural processes for task-switching between skilled movements. Functional magnetic resonance imaging was conducted while thirty-two right-handed healthy participants performed two sequential finger-movement tasks with their left hands. One group (n = 16) trained these tasks through random-practice (tasks were either switched or repeated trial by trial) on one day and blocked-practice (successive intensive practice of each task) on the next day, while the remaining participants practiced in the reverse order. On the first day, performance of both tasks improved in all participants, suggesting that the two skilful tasks can be learned in both practice schedules. However, during the random-practice, the performance in the switched trials initially deteriorated and gradually approached to that in the repeated trials as the practice proceeded. The left (mainly inferior) frontoparietal cortices showed greater preparatory activity for the switched trials compared with the repeated trials in a left-hemispheric dominant manner, and the left intraparietal activity decreased as the performance of the switched trials improved. The results indicate that neural processes for task-switching are associated with the greater preparatory activity in the left inferior frontoparietal cortices, and the efficient switching may proceed concomitantly with the left intraparietal activity reduction.
在这项研究中，我们证明了左额顶叶皮质在熟练运动之间的任务转换的神经过程中的参与。当 32 名右利手健康参与者用左手进行两个连续的手指运动任务时，进行了功能磁共振成像。一组（n=16）在一天内通过随机练习（任务要么逐次切换，要么重复），在第二天通过分组练习（每个任务的连续密集练习）进行训练，而其余参与者则以相反的顺序进行练习。在第一天，所有参与者的两项任务的表现都有所提高，这表明这两项熟练的任务可以在两种练习计划中学习。然而，在随机练习中，随着练习的进行，切换试验的表现最初恶化，逐渐接近重复试验的表现。与重复试验相比，左（主要是下）额顶叶皮质在左半球优势下显示出对切换试验更大的预备活动，并且随着切换试验表现的提高，左顶内活动减少。结果表明，任务切换的神经过程与左下额顶叶皮质中更大的预备活动有关，并且有效的切换可能与左顶内活动的减少同时进行。
