Department of Radiology, Children's Hospital of Philadelphia, 34th St. and Civic Center Boulevard, Philadelphia, PA 19104, USA.
Neuroimage. 2010 Jun;51(2):792-807. doi: 10.1016/j.neuroimage.2010.01.077. Epub 2010 Jan 29.
We measured visually-cued motor responses in two developmentally separate groups of children and compared these responses to a group of adults. We hypothesized that if post-movement beta rebound (PMBR) depends on developmentally sensitive processes, PMBR will be greatest in adults and progressively decrease in children performing a basic motor task as a function of age. Twenty children (10 young children 4-6 years; 10 adolescent children 11-13 years) and 10 adults all had MEG recorded during separate recordings of right and left index finger movements. Beta band (15-30 Hz) event-related desynchronization (ERD) of bi-lateral sensorimotor areas was observed to increase significantly from both contralateral and ipsilateral MI with age. Movement-related gamma synchrony (60-90 Hz) was also observed from contralateral MI for each age group. However, PMBR was significantly reduced in the 4-6 year group and, while more prominent, remained significantly diminished in the adolescent (11-13 year) age group as compared to adults. PMBR measures were weak or absent in the youngest children tested and appear maximally from bilateral MI in adults. Thus PMBR may reflect an age-dependent inhibitory process of the primary motor cortex which comes on-line with normal development. Previous studies have shown PMBR may be observed from MI following a variety of movement-related tasks in adult participants - however, the origin and purpose of the PMBR is unclear. The current study shows that the expected PMBR from MI observed from adults is increasingly diminished in adolescent and young children respectively. A reduction in PMBR from children may reflect reduced motor cortical inhibition. Relatively less motor inhibition may facilitate neuronal plasticity and promote motor learning in children.
我们在两组发展阶段不同的儿童中测量了视觉提示的运动反应，并将这些反应与一组成年人进行了比较。我们假设，如果运动后β波反弹（PMBR）取决于发育敏感的过程，那么 PMBR 在成年人中最大，并随着年龄的增长，在执行基本运动任务的儿童中逐渐减少。20 名儿童（10 名幼儿 4-6 岁；10 名青少年儿童 11-13 岁）和 10 名成年人在分别记录右手和左手食指运动的过程中都进行了 MEG 记录。β频段（15-30 Hz）双侧感觉运动区的事件相关去同步化（ERD）随着年龄的增长从对侧和同侧 MI 显著增加。对于每个年龄组，还观察到来自对侧 MI 的运动相关γ同步性（60-90 Hz）。然而，与成年人相比，4-6 岁组的 PMBR 显著降低，虽然更为明显，但在青少年（11-13 岁）年龄组中仍然显著降低。在测试的最小年龄组中，PMBR 测量值较弱或缺失，并且在成年人中从双侧 MI 中最大。因此，PMBR 可能反映了初级运动皮层的一种与年龄相关的抑制过程，该过程随着正常发育而上线。以前的研究表明，在成年参与者中进行各种与运动相关的任务后，可能会从 MI 中观察到 PMBR-然而，PMBR 的起源和目的尚不清楚。本研究表明，成年人观察到的预期 PMBR 分别在青少年和幼儿中逐渐减少。儿童 PMBR 的减少可能反映了运动皮层抑制的减少。相对较少的运动抑制可能有利于神经元可塑性并促进儿童的运动学习。
