Failure of Motor Learning in Childhood Dystonia

患有肌张力障碍的儿童尽管一生都在练习，但他们的运动表现并没有改善。最近 理论结果表明，这可能是由于两种类型的运动学习失败之一： 类型1：无法识别相关错误， 第二类：不能举出正确行为的例子。 我们提出了一组实验来证明运动学习的失败可能会导致运动能力低下 肌张力障碍儿童的控制。为了验证这一假设，30名患有原发性或继发性肌张力障碍的儿童， 30名对照儿童将使用2块或4块肌肉的表面肌电活动来控制位置 电脑屏幕上的光标。第1类故障可以通过模糊视觉信息人为诱导 关于肌肉活动。2型失败可以通过使用4块肌肉控制4块肌肉的困难任务来诱导。 通过一个未知的线性混合变换的运动维度，孩子们必须发现 一种特定的活动模式在具体目标1中，我们将证明，控制儿童和 肌张力障碍的儿童表现出增加的肌肉共同激活时，有关肌肉活动的信息， 模糊，如运动学习1型失败所预测的。在具体目标2中，我们将证明， 控制儿童和肌张力障碍儿童无法学习困难的任务，直到一个成功的例子， 在同一任务的简化版本中学习。这项研究的成功结果将表明， 运动学习是必要的，并且足以在儿童肌张力障碍中产生部分运动缺陷。它将 还显示了改善肌张力障碍的策略。特别是，如果生物- 提供未观察到的模式（在这种情况下，二头肌和三头肌的共同收缩）的反馈。2型 如果在一个简单的任务中向孩子们展示正确的解决方案，失败可以得到改善，这样他们就可以 然后记住并随意返回到正确的解决方案。这些实验将证明一种潜在的 肌张力障碍运动症状的重要促成因素，它们将指示特定的新治疗方法 机会

Children with dystonia do not improve their movement performance despite a lifetime of practice. Recent theoretical results suggest that this may be due to one of two types of failure of motor learning: Type 1: inability to recognize relevant errors, Type 2: inability to generate examples of correct behavior. We propose a set of experiments to demonstrate that failure of motor learning may contribute to poor motor control in children with dystonia. To test this hypothesis, 30 children with primary or secondary dystonia and 30 control children will use surface electromyographic activity of either 2 or 4 muscles to control the position of cursors on a computer screen. Type 1 failure can be induced artificially by obscuring visual information about muscle activity. Type 2 failure can be induced using a difficult task in which 4 muscles control 4 dimensions of movement through an unknown linear mixing transformation, and the children must discover exactly one specific pattern of activity. In specific aim 1, we will demonstrate that both control children and children with dystonia show increased co-activation of muscles when information about muscle activity is obscured, as predicted by type 1 failure of motor learning. In specific aim 2, we will demonstrate that both control children and children with dystonia are unable to learn a difficult task until a successful example is learned in a simplified version of the same task. A successful result of this study will show that failure of motor learning is necessary and sufficient to produce part of the motor deficits in childhood dystonia. It will also show strategies for improvement of dystonia. In particular, type 1 failure can be improved ifbio- feedback of an unobserved mode (in this case, co-contraction of biceps and triceps) is provided. Type 2 failure can be improved if the correct solution is presented to children in a simplified task, so that they can then remember and return to the correct solution at will. These experiments will demonstrate a potentially important contributor to motor symptoms in dystonia, and they will indicate specific new treatment opportunities.