Institute of Music Physiology and Musicians' Medicine, University of Music, Drama, and Media, Emmichplatz 1, 30175 Hannover, Germany.
Neural Netw. 2013 Dec;48:25-31. doi: 10.1016/j.neunet.2013.06.012. Epub 2013 Jul 6.
Task-specific focal dystonia is a task-specific movement disorder which manifests itself as a loss of voluntary motor control in extensively trained movements. The condition is most frequent in musicians. Until today, the aetiology of focal hand dystonia is not completely understood, but there is growing evidence for an abnormal cortical processing of sensory information, as well as degraded representation of motor functions. It was demonstrated that in the somatosensory cortex the topographical location of sensory inputs from individual fingers is corrupted. Occasionally, a change in sensory information of the hand may at least temporarily improve the condition. This phenomenon is called sensory trick. In this paper, we propose a model of encoding of sensory stimuli which could explain the task specificity of cortical representations of the fingers or other effectors in the context of dystonia. In the framework of this model a sensory stimulus is encoded as a signal vector of higher dimension. A part of its components directly represents the sensory stimulus, while the remaining components describe the context. This model does not only account for the task specificity, but may also explain some characteristics of the retraining process in this disorder.
任务特异性局灶性肌张力障碍是一种任务特异性运动障碍，表现为在广泛训练的运动中丧失自愿运动控制。这种情况在音乐家中最为常见。直到今天，局灶性手部肌张力障碍的病因仍不完全清楚，但越来越多的证据表明皮质对感觉信息的处理异常，以及运动功能的表示退化。已经证明，在体感皮层中，来自单个手指的感觉输入的拓扑位置被破坏。偶尔，手部感觉信息的变化至少可以暂时改善病情。这种现象称为感觉技巧。在本文中，我们提出了一种编码感觉刺激的模型，该模型可以解释在肌张力障碍的背景下手指或其他效应器的皮质表示的任务特异性。在该模型的框架内，感觉刺激被编码为更高维度的信号向量。其组成部分的一部分直接表示感觉刺激，而其余部分则描述上下文。该模型不仅解释了任务特异性，而且还可以解释该疾病的再训练过程的某些特征。
