Furukawa Yuta, Uehara Kazumasa, Furuya Shinichi
Musical Skill and Injury Center (MuSIC), Sophia University, Japan.
Musical Skill and Injury Center (MuSIC), Sophia University, Japan; School of Biological and Health Systems Engineering, Arizona State University, USA.
Neurosci Lett. 2017 May 22;650:97-102. doi: 10.1016/j.neulet.2017.04.033. Epub 2017 Apr 21.
Precise mapping between sound and motion underlies successful communication and information transmission in speech and musical performance. Formation of the map typically undergoes plastic changes in the neuronal network between auditory and motor regions through training. However, to what extent the map is somatotopically-tuned so that auditory information can specifically modulate the corticospinal system responsible for the relevant motor action has not been elucidated. Here we addressed this issue by assessing the excitability of corticospinal system including the primary motor cortex (M1) innervating the hand intrinsic muscles by means of transcranial magnetic stimulation while trained pianists and musically-untrained individuals (non-musicians) were listening to either piano tones or noise. M1 excitability was evaluated at two anatomically-independent muscles of the hand. The results demonstrated elevation of M1 excitability at not all but one specific muscle while listening to piano tones in the pianists, but no excitability change in both of the muscles in the non-musicians. However, listening to noise did not elicit any changes of M1 excitability at both muscles in both the pianists and the non-musicians. These findings indicate that auditory information representing the trained motor action tunes M1 excitability in a non-uniform, somatotopically-specific manner, which is likely associated with multimodal experiences in musical training.
声音与动作之间的精确映射是言语和音乐表演中成功沟通与信息传递的基础。通过训练，这种映射的形成通常会使听觉和运动区域之间的神经网络发生可塑性变化。然而，这种映射在多大程度上是躯体定位调谐的，以至于听觉信息能够特异性地调节负责相关运动动作的皮质脊髓系统，目前尚未阐明。在这里，我们通过经颅磁刺激评估皮质脊髓系统（包括支配手部固有肌的初级运动皮层（M1））的兴奋性来解决这个问题，同时让受过训练的钢琴家以及未受过音乐训练的个体（非音乐家）聆听钢琴音调或噪音。在手部两个解剖学上独立的肌肉处评估M1兴奋性。结果表明，在聆听钢琴音调时，钢琴家并非所有手部肌肉的M1兴奋性都升高，而是只有一块特定肌肉的M1兴奋性升高，而非音乐家的两块肌肉的兴奋性均无变化。然而，在钢琴家和非音乐家聆听噪音时，两块肌肉的M1兴奋性均未发生任何变化。这些发现表明，代表经过训练的运动动作的听觉信息以一种非均匀、躯体定位特异性的方式调节M1兴奋性，这可能与音乐训练中的多模态体验有关。
