Slobounov S, Ray W, Cao C, Chiang H
Department of Kinesiology, 19 Recreation Building, University Park, PA 16802-5702, USA.
Neurosci Lett. 2007 Jun 27;421(2):126-31. doi: 10.1016/j.neulet.2007.04.077. Epub 2007 May 29.
This report aims to examine the role of task-specific practice in the modification of finger force enslaving and to provide empirical evidence for specific EEG frequency bands accompanying such practice may be an end-effectors dependent phenomenon. Nine handed naïve subjects without any training in music participated in a pre- and post-practice sessions separated by 12 practice sessions. Subjects performed a series of isometric force production tasks at 10% and 50% maximum voluntary contraction (MVC) with two rates of force development separately by index and ring fingers. Task-specific practice aimed at suppressing the contribution of neighboring fingers was achieved via visual feedback of force traces. Behavioral data (accuracy of force production and amount of force enslaving) and EEG data in frequency domain obtained via Morlet Wavelet transforms were analyzed. The major behavioral finding is that task-specific practice significantly enhanced the accuracy of force production and individuated control of the "most enslaved" ring finger (P<0.01), but not the index finger. The major novel EEG findings are: (a) modulation of EEG activity within alpha band (8-12 Hz) in the central area of the brain as a function of practice was similar for both fingers and (b) after practice, modulation of EEG activity within gamma (30-50 Hz) band was end-effectors specific. Both behavioral and EEG patterns suggest an effect of task-specific practice on the reduction of force enslaving and that modulation of practice-related plasticity in the human cortex is end-effectors dependent phenomena.
本报告旨在研究特定任务练习在改变手指力量从属方面的作用，并为伴随这种练习的特定脑电图频段可能是一种与终效应器相关的现象提供实证依据。九名没有任何音乐训练经历的惯用手受试者参加了一个练习前和练习后的实验环节，中间间隔12次练习。受试者分别用食指和无名指以两种力量发展速率在最大自主收缩（MVC）的10%和50%水平上执行一系列等长力量产生任务。旨在抑制相邻手指贡献的特定任务练习通过力量轨迹的视觉反馈来实现。分析了行为数据（力量产生的准确性和力量从属量）以及通过莫雷小波变换获得的频域脑电图数据。主要行为学发现是，特定任务练习显著提高了力量产生的准确性，并使“最易受影响的”无名指的控制更加个体化（P<0.01），但食指没有这种情况。主要的新颖脑电图发现是：（a）大脑中央区域α波段（8-12Hz）内的脑电图活动随练习的调制对于两个手指来说是相似的；（b）练习后，γ波段（30-50Hz）内的脑电图活动调制是终效应器特异性的。行为和脑电图模式均表明特定任务练习对减少力量从属有影响，并且人类皮层中与练习相关的可塑性调制是与终效应器相关的现象。
