Department of Kinesiology, The Pennsylvania State University, 275 Rec Hall, University Park, PA, 16802, USA.
Eur J Appl Physiol. 2012 Jul;112(7):2575-81. doi: 10.1007/s00421-011-2239-y. Epub 2011 Nov 12.
The dynamics of postural finger tremor is typically investigated under conditions of natural vision of the finger. Here we investigated the effect of different types of augmented visual information feedback on finger tremor and on inter-limb tremor coordination. Four visual information conditions of postural finger tremor from either the dominant hand only or from both hands were investigated. The visual conditions were: (1) no vision, (2) natural vision, (3) augmented vision with instantaneous acceleration on a computer display, and (4) augmented vision with instantaneous and past acceleration on a computer display. Acceleration was measured with a 3D accelerometer on the distal phalanx of the index finger(s). The amount of tremor variability did not change as a function of visual information conditions. However, removing visual feedback increased tremor predictability and reduced small, random deviations of tremor acceleration output in the one finger condition. In the two-finger condition, augmented visual information increased the irregularity of the combined tremor variability. The no vision condition showed a stronger coupling between fingers than natural vision or augmented vision with past information. The findings revealed that augmented visual information increased tremor irregularity and facilitated coupling in two-hand tremor dynamics.
姿势性手指震颤的动力学通常在手指自然视觉的条件下进行研究。在这里，我们研究了不同类型的增强视觉信息反馈对手指震颤和肢体间震颤协调的影响。研究了来自优势手或双手的姿势性手指震颤的四种视觉信息条件。视觉条件为：(1)无视觉，(2)自然视觉，(3)计算机显示器上的即时加速度增强视觉，(4)计算机显示器上的即时和过去加速度增强视觉。加速度通过指骨末端的 3D 加速度计测量。震颤变异性的幅度并没有随视觉信息条件的变化而变化。然而，去除视觉反馈增加了震颤的可预测性，并减少了单指条件下震颤加速度输出的小的、随机的偏差。在双指条件下，增强的视觉信息增加了组合震颤变异性的不规则性。无视觉条件下手指之间的耦合比自然视觉或具有过去信息的增强视觉更强。研究结果表明，增强的视觉信息增加了震颤的不规则性，并促进了双手震颤动力学的耦合。
