Greater amount of visual feedback decreases force variability by reducing force oscillations from 0-1 and 3-7 Hz
Greater amount of visual feedback decreases force variability by reducing force oscillations from 0-1 and 3-7 Hz
复制标题
DOI：
10.1007/s00421-009-1301-5
复制
发表时间：
2010-03-01
影响因子：
3
通讯作者：
Christou, Evangelos A.
中科院分区：
文献类型：
--
作者：
Baweja, Harsimran S.;Kennedy, Deanna M.;Christou, Evangelos A.
目的是确定视觉反馈增益和力的变化之间的关系，以及视觉增益引起的力的变化是否与频率特异性力振荡和激动肌神经激活的变化相关。14名年轻人（19-29岁）被要求在食指外展的情况下，在其最大自主收缩的2%和10%处准确匹配目标力。力保持在特定的视觉反馈增益水平，不同的试验。每次试验持续20秒，视觉反馈的量通过将视觉增益从0.5改变到1，474像素/N（13个水平;等于类似于0.001-4.57A度）而变化。将力变异性量化为去趋势力数据的标准差。用表面肌电图检测第一骨间背侧肌（FDI）的神经活动。平均力没有随视觉反馈的量而显著变化。相反，与中等增益相比，力可变性从低增益降低（0.5-4像素/N：0.09 +/- A 0.04 vs. 64- 1，424像素/N：0.06 +/- A 0.02 N）。通过0-1 Hz（类似于50%）和3-7 Hz（类似于20%）的力振荡功率降低预测变异性降低。FDI肌肉的活动在视觉反馈增益之间没有变化。这些研究结果表明，在年轻人中，由于0-1 Hz和3-7 Hz的力振荡功率的降低，力的可变性可以随着视觉反馈增益的增加而降低（> 64像素/N vs. 0.5-4像素/N）。
The purpose was to determine the relation between visual feedback gain and variability in force and whether visual gain-induced changes in force variability were associated with frequency-specific force oscillations and changes in the neural activation of the agonist muscle. Fourteen young adults (19-29 years) were instructed to accurately match the target force at 2 and 10% of their maximal voluntary contraction with abduction of the index finger. Force was maintained at specific visual feedback gain levels that varied across trials. Each trial lasted 20 s and the amount of visual feedback was varied by changing the visual gain from 0.5 to 1,474 pixels/N (13 levels; equals similar to 0.001-4.57A degrees). Force variability was quantified as the standard deviation of the detrended force data. The neural activation of the first dorsal interosseus (FDI) was measured with surface electromyography. The mean force did not vary significantly with the amount of visual feedback. In contrast, force variability decreased from low gains compared to moderate gains (0.5-4 pixels/N: 0.09 +/- A 0.04 vs. 64-1,424 pixels/N: 0.06 +/- A 0.02 N). The decrease in variability was predicted by a decrease in the power of force oscillations from 0-1 Hz (similar to 50%) and 3-7 Hz (similar to 20%). The activity of the FDI muscle did not vary across the visual feedback gains. These findings demonstrate that in young adults force variability can be decreased with increased visual feedback gain (> 64 pixels/N vs. 0.5-4 pixels/N) due to a decrease in the power of oscillations in the force from 0-1 and 3-7 Hz.