Age-related differences in force variability and visual display
Age-related differences in force variability and visual display
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DOI：
10.1007/s00221-010-2229-z
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发表时间：
2010-06-01
影响因子：
2
通讯作者：
Sosnoff, Jacob J.
中科院分区：
文献类型：
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作者：
Ofori, Edward;Samson, Jean M.;Sosnoff, Jacob J.
众所周知，老年人的力量输出更具变异性，这种与年龄相关的减少是通过视觉运动处理来调节的。本研究的目的是考察视觉显示的类型是否影响与年龄相关的力量输出控制差异。为了解决这个问题，年轻人和老年人通过食指外展产生恒定的等长力，达到3个力水平[最大自愿收缩(MVC)的5%、10%和20%]。视觉反馈被呈现为补偿性或追踪性展示。补偿显示提供关于相对于标准目标的力幅度的视觉反馈，而追踪显示提供关于相对于标准目标的力轨迹的视觉反馈以及力轨迹的目标路径的预览。力的变异性大小用标准差和变异系数表示。用谱斜率和近似熵来指标力输出的结构。正如预期的那样，与年轻人相比，老年人更具变异性，具有更多的结构化力量输出。此外，这种与年龄相关的力量控制差异在追逐表演中是至关重要的。总体而言，研究结果表明，与年龄相关的力量控制差异是中央调节的。有人提出，老年人在视觉运动处理方面存在缺陷，这可能部分与年龄相关的眼动控制能力下降有关。
It is well established that older adults are more variable in their force output and that this age-related decrement is mediated by visuomotor processing. The purpose of this investigation was to examine whether the type of visual display impacts age-related differences in the control of force output. In order to address this question, young and old participants produced constant isometric force via index finger abduction to 3 force levels [5, 10, and 20% of their maximal voluntary contraction (MVC)]. Visual feedback was presented with either a compensatory or a pursuit display. A compensatory display provides visual feedback about force amplitude in relation to the criterion target whereas a pursuit display provides visual feedback about the force trajectory in relation to the criterion target and preview of the target path of the force trajectory. The magnitude of force variability was indexed with standard deviation and coefficient of variation. The structure of force output was indexed with spectral slope and approximate entropy. As expected, older adults were more variable and had more structured force output compared to younger adults. Moreover, this age-related difference in force control was paramount in pursuit displays. Overall, the findings suggest that age-related differences in force control are centrally mediated. It is proposed that older adults have deficits in visuomotor processing and this may be partly related to age-related decrements in the control of eye movements.