Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement
Ageing of internal models: from a continuous to an intermittent proprioceptive control of movement
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DOI：
10.1007/s11357-012-9436-4
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发表时间：
2013-08-01
期刊：
影响因子：
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通讯作者：
Nougier, Vincent
中科院分区：
文献类型：
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作者：
Boisgontier, Matthieu P.;Nougier, Vincent
为了控制感觉-运动系统，内部模型模拟运动命令和感觉信号之间的转换。本研究旨在探讨成人生理衰老对运动本体感觉控制的影响及其内在机制。为此，一组年轻人和一组老年人在两种速度条件下（自我选择和快速）进行踝关节对侧并发匹配任务。误差、时间和运动变量被用来评估匹配性能。结果表明，与年轻人相比，老年人使用了不同的控制模式，并表明本体感觉控制的内部模型随着年龄的增长而改变。这些变化的行为表现取决于所考虑的速度条件。在自我选择的速度条件下，与年轻人相比，老年人的这种改变表现为纠正子动作的数量增加。这种策略使他们达到了与年轻人的表现相当的终点表现水平。在快速条件下，老年人不能通过额外的矫正子运动来补偿他们受损的内部模型，因此降低了他们的本体感觉控制性能。这些结果为本体感觉运动控制模型的建立提供了基础，该模型将内部模型理论与连续和间歇控制模式相结合。这项研究还表明，运动控制受到虚弱综合征的影响，即对压力源的抵抗力下降，这是老年人的特征。
To control the sensory-motor system, internal models mimic the transformations between motor commands and sensory signals. The present study proposed to assess the effects of physiological adult ageing on the proprioceptive control of movement and the related internal models. To this aim, one group of young adults and one group of older adults performed an ankle contralateral concurrent matching task in two speed conditions (self-selected and fast). Error, temporal and kinematic variables were used to assess the matching performance. The results demonstrated that older adults used a different mode of control as compared to the young adults and suggested that the internal models of proprioceptive control were altered with ageing. Behavioural expressions of these alterations were dependent upon the considered condition of speed. In the self-selected speed condition, this alteration was expressed through an increased number of corrective sub-movements in older adults as compared to their young peers. This strategy enabled them to reach a level of end-point performance comparable to the young adults' performance. In the fast speed condition, older adults were no more able to compensate for their impaired internal models through additional corrective sub-movements and therefore decreased their proprioceptive control performance. These results provided the basis for a model of proprioceptive control of movement integrating the internal models theory and the continuous and intermittent modes of control. This study also suggested that motor control was affected by the frailty syndrome, i.e. a decreased resistance to stressors, which characterises older adults.