Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics
Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics
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DOI：
10.1098/rsta.2009.0214
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发表时间：
2010-01-28
期刊：
影响因子：
5
通讯作者：
Longtin, Andre
中科院分区：
文献类型：
--
作者：
Boulet, Jason;Balasubramaniam, Ramesh;Longtin, Andre
我们报告了在直立姿势中涉及“视觉-姿势控制回路”的实验和建模。我们在实验中操纵了站立时视觉反馈的人工延迟，延迟范围为0到15，增量为250毫秒。利用随机延迟微分方程，我们用视觉和本体感觉两个独立的延迟项明确地模拟了压力中心（COP）和质心（COM）动力学。一个新颖的“漂移不动点”假设被用来描述COM的波动，COP被建模为COM的一个更快的修正过程。该模型在概率密度函数、功率谱密度、短期和长期相关性（赫斯特指数）以及两个范围之间的临界时间方面与数据吻合良好。
We report on experiments and modelling involving the 'visuo-postural control loop' in the upright stance. We experimentally manipulated an artificial delay to the visual feedback during standing, presented at delays ranging from 0 to 1s in increments of 250 ms. Using stochastic delay differential equations, we explicitly modelled the centre-of-pressure (COP) and centre-of-mass (COM) dynamics with two independent delay terms for vision and proprioception. A novel 'drifting fixed point' hypothesis was used to describe the fluctuations of the COM with the COP being modelled as a faster, corrective process of the COM. The model was in good agreement with the data in terms of probability density functions, power spectral densities, short- and long-term correlations (Hurst exponents) as well the critical time between the two ranges.