Lee I-Chieh, Pacheco Matheus M, Newell Karl M
UNC-NCSU Joint Department of Biomedical Engineering, NC State University and The University of North Carolina-CH, 1407-Engineering Building III, 911 Oval Dr, Raleigh, NC, 27695, USA.
School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
Exp Brain Res. 2019 May;237(5):1339-1346. doi: 10.1007/s00221-019-05513-2. Epub 2019 Mar 15.
We examine the proposition that information availability and postural facilitation-usually viewed as opposing views in postural control-are intertwined with the effects of one being related to the other. If that is the case, a single control parameter (precision demands) would capture the changes in postural control relating information and postural facilitation. Using the dynamical systems approach, we investigated whether, manipulating touch requirements as to increase precision demands, would induce quantitative and qualitative changes in postural dynamics. Additionally, we tested whether the COM-COP coupling reflects the qualitative dynamics of the system. Seventeen participants were instructed to maintain quiet standing while maintaining or not a light finger force with either precision or no precision. Standard deviation (SD) of the COP decreased with the precision demands and the correlation dimension (CD) of COP showed higher values for the touch conditions. Participants showed reduced synchronization of COP-COM coupling; following changes in CD. These results point out the integrated nature of information availability, task requirements, and the emergent postural organization reflected in COP-COM coupling.
信息可用性和姿势促进作用（在姿势控制中通常被视为相反的观点）相互交织，其中一个的影响与另一个相关。如果是这样的话，一个单一的控制参数（精度要求）将捕捉到与信息和姿势促进作用相关的姿势控制变化。使用动态系统方法，我们研究了通过操纵触摸要求以增加精度要求，是否会在姿势动力学中引起定量和定性的变化。此外，我们测试了质心-压力中心（COM-COP）耦合是否反映了系统的定性动力学。17名参与者被要求在保持或不保持轻手指力的情况下，以有精度或无精度的方式保持安静站立。压力中心的标准差（SD）随着精度要求的增加而降低，并且压力中心的关联维数（CD）在触摸条件下显示出更高的值。参与者表现出COP-COM耦合的同步性降低；随着CD的变化而变化。这些结果指出了信息可用性、任务要求以及在COP-COM耦合中反映出的姿势组织的整合性质。
