Lafe Charley W, Pacheco Matheus M, Newell Karl M
Department of Kinesiology, The University of Georgia, USA.
Department of Kinesiology, The University of Georgia, USA.
Hum Mov Sci. 2016 Jun;47:186-196. doi: 10.1016/j.humov.2016.03.011. Epub 2016 Mar 24.
Visual information plays an adaptive role in the relation between bimanual force coupling and error corrective processes of isometric force control. In the present study, the evolving distribution of the relative phase properties of bimanual isometric force coupling was examined by scaling within a trial the temporal feedback rate of visual intermittency (short to long presentation intervals and vice versa). The force error (RMSE) was reduced, and time-dependent irregularity (SampEn) of the force output was increased with greater amounts of visual information (shorter intermittency). Multi-stable coordination patterns of bimanual isometric force control were differentially shifted toward and away from the intrinsic dynamics by the changing the intermittency of visual information. The distribution of Hilbert transformed relative phase values showed progressively a predominantly anti-phase mode under less intermittent visual information to predominantly an in-phase mode with limited (almost no) visual information. Correlation between the hands showed a continuous reduction, rather than abrupt "transition," with increase in visual information, although no mean negative correlation was realized, despite the tendency towards an anti-phase distribution. Lastly, changes in both the performance outcome and bimanual isometric force coordination occurred at visual feedback rates faster than the minimal visual processing times established from single limb movement and isometric force protocols.
视觉信息在双手力量耦合与等长力控制的误差校正过程之间的关系中发挥着适应性作用。在本研究中，通过在试验中缩放视觉间歇性的时间反馈率（从短到长的呈现间隔，反之亦然），研究了双手等长力耦合相对相位特性的演变分布。随着视觉信息增多（间歇性缩短），力误差（均方根误差）减小，力输出的时间依赖性不规则性（样本熵）增加。通过改变视觉信息的间歇性，双手等长力控制的多稳态协调模式向内在动力学方向或远离内在动力学方向发生不同的偏移。希尔伯特变换相对相位值的分布在视觉信息间歇性较少时逐渐呈现出主要为反相位模式，而在视觉信息有限（几乎没有）时主要为同相位模式。尽管没有实现平均负相关，但随着视觉信息增加，双手之间的相关性呈现出持续降低，而非突然“转变”，尽管有反相位分布的趋势。最后，性能结果和双手等长力协调的变化发生时的视觉反馈率，快于从单肢体运动和等长力实验方案确定的最小视觉处理时间。
