Bastin Julien, Jacobs David M, Morice Antoine H P, Craig Cathy, Montagne Gilles
Faculté des Sciences du Sport, Institut des Sciences du Mouvement, Etienne-Jules MAREY, UMR 6233 Université de la Méditerranée and CNRS, 163 Avenue de Luminy, 13009 Marseille, France.
Exp Brain Res. 2008 Nov;191(3):301-12. doi: 10.1007/s00221-008-1522-6. Epub 2008 Aug 14.
The constant bearing angle (CBA) strategy is a prospective strategy that permits the interception of moving objects. The purpose of the present study is to test this strategy. Participants were asked to walk through a virtual environment and to change, if necessary, their walking speed so as to intercept approaching targets. The targets followed either a rectilinear or a curvilinear trajectory and target size was manipulated both within trials (target size was gradually changed during the trial in order to bias expansion) and between trials (targets of different sizes were used). The curvature manipulation had a large effect on the kinematics of walking, which is in agreement with the CBA strategy. The target size manipulations also affected the kinematics of walking. Although these effects of target size are not predicted by the CBA strategy, quantitative comparisons of observed kinematics and the kinematics predicted by the CBA strategy showed good fits. Furthermore, predictions based on the CBA strategy were deemed superior to predictions based on a required velocity (V (REQ)) model. The role of target size and expansion in the prospective control of walking is discussed.
恒定方位角（CBA）策略是一种用于拦截移动物体的前瞻性策略。本研究的目的是测试该策略。参与者被要求在虚拟环境中行走，并在必要时改变行走速度，以便拦截接近的目标。目标遵循直线或曲线轨迹，并且在试验内（在试验期间逐渐改变目标大小以偏向扩展）和试验间（使用不同大小的目标）操纵目标大小。曲率操纵对行走运动学有很大影响，这与CBA策略一致。目标大小操纵也影响行走运动学。尽管CBA策略未预测到目标大小的这些影响，但观察到的运动学与CBA策略预测的运动学的定量比较显示出良好的拟合。此外，基于CBA策略的预测被认为优于基于所需速度（V（REQ））模型的预测。讨论了目标大小和扩展在行走前瞻性控制中的作用。
