Dubrowski A, Carnahan H
Department of Kinesiology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
J Mot Behav. 2001 Mar;33(1):37-48. doi: 10.1080/00222890109601901.
In 3 experiments, the authors investigated and described how individuals control manual interceptive movements to slowly moving targets. Participants (N = 8 in each experiment) used a computer mouse and a graphics tablet assembly to manually intercept targets moving across a computer screen toward a marked target zone. They moved the cursor so that it would arrive in the target zone simultaneously with the target. In Experiment 1, there was a range of target velocities, including some very slow targets. In Experiment 2, there were 2 movement distance conditions. Participants moved the cursor either the same distance as the target or twice as far. For both experiments, hand speed was found to be related to target speed, even for the very slowly moving targets and when the target-to-cursor distance ratios were altered, suggesting that participants may have used a strategy similar to tracking. To test that notion, in Experiment 3, the authors added a tracking task in which the participants tracked the target cursor into the target zone. Longer time was spent planning the interception movements; however, there was a longer time in deceleration for the tracking movements, suggesting that more visually guided trajectory updates were made in that condition. Thus, although participants scaled their interception movements to the cursor speed, they were using a different strategy than they used in tracking. It is proposed that during target interception, anticipatory mechanisms are used rather than the visual feedback mechanism used when tracking and when pointing to stationary targets.
在3项实验中，作者研究并描述了个体如何控制手动拦截动作以应对缓慢移动的目标。参与者（每项实验N = 8）使用电脑鼠标和数位绘图板装置，手动拦截在电脑屏幕上朝着一个标记的目标区域移动的目标。他们移动光标，使其与目标同时到达目标区域。在实验1中，有一系列目标速度，包括一些非常缓慢的目标。在实验2中，有2种移动距离条件。参与者将光标移动的距离与目标相同或两倍远。对于这两项实验，发现手部速度与目标速度相关，即使对于非常缓慢移动的目标以及当目标与光标距离比例改变时也是如此，这表明参与者可能使用了类似于跟踪的策略。为了验证这一概念，在实验3中，作者增加了一项跟踪任务，参与者在该任务中将目标光标跟踪到目标区域。规划拦截动作花费的时间更长；然而，跟踪动作的减速时间更长，这表明在该条件下进行了更多视觉引导的轨迹更新。因此，尽管参与者将他们的拦截动作按光标速度进行缩放，但他们使用的策略与跟踪时不同。有人提出，在目标拦截过程中，使用的是预期机制，而不是跟踪和指向静止目标时使用的视觉反馈机制。
