Dessing Joost C, Daffertshofer Andreas, Peper C E, Beek Peter J
Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands.
J Mot Behav. 2007 Sep;39(5):433-46. doi: 10.3200/JMBR.39.5.433-448.
The authors studied pattern stability and error correction during in-phase and antiphase 4-ball fountain juggling. To obtain ball trajectories, they made and digitized high-speed film recordings of 4 highly skilled participants juggling at 3 different heights (and thus different frequencies). From those ball trajectories, the authors determined and analyzed critical events (i.e., toss, zenith, catch, and toss onset) in terms of variability of point estimates of relative phase and temporal correlations. Contrary to common findings on basic instances of rhythmic interlimb coordination, in-phase and antiphase patterns were equally variable (i.e., stable). Consistent with previous findings, however, pattern stability decreased with increasing frequency. In contrast to previous results for 3-ball cascade juggling, negative lag-one correlations for catch-catch intervals were absent, but the authors obtained evidence for error corrections between catches and toss onsets. That finding may have reflected participants' high skill level, which yielded smaller errors that allowed for corrections later in the hand cycle.
作者研究了同相和反相四球喷泉杂耍过程中的模式稳定性和误差校正。为了获取球的轨迹，他们对4名技术高超的参与者在3种不同高度（即不同频率）进行杂耍的高速影片进行了拍摄并数字化。从这些球的轨迹中，作者根据相对相位和时间相关性的点估计的变异性，确定并分析了关键事件（即抛球、顶点、接球和抛球开始）。与关于有节奏的肢体间协调基本实例的常见发现相反，同相和反相模式的变异性相同（即稳定）。然而，与先前的发现一致，模式稳定性随频率增加而降低。与先前对三球瀑布式杂耍的结果相反，接球间隔不存在负滞后一期相关性，但作者获得了接球与抛球开始之间误差校正的证据。这一发现可能反映了参与者的高技能水平，这导致了较小的误差，使得在手的循环后期能够进行校正。
