Sherwood David E
Department of Integrative Physiology, 354 UCB, University of Colorado, Boulder, CO 80309-0354, USA.
Percept Mot Skills. 2007 Oct;105(2):501-13. doi: 10.2466/pms.105.2.501-513.
This study extended earlier work by showing spatial assimilations in sequential bimanual aiming movements when the participant preplanned only the first movement of a two-movement sequence. Right-handed participants (n=20, aged 18 to 22 years) made rapid lever reversals of 20 degrees and 60 degrees singly and sequentially with an intermovement interval of 2.5 sec. Following blocked single practice of both movements in each hand (15 trials each), two sets of 30 sequential practice trials were completed. The sequences began with either the long or the short movement and the participant always knew the goal of the first movement. During the intermovement interval, the experimenter gave instructions to complete the sequence with a short movement, a long movement, or no movement in a random order. Compared to the single trials, both movements in the sequence overshot the short-distance and undershot the long-distance goal. Spatial errors increased when a change in the movement goal was required for the second movement in the sequence. The experiment demonstrated that separate planning of sequential aiming movements can reduce spatial assimilation effects, but interference due to practice organization and switching the task's goal must also be overcome in order to produce accurate aiming movements.
本研究扩展了早期的工作，通过展示当参与者仅预先计划两动作序列中的第一个动作时，连续双手瞄准动作中的空间同化现象。右利手参与者（n = 20，年龄18至22岁）分别和连续地进行20度和60度的快速杠杆反转，动作间隔为2.5秒。在每只手对两个动作进行分组单独练习（各15次试验）之后，完成了两组各30次的连续练习试验。序列以长动作或短动作开始，参与者始终知道第一个动作的目标。在动作间隔期间，实验者以随机顺序给出指令，要求用短动作、长动作或不做动作来完成序列。与单次试验相比，序列中的两个动作都超出了短距离目标并未达到长距离目标。当序列中的第二个动作需要改变动作目标时，空间误差增加。该实验表明，连续瞄准动作的单独计划可以减少空间同化效应，但为了产生准确的瞄准动作，还必须克服由于练习组织和任务目标切换所带来的干扰。
