Development of visuomotor representations for hand movement in young children
Development of visuomotor representations for hand movement in young children
复制标题
DOI：
10.1007/s00221-004-2123-7
复制
发表时间：
2005-04-01
影响因子：
2
通讯作者：
Clark, JE
中科院分区：
文献类型：
--
作者：
Contreras-Vidal, J;Bo, J;Clark, JE
本研究采用视觉运动适应范式，在暴露试验中，将笔运动的实时视觉反馈顺时针旋转45度，考察了幼儿手部运动视觉运动表征的稳定性和适应性。在正常（暴露前和暴露后）和旋转（暴露）的视觉反馈条件下，4岁、6岁和8岁的儿童从一个共同的中心位置（“居中任务”）在水平面上对视觉目标进行线画。对暴露前试验的分析表明，年龄较大的儿童比年龄较小的儿童表现得更快、更直、更流畅，并且表现出更多的模式运动。在运动开始后80 ms计算的初始运动方向显示，随着年龄的增长，运动方向逐渐调整。在引入屏幕光标旋转后，各年龄组儿童的计划（初始方向错误）和执行（运动时间、运动长度、均方根误差和标准化抽搐）错误得分从早暴露到晚暴露均有改善，但4岁儿童受早期暴露扭曲的影响较小。此外，在暴露后试验中，只有年龄最大的一组儿童表现出显著的后遗症，这表明只有这个年龄组学习了扭曲环境的内部模型。在两个较年轻的年龄组中观察到的初始运动方向没有后效，这表明这些儿童可能对手部运动的内部视觉运动表征不太发达（即更广泛），他们的内部视觉运动表征随着视觉运动经验而增强（即调整）。
The stability and adaptability of visuomotor representations for hand movement in young children was investigated using a visuomotor adaptation paradigm in which the real-time visual feedback of pen movement was rotated 45 degrees clockwise during exposure trials. Four, six, and eight-year-old children performed line drawings to visual targets, from a common centered position ("center-out task"), in the horizontal plane under normal ( pre-, and post-exposure), and rotated ( exposure) visual feedback conditions. Analysis of pre- exposure trials indicated that older children performed faster, straighter, smoother, and showed more patterned movements than the younger children. Initial direction of movement, computed at 80 ms after movement onset, showed a progressive tuning of movement direction with increasing age. On introduction of the screen cursor rotation, all age group children showed improvement in their planning ( initial directional error) and execution ( movement time, movement length, root mean square error, and normalized jerk) error scores from early to late-exposure trials, but the 4-year-olds were less affected than older age children by the distortion during the early exposure period. Moreover, only the oldest group of children showed significant after-effects during post-exposure trials indicating that only this age group learned the internal model of the distorted environment. The absence of after-effects for initial movement direction observed in the two younger age groups suggest that these children might have less developed ( i.e. more broad) internal visuomotor representations for hand movements, and that their internal representations are sharpened ( i.e. tuned) with visuomotor experience.