Hay Laurette, Velay Jean-Luc
Neurobiologie Intégrative et Adaptative, UMR 6149 CNRS/Université de Provence, Marseille, France.
Neuroreport. 2003 May 23;14(7):1041-4. doi: 10.1097/01.wnr.0000073425.02536.22.
Some developmental changes in movement control are not monotonic during childhood, which leads us to question how hemispheric relationships develop since they are closely involved with visuo-manual coordination. We tested right-handed children between 4 and 14 years of age performing pointing movements with the right and left hand towards visual targets located in the right and left hemifield. The analysis of movement parameters showed a left hand advantage in reaction time, but this is mainly due to the contralateral movements relative to the semifield of target presentation, suggesting that hemispheric asymmetry is not achieved even in older children. Interhemispheric transfer was evaluated through the difference between crossed (opposite hand and hemifield side) and uncrossed (same hand and hemifield side) movements. The difference was significant at all ages, and decreased with age between 4-6 and 7-9 years. It moved from early asymmetry in favor of the left-to-right interhemispheric transfer to adult-like symmetry at 10-14 years. The long development of hemispheric specificity and interhemispheric communication suggested by our results might be associated to asynchronous development of various processes involved in visuo-motor coordination, leading to qualitative changes in visually directed movement during childhood described in the literature.
儿童期运动控制的一些发育变化并非单调的，这使我们质疑半球关系是如何发展的，因为它们与视觉-手动协调密切相关。我们测试了4至14岁的右利手儿童，他们用右手和左手向位于右半视野和左半视野的视觉目标进行指向运动。运动参数分析显示左手在反应时间上具有优势，但这主要是由于相对于目标呈现半视野的对侧运动，这表明即使在年龄较大的儿童中也未实现半球不对称。通过交叉（对侧手和半视野侧）和非交叉（同侧手和半视野侧）运动之间的差异来评估半球间传递。该差异在所有年龄段均显著，并且在4至6岁和7至9岁之间随年龄减小。它从早期有利于从左到右半球间传递的不对称转变为10至14岁时类似成人的对称。我们的结果表明，半球特异性和半球间交流的长期发展可能与视觉-运动协调中涉及的各种过程的异步发展有关，导致文献中描述的儿童期视觉导向运动的质性变化。
