Clifton R K, Muir D W, Ashmead D H, Clarkson M G
Department of Psychology, University of Massachusetts, Amherst 01003.
Child Dev. 1993 Aug;64(4):1099-110.
The issue examined was whether infants require sight of their hand when first beginning to reach for, contact, and grasp objects. 7 infants were repeatedly tested between 6 and 25 weeks of age. Each session consisted of 8 trials of objects presented in the light and 8 trials of glowing or sounding objects in complete darkness. Infants first contacted the object in both conditions at comparable ages (mean age for light, 12.3 weeks, and for dark, 11.9 weeks). Infants first grasped the object in the light at 16.0 weeks and in the dark at 14.7 weeks, a nonsignificant difference. Once contact was observed, infants continued to touch and grasp the objects in both light and dark throughout all sessions. Because infants could not see their hand or arm in the dark, their early success in contacting the glowing and sounding objects indicates that proprioceptive cues, not sight of the limb, guided their early reaching. Reaching in the light developed in parallel with reaching in the dark, suggesting that visual guidance of the hand is not necessary to achieve object contact either at the onset of successful reaching or in the succeeding weeks.
所研究的问题是，婴儿在刚开始伸手去够、接触和抓取物体时是否需要看到自己的手。7名婴儿在6至25周龄期间接受了多次测试。每次测试包括8次在光照下呈现物体的试验和8次在完全黑暗中发光或发声物体的试验。婴儿在两种条件下首次接触物体的年龄相近（光照条件下的平均年龄为12.3周，黑暗条件下为11.9周）。婴儿在光照下16.0周时首次抓取物体，在黑暗中14.7周时首次抓取物体，差异不显著。一旦观察到接触，婴儿在所有测试过程中在光照和黑暗条件下都会继续触摸和抓取物体。由于婴儿在黑暗中看不到自己的手或手臂，他们在接触发光和发声物体方面的早期成功表明，是本体感觉线索而非肢体视觉引导了他们早期的伸手动作。在光照下的伸手动作与在黑暗中的伸手动作同步发展，这表明在成功伸手动作开始时或在随后几周内，手部的视觉引导对于实现物体接触并非必要。
