Perry Lynn K, Samuelson Larissa K, Spencer John P
Department of Psychology, University of Iowa, Iowa City, IA 52242, USA.
J Exp Child Psychol. 2009 Apr;102(4):445-55. doi: 10.1016/j.jecp.2008.11.006. Epub 2009 Jan 22.
This study investigated how young children's increasingly flexible use of spatial reference frames enables accurate search for hidden objects by using a task that 3-year-olds have been shown to perform with great accuracy and 2-year-olds have been shown to perform inaccurately. Children watched as an object was rolled down a ramp, behind a panel of doors, and stopped at a barrier visible above the doors. In two experiments, we gave 2- and 2.5-year-olds a strong reference frame by increasing the relative salience and stability of the barrier. In Experiment 1, 2.5-year-olds performed at above-chance levels with the more salient barrier. In Experiment 2, we highlighted the stability of the barrier (or ramp) by maximizing the spatial extent of each reference frame across the first four training trials. Children who were given a stable barrier (and moving ramp) during these initial trials performed at above-chance levels and significantly better than children who were given a stable ramp (and moving barrier). This work highlights that factors central to spatial cognition and motor planning-aligning egocentric and object-centered reference frames-play a role in the ramp task during this transitional phase in development.
本研究通过一项任务来探究幼儿如何越来越灵活地使用空间参照系，从而能够准确地寻找隐藏物体。此前研究表明，3岁儿童能非常准确地完成这项任务，而2岁儿童则表现不准确。儿童观看一个物体从斜坡滚下，经过一组门后面，并停在门上方可见的障碍物处。在两项实验中，我们通过增加障碍物的相对显著性和稳定性，为2岁和2.5岁儿童提供了一个强大的参照系。在实验1中，2.5岁儿童在障碍物更显著的情况下表现高于随机水平。在实验2中，我们在前四次训练试验中通过最大化每个参照系的空间范围，突出了障碍物（或斜坡）的稳定性。在这些初始试验中，被给予稳定障碍物（和移动斜坡）的儿童表现高于随机水平，且显著优于被给予稳定斜坡（和移动障碍物）的儿童。这项研究强调，在这个发展过渡阶段，空间认知和运动规划的核心因素——使自我中心参照系和以物体为中心的参照系对齐——在斜坡任务中发挥了作用。
