Hespos Susan, Gredebäck Gustaf, von Hofsten Claes, Spelke Elizabeth S
Department of Psychology, Northwestern University.
Cogn Sci. 2009 Nov 1;33(8):1483-1502. doi: 10.1111/j.1551-6709.2009.01051.x.
Infants can anticipate the future location of a moving object and execute a predictive reach to intercept the object. When a moving object is temporarily hidden by darkness or occlusion, 6-month-old infants' reaching is perturbed but performance on darkness trials is significantly better than occlusion trials. How does this reaching behavior change over development? Experiment 1 tested predictive reaching of 6- and 9-month-old infants. While there was an increase in the overall number of reaches with increasing age, there were significantly fewer predictive reaches during the occlusion compared to visible trials and no age-related changes in this pattern. The decrease in performance found in Experiment 1 is likely to apply not only to the object representations formed by infants but also those formed by adults. In Experiment 2 we tested adults with a similar reaching task. Like infants, the adults were most accurate when the target was continuously visible and performance in darkness trials was significantly better than occlusion trials, providing evidence that there is something specific about occlusion that makes it more difficult than merely lack of visibility. Together, these findings suggest that infants' and adults' capacities to represent objects have similar signatures throughout development.
婴儿能够预测移动物体的未来位置，并执行预测性伸手动作以拦截该物体。当移动物体被黑暗或遮挡物暂时遮挡时，6个月大婴儿的伸手动作会受到干扰，但在黑暗试验中的表现明显优于遮挡试验。这种伸手行为在发育过程中是如何变化的呢？实验1测试了6个月和9个月大婴儿的预测性伸手动作。虽然随着年龄增长，伸手动作的总数有所增加，但与可见试验相比，在遮挡期间的预测性伸手动作明显更少，且这种模式没有与年龄相关的变化。实验1中发现的表现下降可能不仅适用于婴儿形成的物体表征，也适用于成人形成的物体表征。在实验2中，我们用类似的伸手任务测试了成人。与婴儿一样，当目标持续可见时，成人的表现最为准确，黑暗试验中的表现明显优于遮挡试验，这表明遮挡存在一些特殊之处，使其比仅仅缺乏可见性更难。这些发现共同表明，婴儿和成人在整个发育过程中表征物体的能力具有相似的特征。
