Psychology Department, Northwestern University, United States.
Psychology Department, Northwestern University, United States.
Cognition. 2018 Jun;175:1-10. doi: 10.1016/j.cognition.2018.02.009. Epub 2018 Feb 15.
Infants fail to represent quantities of non-cohesive substances in paradigms where they succeed with solid objects. Some investigators have interpreted these results as evidence that infants do not yet have representations for substances. More recent research, however, shows that 5-month-old infants expect objects and substances to behave and interact in different ways. In the present experiments, we test whether infants have expectations for substances when the outcomes are not simply the opposite of those for objects. In Experiment 1, we find that 5-month-old infants expect that when a cup of sand pours behind a screen, it will accumulate in just one pile rather than two. Similarly, infants expect that when two cups of sand pour in separate streams, two distinct piles will accumulate rather than one. Infants look significantly longer at outcomes with an inconsistent number of piles, providing evidence that infants have expectations for how sand accumulates. To test whether the number of cups or the number of pours guided expectations about accumulation, Experiment 2 placed these cues in conflict. This resulted in chance performance, suggesting that, for infants to build expectations about these outcomes, they need both cues (cup and pour) to converge. These findings offer insight into the nature of infants' representations for non-cohesive substances like sand.
婴儿在固体物体范式中成功而在非粘性物质范式中失败，无法代表数量。一些研究人员将这些结果解释为婴儿还没有物质代表的证据。然而，最近的研究表明，5 个月大的婴儿期望物体和物质以不同的方式表现和相互作用。在本实验中，我们测试了当结果不仅仅是物体的相反结果时，婴儿是否对物质有期望。在实验 1 中，我们发现 5 个月大的婴儿期望当一杯沙子从屏幕后面倒出时，它会堆积成一堆而不是两堆。同样，婴儿期望当两杯水分别流出时，会堆积成两个不同的堆而不是一个。婴儿在结果中观察到不一致数量的堆时会明显地看更长时间，这表明婴儿对沙子堆积的方式有期望。为了测试是杯子的数量还是倒出的数量引导了对堆积的期望，实验 2 将这些线索放在一起冲突。这导致了随机表现，表明为了让婴儿对这些结果产生期望，他们需要这两个线索（杯子和倒出）同时出现。这些发现为理解婴儿对非粘性物质（如沙子）的代表性质提供了深入了解。
