Piaget's example would be a baby who's used to sucking on a breast might come to suck on a bottle or on a rattle.

皮亚杰举例说,一个习惯吸吮乳房的婴儿,可能会去吸吮奶瓶或是拨浪鼓

耶鲁公开课 - 心理学导论课程节选

Before six-month-olds, Piaget observed, you take an object the kid likes like a rattle, you hide it, you put it behind something, it's like it's gone.

皮亚杰发现,在六个月之前,你将婴儿喜欢的物体,比如说拨浪鼓,藏起来,隐藏在某物的后面,就像这东西消失了一样

耶鲁公开课 - 心理学导论课程节选