They learn to run a maze faster and faster when they're regularly rewarded but they also learn to run a maze faster and faster if they are not rewarded at all.

在不断得到奖励的条件下,白鼠跑出迷津的速度越来越快,但在完全不予奖励的条件下,白鼠依然能越来越快的跑出迷津。

耶鲁公开课 - 心理学导论课程节选