The rat is placed into a cage with the lever, and the anticipatory sense of mastery might well activate the pleasurable dopaminergic projections to the frontal cortex.

• 接著，这只老鼠被放进另外一个也有槓杆的笼子；由于牠对自己的技巧深具信心，因此可能活化了通往额叶皮质的多巴胺通路而引起快感。