A doohickey is a word you use when you do not know, or you have forgotten, the real name of an object.

当你不知道，或忘记了某种物体的真实名称，就能用到doohickey这个单词。

Sorry, Finn. 'Thingy' is a word which we sometimes use when I can't remember or don't know the name of an object.

抱歉，芬恩。在我们想不起来或者不知道一件物品的名字时我们通常会使用Thingy这个词。

But science has had trouble determining whether dogs and other animals truly create a mental image in their minds when they hear the name of an object.

但是，科学界一直难以确定的是，当狗和其他动物听到一个物体的名字时，是否真的会在脑海中形成一个心理图像。