And it turns out that the dog— when they zapped part of its brain, its leg would kick up.

结果是那只狗,当研究者们电击某个大脑区域时,狗的四肢便会乱踢起来

耶鲁公开课 - 心理学导论课程节选

And I like to extend it all the way up the leg,

我想把它沿着腿一直往上纹，

你如何看待纹身？ - SpeakingMax英语口语达人

He notes: When we see a stroke aimed and just ready to fall upon the leg or arm of another person, we naturally shrink and draw back our own leg or arm and when it does fall we feel it in some measure and are hurt by it as well as the sufferer.

他说过，当我们看到有人要打,别一个人的腿或手臂，我们会不由自主的畏缩，手脚拢起来,当这一下打下来，某种程度上来说,我们会感受到和被打者一样的疼痛。

耶鲁公开课 - 心理学导论课程节选