You bring somebody in the sleep lab, you put electrodes on their scalp and you see what these-- what sort of electrical activities you get in the brain.

把人叫来睡眠实验室，把电极贴在他们的头皮上,你就能看到-,他们有什么脑电活动。

耶鲁公开课 - 心理学导论课程节选