Sleep thought" is the sort of thing you get typically before you fall asleep and it's like "did I take the garbage out, ??

半睡半醒的想法是指那些,你睡着前所想到的东西,例如“我倒垃圾了吗？

耶鲁公开课 - 心理学导论课程节选

When you do Sitting Meditations and Buddhism, this medical school teach, you have your eyes open a reminder, that first of all, you don't fall asleep but also to remind you that you are supposed to be engaging the world as you do it, rather than having your eyes closed and isolating yourself.

当你学习佛教，进行坐禅时，据医学院的方法，你要睁开双眼,提醒自己，首先不要睡着,也是为了提醒自己,冥想时也要参与到这个世界中来，而不是闭上双眼,与外界隔绝。

普林斯顿公开课 - 人性课程节选