Why do these RC's work?

One of the more common reality checks is plugging your nose and trying to breathe through it.
And if you can, you are dreaming.

Another is closing one eye, and trying to look at your nose with the open eye .
And if you can't see your nose, you are dreaming.

I am wondering why these work the way they do ..

For the first one, i assume it is because you can continue to breathe in real life while in REM sleep. So in a dream, you can breathe fine no matter the circumstances as well.
But that is just a guess. Correct me if i'm wrong.


For the second one. I have no idea why that would work...
How come you can't see your nose when you are dreaming?
What is the science behind that ?

Generally, any reality check works along the basis of classical conditioning and association. It's simply a matter of finding something that you cannot physically do in the wake life and attempting to do in the dreaming state (or vice versa in more complex matters).

The reoccuring act of attempting to do certain actions creates the mnemonic of reality comprehension. This is the quintessential element to "reality checking". There is no real science involved into the intangible realities within the dream-world - it's in your head.

Brief and subtle, hopefully that was enlightening.

You got the first part right. You can breath fine no matter what you do inside a dream. Now the second part I think is because you cut yourself out of your dreams a lot of times. I almost never notice what I am wearing in a dream unless I look directly at my clothes. I can't normally tell if I am even wearing shoes or not. Some times you also switch clothing instantly and stuff too. You can also dream in 3rd person.

Basicly I think you mind doesn't create a lot of the things unless they are needed. Might not see your nose because you don't have one, but if you reach for it or look in a mirror, it will appear. I could be wrong though but that is what I think it is.