Time, Deja Vu, and Dreams.

I once was told that deja vu scientifically may be the eye processing information faster than the brain thus causing the feeling of deja vu. I think it is possible that deja vu could also be related to dreams in a way, not exactly directly. I think that since every person has several dreams a night, and only some are remembered, that an object or a sense of deja vu can be derived from the mind or sub- conscience, because maybe when you get deja vu your mind is corresponding it to a piece of a detail from a dream that was not remembered.

Also, I think dimensions and the concept of them are interesting. Is it possible that dreaming, could create a sense of a fourth dimension? Since while you are dreaming, you have a sense of time as longer than the dream physically is, which may only be seconds, but the dream itself may feel like hours? I am not stating that I think it is the fourth dimension, but could it create any sense similar to it?
Dreams apparently only last seconds, or minutes. But dreams can feel longer while experienced. Is there an explanation for that?