Does thinking limit consciousness? Can "thinking" occur when one is unconscious? What causes thinking?

In my humble opinion, thinking is a part of self preservation. Like,, Is there a place ahead where a bear could be hiding.. what is that noise, a wolf perhaps.  Or where can I find something to eat.
as to does thinking limit consciousness?  We consciousness is being aware of one's surroundings, so if you think more, you have the ability of being more aware, thus thinking does not limit, but rather expands consciousness. 
I would have to say yes, one can think and not be aware of ones surroundings, if you are asleep, you can dream, yet not be aware of the surroundings.

Dear RosieG,

ima say short answer NO, thinking does not limit consciousness…

Here is what I currently go with, from Aldous Huxley THE DOORS OF PERCEPTION:
The brain is actually a filter, selecting information with survival value to forward on to us, and blocking non-essentials so we don’t get overwhelmed.

So thinking does not limit consciousness because it can’t; when we are ready, we will naturally shift more and more into unlimited understanding - which is the process of WISDOM.

 * * *

“If the doors of perception were cleansed, everything would appear to man as it is, infinite.”
~ William Blake (1757-1827)

yes, i think people think when theyre asleep and dreaming

https://en.wikipedia.org/wiki/Unconscious_thought_theory