Hi and thanks. I do believe it is a part of and triggered by the reptilian part of our brains. We still rely heavily on that part of our brains and in some cases for good reasons. The brain does most of its work without our "consent", and thank goodness it does.
I think the internal dialogue got to the point with humans where it is constantly on, because it really had to in order to keep us alive. Now however, it is less needed, but it is still there. We cannot get rid of it nor even really turn it off, but we can turn the volume down so it is just a whisper. I talk about that in my next article. Stay tuned and thanks for the comment. Have a wonderful day.