This short and brief response is also to @bena,
I have struggled with this a lot. I can completely understand the notion to discount such experience. My conclusion is that this seemingly can not be "proven" in the traditional sense as it's a construct of the mind and not something external. It's sort of like me trying to prove that the way I see "red" in my mind is the same way you do. It's just not doable. Thus, I think this is something limited to the experiential. This used to bother me, now I just enjoy it.
A few anecdotes from my brain:
I have experienced deeper consciousness where instead of being from my normal 1st person view, it has been from a lower point of view. As metaphor, Imagine you are dreaming and there are 10 people in your dream, including yourself. As normal you are viewing the dream through your eyes and the 10 people seem to be functioning on their own. But then within the dream something happens and I realize the arbitrariness of my perspective and I suddenly become aware that I am actually simultaneously looking into my dream world from all 10 people's perspective at once and a lower level consciousness, which now becomes my conscious perspective, is omni-aware of this fact. It's also very strange as it sort of makes me question which viewpoint is really "me." Particularly when my consciousness shifts between the various perspectives.
I've also had things happen like when I am talking to someone sitting in front of me, I lose my 1st person perspective and my perspective moves to a lower external level where I can now see how my brain is "drawing" both myself and the person I'm speaking to, and the "onion" layers of thought that built those images of us and our environment as well as the sounds of our words.
Even as far as how when we say a sentence of words, I've had perspective where I can see the words expanding to other concepts and deeper meaning of the word. It's usually a very visual and emotional process, but quite interesting. So the words "tasty" "apple" start as two peaks of two mountains, but as the brain unpacks the concept of "tastiness" and "appleness", the thoughts expands outwards, just as the peaks of mountains expand outwards to their base. It's when the bases overlap that I can see the relation of the terms and how they interact with each other. But then imagine that for entire sentences, or stories, or any thought/concept.
When you can shift your consciousness from the peak to the base, it's interesting because you can see these larger concepts. For example, you can "see" taste, or sexuality, or redness, or anything-ness. Very fascinating.
I've also had interesting experiences where starting a an object, say my garage floor, I've been able to see layers of overlapping patterns that my brain seemed to have used to draw the floor. When I see it from the top, I see a floor. But when I move to the side, It's layers of different patterns.
I don't usually shares these on a public forum as I have already spent enough time questioning my own sanity as I rarely hear others talking about this sort of thing. Self diagnosed conclusion: I'm sane. :)