Yes, we also have parts of the brain that are related to patterns and geometry, although I'd personally say that this involves interplay.
Anything that is in some way essential to our survival...
- eyes / face for understanding facial expressions of other individuals in ancient tribes so that the reaction to danger the tribe encounters can be shared quickly by all tribe-members - primal social activities had advantages that worked like this
- life forms so that in the jungle a dangerous animal can be identified quickly, even if camouflaged - this can also save your life
... or just fundamental to abstraction of our world so that we can make a map in our mind by using shapes and spatial relationships etc.
is governed by important and probably specialized aspects of the visual cortex I think.
DMT is considered extra extraordinary and I think it is - but mostly in the sense that it seems to stimulate our visions to the extreme.. and because our mind creates a stream of consciousness and constantly tries to make sense and has the subconscious and your personality involved, we try to come up with some dream-like story sequence that tries to bring together the shapes and entities etc and makes it as coherent as possible... which is a challenge and clearly has bizarre results.
I don't think that it necessarily devalues what we think of DMT if we believe that we interface with parts of our own psyche. That is still amazing and can still be profound, there is a lot of wisdom and power buried there! In that sense you may surprise yourself if it is unlocked and communicated with!
I think it is denial and wishful thinking that there is something supernatural, extraterretrial or extradimensional about DMT experiences. A lot of related substances are known to act in the brain and mess with our perception, some more potent than others. With the milder ones it can be a lot more clear that buttons are pushed in our brain, we can see behind the curtain and presumably understand how the drug acts. It seems silly that once it gets a lot more complicated, intense and harder to understand, suddenly the explanation is sought in magical explanations. Considering that there is a decent explanation for the milder experiences... it is incredibly likely that very similar substances act in similar ways and are not keys to spacetime travel, out of the blue.
What I will say is that traveling through your own psyche in such experiences - while not supernatural - still has all those promises of being incredible and extraordinary like traveling to other, more physical, worlds beyond our own.
And in that world of your mind, there is a 'god' that generates everything there ever was in that world and ever will be and that is the core of that spirit-mind. I think that mind dimension is where things are seemingly warped, but our physical laws of nature remain untouched.
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@ your question: IMO it takes a certain level of dissociation to lose your depth perception because as long as you are not dissociated from your feeling of being located / oriented in a certain way in your environment, I think that feeling is encoded rather pervasively in your proprioception.
When the experience gets strong enough for the experience generated in your 'minds eye' to overrule your sensory experience - then you break through and are fully immersed as they say. In that way, IMO all psychedelics are ultimately also dissociative.
Compare with salvia, an atypical dissociative and visionary drug... which is a lot more known for fucking with your sense of where you are, which tends to make things 2D and in doing so ruins your depth perception usually in an early stage of the trip's intensity. I'd say earlier than with DMT. Same thing with a lot of typical dissociatives.
So yeah I guess that tells us something about what is encoded by the highly 5-HT governed systems i.e. rather general perception and what is encoded by NMDAR i.e. conceptual information including apparently proprioception. But, there is probably overlap as those systems are wired into each other to make the big picture.
I think though that smoked DMT is to brief and dislocating to enable one to change a lifetimes worth of thinking. I think that the ayahuasca experience is so much more intriguing then self-guided therapy (navigating a pulsating landscape entirely made out of globe-circling, flurescent snakes). I don't think of psychedelics as therapeutic in that sense though...
