Okay... Go easy on me, I'm an utter fool and a knave in these matters... But, just some thoughts which aren't groundbreaking in any way but nevertheless interested me:
Since our experience of the world is shaped by our sense apparatus and how the brain processes and organise the information we receive, the world in itself could be very different from how we perceive it... So even though our world seems spatial/in 3D, isn't that just a fabrication by our common neurological layout, so to speak?
Also I'm intrigued by the fact that a lot of "lower" organisms are able to function without a brain at all- Jellyfish, mussles for instance... *
*Would a being like that be just like a robot, acting mechanically on pre-programmed patterns without any awareness at all, or could there be "other" types of organisational mechanisms which wouldn't need a physical centre at all but would still be able to act like a brain, in the form of swarming neurons for instance? something so different it couldn't be easily recognised?
And... While we might not be able to understand or imagine radically different ways of perception-
What about pheromones? Isn't that a form of communication? (Couples matching each other fall in love easily, both body and mind is involved in signalling interest)
Err, I'm not sure how these thoughts fit in with the debate on dimensions - if at all- but I guess I started off thinking about the slightly silly new age idea of "shared reality", wordless communication over short distances and thinking that in the instance of pheromones, that is actually real and no hocus pocus at all... It happens, even though it's a super prosaic everyday thing and of course a far way off from singing whales and hippies with crystals etc...
</ confused off-topic rant >