Part I, and Part II.
In particular, this got my attention;
"There are many interesting details in this account, quite apart from its value as part of the overall argument. Metzinger briefly touches on four varieties of autoscopic (self-seeing) phenomena, all of which can be related to distinct areas of the brain: autoscopic hallucination, where the subject sees an image of themselves; the feeling of a presence, where the subject has the strong sense of someone there without seeing anyone; the particularly disturbing heautoscopy, where the subject sees another self and switches back and forth into and out of it, unsure which is ‘the real me’; and the better-known OBE."
It makes sense to me that multiple self-constructions/constructions of self would exist, given that there are many different body representations all throughout the brain, not just the big S1 map stretched over the top of the cortex, the famous one Wilder Penfield mapped out, and I didn't realize there were names already ascribed to the elicitation of their specific distortions..
A body misperception can be the absence of a familiar body sense just as well as it can be one that's displaced onto a mannequin or onto someone or something else entirely, or floating above.. in each case there will be a corresponding shift in neural traffic flow, the brain not operating in its own familiar manner, and part of it noticing that shift and confabulating predictive perceptual fantasies as to possible reasons why. As in the Charlie Rose Brain Series Part II, in which all the various visual perceptual distortions were touched on, body sense is subject to perceptual distortion. The science on this is younger, but is definitely happening, mostly in Europe, mostly referred to as research of virtual bodies, rubber hand illusions, etc etc. discussedmany times on this blog. It's all very fascinating, and likely to have a lot to do with learning to handle human pain issues much more adeptly with fewer drugs at some point.
Meanwhile, it won't be a bad idea to practice feeling your own normal body better, practice using normal brain pathways, strengthen them so that your brain maps don't get all out of whack some day, and in some misguided attempt at trying to locate body parts, make them spasm or make them hurt to be able to find them more easily - the neurological equivalent of lighting flares to see along a dark path.
1. Book review at Naturalism.org