Headspace
Headspace is a term primarily found in the BDSM Community to refer to a hypnotic trance-state in which the individual enters a mental "space" where for all purposes, he has become his mindform, projected onto him via Imposition. This is more intense than a simple form of transformation, for as far as the person in headspace, this has always been true, and there is no other truth. For example, an individual whom is a "Pup Player" may enter a Headspace during a sexual (or non-sexual) activity, and for the entire duration he is his mindform (in this case, a "Rubberpup", he has always been his mindform, and he cares for nothing other than his mindform.