Mental World: Not really extant, but virtually simulated, “mental worlds” are sometimes used by noeticists and sophotechnicians as fancy ways to diagram, observe, and interact with the myriad agents that make up a mind of any serious level of complexity. (Something like the Country of the Mind from Greg Bear’s Queen of Angels, et. al., if you like, although more explicitly as a metaphorical user interface.)
Wandering around in one of these, or something halfway between it and Cyberspace, is also a privilege granted to those attending a contemplationary who have been granted an audience with one of the Transcend’s high-level routines. Of course, the experience of the Mental World is a little bit different when you consider that you’re inside an entity whose thoughts are entities on the same level of complexity as all of you, or possibly rather more.