I would expect optimization for efficiency to be something evolution does - but I am compelled to note that I mentioned "the Cartesian theater" as a reference to Daniel Dennett's Consciousness Explained, where he strenuously refuted the idea of the Cartesian theater. By Dennett's argument - and even when Consciousness Explained came out, he had a lot of research data to work from - the collocation of all sensory data in a single channel to run past some homunculus recording our conscious experience is unlikely. After all, there already is a data-processing entity right there to collect all the sensory data - that's the entire brain. So within the brain, it should not be surprising that different conscious experiences are saved to memory from different parts. Particularly since the brain is patently a parallel computer anyway.