The hook here has got to be memory--which weirdly is the word that just went through my headphones ('Burning Memories' by Ray Price).
Memory, especially involuntary memory--in Marcel's case, the return of his childhood, then the whole of his life; in Echo's case (in season 2) flashes of, what, the 23 personalities dumped in her, plus the one that she came in with, and how those give her Slayer powers.
What? No slayer powers? Didn't you seen her pwning in the Jamie Bamber episode? I was all "WTF's with all the Slayer fighting powers. Evs."
Srsly, that's how I talk to myself.
The theme of Dollhouse seems to be that we're all programmed by the influential to be what they want us to be*. I recognize that in my experience, all the way from learning to stand in line in kindergarten, to binge drinking in high school, to my present-day pop-culture-obsessed consumerism.
A theme of In Search of Lost Time is that these memories that reappear to us unbidden, with all their force and vividness, are different in kind from things that we purposely remember or seek to recall.
So, if we equate Echo's Caroline personality, the one she came in with, to an involuntary memory, once that sticks with her even though it's supposedly been removed from her body and stored on a hard drive; and we take that equation to mean that it's different in kind from the 'voluntary memory' of the Imprints she takes out on Engagements, a difference seems to be more real, more genuine, just because it is her natural personality, then we have arrived at a rather vacuous connection of Proust and the Dollhouse.
I'll come back tomorrow and see if I can do any better. Why would I do that? Well, there's an essay contest that I really wish I was the kind of person who would submit an entry for. Hey, my brother got something like this published (just a chapter, not the whole book, this one too), why not me?
*okay, I didn't think of that on my own--Joss said as much in an interview I read recently, but I didn't find it with the slightest effort, so no link for you.