I latched onto this term imago from reading A Memory Called Empire, where it meant a specific technology: a digital-neural copy of a personality (usually but not necessarily someone dead) that can be implanted in someone else's brain, and acts as a kind of coach / advisor / mentor figure, with its own agency and personality. The protagonist comes from a small, somewhat marginal culture that uses imagos to preserve and transmit its precious cultural knowledge.
book by Arkady Martine; winner of the 2020 Hugo Award for best novel
I'm not going to summarize the story; but instead will focus on one of the main plot elements, namely imago technology. An imago is a digital-neural copy of a personality (usually but not necessarily someone dead) that can be implanted in someone else's brain, and acts as a kind of coach / advisor / mentor. The protagonist comes from a small culture that uses imagos to preserve and transmit cultural knowledge.
I found the book's depiction of imago technology to be quite well-wrought, particularly in exploring its social impact. And wonderfully original, although it seems like such an obvious idea in retrospect that there must be some precedents in fiction, but none come to mind.
Oh I thought of one: the technology of cold-pack in Ubik by Philip K Dick! In both cases, the dead are made to speak through technology (though in Dick's version they are actual bodies in a cryogenic state of half-life, not an artificial digital copy). And in both cases, the plot involves interference in this process, with the protagonist in a situation where they are desperately reliant on advice from this remnant of a person, and failing to get it due to interference or malfunction. That's weirdly parallel!
Or maybe not so weird; it tracks our actual relationships with the dead: they become memories that fade with time, and we have to get used to not relying on their presence or the echoes of their presence.
Real imago technology would probably not have these problems; rather the opposite. Digital content never fades (well – its more complicated than that, but the default state of digital content is to persist indefinitely through perfect copying of itself).
Another precedent from SF/fantasy: the analeptic alzabo in Gene Wolfe's Book of the New Sun. An entirely different mechanism, but the result is the same: the protagonist's head is filled with the presence of their historical predecessors; who exist as quasi-real people and can occasionally take control over the physical body. That's actually better.
Yoon-Ha Lee's Ninefox Gambit also had a downloaded secondary personality now that I remember it.
It occurs to me that GPT-3-like technology could make pretty decent approximations of imagos right now. Damn, there's almost a business there. This line of thought continued at Imagos Inc