Are there any good books about life after death? (With more of a scientific standpoint)?

I want a fiction book where someone dies and experiences the after life, but I don't want it to be a cliched version of the after life like ghosts or heaven or anything. I want it to be in more of an agnostic/atheist standpoint, and spiritual NOT religious. Is there anything where someone dies and they don't go to a place (like heaven) where everyone who dies goes to, but instead they just sort of wander around in the memories of their dying brain and their afterlife becomes like a dream they might have? Even though she didn't die, something like the end of Contact by Sagan would be good. Thanks.