You might like Craig's paper "Interoception and Emotion: A Neuroanitomical Perspective" https://books.google.com.au/books?id=DFK1QwlrOUAC&pg=PA272&hl=en#v=onepa

You might like Craig's paper "Interoception and Emotion: A Neuroanitomical Perspective" https://books.google.com.au/books?id=DFK1QwlrOUAC&pg=PA272&hl=en#v=onepage&q&f=false https://books.google.com.au/books?id=DFK1QwlrOUAC&pg=PA272&h... He presents evidence that primate emotion evolved from interceptive awareness - goes into fascinating detail about what we know of the underlying, homeostatic, neuroanitomical structures and their evolution.