This and The Feeling of What Happens by Anthony Damasio were very influential for me. The ideas behind interoception and their connection to emotion and though

This and The Feeling of What Happens by Anthony Damasio were very influential for me. The ideas behind interoception and their connection to emotion and thought helped me put start taking this space more seriously. Many people will also cite "The Body Keeps the Score", which is really focused on trauma and therapy rather than theory.