Dehumanization is the experience of seeing other humans (or animals) as not possessing a self-concept. Information metabolism-wise, self-concept is processed by extroverted feeling EM in the context of extroverted intuition IM ("imagined personage").
Although we accept the humanity of others as a cultural imperative, from a cognitive standpoint we can only experience the "reality" of a person's soul through applied N-F. We use Ne-Fe (along with Ne-Si) to identify a person as "like us" and to imagine their experience given potential actions we can take; as such, Ne-Fe is properly the function of conscience. We use Ni-Fe to trace their experiences in time, including their personal history, personal goals, and probable destiny. By the same token, we use assessments of a person's past and intended future to evaluate their relevance to us and whatever threats they may pose, thus offering us cause to ignore the conscience with respect to them. Friction exists between Ni and Ne dominants in part due to this truism.