In my post apocalyptic world, a virus has spread, essentially changing the roles, with infected animals gaining sentience and intellect close to a human and humans degrading into a more animalistic, instinctive version (plus the violent physical changes cliché) . Patient zero, however, was an exception to the rule. Patient zero kept his sentience, but his mind did change.
Patient zero has a relative detachment from the uninfected humans, tending to favor infected organisms over them. However, I want patient zero to be capable of emotion, even if limited.
To put it more in perspective, patient zero sees no one on equal grounds, he sees the infected as one would see a random small child or even a dog they care a lot about, and humans mostly as an annoyance, but interesting and almost cute in rare occasions. Patient zero has his memories of his time as a human, but due to having changed at the age of 12 and having a poorly structured family, his emotions and maturity weren't properly developed, suffering something similar to a slight atrophy after the mutation.
I'm having trouble defining a proper condition regarding this. The way se acts towards humans is in part similar to a psychopathy, but rather than a lack of emotion, it's a feeling of detachment and lack of emotional empathy. So summing up, we have as main symptoms:
lack of emotional empathy to humans, along with a weak connection, not recognizing them as a member of the same species.
empathic feelings, although still limited, towards other infected, but still not seeing himself as one of them.
difficulty with understanding emotion (underdeveloped emotional empathy).
a tendency to rationalize his actions and behaviors, mostly as a way to compensate for the limited emotional capacity.
overall poor emotional capabilities, despite an understanding of social and emotional cues.
My question is: Is it possible to "rewire" a human brain to make it start viewing his own species (if patient zero reproduces with a human, the offspring is a normal human, so technically he didn't become a different species) as something lesser without making it completely incapable of emotion? I failed to find a proper condition that reflected the behaviors I'm looking for, with pseudopsychpaths being the closest I've found, but not quite what I'm looking for.