Altruistic behavior can have different motivations: from the hope that the help you give will ultimately benefit yourself (social exchange theory) to a selfless wish to alleviate someone's suffering.
Selfless altruism is motivated by empathy. According to C. Daniel Batson, "if you feel empathy towards another person you will help them, regardless of what you can gain from it".
Do the brains of non-altruistic (selfish, egoistic) persons – i.e. persons who do not show altruistic behavior in the face of suffering – mirror the observed experience of suffering (and is this information simply ignored) or do their brains not mirror the observed emotions at all?
If selfish brains show mirroring, what hems altruistic behavior in selfish brains, or what facilitates it in selfless brains?