quantamagazine.orgPain and pleasure seem like simple facts of life, however they are anything but that. Neuroscientists still cannot say why physical pain differs from psychological pain, for instance, or why a loved one's touch soothes while a stranger's touch repels. To explore the science behind these sensations, Janna Levin talked to Ishmail Abdus-Saboor, a neuroscientist at Columbia University's Zuckerman…