Jennifer Maas TV Business WriterApple TV Plus drama “Severance” takes place in a world where people are able to undergo a medical procedure that gives them a literal work-life balance by implanting a chip in their brain that essentially splits them into two different conscious versions of themselves: an “Innie” who is awake only at work, and an “Outtie” who is not aware of what they do from 9 to 5.In order to make the sci-fi thriller’s central plot point believable enough that viewers could accept it as a reality of the life of Mark Scout (Adam Scott) and his severed colleagues at Lumon Industries and move on to the larger ethical implications of severance, director Ben Stiller and series creator Dan Erickson brought in a real-life neurosurgeon to make all of this look possible. And, according to the M.D., it’s not actually impossible at all, given enough time.