They are going to use SCIENCE. Which is different from science in that the former doesn't have to make sense by real world logic
Them taking your brain fits perfectly with real world logic. If people can be put on machines to breathe, and circulate blood, and even pee for them, I'm pretty sure the 2077 future will have created the 'iron brain' where you can survive without a brain as long as you are connect to the machine. Heck, it's so futuristic that you may just need to have a little metal plate in place of your brain to connect it by infrared. It just seems heinous to us now because we aren't at that advanced level yet. But in the future, everything that seemed impossible, is possible. A bunch of people didn't believe the airplane could ever fly, yet it did.