"It's entirely misleading to suggest that a head transplant or a brain transplant is actually really still connected in anything except in terms of blood stream to the body to which it has been transplanted. It's not controlling or relating to that body in any other sort of way." ~Dr. Steven Rose
If we attach adequate brain-computer interface to the brain, a person can continue living, even without having control over the brain-sustaining contraption (human body or something else). (Assuming the brain can be made conscious/awake.)
Are there BCIs that can pass signals to the brain as well as reading them from it?
Amazing video. This is really "out there" medical research that actually worked, and not surprisingly, was closed down.
http://www.vbs.tv/newsroom/dr-white-s-total-body-transplant-2-of-2--2