I know this is more of a silly question. The brain can only survive a certain amount of time without oxygen before being brain dead, and of course being deprived of oxygen can create wonky hallucinations. There are a handful of NDE's out there of people who have had near-death experiences that have lasted over 10 minutes, if not longer. There's so many different factors that would go into trying to conduct such an experiment. If scientists genuinely wanted to, could this be possible?