The hope is that the brain stem cells will wipe their history and start things anew, much like some animals regrow whole segments of their bodies. This trial isn't expected to bring people back to life, though -- it's just a "proof of concept" study that will see if the idea is viable.

Dr. Bansal, Bioquark and Revita Life are taking care to walk a fine ethical line. The patients are officially brain-dead, and their bodies are only functioning due to life support. The bigger debate may revolve around whether or not there's any chance of modern technology bringing someone back to life. As Cardiff University's Dean Burnett tells the Telegraph, there's a big difference between reanimating parts of the brain and doing enough to completely revive someone. While the brain might start regulating body functions again, you might never get the person you knew before.