Nah, there have been cases with short temporary flat EEG that came back to life, which is why the guidelines specify the duration for declaring someone dead in

Nah, there have been cases with short temporary flat EEG that came back to life, which is why the guidelines specify the duration for declaring someone dead in this way. Those people suffered no memory or identity loss, so electric activity is not related. Connectome structure and tuned bioelectrical responses based on cell cytoplasm gradients, receptor structure and number tuned by a bunch of either RNA or proteins the most likely candidate. So the better analogy is it's like flash memory, left unpowered but running for too long the neurons will change. Restarting the brain from that flatlined state is therefore possible, we just don't know how to do that properly. Most importantly, it won't do any good if the brain is damaged and is rarely useful.