In this disorder, nothing at all arouses any kind of emotional response. Sights, smells, sounds, touches, and tastes have no impact. As with Capgras, the brain has to make sense of this bewildering lack of emotion, and it does in it a very strange way: the patient believes that they are, in fact, dead. Being dead is the only way to feel nothing, so given complete apathy to everything, the brain concludes that it must be dead.
Once convinced of being dead, it is nearly totally impossible to use logic to convince the person that they’re alive. For example, they’ll admit that dead people don’t bleed, but if you prick them with a needle, they’ll say that dead people must bleed. No evidence, no matter how damning to their belief, will make them see the truth.
This boggles my mind. Imagine a life without any emotional response to anything. Even if you knew that you were alive, it certainly must feel like death. I’m curious about how many sufferers end up killing themselves (although if they already think they’re dead, perhaps they feel no need). What an unfortunate condition.
Besides being quite bizarre, this also teaches something about how the brain works. Once it has become convinced of a version of reality, it is nearly impossible to convince it otherwise. Although I doubt that anyone needed convincing of that little fact; we all have personal experience with it. Interesting, nonetheless.