People who experience total facial paralysis experience profound changes to their subjective consciousness, particularly their emotional capacity changes. Anger is often the first thing affected. First, they lose the ability to feel anger. Then they lose the ability to remember what anger felt like. Then they lose the ability to recognize anger in other people. (These changes progress over years)

People placed into situations of total sensory deprivation very often see their conscious self dissolve into 'hallucinations' across all their senses.

Quadriplegics that acquire their paralysis from disease or accident suffer psychological and emotional changes which are more substantial than would be expected from the injuries alone (I was never clear on how exactly this was distinguished, so take it with a grain of salt).

I have never understood why people who talk of 'uploading their consciousness' or just creating a human-like consciousness in a computer would assume that the simulated consciousness would function markedly different from, in the best case, a person experiencing profound sensory deprivation. Consciousness can not be sustained if the feedback loop of the body, perception, and environment is broken. Consciousness is an emergent property of a feedback loop. If there's no feedback loop, the property doesn't emerge.

Watching the Netflix 'More Human Than Human' documentary, one of the people featured commented when comparing Siri and the AI in the movie Her that systems only need to become 'a little more sophisticated' to reach that level. That is a big problem. It's not 'a little more sophisticated' at all. It requires emotions, and the vast majority of people do not even know what emotions are. I'll spoil it for you. Emotions are a trained response, the product of neurological feedback to the response of prediction operating on primarily internal perception. Often the relation of moving from one topic to another in a conversation is not based upon the subject matter of the text. It is based upon shared cultural experiences garnered over a lifetime and similarities in the emotions evoked by certain things.

Even pursuing the goal of creating a 'truly intelligent machine' is dangerous, philosophically speaking. What happens when we create a bot that does antisocial things? We shit it down. We scrap the project. We saw that with Tay by Microsoft. This is dangerous. It is clear that once we DO produce a human-like intelligence... it will be better than us. It won't have any of the rough edges or not-safe-for-work parts. At everything we value about human beings, it will top us. We can look at history to see how humanity responds when something which was previously seen as 'fundamentally human' is taken out of our quiver. It is not pretty. The folk legend of John Henry shows that the man who is willing to kill himself to be better than a machine is not an idiot - he is a hero to motivate the masses. I don't think it is a stretch to imagine a future when humanities worst qualities become what we see as virtue because AI 'can't' do it. A robot can't hate. It can't be violent, bigoted, angry, etc. When that is the only thing humanity has left that defines them as 'more' than the world... why should we be sure they won't come to see that as their virtue? We have already seen all of those things valued as virtue in our history when similar pressures weren't even at play.

Then there's the more unknown approach. A machine-based intelligence which is not given a body. That's really the big question mark. We can be confident, very confident, that it will not be recognizably human in any way, shape, or form. Most of our attributes as humans are derived directly or indirectly from the biological facts of our existence. An organism sharing none of those things will share none of those attributes. And it will be weird in surprising ways. I don't think there is any reasonable danger of such an intelligence "taking over the world" in any substantial way. All conflict is rooted in resource contention. And we have nothing that such an intelligence would want or could use. If it wants energy, the only real resource we would share a need for, it would be best off launching itself into space and sitting in orbit with a bunch of solar panels. We don't have any idea what a singular intelligence, one with no concept of "individual" because there is only one of them, would be like. One which has no inherent mortality. One which does not deal with disease. One which has no concept of family. One which has no sense of age. These are things which define us and make us human, and it will lack all of them. It would probably be a great challenge to convince such an intelligence that we existed, that we were real, that we could communicate with it, and get it to want to. It could simply conclude that it will wait for 10,000 years and hope we are extinct by then.