What issues would arise with full body prosthetics?

Question

PREMISE

I'm working on a story where cryogenic technology was made viable in the early 21st century (2026 or thereabouts) and became widespread due to an ageing elite seeking to put off their death, the private space industry using it to bypass issues with transporting untrained people through the expanse of space, the insurance industry as an option that people offered to people who don't necessarily understand what they are signing up for, and simply people with terminal illnesses trying hoping for a future cure.

Fast forward a century or so and there are millions of people in cryostasis, possibly hundreds of millions, often in poor physical condition with no one to pay for their resuscitation. What makes these people doubly unfortunate is that it was decided the most cost-efficient method of storing someone in cryostasis was to remove whatever is unnecessary to minimize their storage footprint. Thus, a large percentage of these people are rendered as little more than a head or simply a brain and ancillary bits (not sure if the spine would be preserved yet).

The end result is that those waking in the future are, due to a legal case, effectively indentured workers for whoever it was that resuscitated them. These people have rights; of course, those in charge are wise enough to know that nobody wants people with full prosthetic bodies staging a revolt. This is due to the fact that most people being resuscitated are fitted with rather strong and durable full-body prosthetic as hazardous work environments tend to have the highest demand.

SETTING DETAILS

This scenario is set some 200 or so years in the future.

Humanity has colonized the solar system through the use of an STL propulsion system derived from research into the Alcubierre drive. (Its gradually getting better)

Stations, moons, asteroids, and small rocks have been and are being colonized or mined.

Indentured workers have roughly equal rights as regular workers but with exceptions. They can leave the employ of those that resuscitated them, but only if someone else picks up their debt contract and in the worst-case situation they can go back into stasis. Shenanigans such as putting full-body prosthetic workers on less than subsistence living are cracked down on. It's not perfect, it's not pleasant, but that is the reality they woke to, and they have a second chance at life.

The full-body prosthetics vary to a fair degree in quality and build. At the shallow end would be Civilian, something like a Frame from Destiny but with a braincase in its abdomen, to simulacrum grade, which could be a Ghost in The Shell type full-body prosthetic.

The power players are a mix of planetary governments, state states, and megacorps with some smaller organizations operating in the background.

Thematically I was aiming for a setting between Cyberpunk/Shadowrun (sans fantasy elements) and The Expanse (sans protomolecule).

THE QUESTION

Edit 3: Removed original question for being too broad.

Edit: To clarify these people are effectively brains in a jar cyborg.

EDIT 2: (to specify the question further) Specifically, and most relevantly, I would be wondering about the person(s) well being with them awakening to their new existence as a 'brain in a jar' cyborg. Namely, what issues would arise psychologically and physically?

I don't necessarily need to know how such things would be addressed, but what they would be so that I may inquire into them through alternate means.

Answer 1

Depression and no physical entertainment

Although you suggest you prefer no psychological issues, I think these are very much tied to the other problems.

The brain is very much linked to the body in many ways, most we don't fully understand. A few big ones are influencing what we want to eat (gut bacteria), metabolism/growth/development (thyroid), and even just moving. Without gut bacteria, you probably have no craving for a certain food, making eating bland. Without a stomach, you don't feel you need to eat. Without the feeling of healthy exercise, you'll not be able to get a good dopamine and serotonin response. Each of these contributes to unhappiness and eventually depression. What is life worth if you can't even have basic enjoyment? Of course you can say all this is being simulated, but that means you require an incredible amount of technology inside of them, while you suggest they are simple full body prosthetics for the time period.

What's more, most of the entertainment will be moot. Only cognitive entertainment will be stimulating. Why would you run if your prosthetics never change? Would you have sex without such organs? Even something simple as a hug might be ineffective if not enough receptors are placed on the person. And as above, why would you have restaurants if taste is merely something to distinguish the food and not giving any satisfaction due to missing gut bacteria? These things would be for real people, or for people with advanced full body prosthetics, making them high society.

To combat this, electrodes in the brain would be able to stimulate certain area's for certain actions. This can be compared to the rat who had electrodes in his brain. Every time he pulled a lever, the brain was stimulated and the rat got an orgasm. The rat starved as he was only pulling the lever, but your humans would have certain safeguards from this to happen. Doing certain tasks will give you that much desired spark of hormones and stimulation. This can immediately be a reason for them to keep working, or even become workaholics. They feel only happy when they are working and taking care of themselves. Otherwise the stimulation stops and they will feel bland, not even caring enough to rise up.

As an extra measure, you might have some advanced machinery that can fulfil all the functions of the body. People can be hooked up for the correct slow release hormonal cocktail to fulfil as many bodily functions as possible, while still having basic frames.

This doesn't mean all your problems are over. Again, lots of functions are diminished or not present, but my guess is that they would work. Unfortunately it's hard to give this a hard science approach, as this hasn't happened yet.

What it basically comes down to is that the lower classes are working hard and mostly happy for it, but they'll likely get some form of psychological damage over time. Some (cognitive) entertainment area's will probably rise in popularity, like quizzes, video games or painting. Most other forms of entertainment will be high society.

Technological advancement

Transistors can be made very tiny these days. A nerve axiom/dendrite is magnitudes larger than transistors. In my research at the university I suggested that this can be used to conduct electricity from one nerve to another. If nerves are damaged they normally die off, but that is probably because they aren't used any more. If an artificial connection is made that transmits the electricity from one to another, it's likely they don't die off as they are being used. This idea can be used to connect the brain with the prosthetics in such a way it's indistinguishable from a normal body. It might even increase some reaction times, as conductivity through nerves isn't as fast as through copper. Some extra transistors can be placed for the stimulation of the brain when certain (work) patterns are detected either in the prosthetics/brain. The transistors do need to be the right size to transmit as much of the electric potential as possible within the brain. That being said, in the prosthetics you can have an as low power as possible connection for receptors for example, only up-scaling it for the brain. This will save power.

The prosthetics don't need to closely follow the human body. After some adjustment period, new things can be learned, like that a prosthetic arm has nearly 360 degrees flexibility. Keep in mind that the brain can modify it's previous association with the arm. A third arm for example would require a new area in the brain, or it would get very crowded. Although you might be able to combat this with a higher density brain. The cerebellum and brain stem are higher density in nerve cells than the rest of the brain, as it's much more well developed.

For the rest you need hormone generation and a form of circulation system to keep the brain alive, but my knowledge here is more limited.

Answer 2

Power

I am supposing that these bodies are not powered by food, but rather by batteries. If so, they will need charging.

Sure, you can put a charger on your bed so you can recharge while you "recharge". But you need to go back to your recharging station every now and then, just like a vampire that needs to go back to a coffin.

You can tey some alternatives. But solar doesn't charge fast enough unless you have a whole farm forr yourself. And nuclear fries your brain over short time.

Answer 3

Societal issues:

Class warfare. You have effectively reinstituted slavery. This is a perfect setup for all kind of conspiracies, rebellions, insurrections, social movements etc.

Technological issues:

Anything you like. According to your premise, a self-contained "shell" is viable. Also, I assume, Neurodegenerative Diseases are cured (otherwise you end up with an army of laborers all suffering from dementia). So, you are free to play with whatever specific limitations different types of shells may have. For example, they need to recharge (how often?), they need to do "fluid exchange", they need a more extensive regular service, they may have limitations (or enhancements) to standard human 5 senses, they may have particular weaknesses or vulnerabilities that natural humans won't have (like Tin Man is susceptible to rusting, even from his own tears).