Logical explanation for why Brainbots would not retain their original identities memories

Question

So, my setting is a post apocalyptic one, 197 years after WW3 kicked off and destroyed pretty much everything. The current date is 2259. Before WW3 started, the USA was experimenting heavily with robotic machinery and engineering. Dr. Erwin Joshua proposed a new idea, however. Instead of using actual computer systems and etc. to create AI, use human brains, encased inside of robotic bodies.

Around that time, Daniel Tyson, infamous serial killer, was executed. Since he obviously wouldn’t be missed, Joshua and his team took his brain, and preserved it. Than, after building a robotic body, they hooked up his brain to the robotic body. But, Tyson doesn’t keep any of the memories from his human days. Many more executed criminals undergo the same process, same story for them.

My question is, what would be a logical reason why Tyson, and all other Brainbots produced do not keep their old memories after being revived?

https://www.worldanvil.com/w/after-doomsday-dattawan

Answer 1

You could supply chemicals which make the neurons in the parts of the brain responsible for our memories retract. And many other such solutions, some of them beyond our current technology.

Even better: Don't take the physical brains but scans of their structure in an artificial brain. There, you can change anything as you like.

Either solution, though, is likely to not be complete. It seems brain cells exchange proteins so they know who they hooked up with (successfully) before, so your natural brain could find some memories again.

Both scans and natural brains, if they come from criminals, are likely to contain some of the "shortcuts" which made them criminals before - impulsiveness, impatience, aggressiveness, a like for 'easy' solutions, a dislike for structure and so on.

If you want it accidental, you might not remove memories but hook up the brain to the machine with slight errors in the wiring, so that all the memories get scrambled. The brain will learn to adapt, some memories will come up when the brain repairs itself by chance in the right spot, but the person won't be able to know which ones are true and which ones are ghosts of messed up memories. A person with that problem and the intent to keep their mental health is then likely to let their old memories fade away and replace them with new ones. While other people may spend a lot of time trying to find ways to verify which memories are real and which are wrong.

Answer 2

Retrograde amnesia is perfectly reasonable side-effect of the procedure itself.

There would be considerable physical trauma to the brain from being removed and implanted. Hypoxia would be likely during the process. Blood circulation would almost certainly have suffered at several points. All of these can cause amnesia if they happen to relevant parts of the brain and in your case they would affect the entire brain.

Additionally you would also need to connect the brain to the robotic body. This would probably involve inserting electrodes of some sort within the brain itself and using medication to boost neural plasticity. Both of these also cause amnesia because they make neural networks likely to rearrange.

Honestly I think that you'll end up needing to teach your brainbots how to talk and walk since they will likely lose large parts of semantic and procedural memory as well.

Only thing to look for is that older memories are more likely to be retained. If you want to retain some language and movement skills, your victims will probably have some recollections of their childhood. So you might want to look out for serial killers who were unhinged by childhood trauma. Although I'd think personality and most mental issues would also reset. The mental conditioning you probably want to do to make them usable would probably also block any effects from vague childhood memories even without specific effort.

Answer 3

Neuroplasticity. A robot body is radically different from a human body, meaning different parts of the brain may need to be retasked to do something completely different. Because the retasking is so extreme some memories may be lost because that brain tissue is doing something else rather than storing said memory. This may especially be the case if we add new senses not present in humans, say radar? We may claim to make this retasking process faster by 'resetting' the brain with special drugs. Although I must admit there is not much experimental evidence for this. It has been found with animal neural interface experiments that monkeys don't appear to lose motor skills when they learn to control a wheel chair with their brains. At least with the motor skill tests we can perform on monkeys. However, it has been speculated that finer motor skills, say playing the violin, could degrade.

Answer 4

Old memories were overwritten with new job-specific data

https://robocop.fandom.com/wiki/RoboCop

RoboCop, as he was more widely known, a cyborg with computer and mechanically assisted reflexes, memory and a 'lifetime' of law enforcement programming and a selection of dynamic software for plotting strategies and ballistic vectors in any situation.

Just like the robot body he got was designed the job, Robocop's memory was what he needed to perform his job. Old memories were wiped to make room for the new and more useful stuff.

Of course that key to the plot and other movies where people get brain wipes is that the memories are not gone completely - some human memories are somehow unwipeable.