How could you possibly claim people are simply incapable of recreating mental states and that all they do is plausible post-hoc rationalization? Surely people can sometimes remember what they were thinking before making a decision? And in fact I would think people can do this more frequently than GPT can. Or are you really claiming those studies proved an implausible negative here?
Second: Being unable to reconstruct a prior mental state =/= remembering a thought process. I'll use an accursed programing analogy because we are on an accursed programing website: it's like the difference between debug logs and time-travel debugging. In plain language: humans retroactively reason about their thought process based on the artifacts produced by that thought process. The quality and reliability of these artifacts will vary heavily, but the reasoning itself is always backward-looking and speculative in nature.
Almost everything I've seen and read about this suggests the opposite. Activating memory changes memory. Intermediate events between the initial activation and the final questioning can also change those memories. And furthermore, that you are only aware of your conscious memories (and even most of that is forgotten) and that memory is accessed unconsciously all the time.
It's all post ad hoc.
The reason I linked the split brain experiments is to show that what you think is the reason for making a decision, even if you "remember" the thought processes before can just be wrong. Asking one side to perform an action and asking the other side to explain the reason for performing the action ended up producing some really wild results.
"Can" just be wrong and "produces some" wild results, sure. In the previous comment were claiming they're always fabrications (as, I note, seems to be the case with GPT!), not just that they could be.
The fact that both GPT and the human brain can sometimes fabricate things similarly does not mean the human brain (or GPT for that matter) does this all the time, let alone that they do this equally frequently, or always to equal degrees. The studies might be showing surprising results, but you're greatly exaggerating what the studies actually show.
Our brain store "key" moments it thinks it is important, then make up the rest of it. But this process is not really trustworthy on the finer details and is extremely receptive to any sort of suggestion because it simply doesn't have any factual data, so happily jumps to anything which seems to fit the narrative. This is especially true in scenarios where you experience strong emotions. Anything feels like to fit (like, someone paints a scenario which creates the same type of emotion) our brain just accepts it as a matter of fact and puts the puzzle in.
It's why implanting false memories is extremely easy and leading questions work so well. https://en.m.wikipedia.org/wiki/Lost_in_the_mall_technique
Anything that you remember from your life is mostly fabrications with a couple of actual memories used as a scaffolding, and your brain just built the rest of the structure around it - constantly changing it.
The brain is not a 'good' memory device. It is a really terrible one. Pick up any hard drive and write data to it and it's going to be a massively more faithful and reliable memory device.
Memory is not the power of the brain. Filtering is by far one of our greatest brain powers. At extremely low power levels we can input absolutely massive amounts of sensing data and capture information form noise. For example have someone put up a wall of pictures in a room. When you first see it your brain will capture a bunch of information, but every time after that it turns into more filtered noise you don't capture. And this noise is really easy to switch out with different objects and thoughts. When one of your trickster friends switches out the picture of your grandmother for Hitler, it's exceptionally unlikely you'll notice.
But what's even better about this is when someone points this out to you, how they point it out to you will influence "when you noticed it". If they say something like "We switched out this picture months ago and you noticed it pretty quickly" your brain will rewrite history when you recall this gag later and you will think you noticed it months beforehand unless you go to a pretty significant effort not to be gaslit.
We should have a healthy dose of humility here and realize we know very little about either the brain or the meaning hidden in those ~200 billion parameters.
"Unreliable" is a far cry from "lie to ourselves all the time". Some of the time, sure. But all the time? Everything I'm telling myself is a post-hoc fabrication just like with GPT? Like you're telling me I can't even trust my memory of who my mom and dad are, or which country I live in? I'm justifying all of these post-facto somehow?