Isn’t the internal stimulation just the nervous system zapping things to get a response? And doesn’t that need a trigger to get it going?

yes but between external stimuli, vision for example, and internal stimulation, memories, you generally need both in order to be able to conceptualize it and make practical use of it.

Anyway, I feel like I’m heading into contested territory here, but I gotta ask. At which point can we consider babies as conscious?

personally, by the time memory is formulated and they can start to remember things. Otherwise it's debatable whether or not something can experience in a conscious literal sense, the effects of pain and suffering. We know that most animals must experience some level of consciousness, but between birth and the capability of general consciousness, the specific level of consciousness available is not very clear to anybody.

We know that newborns have a lot of fundamental primal responses, holding their breath, hanging onto things, facial recognition. ETC. we know that young animals also experience similar things, though it's contested how much of this is just a primal built in, or a learned behavior.

And if we're talking about learned behavior in the context of consciousness it's even weirder because the matchbox tic tac toe (MENACE) experiment proves that a collection of matchboxes playing tic tac toe can clearly demonstrate the ability to learn and reflectively act upon it's learned experience, however, it is in no way a conscious entity, it is merely a statistical representation of a conscious entity.

if we're talking about consciousness in the form of abortion, generally i follow up to about the first trimester, with the usual "if deemed necessary" post first trimester. As most abortions happen very early on. Although realistically, i'm never going to have children, so it's not really my problem to deal with, so my ultimate opinion doesn't exist past "non infringement of rights"

Most people will claim their earliest memory is at the age of 4 or 5 years old. So that time is probably considered as the general start of conscious identity. Yet some have reported that simulating the conditions in a womb such as sleeping in a fetal position or floating aimlessly within a larger body of water will grant them an instinctual sense of serenity. So it can be argued that at some level, we remember our time in the womb, even though we are not able to recall it directly.

i believe it's about 2-5 years old that memory starts to develop in general, though don't quote me on that. I don't think it's "remembering being in the womb" so much as it is post-hoc rationalization and creation of those memories, and also primal programming that influences us to be receptive to those things more generally. It could also be in the case of fetal position, that a subtle psychological reasoning is present. Having your extremities nearer to the rest of your body means you have less to worry about, and puts you in a more defensible position for example.

And I’ve seen babies aged around 1-2 years old trying (unsuccessfully) to hide from their parents in order to attempt an action that had been forbidden several times before.

we see similar things with animals as well, birds, dogs, cats etc. They all do similar things, and they almost definitely have a lesser level of consciousness. In fact we ascribe them a higher level of consciousness than they likely have. It's attributable to a simple level of relations between objects. Doing X is bad because Y doesn't like it. Therefore if i do X outside of the existence of Y it is no longer bad. Which is probably a reason that we see this behaviorism. Though it is obviously later learned that regardless of what happens and where, it is bad. And we do still see that behavior with a guilt response upon being caught. Though presumably this is due to some level of independent thought.

How early does our capability to store memory actually start? And at which point will the amount of stored and remembered experience be enough to count as consciousness?

I'm a bit of an absolutist in regards to this one, but i think that generally, the first thing you can remember, constitutes your first memory. However i don't think it has to be something that you explicitly remembered as your brain can segregate things into different groups, and intentionally block out certain parts of it, while making others more explicitly important, but even that aspect, has an influence on your memory, the things you remember, and your general behaviorism so i would count that as "memory" also, even though it's probably not.

How early does our capability to store memory actually start? And at which point will the amount of stored and remembered experience be enough to count as consciousness?

Consciousness as a concept is pretty tricky to nail properly in a sterilized environment, but personally i subscribe to the meta theory, where once you can personally conceptualize your own consciousness, the second you realize you are capable of being a conscious entity, is the second where you gain consciousness.

as for how it starts, it's pretty clear through biology that it's related to the structures of the brain, neurons inside of the brain and the paths built between them that are made more robust through continual usage are what constitute the ability to remember things, if you do not use them, you lose them, and it makes way for new paths and new memories to form, however there is generally some form of residual memory, similar to how data is written to disk and deleted.

apologies if this is somewhat schizo and badly formatted, i'm writing this while listening to a debate and playing factorio in the background, and i also spent some time talking in discord, so it's probably a little bit disjointed lol.