You've exclusively described contexts with tons of active stimuli (temperature, interoception, balance, and frankly most of the other senses you named).
But more importantly, suppose we grant that humans function independently of stimuli. Why does that matter? How does this premise imply anything about an agent's capacity for internal experience? In the counterfactual where our brains don't work when surgically placed in life-support vats, does that mean our prior experiences weren't real?
I'm genuinely so confused at this connection between subjective experience and the necessity of stimulus.
Reacting to stimulus doesn’t require subjective experience. A light switch reacts to stimulus.
Reacting without stimulus does. A stopwatch maintains an internal state, the neural networks used by LLM’s don’t.
Someone who starts lucid dreaming can have zero awareness of their body and still do stuff like make up a story which they then recall after waking up.
PS: Balance over all but very brief periods depends on noticing your body weight pressing on something this is one of the reasons people can get disoriented under water. Temperature can be lost track of for similar reasons, rapid changes are noticeable but slowly moving in the neural region ~30-36 °C and all people can detect is a lack of extreme heat or cold not some objective temperature.
But more importantly, suppose we grant that humans function independently of stimuli. Why does that matter? How does this premise imply anything about an agent's capacity for internal experience? In the counterfactual where our brains don't work when surgically placed in life-support vats, does that mean our prior experiences weren't real?
I'm genuinely so confused at this connection between subjective experience and the necessity of stimulus.