In the squishy mess of definitions about what might be consciousness, free will, cognition, and related topics - there is considerable overlap and this makes it hard to pin down what is even being defined.
In my own considerations I am a strict materialist with a strong focus on the mechanisms underlying behavior, both observable and self reported. I will add that with the new visualization tools some of the mechanisms that used to be “forever in the subjective realm” are now observable.
That said - I am picking up on two threads where I may be able to shed some light on the underlying mechanism.
@Paul_Lamb and @Falco have been jousting on the “you vs. me” and the boundary between your internal universe and the external universe. As I mentioned elsewhere - the cortex has projections from your skin (usual external boundary), vision, hearing, vestibular system, various joint angles, and muscle sensors to one of the lobes. This is broadly connected with your memory system and learned interactions with your environment (loosely - your personal space) in part of the parietal lobe. This personal space covers things you can interact with using your body and the learned part is part of your sense of agency in manipulating things in this space.
Peri-personal space as a prior in coupling visual and proprioceptive signals
https://www.nature.com/articles/s41598-018-33961-3.pdf
The sense of agency is a curious thing - often probed in labs with surprising results; see phantom limbs for example. This learning is as valid as learning how to run your internal musculature and extends your inside to your near outside.
This fuzzy line between inside and outside is not surprising if you think about what the cortex does - the brain in a box with no idea what it is hooked to. The sensations from the interaction of limbs and vision is learned just as well as learning to balance and walk. This learning IS your sense of agency.
The contents of consciousness are the current total state of the “global neural workspace” as I have linked several times before on this forum. Everything is available to this blackboard - perceptions, and memory all at the same time. As processing happens, with the influence of the sub-cortical structures in the driver seat - the final results of this evolution of the contents of consciousness are digested as perceptions and tucked away in your personal narrative. For any part of your brain function to register in this narrative it must have a cortical representation. This means that all of the sub-cortical structures control what the cortex is doing but are themselves - unexperienced except as the results of these influences. The unconsciousness part of our mind.
But the sense of self in these considerations - that is as slippery as anything else here. I touched on this exact thing in this post:
See this snippet: In part of this system, we have a gyro stabilized reference platform (the vestibular system) that is directly mapped to the eye tracking system to keep the eyes from being distracted by self-motion. (At that point, in that little spot on the brain stem, there is the closest thing that if you had the correct instrumentation, you could measure as the neural correlates to a sense of self.
In the motion control and planning part of your brain, this is the self-reference frame that is the me in your perception and motion planning.