I got asked privately to elaborate a bit more on what goes on internally when it comes to what I talked about in the post Revisiting Click.
Basically, I believe that the differences between having a choice and no choice when it comes to obedience corresponds to different mental states and levels of subspace. How much "you" remains can shift quite a bit as well as fundamental behavioral patterns. Internally, I think much of it has to do with the level of mental surrender and what that does to your fight or flight response.
Something I should note is that not everyone behaves purely in a fight or flight way. Trauma has the capacity to add a third option to the list which creates fight, flight, or freeze and surrender. You can see this a bit in the animal kingdom, especially when it comes to hierarchies based upon rank in pack dynamics. Some will fight it out, some will run away, and others will tip over and expose their bellies, feeling helpless and surrendering to the greater power. I'm not sure if that third response makes me unique or less common, but I consider it to be a core factor of my submission. The more that I think about it, I have to believe that those who can reach slavespace are likely familiar with this.
To illustrate this with an example, let's say she puts the sub in a collar and instructs them not to remove it. At some point she instructs him to run an errand. The sub is aware enough of "self" to probably run through the mental debate of whether they should run the errand in the collar or if they should take it off. This mental debate implies that their thought process is still very human and what they choose to do will represent which side "wins," their desire to be obedient or their desire to avoid being embarrassed or humiliated.
If she puts the sub in a collar and locks it around his neck, he cannot remove it. If instructed to run the errand there is no debate of removal, he simply accepts his fate as inevitable. While he may attempt to hide the collar under a shirt collar, coat, or scarf, none of these are disobedient acts. Even with the collar hidden, he will be trapped within his mind knowing that he is wearing it.
The primary contrast is debating the strength of his obedience vs. attempting to cope with the unavoidable. (Yes, I am treating the "skipping the errand" option as a non-option as that is the sort of thing that gets you dismissed). When given the choice of obedience, the sub's immediate responses fall to obedience (fight or flight). When choice is removed, the sub's immediate responses are far more likely to simply try to make the best of the situation (freeze and surrender).
I believe that subs grow acclimated to a specific range of subspace as this generally represents the level of consistent control the Domme prefers to exert. I see the differences in this topic as being rooted in how much "human will" she wants the sub to maintain. Choice gives the sub the ability to say no. Removing choice takes that ability away, which leaves obedience as the only option.
I tend to prefer that loss of choice. It triggers a loss of self and it allows me to reach deeper levels of subspace. This requires the impulse of fight or flight to fall away in favor of freeze and surrender. My sense of self dissipates and I begin to see the world differently, in such a way where I desire that which she desires. I don't think this happens as easily when I still have the freedom to say no.
I have heard of Dommes taking the opposite approach to test a submissive. If the sub is accustomed to locks, seeing how they will behave the same in the absence of locks. If the sub is accustomed to the honor system, putting on the locks and seeing how they deal with the loss of choice. While I can see this being used in small doses, I think this actually pushes the sub in a very uncomfortable way by forcing them out of their normal subspace and into unfamiliar territory. Flip-flopping regularly will likely keep the sub feeling confused.
In summary, as subs cope with submission, their minds learn to naturally respond to
the hardships placed upon them by the Domme. That method of coping is
steered heavily by whether or not the Domme permits them the freedom of
choice. Over time their default method becomes an automatic response. Locks can help contribute to maintaining a deeper space and train the sub's mind to stop considering the existence of options and steering them down the path of surrender as a natural response.