Rather than continue to talk past each other, I'll try to change the question so that we can get a different perspective on the relationship between "A" and "B". (
We're both fans of pondering the imponderable...right?)
"A" is the microscopic world of interacting quantum fields.
"B" is the macroscopic world of particles, forces, matter, and brains.
So here's the question. Are actions in the macroscopic world (us) responsible for changes in the microscopic world (the quantum fields), or are actions in the quantum fields responsible for the changes in us?
Which is it? Does our macroscopic world cause changes in the quantum fields, or is it the other way around?
If the former is true, that the macroscopic is responsible for changes in the microscopic then you actually have a case for the brain being responsible for consciousness. On the other hand, if the microscopic is responsible for changes in the macroscopic then it's actually the microscopic that's responsible for consciousness, and the perception that it's the brain that's the causal agent is simply an illusion, because it's those darn quantum fields that are the cause, and the brain is just a material projection of what's happening in the fields.
There is of course a third option, that there's an interaction between the two such that we're living in an observer created reality, arising out of a quantum reality, but not entirely subjugated to it. Whatever that means. (
Of course that then leads to the whole chicken and the egg problem)
Here's to pondering the imponderable.