What are you looking for? Neuroscience is dedicated to such questions. You refer to one yourself in your quote below.
Right now, I’m going to have my material brain conceive of a circle. 3 - 2 - 1 There it is, a full on abstracted circle! You have no scientific basis for denying that was an activity of the brain.
I have not read anyone who denies that concepts exist.
Seriously? What part of “it remains possible that a material universe can give rise to emergent rational consciousness” is not coherent?