The introspective ability to hold abstract concepts in the mind is the source of the statement that humans can do so.

It is what Aristotle called the intellectual soul, not qualia. Qualia is an experience and has no relation to holding abstract concepts. As I already wrote, Turing machines cannot do it for they suffer from multiple realizability, any abstract concept can be implemented in multiple physical constructs and any physical construct can be interpreted to be any number of different abstract items. I have not written that only "wetware" can do it, I have written that turing machines cannot do it and that no purely physical construct can do it (including purely newtonian/quantum wetware).