But that experiment is founded on the assumption that the root of consciousness is the brain; and that consequently, consciousness can be subdivided, like the brain, until there's very little left.

But I contend that that begs the question: it assumes that the root of consciousness is material, and it assumes that consciousness is divisible. So you have made assumptions that are incompatible with consciousness being fundamental and indivisible.

That is: it's not surprising that you disagree with me, because you've assumed that I'm wrong.