Will "correlations" do instead?
Brain imaging to find the areas and activities
that covary with conscious states,
as the necessary and sufficient
conditions of consciousness?

But how did we identify those correlates?
Because they were correlates of behavior:
and of our own feelings
i.e., by Turing-testing.
What is our basis for favoring R-eng over F-eng then,
if they are Turing-Indistinguishable (behaviorally)

and the Turing Test is our only face-valid criterion