I doubt it's possible. I'm sceptical that one can cleanly sort every experience-related bodily mechanism into a "cognitive" category xor a "perceptual" category. Intuitively, for example, I might think of my eyes as perceptual, and the parts of my brain that process visual signals as cognitive, but if all of those bits of my brain were cut out, I'd expect to see nothing at all, not an "unmediated" view of the world — which implies my brain is perceptual as well as cognitive. So I expect the idea of just shutting down the cognitive mechanisms and leaving the perceptual mechanisms intact is incoherent.
(Often there're also external physical mechanisms which are further mediators. You can't see an object without light going from the object to your eye, and you can't hear something without a medium between the source and your ear.)
So are people who claim unmediated experience lying?
Another month has passed and here is a new rationality quotes thread. The usual rules are: