Functionalists about consciousness identify consciousness with a role; physicalists identify consciousness with an implementer of that role. The global workspace theory of consciousness fits the functionalist perspective, but the physicalist sees consciousness as a biological phenomenon that implements global accessibility.
There are two concepts of consciousness, access consciousness and phenomenal consciousness. But just as the concepts of water and H2O are different concepts of the same thing, so the two concepts of consciousness might come to the same thing in the brain. Some recent papers by Crick and Koch raise issues that suggest that these two concepts of consciousness might have different (though...