Human consciousness can exist independent of brain-activity.
Reductionism/Epiphenomenalism has long been a pet notion of psychology, specially in behaviourism. Now that psychology’s own principles have been shaken after recent discoveries in genetics the idea that consciousness is merely an effect of brain-activity is being questioned again.
Brain specialists, Prof. J.C.Eccles, Sir Cyril Burt, Dr.Wilder Penfield and Prof.W.H.Thorpe stated that in their opinion the brain appears to be more a complicated organism to register and channel consciousness rather than produce it. “The brain is messenger to consciousness”, Eccles said. In his famous debate with philosopher Popper “The self and its brain” this matter was examined further.
David J.Chalmers Ph.D. writes in the Scientific American (1997):
Consciousness, the subjective experience of an inner self, could be a phenomenon forever beyond the reach of neuroscience. Even a detailed knowledge of the brain’s workings and the neural correlates of consciousness may fail to explain how or why human beings have self-aware minds.