Qualia are subjective ( qualitative) sensations such as " pain" or "red" which seem to require a first-person account. (see subject ) Many of the philosophical objections to a scientific explanation of consiousness have to do with qualia, and so does much of the skepticism of scientists about the whole subject. No one can give an account of how the flux of ions and electrical currents in the neurons of the brain can give rise to the whole subjective world of sensations, and qualia seem to remain essentially private.
V.S. Ramachandran's account of qualia assumes that some direct transmission might be possible, (providing just the right stimulation to the brain) and makes the philosophical problem into one of translation. He provides a kind of Darwinian account of qualia, stressing their functional requirements as part of decision-making based on perceptual representations. He describes qualia as irrevocable inputs, held in short-term memory, which are involved in time-sensitive choices.
According to Ramachandran, "qualia-laden perception is irrevocable by higher brain centers." (p.237) Unlike conceptual inferences, beliefs, and internal images, about which one can change one's mind, qualia are the perceptual components of decision-making processes that must be made quickly and without hesitation. In order to function, the perceptual system needs to be able to say "this is it." "Qualia are irrevocable in order to eliminate hesitation and to confer certainty to decisions." (p.242)
Gerald Edelman believes that "every different conscious state deserves to be called a quale." (Universe of Consciousness, p. 168) He does not consider it particular important to distinguish between some "pure" sensation of red, for example, and the conscious perception of a busy New York Street. For Edelman, any consious state can be defined as a point in an N-dimensional neural space that defines the possible states of the "dynamic core" of consiousness. Like Ramachandran, Edelman stresses the dynamic, coherent, and functional workings of neuronal groups.