Update2: The explanatory gap


Studies on consciousness focuses mainly on three things: WHAT is/are the nature/features of consciousness, HOW does consciousness come to exist, and WHY it is this way (roles in evolution). Discussions on consciousness also usually refer to the “explanatory gap” between some aspect of our conscious mental life and objective physical explanation of that aspect. It seems that whatever physical account of a subjective conscious experience we might imagine will leave it completely puzzling why there should be such a connection between the objective physical story and the subjective conscious experience (Nagel 1974).

I will explain this explanatory gap, which is also called “the hard problem of consciousness”, in more details. Under this concept, the easy problems of consciousness are those phenomenon that can or will be explained in terms of computational or neural mechanisms, while the hard problems are those that seem to resist those methods.

The easy problems include those of explaining the following phenomenon: 1 the ability to discriminate, categorize, and react to environmental stimuli; 2 the integration of information by a cognitive system; 3 the reportability of mental states; 4 the ability of a system to access its own internal states; 5 the focus of attention; 6 the deliberate control of behavior; 7 the difference between wakefulness and sleep (Chalmers). Though now we don’t have a complete explanation of these phenomenon, there is every reason to believe that the methods of cognitive science and neuroscience will succeed.

The hard problem of consciousness is not the same. It centers on our subjective experience. As pointed out by some theorists, our experience/consciousness is always accompanied by a subjective “what-its-like-ness”, a concept raised by Nagel in his 1974 paper (introduced in my first article). What is perplexing is the question of how the subjective experiences are generated from an objective, physical basis. We have no good explanation for questions like why is it that when our cognitive systems engage in visual information processing, the signals are transformed somehow into the subjective visual experiences we are having in daily lives.

This further question is the key question in the problem of consciousness. We know that conscious experience does arise when the brain performs its functions, but the very fact that it arises is the central mystery. Some theorists acknowledge that there is an explanatory gap between brain functions and subjective experiences, and thus turn to dualism and argue that consciousness should be another fundamental substance, while some others contends that the gap will be eventually closed with the completeness of science, or that our concept of consciousness and its subjectiveness are just illusions and this consciousness doesn’t exist. I will discuss more about various opinions from neuroscientists, cognitive psychologists and philosophers in the next post.