The hard problem was discussed in the December 1995 issue of Scientific American.
Researchers use the word 'consciousness' in many different ways.
To clarify the issues, we first have to separate the problems that are often clustered together under the name. For this purpose, I find it useful to distinguish between the 'easy problems' of consciousness and the 'hard problem' of consciousness. Although all these questions are associated with consciousness, they all concern the objective mechanisms of the cognitive system. The hard problem, in contrast, is the question of how physical processes in the brain give rise to subjective experience. When we see, for example, we experience visual sensations, such as that of vivid blue.