Ramachandran and Hubbard's contribution is in terms of exploring "the neural basis of qualia" by "using pre-existing, stable differences in the conscious experiences of people who experience synaesthesia compared with those who do not" but, they note that "this still doesn't explain why these particular events are qualia laden and others are not (Chalmers' 'hard problem') but at least it narrows the scope of the problem" (p. 25).