In addition, this hypothesis is definitely testable. I made a claim above. Create a new sensory input / type of stimuli, and we will perceive a "new" qualia that was never perceived before, just like colorblind people that have never seen color and don't have any idea what you're talking about who would suddenly be able to see colors.
There have been cases of people blind from birth who, by some medical treatment were enabled to see. No references to hand, but Oliver Sacks probably writes about this somewhere. They clearly get new qualia, which are moreover clearly different from those who were sighted from birth.
I thought to use this too, but I was once or twice given the argument that blind people who are made to see are only "accessing" a Given-By-External-Power-To-Humans-At-Birth qualia from outside reality - the argument Eliezer tried to take down in the metaethics sequence about morality being "a light shining from outside" that humans just happen to find and match, applied to qualia. It's a very good stopsign and/or FGC, apparently.
Because of this, I looked for a more definitive test that these philosophies - those that would discard "creating" sight as a valid new qualia - do not predict (and arguably, cannot, in terms of probability mass, if they want to remain coherent).
[Cross-posted.]
1. Defining the problem: The inverted spectrum
A. Attempted solutions to the inverted spectrum.
B. The “substitution bias” of solving the “easy problem of consciousness” instead of the “hard problem.”
2. The false intuition of direct awareness
A. Our sense that the existence of raw experience is self-evident doesn’t show that it is true.
B. Experience can’t reveal the error in the intuition that raw experience exists.
C. We can’t capture the ineffable core of raw experience with language because there’s really nothing there.
D. We believe raw experience exists without detecting it.
3. The conceptual economy of qualia nihilism pays off in philosophical progress
4. Relying on the brute force of an intuition is rationally specious.
Against these considerations, the only argument for retaining raw experience in our ontology is the sheer strength of everyone’s belief in its existence. How much weight should we attach to a strong belief whose validity we can't check? None. Beliefs ordinarily earn a presumption of truth from the absence of empirical challenge, but when empirical challenge is impossible in principle, the belief deserves no confidence.