Evaluating this problem through pain is certainly interesting but I can't help feeling that it is terribly lacking. In my humble opinion, the specialised and reductionist approach to this specific subject matter makes biologists incapable of seeing or tackling the whole picture.

The preceiver is not the preceived and perception is a function of sentience not brain tissue. seeing is the function of the eyes but vision is preceived by a higher level of being. A tape recorder or computer can record and relay sound but you need the mind to discern language from music from random sounds.

I think this pain thing is one example of bias towards a purely materialist approach to science that is limiting the understanding and investigation of the scientific community.