Comment 21 by Alternative Carpark :

Bollocks. I find synæsthesia fascinating, but I doubt most of these clowns have ever even heard of it. And even if they had, I don't think they would like to have their perceived powers written off as a genuine physiological anomaly. Anyway, if this was indeed the case, it could quite easily be tested for. I believe it the Amazing Randi himself who conducted a test to disprove auras.

I have to be pedantic here and point out that all he did was prove that THAT person wasn't able to read auras in the way he claimed. Proving that one individual does not have a power to read auras like they claim to have is a far easier task than proving that auras don't exist period.

That's why the burden of proof has to be the way it is - the person who claims the power has to show it.