Functional Focal Retrograde Amnesia
From LostRing
Total Amnesia
A rare condition that afflicts each of Ariadne, Markus, Noriko, Diego, and Meihui.
Ariadne's affliction has been intensely scrutinized, but no medical origin has been discovered:
I got a lot of attention from the doctors. Apparently, my kind of amnesia is extremely rare. So rare, in fact, the doctors thought I might be faking.... After six days of tests and observations, the doctors couldn’t find anything wrong with me.
(from Ariadne's blog post How I got here (Part I))