Re: Proprioception Throws
One thing that I forgot to add was that as you thought you were "falling" the falling reflex would take over and you would automatically tighten your grip. This may partially explain why some have commented about the "magnetic" quality of Takeda and Ueshiba's wrists while being thrown.
@ Jason: I have been to Ikeda Sensei's seminars and seen pretty much all of the ukes have their head snapped back during a throw. So I am not sure what level of self awareness you need to have to counter this type of throw.