I go into that mode for awhile. I also find sensory deprivation almost essential to recovery, or being silent and in the presence of trees. The image I have of myself in those situations is like people being annihilated in a nuclear blast -- that I just crumble to ash -- I feel obliterated. Or sometimes it's a slow internal implosion.
In the hospital, however, I am a holy terror such that I don't even recognize myself, and that's just as beyond my control as the shutting down is. Both can be very scary.