I was trapped in one of those tanks a while back. My brain exploded after about half an hour and two cleaners had to be called in to wipe the walls down. Like a poker game, or riding a very small piece of metal very quickly down a hill, distraction can be a great diversion for avoiding thoughts of DP while you're still unable to control them through will power alone. I wont let anyone take my lovely distractions away from me anymore.
... and those poor, poor astronauts!
... and those poor, poor astronauts!