I used to play a game in the Military called Kim's Game. Consisted of objects on a table, and you have a minute to see how much detail you can see. Then the instructors would make us do something physical like a run. Then out of the blue we would be asked what we remebered from the table.
The point was, get away from using your BRAIN. Don't think about PRing. Find something that is completly opposite of what you are doing.
LSD