There is an article at Science Daily about researchers who can predict "with unprecedented accuracy" how well people will do in strategic video games by analyzing their brain. Apparently instead of monitoring the brain before or after learning a task, they are able to monitor the region important for procedural learning, coordinated movement and feelings of reward DURING the learning process.
Could you imagine having this kind of information as you are creating the tutorials for your game? Not only could you get crucial information on how well your methods are teaching people, but could even come up with completely new ways of teaching for the various ways people can absorb information best.
They then monitored the people for 20 hours of playing this new video game and could begin to predict just how much better they would get during that time based in the prior information received. I think this could be a great way to see just how well the game reinforces its mechanics during play and narrow down areas that could use better teaching along the way.
This research was done here in Champaign, IL... I might contact them to see if we could set up some experiments along these lines. MUWAHAHA