One simple but effective technique is to practice the above three stages by focusing at a point where the eyebrows meet the bridge of the nose. Do this completely relaxed with eyes closed and adjusting the focal point slightly forwards/backwards until you feel a sudden relaxation/jolt (slight but distinct) within the body. Its like a physiological trick but once experienced you will know it and can then use it to calm down and concentrate whenever and wherever as needed.
So this is neurofeedback. But is it any better than existing neurofeedback which already makes use of computer games?
Someone wrote this article in a last night frenzy before some submission deadline didn't they? :P
Now there is a path forward to be able to focus on a single cell in my body. LoL
I don't think I would have understood the reference without having being told this recently; it is a trial that requires to be fully concentrated on sensing how the stone reacts to the moves.