Magicians rely upon this effect in their slight-of-hand tricks. If a magician can get a person to concentrate on one thing, such has his right hand, then that person’s processing capacity will reach its limit and the parietal cortex will not be available to pay attention to new things. At this point, movements by the magician’s left hand will go unnoticed.
This phenomenon is also useful to martial artists. When sparring an opponent, you should not concentrate on any one area. When you concentrate on one area, it takes time for you to switch focus back to general awareness. During this time, an opponent's strike from another area will not be noticed. It is better to look beyond and through the opponent so you may notice any movements that may alert you to an attack. You may also use this phenomenon against an opponent. If you can get your opponent to concentrate on one thing, such a persistent, annoying jab to the face, then a kick to the opponent's midsection will go unnoticed.