Starting in a standing position, cross one ankle over the other. Keep kness slightly bent. Then hold both arms out straight from the body, with palms facing the sides of the body. Then cross the wrists so that the palms are touching. Then rotate the clapsed hands into the body so that they end up on the chest with the elbows pointing down. While in this position, rest the tongue on the roof of the mouth behind the teeth.This can be done sitting or lying down as well but if done standing, it will challenge balance more. For greater challenge, do it with eyes closed.
Rationale: Cross body movement of all kinds strengthens the corpus callosum between the sides of the brain. The challenge to balance stimulates the vestibular system. The tongue movemnent interrupts a reflex tongue thrust that the challenge to the balance stimulates, and also perhaps helps to integrate the brain stem with the limbic system. Those with poor balance tend to over-use the vision system to keep balance, so closing the eyes lets the vestibular system engage more. The vestibular system should be supporting eye movement, not the other way around.
Source: Dr Paul Dennison, described in the book Smartmoves by Carla Hannaford, Ph.D