Kechari Mudra Technique

What is Kechari Mudra?

From The Art and Science of Yoga, by Swami Kriyananda
A mudra is a yoga position that is designed especially to awaken spiritual energies in the body. Of all mudras, Kechari[pronounced ke–CHAR–ee] is one of the most important.
Unfortunately, it is also one of the most difficult. The tongue must be brought back behind the soft palate so that its tip connects with certain nerves in the nasal passages. If the tongue cannot be brought back that far, its tip may be placed against the uvula (the soft fleshy appendage that hangs from the soft palate at the back of the mouth).
The chief purpose of Kechari Mudra is to awaken Kundalini.
The positive and negative energies in the tongue and nasal passages (or uvula), when joined together, create a cycle of energy in the head which, instead of allowing the energy to flow outward to the body, generates a magnetic field. This field draws energy upward from the body and from the base of the spine to the brain.
It is said that the tongue turns back of itself in Samadhi. The practice of this mudra helps to hasten the advent of deep spiritual states of consciousness.