As Yogananda describes Kriya Yoga, "The Kriya Yogi mentally directs his life energy to revolve, upward and downward, around the six spinal centers (medullary, cervical, dorsal, lumbar, sacral, and coccygeal plexuses) which correspond to the twelve astral signs of the zodiac, the symbolic Cosmic Man.
In Kriya Quotes from Swami Satyananda, it is written, "Kriya sadhana may be thought of as the sadhana of the 'practice of being in Atman' [REF].