Covering the Head
Yogi Bhajan taught us that the hair is alive and has an energy function. We are training ourselves to be aware of and master our subtle energies. He recommends covering the head and hair with a cotton cloth or wrapped turban.
Wearing a head covering enables you to command your sixth center, the Ajna Chakra. Covering the head provides a sense of containment and focus while practicing yoga or while doing work that requires clarity of thought. It literally helps "keep your head together." Covering the head creates a focus of the functional circuit of the hemispheres of the brain, and tunes the neurological system. The whole head is to be covered, not just the crown chakra.
Turbans as Technology
Head coverings of any kind are useful for a meditative practice. Turbans in particular are useful for holding energy in, and for creating a meditative focus at the third eye point (brow point). In addition, the turban provides a nice cranial adjustment. Some teachers wear a turban or head covering for these yogic reasons alone.
The skull is made up of tiny bones that are constantly moving even if only by micromillimeters and the degree to which they move impacts levels of calmness or anxiety. Covering the head stabilizes the cerebral matter and the 26 parts of the brain, which are interlocked with the neurological system and electromagnetic field.
The benefit of wearing a turban is that when you wrap the 5 to 7 layers of cloth, you cover the temples, which prevents any variance or movement in the different parts of the skull. A turban automatically gives you a cranial self-adjustment. You can pay for a cranial adjustment, or you can tie a turban for free!
Question: Is it important to wear a head covering during sadhana?
Yogi Bhajan: During sadhana, be sure to cover your head with a non-static, natural cloth like cotton, and keep the hair up. The hair regulates the inflow of sun energy into the body system. To let the solar energy flow without obstruction, let the hair grow to its full natural length, and take good care of it. If this is done, the amount of energy that goes downward from the Seventh Chakra increases tremendously.
The kundalini energy is activated by the radiant force of the solar plexus and moves upward in response to the solar energy coming down. This balances the body energy and maninains the total equilibrium. If the hair is down, unkept, or uncovered so that it is electrically imbalanced, this natural process of raising the kundalini energy will be impeded.