Yoga nidra
Yoga nidra (, ) or yogic sleep in modern usage is a state of consciousness between waking and sleeping, typically induced by a guided meditation. A state called yoga nidra is mentioned in the Upanishads and the Mahabharata, while a goddess named Yoganidrā appears in the Devīmāhātmya. Yoga nidra is linked to meditation in Shaiva and Buddhist tantras, while some medieval hatha yoga texts use "yoganidra" as a synonym for the deep meditative state of samadhi. These texts however offer no precedent for the modern technique of guided meditation. That derives from 19th and 20th century Western "proprioceptive relaxation" as described by practitioners such as Annie Payson Call and Edmund Jacobson. The modern form of the technique, pioneered by Dennis Boyes in 1973, made widely known by Satyananda Saraswati in 1976, and then by Swami Rama, Richard Miller, and others has spread worldwide. It is applied by the US Army to assist soldiers to recover from post-traumatic stress disorder. There is limited scientific evidence that the technique helps relieve stress. Historical usage Ancient times The Hindu epic Mahabharata, completed by the 3rd century CE, mentions a state called "yoganidra", and associates it with Lord Vishnu: The Devīmāhātmya, written around the