Yoga Nidra (योगनिद्रा)

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Yoga Nidra, also known as ‘Yogic Sleep’, is a simplified form of an ancient tantric relaxation technique. The most general description of the practice is that it combines guided mental imagery with a specific yoga posture called Shavasana or the 'corpse pose'. The goal of Yoga Nidra is to promote a profound state of relaxation, which differs from sleep in as much as there is still an awareness of one’s surroundings.

The calm inner stillness induced by Yoga Nidra is claimed by practitioners to be an effective stress management tool as well as a means for attaining greater receptivity to personal resolutions. These resolutions can range from the goal of achieving self-transformation, enhancing creativity, or improving one’s learning ability. Additionally, Yoga Nidra is claimed to promote beneficial changes in physiological and mental health.

Clinical studies have shown that Yoga Nidra meditation is associated with positive physiological changes, including improvements in several hematological variables, red blood cell counts, blood glucose levels, and hormonal status. Two neuroimaging studies have shown that Yoga Nidra produces changes in endogenous dopamine release and cerebral blood flow, a further confirmation that its effects on the Central Nervous System are objectively measurable. The practice has also been shown to reduce psychometrically measured indices of mild depression and anxiety, although these benefits were not shown in an experimental study to extend to severe depression or severe anxiety.

परिचयः ॥ Introduction

It has been suggested that the various techniques of yoga often produce a number of both physical and mental changes referred to as the relaxation response. One such technique is Yoga Nidra meaning ‘yogic sleep', ‘psychic sleep’, or 'sleeping consciously'. It is a meditative procedure whose goal is to transform the mind and body.

The name 'Yoga Nidra' is derived from two Sanskrit words: 'Yoga,' which means union, and 'Nidra,' which means sleep.

Adi Shankaracharya wrote in his text Yoga Taravali that

विच्छिन्नसंकल्पविकल्पमूले निःशेषनिर्मूलितकर्मजाले | निरन्तराभ्यासनितान्तभद्रा सा जृम्भते योगिनि योगनिद्रा ||२५|| vicchinnasaṁkalpavikalpamūle niḥśeṣanirmūlitakarmajāle | nirantarābhyāsanitāntabhadrā sā jr̥mbhate yogini yoganidrā ||25||

Meaning: When the ego has become quiescent, i.e., when the messages between the perceptions of the senses are no longer being registered in the mind, and when the feeling of personal identity has slipped away, this is when the quieting process of Yoga Nidra starts. Further more it says,

विश्रान्तिमासाद्य तुरीयतत्त्वे विश्वाद्यवस्थात्रितयोपरिस्थे | संविन्मयीं कामपि सर्वकालं निद्रां सखे निविशनिर्विकल्पाम् ||२६|| viśrāntimāsādya turīyatattve viśvādyavasthātritayoparisthe | saṁvinmayīṁ kāmapi sarvakālaṁ nidrāṁ sakhe niviśanirvikalpām ||26||

Meaning: O friend, getting convinced of and getting established in the state of turiya — which is beyond the three states of vishva, waking; taijasa, dreaming; and prajna, deep sleep — constantly experience the bliss of Yoga Nidra that is full of consciousness, free from doubts, and inexplicable. The ancient Vijnana Bhairava, a major source document for yoga, describes roughly 112 types of yogic meditation practises. Of these, Yoga Nidra is defined as

अनागतायां निद्रायां प्रणष्टे बाह्य गोचारे | सावस्था मनसा गम्या परा देवी प्रकाशते ||७५|| anāgatāyāṁ nidrāyāṁ praṇaṣṭe bāhya gocāre | sāvasthā manasā gamyā parā devī prakāśate ||75||

Meaning: When sleep has not yet fully appeared, i.e., when one is about to fall asleep, and all the external objects (though present) have faded out of sight, then the state (between sleep and waking) is one in which one should concentrate. In that state, the Supreme Goddess will reveal Herself.

In the epic Mahabharata [5], Lord Krishna is related with Yoga Nidra

[The Ocean] becomes the bed of the lotus-naveled Vishnu

when at the termination of every Yuga that

deity of immeasurable power enjoys Yoga-Nidra,

the deep sleep under the spell of spiritual meditation.

— Mahabharata, Book 1, section XXI

Yoga nidra is believed to be old as yoga itself in terms of history, with the first reference of it being in the Upanishads (circa 600 BCE). Yoga nidra is sometimes referred to as the third of four levels of consciousness in the Mandukya Upanishad

amātraś caturtho’vyavahāryaḥ

prapañcopaśamaḥ sivo’dvaita

evam auṁkāra ātmaiva,

saṁviśaty ātmanā’tmānaṁ

ya evaṁ veda ya evaṁ veda || 12 [7, 8].

Meaning: In the third or deep sleep state, the need or desire for any object of external experience has been lost. Essentially, it is a state of dreamless sleep or undifferentiated consciousness. At the same time, those who are in this state experience bliss, and have also achieved a condition in which there is a clearer understanding of the two states of sleep that have preceded it.

(Yoga Nidra is different from Sleep, Dream State and Samadhi. It is perhaps more appropriately thought of as a valuable stepping stone on the path to Samadhi.)

The Practice of Yoga Nidra

Yoga Nidra practice is performed in Shavasana, which implies a depth of release that goes beyond simple relaxation. This asana is described as a relaxation tool in various Indian hatha yoga texts.

Appearing in the Hatha Yoga Pradipika (Light on Hatha Yoga), a fifteenth century manual on Hatha Yoga written by Svātmārāma [9] has this passage

Uttānam ś a b avadbhūmau ś ayanam tachchavāsanam |

Śavāsanam śrāntiharam chittaviśrāntikārakam || 1:32

Meaning: The practitioner of yoga nidra should lie flat on the ground facing upwards, and assume the posture or condition of a dead body, a physical and mental state that is referred to as Shavasana. In this position, normal fatigue is dissolved.

Gheraṇḍa-Saṃhita (“Gheranda's collection”) [10], likely a late seventeenth-century manual on Hatha Yoga, says

Uttānam Savodbhumo Śhayanāntu śhavāsanam |

Śavāsanam shramharam chiittavishrāntikaranam || 2:19

In Hatha Yoga, lying flat on the ground like a corpse is called the "Mirtasana,” (‘Mrit’ = Corpse/dead body; Asana = Pose; Corpse Pose). It is believed that this posture dissolves fatigue and quiets the agitation of the mind and is used as a relaxation practice.

Haṭha Ratnāvalī (a Treatise on Haṭhayoga) [11] written in the seventeenth century by Śrīnivāsayogī says

Prasaryā hastpadau cha vishranyā shayanam tathā |

Sarvāsanam shramharam shayitamtu shavāsanam || 3:76

Lying comfortably extended arms and legs, this is Shavasana. It removes all kinds of fatigue due to the practice of different asanas.

Yoga Nidra practice involves a specific set of steps, initially quite deliberate, but becoming more natural and automatic with time and experience [16]. These steps involve

• preparation for the practice
• presentation of one’s self of a personal resolution or commitment to later action (Sankalpa)
• directing of awareness to various body parts
• breath awareness
• recall of various feelings and sensations, mental visualization, a restatement of the personal resolution or Sankalpa
• ending of the practice session.

Step 1: Shavasana

Before initiating the mental steps that are required to enter into the conscious sleep state of yoga nidra, the practitioner adopts the classic Shavasana or “corpse pose”.

This posture, one of the most important in yoga practice, includes turning the palms upward and preventing contact between the limbs of the body. This minimizes the sensation of touch, and is considered to be a key preparatory stage for relaxing the body and inducing quiescence in the mind. It is also required that practitioners refrain from making any bodily movements and remain awake and aware of all instructions delivered. Lying supine with the eyes closed, the practitioner spreads his arms and legs (to about 45◦), and breathes deeply.

Step 2: Sankalpa

The next stage of the yoga nidra technique is for the practitioner to mentally affirm to himself a personal resolution, a “Sankalpa”, which should be short, clear, and positive (i.e., usually dedicated to some goal of self-realization or improvement). The goal could be quite profound or something as basic as overcoming a personal habit. The practitioner should mentally repeat the chosen Sankalpa three times with complete determination. The state of mental dissociation that this resolution produces is expressed in what yoga nidra masters refer to as passivity. In this passive state, there is a separation of the self from the experiences that would normally be emotionally arousing. Under these conditions, the autosuggested resolution is absorbed more quickly into the unconscious.

Step 3: Mental Visualization

In the third stage, the practitioner’s mental visualization is shifted among different body locations in a systematic and organized manner. The sequencing of this mental awareness proceeds in defined steps:

• The practitioner starts with the right side of the body, with awareness first being directed at the right-hand thumb and then ending with the little toe of the right foot;
• awareness is then directed at the left side of the body, and the sequence is repeated, i.e., from the digits of the left hand to the digits of the left foot;
• next, awareness is directed toward the back of the body, progressing from the heels to the back of the head;
• and, finally, the sequence is repeated for the front of the body, from the forehead and the individual facial features to the legs.

It has been suggested that this overall exercise might in itself be an effective means of establishing relevant motor skill learning. This further enhances the value of the process as the student of yoga nidra advances to the later and deeper stages of practice.

Step 4: Breath Awareness

In the breath awareness stage, several techniques are employed simultaneously to enable the practitioner to focus on the natural breathing process without attempting to induce any changes in its flow. Visualization is very important for the mastery of this. The yoga nidra student is instructed to visualize the breath flowing in and out of the nostrils, the chest, and abdomen, as well as between the navel and the throat. Additionally, the student is asked to mentally count each incoming and outgoing flow of the breath.

Step 5: Recalling Experiences and Sensations

In this stage, the student is instructed to recall physical or emotional experiences and their associated sensations, but to do so with an increased vividness, so that the impact can be made to the maximum extent. Various examples of this process include experiencing opposite feelings or sensations such as heaviness and lightness, heat and cold, pain and pleasure, and so forth.

Step 6: Visualization in Chidakasha

Visualization is again a central process in the next stage of practice. The student is instructed to direct the awareness toward the dark space in front of the closed eyes, the area being referred to in yogic terminology as Chidākāsha (internally visualized as being centered just behind the forehead). The yoga nidra practitioner then is asked to visualize various scenes or situations in the Chidākāsha.

Step 7: Repetition of the Sankalpa

The Sankalpa, as described in stage two, is again mentally repeated by the student three times “with full dedication, faith, and optimism”.

Step 8: Gradual Outward Redirection of Awareness

Just prior to terminating the yoga nidra session, the mental focus is slowly directed toward external sounds, objects, and persons. The practitioner gradually becomes aware of his body and surroundings, and turns to his right side but remains lying down for a few minutes more. Each body part is slowly moved and the body is stretched. Gradually the practitioner sits up, and whenever he feels comfortable, slowly opens his eyes.

Yoga Nidra - A Form of Pratyahara

Practitioners of yoga nidra may appear to be asleep, but their consciousness is operating at a deep level of awareness [12]. This level of consciousness is accompanied by a profound sense of relaxation. Yoga nidra is derived from 'pratyahara,' one of the eight ashtanga (eight-limbed) branches of the yoga system as conceptualized in Patanjali's (an Indian sage who lived circa 200 B.C) well-known codification method of yogic practice and tantric ritual of ‘nyasa’ (“to place”; a practice in which mantras [a sacred utterance, a numinous sound, a syllable, a word or phonemes, or a set of words] are placed and felt at different parts of the body). Thus, the meaning of ‘Nyasa’ is ‘to place or to take the mind to that point’. Yoga nidra is neither nyasa nor meditation as nyasa and meditation both are done in a sitting position while keeping your spine straight. Unlike mediation and nyasa, yoga nidra is performed in a supine position. Furthermore, while meditation is practiced in an aware awake state, yoga nidra is classified as a sleep state in which awareness is preserved [13]. Yoga Nidra is a ‘pratyāhāra’ (control or withdrawal of senses) practice in which mind and mental activities are disengaged from perceptual awareness. This results in profound relaxation, stress reduction, initiating healing processes, and personal transformation. “There is a method called yoga nidra in which you can have conscious sleep

Yoga nidra is a state between sleep and samadhi.”

- Swami Rama

The connection with the environment is never fully lost with yoga nidra; it is just that the arousal-producing effects are reduced. The deeper layers of mental activity become more accessible to the practitioner with prolonged practice. Yoga Nidra bears some resemblance to sleep inasmuch as in both states there is a disconnection from the arousal promoting effects of the environment, a decrease in sympathetic nervous system (SNS) activity (i.e., a reduction in stress responses), and a manifestation of ‘dream-like’ visual experiences [1]. It is claimed that during the deep state of relaxation that yoga nidra induces, an awareness of one’s surroundings is increased and that receptivity and learning abilities are enhanced [14].

Yoga Nidra is usually practiced for about 30 min to an hour at a time. During the deepest part of the state, which is considered qualitatively different from ordinary waking consciousness, practitioners are thought to be re-aligned with the most spiritual part of their inner nature. Practitioners of yoga nidra claim, however, that it is not a substitute for sleep, but that its benefits go far beyond that of relaxation. It is further claimed that 1 h of yoga nidra practice equates to about 4 h of sleep [15]. This has led to the suggestion that yoga nidra is a “third mental state”, related to both sleep and relaxation, but still possessing properties that make it unique. It is asserted that yoga nidra is qualitatively different from normal relaxation inasmuch as many of the ongoing mental preoccupations of daily life are thrown off, even though awareness of the environment remains intact. Additionally, however, it is thought that yoga nidra is also different from sleep, since in ordinary sleep, one’s mental tensions cannot always be resolved. It is claimed further that with time, the practice can produce a major transformation of the self, one that extends to the promotion of physical, emotional, and spiritual health and well-being.

Scientific Studies on Yoga Nidra

Scientific studies have investigated the effects of the Yoga Nidra practice on numerous neurological, neurocognitive, and psychological disorders, as well as its systemic physical effects. The latter have included pain responses, cardiovascular effects, inflammatory conditions, immune system effects, diabetes, and long-term degenerative diseases.

Selective studies are enlisted below:

Yoga nidra has been widely employed as a technique for managing stress and associated stress-induced disorders.

A randomized and controlled study on the effects of yoga nidra on feelings of general well-being, including psychological variables such as depression and anxiety, in patients suffering from menstrual irregularities showed that measures of both anxiety and depression decreased significantly in the yoga nidra practising group. Additionally, measures of positive well-being and general health and feelings of vitality also improved significantly.

A study has been done on the effect of yoga nidra practice on stress levels in the first-year nursing students. The investigators found that following 20 days of yoga nidra practice, the mean stress scores were significantly reduced supporting the conclusion that yoga nidra is a practical and easily applied stress prevention technique for students of demanding professions such as nursing.

In another study, the authors investigated the effect of yoga nidra practice on skills among wrestlers. More specifically, the researchers sought to determine if yoga nidra could improve their reaction times and anticipation times. Yoga nidra practice (45 min each day for 45 days) improved the wrestlers’ performance by improving their focus and attention. Compared to the control group, the scores for the simple visual reaction time (SVRT) and choice visual reaction time (CVRT) for the experimental group were found to be significantly faster.

A study measured the effects of yoga nidra meditation on hormonal imbalances among 75 female patients with menstrual irregularities. Compared to a matched sample of 75 controls, the yoga nidra group showed a significant rebalancing of hormonal status.

A study has been done on the effect of yoga nidra on blood pressure and psychological variables in hypertensive patients. The before and after comparisons showed that yoga nidra practice was associated with significant and beneficial changes in blood pressure as well as pulse rate, respiration rate, stress, anger, and fear. These findings support the value of yoga nidra in reducing hypertension and associated psychological conditions. An increasing number of studies have shown that yoga nidra improves heart functioning, including the lowering of blood pressure.

A recent study compared a widely practiced yoga technique, Nadi Shodhan Pranayama (Alternate Nostril Breathing against yoga nidra in terms of their respective effects on several psychophysiological measures. It was found that, compared to the nadi sodhan pranayama group, yoga nidra practitioners showed significantly greater reductions in blood pressure (systolic and diastolic), pulse rate, breath rate, and BMI, as well as reductions in anxiety as measured by the Hamilton Anxiety Rating Scale (HARS).

Synopsis

Yoga nidra, also known as yogic or psychic slumber, is a state of consciousness (awareness) that occurs between waking and sleeping, similar to the “going-to-sleep” stage (hypnagogia), and is usually brought on by an active guided meditation technique. Yoga Nidra is a type of profound relaxation method (the deepest form of all meditations) that is usually performed while lying down in a supine position and consists of a series of perceptual exercises such as focusing on the breath or specific regions of the body. The practitioner follows directions for numerous types of activities without becoming distracted while remaining completely awake and concentrated. Although practitioners appear to be sleeping, their consciousness is operating at a higher degree of awareness. Thus, yoga nidra is a form of Pratyahara (withdrawal of the senses), which entails gradually dissociating and dis-identify oneself emotionally from one's body and mind. It corresponds to the higher levels of Raja Yoga.

Ref: https://www.researchgate.net/publication/359730732_The_Origin_and_Clinical_Relevance_of_Yoga_Nidra