I’m using the figure-ground concept figuratively, to draw attention to what we miss because of our propensity to think that what dominates our attention is necessarily the most important. Familiarity breeds invisibility. This is why Wittgenstein insisted that philosophy must include reminding ourselves of what we know so well that we ignore it.

Think of your skin. It is the largest organ in the body, and it performs a variety of functions crucial to health and indeed life itself. It breathes, combats would-be invasive organisms, absorbs nutrients, senses the environment, lubricates itself, excretes, and stops us from exploding, leaking, drying up and getting too hot or cold. It is even credited with a mind of its own, as it is an intelligent part of the neuro-immuno-endocrine system of the body, able to monitor itself and the environment and adjust accordingly. Without it we should fall apart, in all senses.

Another example of the importance of the familiar is sleep. We think of waking life as where the action is, and sleep as a sometimes welcome, sometimes inconvenient, interruption to the main story. For some time, however, researchers have known that this is far from the case in the psychological realm, and have suspected that sleep has a crucial role to play in the physiological realm too. The latter has now been emphatically illustrated by the discovery of a connection between sleep deprivation and type 2 diabetes.

Several large-scale genomic studies published last month in Nature Genetics (vol 40, p 1399) have revealed a link between blood sugar levels and the biological clock that cues our sleeping and waking cycles. The link is very significant given that type 2 diabetes is increasing dramatically in the developed world, while average amounts of sleep are decreasing. The research suggests that the link is a protein that recognises the sleep hormone melatonin. It’s clear that the less one sleeps, the less insulin one produces, though exactly how melatonin affects the insulin-producing cells in the pancreas remains to be worked out. The intriguing possibility is that this is somehow related to the fact that sleep-poor individuals also tend to be at increased risk of obesity and immune problems.

Even more intriguing, could these physiological pathologies be directly linked to psychological pathologies caused by sleep deprivation? There is ample evidence that having too little sleep degrades mental function: sufferers perform tasks more slowly, are forgetful, and at the limit become confused and even psychotic. Chronic sleep deprivation is not only associated with poor learning skills but typically with depression.

If so, the physiology of sleep may hold the key to combating depression, enhancing learning and problem-solving, and discovering the reason for memory problems in old age. It is an exciting prospect. The real action on health and mental welfare might be taking place in the silent background of night, not in the noisy foreground of day. A key player in the well-being of body and mind may turn out to be melatonin, so far underrated and reserved for the occasional long-distance flier.

31 December 2008 by A. C. Grayling

state, or does this practice have a tendency to bring to the surface negative thoughts? Also, during the “pain” part of the meditation, I found myself crying.  Then I felt like I was doing something wrong because I thought Yoga Nidra was supposed to help me be detached or to see the experience from a less attached place, rather.  Am I doing something wrong here?   Thanks!”

Reply to a student:
Your experience is not uncommon. The deeply transformational aspect of the yoga Nidra practice comes from the fact that during it we access the unconscious thoughts which govern our lives. It is within the hidden realms of the mind that pattern blueprint of our interpretations of reality lie.
If the experiences in the yoga Nidra practice feel particularly vivid this means we are accessing these vast storehouses of reactions and beliefs.

The mind (particularly in a trance state) cannot distinguish between something vividly imagined or remembered and something actually experienced. This is corroborated by multiple brain scan studies.  
The reason we purposely visualize pain and pleasure, heat and cold etc. is to activate multiple neural networks and develop means to more easily understand our motivations and thus, if needed, alter them.  The 3 primary functions of the physical brain are 1) The intake of food and water 2) maintaining the body’s temperature in a narrow range & 3) the interpretation of pleasure and pain.

In the scriptures on Yoga Nidra there is mention of the practice clearing vritis or debris from our internal systems which prevent us from seeing reality as it is, the large aspect of the oft sought after state of enlightenment. The clearing of vritis is said to expedite the process of extracting oneself from the cycle of karma.

You mentioned that you “don’t feel detached” in the practice, Yoga Nidra allows one to experience deeply from an ultimate observer’s stand point eventually translating every moment into a consciously aware state (even while sleeping and dreaming you are able to observe and if you desire control your dreams) This is full consciousness, an awakened state, where no separations exist between all things including the conscious and the unconscious. This is one of the many benefits of regular practice.

Hope this helps

Armand