Nervous System and our Brain

by Rachel Hanrahan

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Since the industrial revolution our society has emphasized the value of production and consumption. Being busy affirms our importance and a belonging to our society as very little value is placed on just being. However we are human ‘beings’ and our physiology in particular our brains and nervous system has not evolved to meet our changing times finding it’s still wired to the times of the mega fauna.

The power of doing nothing is transformational; we literally begin to access the parasympathetic activation of our nervous system the branch that doesn’t often get activation in our busy lives. We need a balance between our doing (sympathetic nervous system) and our being (para sympathetic nervous system) to live healthy long lives. This balance can be hard to find as so many parts of our lives ask us to do, we literally need tools to teach us how to stop and yoga nidra is one such tool and technology we can access easily.

When you lie down with yoga nidra you are guided into accessing deeper brain waves. Through techniques such as body sensing, breath work and observing thoughts we begin to access the para sympathetic nervous system the place of non doing and deeper inner peace. This happens by the techniques of yoga nidra triggering the relaxation response.

The relaxation response balances the sympathetic and parasympathetic nervous systems, and balances the left and right brain. Through the process of yoga nidra, your brain shifts from beta, an awakened state with lots of brain activity, to alpha, being more relaxed state. When you access the alpha brain wave state, the mood-regulating hormone serotonin gets released, and this calms you down. When you don’t access this brain wave state often you can feel more anxious at life. Alpha state helps you to power down and come into rest state with slower restorative brain wave activity.

As we deepen into our practice of yoga nidra we move through alpha, into a theta brain-wave state, the dream state. In theta, your thoughts slow down to 4 to 8 thoughts per second. Emotional integration and release happen here, and structures in the brain change. It’s where your being enters the gap of nothingness. After theta, you are guided to delta the most restorative state, where your thoughts are only 1 to 3.9 thoughts per second, your organs regenerate and the stress hormone cortisol is removed from your system. It’s here our bodies have a chance to restore their systems. The medical world utilises this state in anaesthesia and when placing patients in comas.

In our culture, very few of us access deep states of sleep and rest like theta and delta regularly, consequently our bodies don’t get the chance to restore themselves. Through the guided experience of iRest yoga nidra you can access the deeper delta brain wave state inaccessible through conventional sleep. It is below the fourth state of consciousness, below delta, where your brain is thoughtless. This state of deep surrender, where your consciousness is so far away from the physical body not everyone who practices yoga nidra accesses or touches this state, yet the phenomena of it is available through regular practice. This state is not a practical state for everyday life yet here you are able to rewire your thoughts and emotions because your subconscious mind is open to intentions and affirmations, more so than your waking state. From this state in yoga nidra you are guided back to your full awake state. changed my life because my anxiety couldn’t be controlled and I had frequent panic attacks. It doesn’t make me tired and I like its rapid effect.

Through the practice of regular iRest yoga nidra we rest more and balance our nervous system and access the deeper healing brain waves accessing a freedom of spirit between emotions and thoughts and the ability to carry a sense of ease through our day and as a result from what my students tell me, less likely to find ourselves triggered, anxious or depressed by what life throws at us.


Rachel Hanrahan

iRest yoga nidra certified teacher

Offering courses at Kundalini House

Tuesdays 5:15pm – 6:15pm.