Welcome & Namaste,

In this post we are going to explore human brain waves and how they relate to different states of consciousness (as discussed in the Mandukya Upanishad) and how they relate to Yoga Nidra.

The fastest brain waves recorded in human beings are called GAMMA brain waves. They are above 30Hz (number of waves per second). The highest GAMMA waves that have been recorded in humans are up to 200Hz during the "vibrational state" or "out of body" (non localized consciousness) state. Also, in profound states of meditation GAMMA brain waves up to 100Hz have been recorded. In their regular range, GAMMA waves are more like 30-44Hz

The next highest frequency brain wave in humans in BETA brain waves which can be broken down into three types. All three BETA waves relate to "Vishva" which is the waking state as described in the Mandukya Upanishad. In this state, we are in a "path-duration-outcome" mode (high frequency - low amplitude brain waves) due to processing large amounts of sensory information.

The highest BETA waves are between 18-30Hz and are more related to states of agitation, anxiety, & overstimulation. They can also be present in states of panic and even excitement, when adrenaline might be pumping through our system. Often times when we're in high BETA, our sympathetic nervous system is quite active.

Mid-BETA waves are between 15-18Hz are the brain waves that are present when we are highly engaged in thinking, problem solving, writing, calculating, conversing with others. It's a state where we are alert and active but likely not agitated or aroused. 

Low-BETA are between 12-15Hz and are likely the type of brain waves that are present right now as you read this post. They are present when reading, writing, doing tasks like knitting, listening to podcasts or music. There is a relaxed yet focused feeling state. 

ALPHA (8-12Hz) brain waves are present in meditative states, when you are practicing yoga, getting a massage perhaps, these types of things. They are common when you are in states of pratyahara (internalized awareness) like in restorative yoga or the beginning phase of a Yoga Nidra. They can also be present in Taijasya (of the Mandukya Upanishad) which is the dreaming state (REM sleep) in which high frequency and desynchronized brain waves are also present and one is processing the inner content of the mind – emotions, experiences, memories, etc. Most commonly, they are present in states of relaxed awareness and states of calm. 

Next as we move down the brain waves we get into slow waves (low frequency, high amplitude) which the first is THETA. These brain waves are between 3.5-8Hz and are present in deep relaxation, hypnosis, Yoga Nidra, dreaming (Taijasya), daydreaming and are associated with creativity & intuition. 

The lowest frequency of brain waves recorded in humans is DELTA brain waves. These are present in deep sleep - Prajna (of the Mandukya Upanishad) which is the dreamless sleep (Non-REM) – Slow-wave sleep that is synchronous and allows for tissue regeneration, healing and cellular repair to occur. This is also when the glymphatic system engages to clear away debris and toxins there accumulate between neurons in the brain. The glymphatic system is a network of vessels that clear waste from the central nervous system. These are the brainwaves present when someone is in a coma, and the body is putting all energy towards healing & regeneration. 

So what brainwaves are present in Yoga Nidra?

The state of Yoga Nidra is being studied more and more and it is now known that it is a unique state of consciousness where deep sleep - slow wave delta brain waves are present simultaneously with alpha (meditative) brain waves. Until recently, it was not scientifically verified that someone could be alert & aware while simultaneously the body and brain were in a deep state of sleep. This deep resting state with trace awareness has also recently been given a contemporary scientific name: non-sleep-deep-rest/NSDR. 

Let me know if you learned something new in the comments below!

And please know that I have other colour schemes of this illustration below! Please feel free to pin them to your Yoga or Meditation Pinterest Board! If you share these graphics anywhere, please always be sure to link back to this blog post! 🙂