A few weeks ago, when I was commuting, I noticed a blind man in the metro station walking in an insecure manner. He almost lost his balance when he stepped onto the elevator. He did have a cane but seemed unsure how to probe the surroundings with it. I grabbed his arm and helped him down the elevator, then to the carriage and finally to his destination which luckily was very close to mine. While sitting in the carriage, we had a chat about life and things and I asked him what he had been listening to with his wireless earphones when I met him looking lost in the metro station. He said that he had been listening to an application to induce delta brain waves. Perhaps, I suggested the man politely, this was not a good idea. Delta waves are the ones which are most dominant during our deep dreamless sleep and in deep meditation. But how safe is for someone who lacks one sense – seeing – to trick the mind into the state of complete relaxation and rest while walking busy places, filled with people, moving objects and uneven ground?
Brainwaves are a fascinating topic. Scientifically they came to the picture in the early 20th century when electroencephalography (EEG) enabled to start measuring electric activities in the brains of humans. A lot regarding the function of different brainwaves is still a guesswork so be careful with what to read and believe, including the below.
Yoga, as one of its ground principles according to the Bible of Yoga – Yoga Sutras of Patanjali – goes, can reduce modifications/fluctuations/waves (vritti in Sanskrit) of mind. 2nd principle of yoga: Yogas citta vrtti nirodah. Reducing fluctuations of mind does not sound very scientific but there are 5 vrittis (modifications/fluctuations) as there are 5 primary brainwaves. Even more interestingly – dominance or lack or activity of certain brainwaves affects cognition, knowledge, imagination, sleep and memory (the 5 vrittis). When scientifically observed and measured, practicing yoga teaches the mind to activate lower frequency brainwaves. The dominance of lower frequency brainwaves enables the body to relax and the mind to become calmer. Reducing the frequency helps turning senses inward, to focus, to memorize better. Running on lower frequencies also helps relieving anxiety, fears, misconceptions.
While I am writing this, a lot is still guessed about the purpose of the brain waves and how they affect the consciousness. The waves are the result of electrical activity in the brain, the wave like change in the electric current (oscillations) of neurons. Those waves exist in all mammals, humans are not exceptional. But let’s go through those five waves and what is known about them. Note that the waves are measured in Hertz (cycle per second).
- Delta is a slow brainwave 0.1-4HZ that becomes dominant in deep sleep. Delta activity is big in babies and children and subdued in the elderly. If impaired, the lack of delta activity can cause insomnia and block healing (growing in children). There is a clear connection between delta wave disorders (low activity in deep sleep or too little sleep) and sleeping disorders. During active delta, the metabolism slows down.
- Theta is also a slow brainwave, about 4-8HZ. It is active in sleep (with dreams) and during meditation. Its function is associated with memory as theta activity seems to increase during tasks which require memory and special navigation.
- Alpha is a little faster brain wave, about 7-12 HZ. Alpha waves first appear when we turn about 3 years old. It is active during wakeful relaxation, especially with eyes closed. As soon as we open them, beta waves will activate.
- Beta wave is even faster, about 12-38 HZ. It is active when we are awake, conscious and making decisions, solving problems, logical tasks, learning new things. It is overactive when we are stressed and the wave gets more active as we age. Active beta is never a relaxed state of mind for the mind nor the body. Beta running on the higher end of the frequency is associated with stress, excessive production of adrenaline, continuous signals to the sympathetic nervous system – the flight-and-flight mode.
- Gamma waves are the fastest – 25-100 HZ, the “normal” frequency at 40 HZ. The function of this wave is disputed over but as this wave sweeps about 40 times per second from the back of the brain to the front, it seems to create our self-awareness or cognitive awareness, perception. This idea is supported by the fact that this wave stops with people in coma or anesthesia. Gamma waves are also related to the binding problem – combining separate associations and memories into single experience. It is also associated with shared experiences or being on the same “wave length” with other people. It is assumed that gamma waves are to do with creating the experiences/associations/feelings of love and compassion. It has also been observed that some synchronizing of gamma waves occurs with people who are present in the same location, especially during meditation.
How are those waves connected to yoga practice? Well, each time electrodes are put around the scalp of experienced yogis or monks who practice meditation, it has been observed that they have more control of their brain wave activity. They relax easier and are sometimes able to have delta activity during meditation, not only in deep sleep. And by controlling their brain waves they have shown that they have a better control over their bodies. Sometimes to the level of extraordinary.
Often people practice yoga because they wish to become more flexible. But yoga is first and foremost an exercise of the mind. Taming your brain waves could be one of the reasons to step on the yoga mat.
More reading:
Wikipedia on brain waves
http://upliftconnect.com/brainwaves/
http://www.brainworksneurotherapy.com/what-are-brainwaves