Resonant entrainment of oscillating systems is a well-understood principle within the physical sciences. If a tuning fork designed to produce a frequency of 440 Hz is struck (causing it to oscillate) and then brought into the vicinity of another 440 Hz tuning fork, the second tuning fork will begin to oscillate. The first tuning fork is said to have entrained the second or caused it to resonate. The physics of entrainment apply to bio-systems as well. Of interest here are the electromagnetic brain waves. The electrochemical activity of the brain results in the production of electromagnetic wave forms which can be objectively measured with sensitive equipment. Brain waves change frequencies based on neural activity within the brain. Because neural activity is electrochemical, brain function can be modified through the introduction of specific chemicals (drugs), by altering the brain's electromagnetic environment through induction, or through resonant entrainment techniques.
Because the brain filters and interprets reality in a split-brained way, we tend to see things as separate and opposed, rather than as connected and part of the oneness spoken of by the great spiritual teachers (and, in the last few decades, by quantum mechanical physicists). Thus, at a deep level, the dual structure of our brain, in conjunction with brain lateralization, predisposes us to see and experience ourselves as separate from, and often in opposition to, the rest of the world—instead of experiencing the elegant interconnectedness between us and everything else. Our childhood associations and programming build on this inborn tendency by training us to seek this and avoid that, to move toward pleasure and away from pain, to do good and not bad, and so on. The greater the lateralization in the brain, the greater the feelings of separation—and the greater the feelings of separation, the greater the fear, stress, anxiety, and isolation.
It takes slightly more time to practice guided imagery, but this is a great way to leave your stress behind for a while and relax your body. Some find it easier to practice than meditation, as it allows more engagement of the conscious mind. You can focus on imagining relaxing environments you would love to visit, or on memories of your "happy place" for when you're stressed. You can play natural sounds in the background as you practice, to promote a more immersive experience.
Your brain cells reset their sodium & potassium ratios when the brain is in Theta state. The sodium & potassium levels are involved in osmosis which is the chemical process that transports chemicals into and out of your brain cells. After an extended period in the Beta state the ratio between potassium and sodium is out of balance. This the main cause of what is known as "mental fatigue". A brief period in Theta (about 5 - 15min) can restore the ratio to normal resulting in mental refreshment.
Exercise and stress research has typically focused on aerobic exercise. There have been consistent findings that people report feeling calmer after a 20- to 30-minute bout of aerobic exercise, and the calming effect can last for several hours after exercise. Recently, there has been an increased amount of research on the role of mind-body types of exercise such as yoga or Tai Chi. Unfortunately, there is somewhat limited research on the role of resistance exercise in stress management.
2. The other thing you cannot afford to do is evaluate whether or not a technique is having an effect based upon having (or not having) any of those superficial, irrelevant, distracting phenomena discussed above, like face flushing, seeing light swirls, having sensations of this, that or the other thing, etc. Those kinds of phenomena will just lead you down the wrong path and steer you away from the true benefits of meditation. If you’ve already fallen into the trap of this sort of conditioning, using something like the Release Technique, the Sedona Method, or even EFT can be helpful in breaking established conditioned associations.
While a practical understanding of brainwaves has been around for as long as people have been singing, chanting, and drumming, a scientific view of the electrical activity inside the human brain was not published until 1924 when German psychiatrist Hans Berger developed a machine for sensing and recording activity in the brain by attaching small electrical sensors to the scalp of his patients and recording the resulting electrical activity. Berger’s inventions and discoveries were built upon the earlier work of Richard Caton who published animal studies on brainwave oscillations in 1875.
Move-Thru-It Strategy: to support optimum recovery rates, use 6-8 pumps or 3-4 droppers. Repeat every 1-3 hours for a day or two (with a good night's sleep). The idea here is a persistent frequency. Once you have achieved initial results, you can switch to more conventional usage patterns such as 3-4 times a day. For example: Kick-Ass Immune, Get Over It
It cannot be any wonder then that we are almost desperate to find some sign, some indication that meditation and brainwave entrainment is having tangible, definable effects. We seize on these odd little experiences like ‘flushing of the face’ or ‘seeing spirals of color’ when our eyes are closed, hoping these are signs suggesting the elusive relief we’ve been after is finally within our grasp. We ask others to validate our experiences so that we can reassure ourselves we’re on the right track at last.
Isochronic tones work just the same in delta as they do in alpha, theta and beta and they are widely used in the brainwave entrainment community to help people sleep. Like you, I’ve also seen some websites saying they don’t work in delta, but it’s a bit like the game of Chinese Whispers, where someone makes a comment and then after it gets passed around and shared a lot the message gets distorted and appears to be a fact. I don’t know of any scientific reason why they wouldn’t work in delta. I remember some people talking about this on a brainwave entrainment forum many years ago. They were saying they found isochronic tones a bit too abrupt for using to help them sleep and they preferred binaural beats, as they thought they were a more soothing sound. That was just a personal preference shared by a couple of prominent forum members at the time and some people then took that as a fact for everyone. That’s where I think that belief originated from.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement.