Last year I wrote several entries about brainwave entrainment and the two products I have bought and used for this purpose, first Holosync and later LifeFlow. I have tagged this entry with the same tags, so you should be able to use the tag feature of WordPress to quickly get a list of the other entries where I have used those tags.
This is a more basic overview, for those who are absolutely new to this field.
Our brain uses a combination of electricity and chemistry to do its work. Signals traverse the neurons – the nerve cells – as a change in the electric potential. Then in the gap between cells, it is converted to a chemical signal carried by a neurotransmitter. If the receiving cell reacts, it more or less recreates the signal and passes it on. Whether it does this, and whether the signal is stronger or weaker than it first was, depends on other signals the cell may also receive, and its experience with signals from that particular cell.
As you may guess by now, measuring the electromagnetic output of the brain will not allow your doctor to read your thoughts. It can only give a rough outline of what is going on in there. In fact, it is different from an EEG (electro-encephalogram) to say whether a person is dreaming or just thinking hard. But certain conditions show up very clearly, such as an epileptic attack or, on the other hand, sleep.
In sleep, the brainwaves slow down. For historical reasons, the usual thinking waves are called beta. They are quick, jagged and don’t go very far up or down usually, though there may be an occasional spike.
The next type is alpha. This appears when we are about to go to sleep, but also during daydreams and other relaxing situations. You can usually create this type of brainwave by simply sitting comfortably alone, closing your eyes, relaxing and then looking slightly upward inside your closed eyes. Don’t roll them back so hard it hurts. In this state of mind it is almost impossible to solve mathematical or logical problems, or anything else that normally requires concentration. These brainwaves are slower, rounder and more regular.
The alpha state is the one where we start doing meditation. However, the alpha brainwaves are not the meditation. This is extremely important to understand. Why then do we use this state of mind? Because 1) this is something every person experiences every day when they go to sleep and often throughout the day as well, and 2) it is a state of mind where consciousness is somewhat reduced. As I said, you cannot do mental work in this state. Most people will automatically start daydreaming (autists don’t) and their thoughts begin to drift aimlessly. Meditation consists of setting up an anchor (a mantra, a simple sequence of counting, observing your breath or something similar) and binding your awareness to it so it does not drift. Over a period of months or years, you gradually learn to remain fully conscious in a state of mind where you normally are not conscious. This is what meditation really is about: The expansion of consciousness.
Below alpha waves (frequency 12-8 Hz) are theta waves (7-4 Hz). These fill most of the night. Just after you fall asleep, or when you nap on the sofa, you remain vaguely aware of the world around you, even though your brain has already begun to produce mostly theta waves. In this situation you can still be easily roused, but you rather prefer not to unless there is some crisis. However, when you return to the same brainwaves after going into deeper sleep, this awareness has been erased, and you remain more or less unconscious throughout the night. In the elderly, some nights there is no deeper sleep, and they may therefore imagine that they have not slept at all, even though they did so for several hours.
The final level is delta (2-0.5 Hz). The brainwaves here are very slow (0.5 Hz means each wave takes two seconds!) and with a much greater amplitude (that is to say, the electric potentials on both sides are much higher). This is the deep sleep that wipes out the awareness of the mind. It is also associated with restoration of the body and brain, maintenance of the immune system and release of Human Growth Hormone.
All of these states can be induced through brainwave entrainment. You can use light or sound, sound being most used because it has no risk of triggering epilepsy. The human ear cannot hear sounds with a frequency this low, so it is made indirectly. The most popular approach is binaural beats. You need headphones for this, as it sends a different signal to each ear. The difference in frequency becomes the frequency of the resulting brain waves. For instance, a tone of 210 Hz and one of 200 Hz will give rise to a 10 Hz wave in the brain. This was discovered rather by accident. Later other methods have been devised that don’t need headphones, the most effective is probably isochronic tones. Here an audible signal is turned on and off (or from one frequency to another) at a rapid interval that corresponds to the target frequency.
With these techniques it is possible to invite the brain into brainwaves normally only found in sleep. You cannot overwhelm the brain and force it into these states though. On the way from the top of the brain stem where these frequencies are generated from the sound input, the waves have to pass through the limbic system. If this system is aroused (through intense emotions such as fear, anger or lust) the signal will be blocked. Conversely, if you willingly relax and don’t concentrate on anything else, the signal will spread more quickly.
If you play a track designed to cause theta or delta brainwaves, it is normal to fall asleep the first times you listen to it. In fact, if you don’t mind, you may continue that way. But if you strive to be alert, you will normally be able to stay awake longer and longer, and eventually throughout the session.
LifeFlow by Project Meditation takes a slightly different approach, as you get 10 tracks, one for each Hz of frequency from 10 to 1. You are supposed to spend at least a month with each, until you are thoroughly familiar with them, starting with those you recognize from waking life, and getting steadily deeper. This way you should be able to remain conscious even at the lower levels, though it may usually take a couple years for a newbie to get there.
Again, the essence of meditation is the expansion of consciousness. A host of problems in life stem from the fact that our “normal” consciousness is a fragile thing. A simple insult may be enough for it to be swapped out temporarily for an altered state in which you behave like a total stranger. The same goes for hunger, fear, lust or revulsion. Because of this, people find themselves unable to reach their life goals or even to maintain the life they already have. Seen from the perspective of someone more stable, they are like foam on waves on a storm sea, thrown helplessly about, broken apart and formed again, but doomed to once again be ripped to shreds. Anyone who has a deep and stable consciousness is certain to feel compassion when seeing this sorry state of being, but most people are sure this is as good as it gets, this is all there is.
I believe this is how some of the world’s great religions came into being, through the compassion of great souls who had a deep, stable consciousness. But because people tried to understand it without doing the practice (in other words, because of “theology”) the religions degraded into cheat codes for getting health, prosperity and generally tricking the gods into ignoring your destructive behavior and treating you as if you were someone else. As opposed to, you know, becoming that other person, from the inside out.
There is a distinct risk that the same may happen with brainwave entrainment. Already the claims made by various suppliers go a ways beyond what you should reasonably expect. But you should definitely expect some benefits if you use it regularly.