Brain waves are currents that flow on neural pathways through the brain. There are 4 main types of brain waves beta, alpha, theta and delta and they are measured in Hz which is basically pulses per second. The frequency of these waves is different in different places in the brain at one time and therefore, one part of the brain could be at 5 Hz and 10 Hz in another. What characterizes the brains state is the frequency that predominates in the brain. The brain rarely enters gamma state which is faster than beta state and anything lower than .1 Hz is only experienced in dead people.

The Different States
Beta (13 to 30 Hz) mostly associated with awake states, mostly interaction with world, calculating information, it is usually localized in one small area of the brain, it is experienced in fear, anger, worry, hunger, surprise, normal waking consciousness, and active thought processes, if you are reading this you are in beta, it is a focused thought state

Alpha (7 to 13 Hz) mostly associated relaxed state and dreaming, mostly inward looking with little interaction with the world it is regional and can span a whole lobe of the brain, a state of creativity, multi-tasking activities and broad focus activities, bridge between conscious and unconscious, derived from the white matter of the brain, has a tendency to be found more in the right brain in frontal lobes

Theta (3 to 7 Hz) mostly associated with dreaming and REM states, experienced also in deep meditation by masters, free-flowing thought, creativity, usually spans many lobes and is most commonly found in the midbrain, switching thoughts, fantacizing,

Delta (.1 to 3 Hz) mostly associated with deep dreamless sleep and coma's especially in the medula, very unusual deep meditation, hightest amplitude

Waves in the Stages in Life

Delta are found in infants under the age of 1 yrs old. Children under 13 are most commonly in theta although they experience alpha as early as 8 years old. Theta can be found in teenagers and young adults in certain states, but is rarely found in adults over thirty. Alpha first appears in childhood and is very common in teenagers. Many believe that not being able to control alpha states is the cause of A.D.D., alpha being a less focused broader attention than beta. BETA is common low-voltage activity of a high frequency and is prominent in the frontal lobes during adulthood.

Brain Waves in Meditation

Meditation is commonly thought of as the practice of sitting alone silently, with a focus on controlled breathing, repeating a mantra, or envisioning some seen. Other meditation practices involve singing, dancing and chanting. Some look for relaxation in meditation while others are looking for some type of spiritual experience. Many religious philosophies from the east seek the annihilation of the self and the union of the individual with the great oneness. When a person is relaxed and closes his eyes there is an increase in alpha activity in his or her mind. When a person falls asleep he enters into states even deeper than alpha. These states are often thought to be the unconscious activity of the mind. When a person medititates it can have a similar effect to the brain as sleeping. Masters of meditation can even enter the state most commonly associated with infants, delta state. Many can also at will put their mind into alpha without closing there eyes and without ceasing to move. There is a split in eastern philosophy about meditation. Some like the great yogi's believe in the putting off of the natural body and this is seen through there meditation. They tend to close their eyes and cease to move when entering into meditative states, whereas Zen masters often keep their eyes partially open and continue to move slowly in meditation. This comes from a philosophy of trying to connect both the inner and outer worlds. Many years of study have gone into testing the brain waves of those in meditation.

From a Class given at the Tom Brown School of Tracking and Native American Spirituality

Tom Brown in recent years has been experimenting with Biofeedback and meditation. Like many before, he has found that through meditation one can get into alpha states. In the Native American Philosophy of this school there is, like in the Zen philosophy, a movement to connect the inner and outer world. Through the practice of the Stalk Walk or Fox Walk one can continue to move while staying in alpha state. Also he has found that those who survive off the land often enter into a constant state of Alpha while still going about daily tasks. Many people from native cultures are found to constantly be in alpha state. One large trick that he has found to retaining this state while active, is to use what he calls wide-angle vision(WAV). WAV is opposite to tunnel vision and uses the peripheral vision to take in surroundings. You can put yourself into wide-angle vision by putting fingers at the side of your eyes about two inches out and try to be aware of both fingers at the same time. This way you can take in everything in your surroundings at once. It has been found that there isn't an actual change in the vision, but one in the mind, when you switch into WAV. This means your brain looks at the same information in different ways according to how you choose to receive it.

"Intentional blurring of visual focus tends to increase alpha abundance. When the subject was asked to look for detail, thereby focusing on visual stimulation, alpha activity tended to block on all channels."
Expanding Dimensions of Consciousness

"In studies of Zen monks A. Kasamatsu and T. Hirai of the University of Tokyo found that during meditation with their eyes half-open the monks developed a predominance of alpha waves-the waves that ordinarily become prominent when a person is thoroughly relaxed with his eyes closed… Subjects with a great deal of experience in meditation showed… rhythmical theta waves."
Altered States of Awareness

Using the Full Brain

Using WAV you have a more holistic view of sight information coming in. This change from tunnel to wide-angle is not in the eyes, but is a process of the brain. This more holistic view of the sight, exists with the hearing and likewise in all the other senses. Theoretically you could train you mind to take in all your senses at once. This would be a full use of the brain. This process in the scientific world is called synchrony. The brain is split into sectors and each has a primary function and reads certain information taken from the senses. Like one can untunnel his sight, he can untunnel his other senses and experience all senses at once. Through synchrony of alpha waves in different parts of the brain, one falls partially into theta. Theoretically the same process could take you to delta, but this has not been recorded to my knowledge. It is theorized that many of the worlds greatest discoveries were discovered in alpha and theta states. That is why many discoveries have come not in the laboratory, but in the bathroom while one was in a relaxed state. Einstien is thought to have been constantly in alpha.

"We have been informed that analysis of the resonance of the frequencies of a number of mantras shows that they have a value of 6-7 Hz which is the high theta EEG range… Therefore, in thinking a mantra, a significant stimulus is introduced in the temporal lobe and probably directly into the series of cell clusters and fiber tracts that have come to be known as the limbic system… we theorize that introducing a driving mechanism with a dominant frequency of 6-7 Hz may act with considerable rapidity, to dampen the limbic system activity and produce a relative quiescence in this critical subcortical area."
Expanding Dimensions of Consciousness

"Phase synchrony among the lobes is observed to enhance the maginitude and frequency of the subjective phenomena associated with alpha and theta… When one greatly diffuses or opens his attentional focus, one can apprehend all of one's experience simultaneously. There is then no necessity to direct control one's attention in any way, and thus, there is no occasion for control anxiety… In my opinion, multichannel, phase -sensitive EEG biofeedback, properly used, will through the training of attentional flexibility significantly enhance functional capacity and sense of well-being."
Expanding Dimensions of Consciousness

"It has been said that Einstein would read complex physics journals and at the same time produce continuous large amplitude alpha activity. As the legend goes, Einstein was observed to produce beta activity only on the occasion, when he discovered an error in reasoning reported in the physics journal that he was reading."
Expanding Dimensions of Consciousness

"A further thing that schizophrenics do 'better' than the rest of us… is simple sensory perception… They are more alert to visual stimuli… This is seen in their ability to block EEG alpha waves more quickly than normal persons following abrupt stimulus. Unable to narritize or conciliate, they see every tree and not the forest… Schizophrenics tend to get stuck on one hemisphere of the brain or the other and so cannot shift from one mode of information processing to another as fast as the rest of us."
Origin of Consciousness

While the arguments for a fundamental unity of consciousness are anchored in our continuous subjective experience and thus justified by it, it is much harder to argue for a corresponding unity of brain functioning. A fleeting look into a textbook on neuroanatomy provides a picture of the brain as a highly complex and hierarchically structured system, and even this initial picture of structural complexity fades out when compared to the functional complexity of each sensory or motor subsystem. The complexity of the brain as a whole, then, exceeds any imaginable representation… I would like to illustrate my point by a simple metatphor… An orchestra perfoming a musical opus may serve as an excellent metaphor for the brain's functioning. The sound is produced by a synchronized action of specialized structures (players with instruments) nonetheless, it is the Gestalt of the musical composition that determines the actions of the sound-generating structures. These are trivial facts, at least form the point of view of a music lover: however, a modern neuroscientist might have a different opinion. The music is, no doubt, the sound of music: thus, according to his methodology, he has to examine how and where the sound is generated. Consequently, the scientist would want to have a closer look at the details of the orchestra's operation… This is what neurosciences are doing nowadays in the effort to understand the brain's functioning. And yet, I maintain that in doing so, we might easily--well, we surely will-miss the meaning of the musical piece that is being played.
Article

Dreams and Visions

When one falls to sleep he goes into states of alpha in dream sleep and lower states like theta and sometimes delta in very deep sleep. Scientists studying eastern meditation masters discovering visions have been seen to come in states of low theta and delta. Tom Brown claims that through different guided meditations and other rituals the shaman of the Apache tribe would find themselves free to roam the spirit world.