The EEG (electroencephalograph) measures brainwaves of different frequencies within the brain. Electrodes are placed on specific sites on the scalp to detect and record the electrical impulses within the brain. By using this technique, scientists have been able to map and measure the functions of different brainwaves.
If we use the correct stimulation, certain brainwaves can be ‘exercised’ or enhanced in order to create, or develop, a specific response.
The first brainwave I’d like to discuss is theta. Theta activity has a frequency of 3.5 to 7.5 Hz and is classed as "slow" activity. It is seen in connection with creativity, intuition, daydreaming, and fantasising and is a repository for memories, emotions, and sensations. Theta waves are strong during internal focus, meditation, prayer, and spiritual awareness. It reflects the state between wakefulness and sleep. It relates to the subconscious. It physiologically correlates to healing and the integration of mind and body. When stimulated or enhanced it can induce drifting or a trance-like state.
Secondly, Alpha waves are those between 7.5 and 13(Hz). Alpha waves will peak around 10Hz. Good healthy alpha production promotes mental resourcefulness, aids in the ability to mentally co-ordinate as well as enhancing an overall sense of relaxation and fatigue. In this state you can move quickly and efficiently to accomplish whatever task is at hand. When Alpha predominates most people feel at ease and calm. Alpha appears to bridge the conscious to the subconscious.
Alpha is a common state for the brain and occurs whenever a person is alert (it is a marker for alertness and sleep), but not actively processing information. They are strongest over the occipital (back of the head) cortex and also over frontal cortex.
When your alpha is within normal ranges we tend to also experience good moods, see the world truthfully, and have a sense of calmness. Alpha is one of the brain's most important frequencies, used to learn and use information taught in the classroom and on the job. You can increase alpha by closing your eyes or deep breathing.
Alpha-Theta stimulation, or training, can create an increase in sensation, abstract thinking and self-control. It is integral in the process of relaxation and generating the required psychological environment for restfulness and sleep.