For many years scientists had wondered what eastern sages did when they sat for hours with their eyes closed. They finally got an answer when in 1929; Dr. Hans Berger discovered an instrument called the electroencephalograph. This is an instrument that can be used to measure the frequency of brain waves.
Our brain functions electrochemically. Using the electroencephalograph, scientists found that depending on the activity of the brain the flow of electricity in it varies.
At the normal conscious state the frequency of brain wave remains between 14 and 26.9 cycles per second. This is called the Beta Level. In this level our consciousness is limited by space and time.
When we feel calm and peaceful our brain wave frequency drops to the Alpha Level, or between 8 and 13.9 cycles per second. In this state our consciousness is focused inward, and it can transcend space and time.
During light sleep our brain wave frequency is at the Theta Level, i.e between 4 and 7.9 cycles per second. The electrical activity in our brain continues even when we are in deep sleep. This is called the Delta Level, in which the brain frequency is between .5 and 3.9 cycles per second.
When we are restless and agitated the frequency of our brain wave rises to between 27 and 84 cycles per second. This is called the Gamma Level.
Scientists have found that the brain functions at the optimum level when the brain wave frequency is at the Alpha Level or lower. All of us have experienced this level. Remember how sometimes when you are calm and peaceful, everything seems simple and easy, everything seems to flow? This is the Alpha Level. And as the frequency of the brain wave rises, the efficiency of the brain drops. Remember all the stupid things you have done in a feat of rage? Nothing but destruction can be achieved at the Gamma level.
Most of us cannot control the frequency of our brain waves. But when the electroencephalograph was discovered, scientists found that meditators can bring the frequency of brain wave down at will. Expert meditators can reach the alpha or theta level but still remain alert. As their consciousness expands they can utilize the immense storehouse of power in their mind and brain for the benefit of themselves and others.