Thus, the combination of electrical activity of the brain is commonly called a Brainwave pattern, because of its cyclic, 'wave-like' nature. Our mind regulates its activities by means of electric waves which are registered in the brain, emiting tiny electrochemical impulses of varied frequencies, which can be registered by an electroencephalogram. These brainwaves are known as:
- Beta emited when we are consciously alert, or we feel agitated, tense, afraid, with frequencies ranging from 13 to 60 pulses per second in the Hertz scale.
- Alpha when we are in a state of physical and mental relaxation, although aware of what is happening around us, its frequency are around 7 to 13 pulses per second.
- Theta more or less 4 to 7 pulses, it is a state of somnolence with reduced consciousness.
- Delta when there is unconsciousness, deep sleep or catalepsy, emitting between 0.1 and 4 cycles per second.