What are Brainwaves: How Brainwaves are Measured

Part 2 of a 2-Part Series

Brainwaves HealthyOur brainwaves change according to our physical activity, our mood, our thoughts and feelings, and whether we are awake or asleep. Like musicians playing their instruments during a symphony, our brainwaves work together in harmony.

Click here to read part one.

That the brains of mammals produce electrical pulses has been known to science since 1875. Actual recordings of brain waves in an animal were made in 1912. Brain wave activity in the human brain has been studied since 1924, when the first recording of human brain wave activity was made.healthy Brainwaves

Electricity is measured in units of frequency known as hertz. A hertz is defined as one cycle per second and is named for Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves. An electroencephalograph machine (EEG) measures the brain’s electrical activity.

Brain wave activity originates with the electrical activity of individual neurons communicating together and is happening continuously throughout waking and sleeping. Although we now know the human brain produces seven different electrical brain wave patterns, four basic patterns are the most studied and the most understood.

 Brainwave MeasurementAlpha, Beta, Delta, and Theta

  • All brain wave patterns are active all of the time. However, brain wave patterns vary and dominate depending on level of a person’s activity, concentration, or mood, and whether awake or asleep.
  • Beta is a fast wave. It varies between 12 to 38 hertz depending on our level of activity, concentration and focus, as well as our mood and level of excitement or anxiety. Beta is dominate during our waking hours. Important in activities of problem solving, judgment and decision making, beta waves are essential for healthy waking activity.
  • Alpha waves are also dominate during waking hours, but they are a slower wave of 8 to 12 hertz. Beta takes a lot of energy and the brain needs to relax intermittently. Alpha waves represent the brain’s relaxation or resting state. The brain constantly uses Alpha along with Beta. Alpha occurs when we close our eyes, think quiet thoughts, day dream, meditate, or feel calm. Alpha is important for overall mental coordination, mind/body integration, calmness and alertness, and integration of learning.
  • Theta waves are slow waves of 3 to 8 hertz. These dominate during sleep during deep meditation. Theta reveals our brains withdrawing from the external world to focus within. During Theta, learning and memory record. It is while in Theta that we experience our dreams. Theta is also a healing and regeneration state for the body.Brainwaves Health
  • Delta waves dominate during deep, dreamless sleep. They are slow waves of .5 to 3 hertz. Deep body regeneration and healing occur during Delta. There is complete disengagement from the external world as the brain and body go deeply inward. It is difficult to awaken a person from Delta sleep and children are almost impossible to waken from Delta.


As mentioned earlier, our brainwaves work together in harmony, but when there is a disruption of this harmonic condition, there is a disruption in brain function. Brain wave balance is critical to emotional and neurological health. Anxiety disorders, sleep problems, nightmares, autism, impulsive behavior, anger/aggression, depression, chronic nerve pain and spasticity reveal over-arousal of certain brain areas. Scientists attribute under-arousal of certain brain areas to attention deficit, chronic pain and insomnia.

Conditions as tic disorders, epilepsy, panic attacks, bipolar disorder, obsessive-compulsive disorder, migraines, sleep apnea, teeth grinding, vertigo, and tinnitus (ringing in the ears) reveal instabilities in brain rhythms. Traumatic brain injury(TBI) concussion, stroke, and coma all affect brain wave balance and brain function.

Brainwave AdaptabilityAdaptability

The brain is constantly changing and evolving; constantly creating new neurons.  Neuroplasticity equals adaptability, growth and change. Neuroplasticity allows the brain to heal itself from injury. Due to advances in EEG technology, it is possible to provide feedback to the brain on whether brain waves are in sync.

During neurofeedback, technicians place electrodes on the scalp, attached to specialized EEG machines. These display images on computer screens and generate sounds to detect and measure different brainwaves. The images and sounds provide information, known as feedback, and allow the brain to learn to reharmonize the various brain waves and allow the brain to reregulate and return to harmonic balance.

Our brains determine our emotional states, our perceptions, and our reactions to the world around us. Our brains are complex, magnificent, and mysterious.  We still have much to learn about who we are and how our brains work.