Activity in the brain is often measured by observing and recording “brainwaves” which are rhythmic or repetitive neural activity. Brainwaves can be observed through an Electroencephalography (EEG) which is a test that measures electrical brainwave activity along the scalp. Brainwaves are categorized by frequency with each category having different positive and negative effects, depending on your current and desired level of arousal or alertness.

This EEG is an example of someone with a sleep disorder, who went from alert to a light sleep, and woke again over a period of ten seconds. 

Brainwaves indicate both the level and type of arousal in a part of the brain. When a person is awake and engaging in a task, delta, theta, and alpha activity should be low, revealing beta as the dominant wave. As a person relaxes, alpha quickly increases. As a person becomes deeply relaxed and especially with eyes closed, theta will become the dominant brainwave and as a person falls asleep, delta becomes the dominant brainwave with occasional short bursts of sensori-motor rhythm (SMR) in the sensori-motor strip to prevent sleep-walking.

Brainwaves are situation specific. Therefore, any brainwave can be either a benefit or detriment to the activity a person is trying to engage in.  Stress, hectic lifestyle, and less than optimal diet suppresses relaxing brainwaves. And likewise, when we are tired during the day, the brainwaves which are essential for mental performance are suppressed. It’s easy to see that if a person’s brain is making the wrong frequency for a given situation, the result will be detrimental to his/her ability to succeed at the task at hand. The brain needs to flex with the various activities that one is engaging in.

Gamma Waves are the fastest brainwave frequency ranging from 35 - 100 Hz. They are associated with complex cognitive or motor tasks and are thought to play a role in consciousness awareness and higher mental activity. Enhancing gamma wave activity may contribute to improving focus, mental clarity, and cognitive functioning.

Beta Waves are quick, low amplitude waves of 14 to 35 times per second (Hz). Beta brainwave patterns are generated naturally when in an awake, focused, and alert state of consciousness.

Alpha Waves are between 8 and 14 Hz and occur during sensorial rest (e.g. when the eyes are closed), intellectual relaxation, deep relaxation, or meditation.  Alpha brainwave rhythms produce: peaceful feelings, warm hands and feet, a sense of well-being, improved sleep, improved academic performance, increased productivity in the workplace, reduced anxiety, and improved immune functioning.

Alpha/Theta Border (7 to 8 Hz) is where exceptional insights and personal transforming experiences can occur. The frequency of Schumann Resonance sessions are in this range.

Theta Waves are between 4 and 8 Hz and are commonly referred to as the dream or “twilight” state. Theta is associated with hypnogogic states, REM, and dreaming. Memory development is enhanced in this state. In the Theta brainwave state, memory is improved (particularly long-term memory) and access to unconscious material, reveries, free association, sudden insight, and creative ideas is increased.

Delta Waves are from 1 to 4 Hz in frequency and are observed when in a sleeping state. As we fall asleep the dominant natural brainwave becomes Delta. There is growing evidence that individuals may maintain a slightly conscious state while in Delta.

Sub-Delta Waves are 0 to 1 Hz and is not considered a brainwave state but affects autonomic functioning. Deeper structures in the brain, such as the insula, hypothalamus, and brainstem respond to sub-delta stimulation. People with hypertension and fibromyalgia respond positively to this frequency.