Neurobiofeedback (Biofeedback)

History of EEG

In 1924 a German physicist named Hans Berger found brainwaves via his invention, the electroencephalogram (EEG). For five years he waited to compile enough evidence to introduce the scientific and medical community to his water-tight research documenting the recording of electrical activity of the human brain from the surface of the head. Although German medicine and science scoffed and met his discovery with incredulity, today the EEG stands as a phenomenal tool allowing us to peek under the lid of flesh and bone into the dimensions of psychology and consciousness.

Delta (Delta brainwave) 

Delta is the slowest brainwave, oscillating between 0-4 times-per-second (0-4 Hz). Humans' raw EEGs show most brainwaves at any given time (kind of like how homogenized milk contains skim milk, 2%, and whole milk), but delta is the dominant brainwave during deep sleep in healthy, adults. It is high amplitude (meaning the wave forms are big, relatively speaking). Babies in utero and in early infancy (between 3 months to 1 year) spend a great deal of time in delta it is thought to be responsible for neurogenesis (the genesis of neural connections). Delta has been linked to the production of human growth hormone and serotonin. From a psychological perspective, delta has been linked to the unconscious, as well as the Jungian notion of the collective unconscious (Wise, 1995). 

Theta (Theta brainwave)

Theta brainwaves run at 4-8 oscillations-per-second (4-8 Hz), and are the dominant brainwave in REM sleep, dreams, and hypnosis. This is the subconscious and the borderland to consciousness. Theta is a powerful state for learning in an uncritical fashion. Hypnotherapists will take clients to the cusp of theta and alpha (read: unconscious and conscious) because humans arc highly suggestible in this space. Jung felt that dreams were signs referencing complex psychological, emotional, and transcendental realities. Dreams access the storehouse of memories in the limbic system (the amygdala and the hippocampus); our individual dreams are often of a collective reservoir, containing ancient and primitive themes and narratives. When we are in theta, our subconscious offers us images that are symbolic of those repressed or otherwise inaccessible memories and information

Alpha (Alpha brainwave) 

Alpha is an interesting brainwave—really, the king of brainwaves. Alpha is the most obvious brainwave to spot with the naked eye—it has high amplitude and is often rhythmic. It was the first discovered and classified by Berger, as well as the first brainwave used in experimental self-regulation (later called EEG Biofeedback) by, University of Chicago professor Joe Kamiya in 1959. Alpha is the first conscious brainwave and the bridge that links the unconscious brainwaves of theta and delta to the active thinking brainwaves of beta and gamma. Alpha is 9-12 Hz, a relaxed and focused space,  responsible for the state of flow, being in the zone, and creating. When we close our eyes, we signal to our body that we are in a position to relax and safely fall asleep. When we close our eyes, a normal response is an increase of 50% or more alpha in the back of the head.

Beta (Beta brainwave) 

Beta brainwaves cover a large spectrum of 12-38 Hz, and are the brain state of our normal waking consciousness. Beta encompasses all forms of action, thinking, and problem solving—from the mundane (making grocery lists), to the complex (computing mathematical equations). Beta is broken down into three categories (I, II, and III). Beta i is 12-15 Hz and the calmest of all beta brainwaves, often coupled with stillness, presence, and low muscle tone. Beta II is 15-23 Hz and is at work when we undertake tasks involving detail, processing, and meaning comprehension. Beta III is 23-38 Hz and shows during states of high focus and engagement. This state can also be indicative of anxiety and stress.

Gamma (Gamma brainwave) 

If alpha is king, then gamma is guru. Gamma brainwaves are 38+ Hz, and have been associated with states of inspiration, hyper-alertness perception, and even enlightenment. Recent studies involving practiced meditators have shown gamma synchrony as a common finding in levels of heightened meditation and awareness. Gamma has been classically difficult to capture since it's very fast and low in amplitude. It can be easily confused with the muscle artifact from scalp tension in EEG and is, for that reason, currently a difficult brainwave to train via neurotherapy.


Neurobiofeedback Resources



Disclaimer: The information on this website is not intended to be a substitute for medical diagnosis and treatment. If you are experiencing physical pain or emotional crisis, consult a medical and/or mental health professional.

© 2017 Carl Sayles, PsyD