Small amplitude:
EEG BIOFEEDBACK: (NEUROFEEDBACK)
EEG (electro-encephalographic) biofeedback, now more commonly known as neurofeedback, is a specialized form of biofeedback that aims to re-train brain waves.
Our brains generate electrical activity (brain waves) all the time. The waves that one can measure at any one time depend on the state the brain. The state of the brain varies from being drowsy and sleepy, to being fully awake and focused. As we engage in different activities, the electrical activity of the brain also changes. In biofeedback, we are interested in four different brain waves, ie. theta, alpha, and beta.
These waves, which we see as tracings across the computer screen, differ from each other in two respects. Firstly, they differ in size or amplitude.
High:
Small amplitude:
The waves also differ in the number of cycles per second (hertz) (Abbreviated as Hz). The can be slow waves, or fast waves.
Slow waves:
Fast waves:
Theta waves are slow high amplitude waves. There are only 4 - 7 cycles (Hz) per second, hence they are described as slow. They are present during sleep. Brain waves that are slower than 3 Hz are called Delta waves and they are found in coma.
Theta waves are abnormal in awake adults. They are implicated in anxiety, and in neurological conditions such as epilepsy, traumatic brain injury, and Attention Deficit Disorders (ADD/ ADHD).
In neurofeedback, we treat epilepsy, traumatic brain injury (slowed information processing associated with inattention and memory problems), and ADD/ ADHD, by retraining patients to inhibit theta waves, whilst they increase beta waves. In insomnia that is associated with tension and anxiety, some patients benefit from training to increase theta waves.
Alpha waves have moderate amplitude and medium speed (8 - 12 Hz). They are associated with closing of one's eyes. Alpha waves are associated with calmness and relaxation. Interestingly, when we pray, or when we meditate, we tend to close their eyes. Perhaps we are unwittingly trying to get ourselves into alpha states. People in alpha states are awake but relaxed.
In neurofeedback, we use alpha training and sometimes alpha/theta training for the treatment of depression, anxiety, post-traumatic stress disorder (PTSD), general stress, and addictions (alcohol, cigarettes, and other drugs). Healthy individuals may use alpha training to enhance their relaxation skills.
Beta waves are fast low amplitude waves, cycling at 12 - 40Hz. These waves are associated with arousal, problem solving, attention and concentration, and other intellectual processes. Beta waves are classified into low beta, also known as Sensory-Motor Rhythm (SMR (approx. 12 - 15 Hz) Beta (16 - 20 Hz), and High Beta (22-40Hz).
Low beta is associated with the organization of brain processes, whilst the high beta is more associated with arousal, and is implicated in anxiety states.
In neurofeedback, retraining of beta waves is used in the treatment of epilepsy, ADD/ADHD, learning disorders, depression, migraines, traumatic brain injury, and premenstrual syndrome. In insomnia, patients who are relaxed but are still sleepless benefit from training to increase the SMR.
Copyright © 2001, Dr. JFL Mureriwa. All rights reserved.
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