What are "Brainwaves" and How do they relate to Neurofeeback Training?
- Brainwaves are the electrical activity produced by your brain recorded in real time
- Brainwaves are also known as the EEG (electroencephalogram = electrical brain picture)
- Brainwaves result when thousands of brain cells called neurons are communicating
- When brain cells fire and then relax an "up and down" pattern called a wave is produced
- Brainwaves pass up through your skull bones and scalp and can be recorded with special sensors
- Brainwaves recorded on your scalp can then be displayed on a computer monitor in nearly real time. This means you essentially get to watch your brain working moment by moment.
- Brainwaves occur at different speeds, in different patterns, and in different amounts.
- Different patterns of brainwave activity relate to different mental states and levels of functioning
- Brainwaves can be "quantified" mathematically and compared to normative databases.
- Normative databases are made up of the EEG activity of many individuals that are considered "normal" or average and healthy for their age.
- Using a normative database, an individuals EEG activity can be compared to the normal group.
- Patterns of difference from the normal group usually correlate to the symptoms the individual experiences.
- Using neurofeedback, the brainwave patterns that differ from the normal database and correlate to your symptoms can be trained toward normal which usually results in symptom reduction.
- For example, in ADHD it is common to see an excessive amount of Theta brainwaves and often a reduced amount of Beta brainwaves towards the front of the head (frontal lobes). This pattern of excess slow activity and deficient fast brainwave activity, especially when seen in the frontal lobes, correlates with ADHD symptoms. Using neurofeedback training, trainees can learn to reduce the theta activity and increase the beta activity which usually results in a reduction in ADHD symptoms and an improvement in the ability to remain focused.
What are the Different Types of Brainwaves?
1. Infra-slow Oscillations & Slow Cortical Potentials (SCP’s) (0.001 – 1 Hz)
- Infra-Slow Oscillations (ISO's) / Slow Cortical Potentials (SCP's) are slowly shifting positive & negative oscillations that last multiple seconds
- You can think of ISO's and SCP's as the ocean tide that the surface waves "ride on".
- These slow oscillations reflect changes in the metabolism of brain support cells called glial cells that nourish and protect brain cells called neurons.
- Slow oscillations may be trained with specialized neurofeedback protocols and can change how "aroused" the brain is. Slow oscillation training has been shown to be effective in treating ADHD and Seizure Disorders and has been applied to many other clinical conditions. Slow oscillation training has been most well-researched outside of the USA and slow oscillation training is becoming more popular but is not the predominant type of neurofeedback training in the USA.
2. Delta Waves (1 - 4 Hz)
- Delta waves are large slow EEG waves that oscillate from about 1 to 4 times per second.
- Delta waves are rarely seen in healthy adults while they are awake but are prominent and normal during sleep and in infants, children, and teenagers.
- Delta waves that occur in awake adults can indicate abnormalities including head injury, various degenerative brain diseases (Alzheimer's, Dementia, etc.), metabolic problems with the liver, toxin exposure, lesions, tumors, in certain types of epilepsy, and damage from strokes, etc.
- Delta activity that occurs during sleep is correlated with hormone release that helps the body heal and memories to be stored in long-term storage.
- Disruptions of Delta wave activity during sleep has been correlated with the development of a variety of mental disorders including ADHD, Depression, Anxiety, Schizophrenia, Sleep disorders, Parkinson's Disease, and autoimmune diseases
3. Theta Waves
- Theta waves oscillate from about 4-8 times per second (Hz)
- Theta waves in healthy awake adults are not generally seen in the scalp recorded EEG but can occur if someone is becoming drowsy.
- Theta waves can be considered normal in the EEG of children and adolescents.
- Theta waves are important in the storage and recall of memories in the hippocampus.
- Inducing a "Theta state" through techniques like hypnosis and Alpha-Theta Neurofeedback can be helpful in resolving traumatic memories due to PTSD.
- Excessive Theta waves when compared to a normative database usually reflect slowed brain metabolism and less than optimal functioning and can relate to...
- Learning disabilities
- Head injuries
- Certain neurological disorders
4. Alpha Waves (8-12 Hz)
- Alpha waves (most commonly seen at the back of the head) are the dominant waves seen when someone is relaxed but alert and their eyes are closed.
- Alpha waves can be thought of as the brain's "idle rhythm". Much like a car that is idling smoothly at a stop sign is running but at rest, a brain in an Alpha state could be thought of as running but resting.
- The speed of the posterior Alpha rhythm is one of the best indicators of cognitive functioning. In healthy adults, an Alpha speed of about 10 Hz is considered normal. If the Alpha speed slows too much it can relate to poor brain function and could be due to unhealthy aging, head injury, toxic exposure.
- Excessive Alpha in the front of the brain or appearing as an imbalance between hemispheres can relate to depression, anxiety, and attention issues.
- Neurofeedback training of Alpha waves (either to increase or decrease the amount or speed) has been used for optimal performance training, reduction of ADHD symptoms, and improvements in depressive and anxiety disorder symptoms.
5. Beta Waves (13 - 35 Hz)
- Beta waves oscillate between about 13 and 35 times per second
- Beta waves are prominent during states of concentration and problem solving and tend to correlate with an increase in brain blood flow and metabolism
- Neurofeedback training may reward beta activity in the 13-20 Hz range (often with inhibition of slower brainwaves such as Theta) for the improvement of cognitive functioning.
- Neurofeedback training may inhibit excessive amounts of beta or beta activity that is too fast is used to promote relaxation and reduce anxiety and obsessive-compulsive disorder symptoms.
- Excess Beta activity and / or spindling Beta often reflects an over-excitement of the brain. Excessive amounts of Beta or having beta "speeds" that are too fast is sort of like having a car that is set at too fast an idle.
- Excess beta and can relate to the symptoms of...
- Mania during Bipolar Disorder
- Anxiety disorders
- Sleep Disorders
- Obsessive-Compulsive Disorder
6. Mu rhythm (8-13 Hz seen most commonly at the top of the head (10-20 sites C3 & C4)
- Mu rhythm can be thought of as the Alpha rhythm of the sensory and motor systems
- It is most commonly seen at the top of the head where the sensory information of the hands and fingers gets relayed.
- When mu is seen it usually means that your hands are still and you aren't imagining movements.
- It is normal to find mu in children and adults but mu rhythm is found more frequently in individuals with ADHD and Autism
- Mu seems to play a role in what is called the "mirror neuron system" which is responsible for helping us to be able to learn through observation. This system seems to be effected in autism making it difficult for people who struggle with autism to recognize and adapt to the social behavior of others.
- Research is exploring the training of mu brainwaves with neurofeedback to improve functioning in individuals with autistic spectrum symptoms.
7. Gamma Waves (30 - 600 Hz based on differing classifications)
- Gamma brainwaves are very fast brainwave activity
- Gamma brainwaves have a variety of functions but seem to help neural networks work together especially when fast recognition is needed such as initial visual recognition of objects ("what do I see and is it a threat?"), initial auditory information recognition (what is that faint sound I hear?), selective attention, etc.
- Most normative QEEG databases do not have normative data for Gamma activity and Gamma neurofeedback has not been a primary approach for most neurofeedback practitioners.
- Gamma neurofeedback has been utilized, especially in addressing learning disorders and is a growing area of neurofeedback training investigation.