What is neurofeedback training
Neurofeedback Training — Neurofeedback is a form of biofeedback. In biofeedback, as the name suggests, precise instruments measure biological markers, such as brain waves(EEG), heart rate(ECG), breathing rate, skin conductance etc. Further, they provide feedback to the user in real time about everything occurring in their body. It is an experiential learning technique, which provides the user the skill to self-regulate and gain greater control over their body. Neurofeedback just focuses on the changes in the brain wave patterns and provides feedback based on them.
How does it work?
Until around the 1970s, neuroscientists believed that the brain’s structure and function was essentially fixed throughout adulthood. In the last 5 decades, scientists have discovered the amazing ability of the human mind to change and grow at any age [1]. Neurofeedback is actually designed to take advantage of this ability.
The fundamental principle behind Neurofeedback is Operant Conditioning. Let us consider the story of the professor whose students trained him with operant conditioning. The professor had the habit of pacing right to left while delivering his lecture. Each time he moved to the right side of the room, the student paid utmost attention. Each time he moved to the left side of the room, they paid less attention. By the end of the lecture hour, his shoulder was pressed against the right wall. In this example the professor was unaware of the ruse and the pacing was a natural event, but with reinforcement he received from the class and his desire for class’s attention had him engage in the process. Similar to this, our brain waves fluctuate outside our conscious awareness. Reinforcing desired brain wave patterns in real time is Neurofeedback [2].
Now the question arises, what are desired brain wave patterns? Following table shows positive and negative implications associated with different brainwave frequencies.
Frequency bands and characteristics [2]
BandFrequency RangeNegative reflectionpositive reflectionDelta (δ)1–4 HzBrain Injury, Sleep deprivationSleep, abstract Mental processingTheta (θ)4–8 HzADHD, Depression, poor judgementCreativityAlpha (α)8–12 HzMental fog, slow processing, insomniaInternal reflection, brain synchrony, peak performanceBeta (β)12–30 HzAnxiety, Insomnia, Migraine, OCD, perfectionismAlertness, focus, peak performanceGamma (γ)35–80 HzPoor abstract thinking and memory consolidationHigher mental processing peak performance
Types of Neurofeedback Training
- Frequency/power neurofeedback: Also called ‘surface neurofeedback’, this technique is used to change the amplitude of specific brain waves in specific brain locations to treat ADHD, anxiety and insomnia.
- Slow Cortical potential neurofeedback: This enhances the direction of slow cortical potentials to cure epilepsy, migraines, ADHD etc.
- Low energy neurofeedback system: This technique delivers a weak electromagnetic signal to alter the brain waves of the patient when they are in a motionless state. It helps in treating ADHD, traumatic brain injuries, insomnia, depression, anxiety, restless legs syndrome and anger.
- Hem encephalographic neurofeedback: This provides feedback on the cerebral blood flow and is useful in treating migraines.
- Live Z score neurofeedback: This introduces the comparison of variables of brain electrical activity to a systematic database and provides continuous feedback. Also, it is helpful in treating insomnia.
- Low resolution electromagnetic neurofeedback: This is used to treat depression, addictions and OCD.
- Functional magnetic resonance imaging: This regulates the brain activity based on the activity feedback received from deep subcortical areas of the brain.
Z-score Training
Neurofeedback Training | Device | Equipment | Z-Score
Once we capture EEG, we need to make sure which region of the brain we need to train, for that we need to identify regions of the brain which are outside the “normal” range. To identify these regions, there has to be a baseline to compare to.
The following section is going to be a little mathematical, if you are not interested you can directly go to the next subsection.
To generate the baseline, EEG data is recorded from hundreds of participants in 3 to 80 years in age. Numerical analysis are done on this data to calculate mean and standard deviation for each age group, these databases are called normative databases. Normative because the data captured from people follows normal(gaussian) distribution. Don’t run away just yet, all it means is that we need the calculate z-score using the following formula to compare our EEG parameters to database.
where, x is the input parameter, μ is mean and σ is the standard variance from the database for that particular parameter. The following image represents a standard normal distribution, with x-axis representing z-score value and the y-axis representing probability of that value. One interesting thing to notice from the curve is as you go towards the either tail of the curve probability goes down. 95.4% of the entire population falls in between -2 and 2. Hence the neurofeedback providers are usually more interested in z-scores outside this range to train.
Image source: https://www.drdawnwright.com/empirical-rule-and-z-score-probability/
Demo Session (Neurofeedback Training)
Neurofeedback Training — Assume, you are facing problem focusing on any thing and visit a neurofeedbacktraining practitioner. Most probably, the practitioner would use 19 channel EEG cap connected to their computer. Software in their computer will analyze your EEG data with expected activity and might report something like:
If you remember 10–20 placement system, then you can see areas marked in red(z-score > 2) are the ones which are higher as compared to the population average. This also explains, the problem you are having with focus. If you have a look at the table above negative implication of theta wave were ADHD, depression. Even though it is not enough for a diagnosis but it can explain trouble in focusing.
Over the following session, the practitioner will try to inhibit theta waves recommending some focusing exercises and as soon as you loose focus you will receive feedback via audio or visual, not letting you loose focus. Usually over 10–30 sessions this will train your brain how to control your focus yourself.