Would you like to see your thoughts live and try to change the ones you don’t like? In general terms, that’s what neurofeedback is all about . It’s a “training technique” that allows us to observe our brain activity in real time to learn how to modulate it voluntarily, thanks to the use of electroencephalography (EEG).

Let’s imagine the brain as a musical instrument. Brain waves act like notes that can be chaotic at first. However, through feedback practice, patterns begin to be identified and the harmony between thoughts, emotions, and behaviors improves. In other words, neurofeedback could help “tune” the brain.

But is this a melody with a solid scientific basis, or are they just isolated chords with no connection to each other? This article explores whether neurofeedback can participate in the orchestra of effective therapies or whether it needs further rigorous testing before taking center stage.

Composing thanks to electroencephalography

The purpose of electroencephalography is to record the tiny electrical signals generated by neurons. To do this, small electrodes are placed on the scalp following a standardized system called the ” 10-20 ” electrode pattern. This method ensures that different areas of the brain are adequately covered .

International System for Extracranial Electrode Placement. The term 10-20 refers to electrode placement 10% to 20% of the total distance between specific locations on the skull. Letters indicate the area (Fp, prefrontal; F, frontal; C, central; P, parietal; T, temporal; and O, occipital), while numbers designate the hemisphere (even for the right, odd for the left), and midline electrodes are marked with a z; thus, Fz is located frontally on the midline. Adapted from Novo-Olivas et al., 2010.

The captured brain signals are then translated into waves based on their frequency, measured in hertz (Hz), and their amplitude, measured in microvolts (μV). These waves (which are also used to analyze synchronization between different brains ) are taken as an indicator of the person’s mental state.

Briefly, waves and their association with mental states are as follows:

• 

  Different types of brain waves: delta, theta, alpha, beta, gamma. Adapted from Arns, 2020.

  Delta (0.5–4 Hz), deep sleep.

• Theta (4–8 Hz), relaxation and daydreaming.
• Alpha (8–12 Hz), calm.
• Beta (13–35 Hz), active attention.
• Gamma (>35 Hz), complex cognitive processes.

By recording the EEG signal at a specific point, it’s possible to identify which type of wave predominates. This provides clues about the functional state of that area: relaxation, attention, etc. In other words, the rhythm of the waves helps us understand the “resonance” of a given part of the brain at any given time.

Listening to the brain to rewrite the score

The main objective of neurofeedback is for the person to learn to detect imbalances in the waves and regulate the brain’s “rhythm” according to therapeutic needs.

Currently, there are several types of neurofeedback and various training protocols . For example, the alpha protocol (based on increasing these waves) is commonly used to relieve pain and anxiety (alpha waves increase during meditation and mindfulness ).

The beta protocol is used to improve focus and attention , while the alpha/theta protocol is one of the most popular workouts for stress reduction .

These are just a few examples, but there are more .

This diagram illustrates the neurofeedback training cycle . In a typical session, the EEG displays dynamic brain wave patterns (bottom of the image). These patterns are processed in real time, extracting the parameters of interest that are then fed into a control system. Audiovisual feedback is then modified and presented to the participant in an understandable way (a video game, a movie, or a graph that moves up and down), thus establishing an interactive feedback loop. The goal is for the person to learn to regulate their own brain waves by implementing various strategies, and they receive reinforcement (instrumental conditioning) when they generate the desired EEG pattern. At the end of the treatment, the person should be able to self-regulate their own thoughts (represented by brain waves) autonomously. Adapted from Omejc et al., 2019.

It is important to highlight the complexity of the procedure, both due to the difficulty of accurately recording EEG activity in different brain areas and interpreting and relating these signals to mental states (or disorders). Despite these limitations , neurofeedback has been applied to treat various disorders.

A symphony of therapies

The first therapeutic study with neurofeedback was published in 1972 and was applied as a treatment for epilepsy , with positive results.

Subsequent work indicated that the benefits could be maintained even a decade after treatment, making neurofeedback a suitable adjunct for drug-resistant epilepsies.

More than 50 years after the first study, this procedure has been used in a multitude of psychological disorders and other clinical problems , which could be listed like the songs of a musical group.

Along with epilepsy, which is thought to be the oldest hit , the disorders where it has been most used are: ADHD (a controversial label due to its origin and the use of psychotropic drugs in childhood), depression, anxiety, autism, insomnia, learning difficulties (dyslexia, dyscalculia, and dysgraphia), drug addiction (including alcohol), schizophrenia, post-traumatic stress, and Alzheimer’s.

Some less popular clinical problems (where it has been used less) are: migraines , eating disorders , Parkinson’s , fibromyalgia and OCD .

It has even been used in healthy people to promote health , encourage musical creativity and improve athletic performance .

Improvising between awkward silences

But neurofeedback ‘s popularity doesn’t always reflect its effectiveness. For example, in children labeled with ADHD, the International Society for Neurofeedback and Research classification indicates it achieves a level 4 efficacy (out of 5). However, recent meta-analyses show no significant benefits.

There are also doubts about whether the success achieved in some studies is actually due to the treatment or a possible placebo effect , since suggestion alone can reduce the symptoms of so-called ADHD. Additionally, no specific effects have been found in adults .

Neurofeedback specifically targeting depression has little support from existing studies (most fall into Level 2). The main complication preventing further evidence is the relatively high number of uncontrolled studies. Although the technique has been used for several decades , it is still perceived as promising for reducing depressive symptoms in the future.

In the case of anxiety disorders, particularly positive results have been obtained . However, bioethical studies warn that associating these results with the effect of neurofeedback could constitute unintentional deception (it could result in an erroneous attribution of the benefits obtained from the procedure, even if there is no intention to deceive).

To the beat of uncertainty

In short, neurofeedback has been used primarily as a complementary treatment for various disorders and conditions, but current research does not support its effectiveness. The lack of standardized protocols , the limited presence of double-blind studies , and the limited use of placebo groups (due to ethical issues , particularly relevant in childhood) make it difficult to establish a cause-and-effect relationship.

In summary: efficacy beyond the placebo effect is not proven .

The truth is that people who have used this tool express “high satisfaction” with the experience, without deeply questioning how or why it works. However, from a scientific perspective, subjective satisfaction is not enough. Neurofeedback fails to hit the right note: it requires more rehearsal or withdrawal from the setting.

Author Bio: Jorge Romero-Castillo is Professor of Psychobiology and researcher in Cognitive Neuroscience at the University of Malaga