Neurofeedback Explained: How Brainwave Training Works

Picture a movie that only plays at full brightness when your brain behaves the way you want it to. Settle into calm focus and the picture blooms and the volume swells. Let your attention drift into a familiar loop of worry and the screen dims and the sound falls away. Nothing in the room is doing the work except the electrical rhythms coming off your scalp. That, in a sentence, is the mechanism at the center of neurofeedback, and it is the subject of a one-hour introductory webinar from the NeuroMeditation Institute, presented by the psychologist Jeff Tarrant, who has worked in the field for about 25 years. He walks through what neurofeedback is, why a brain might need retraining in the first place, how EEG measures the electrical activity behind thought, how a quantitative EEG assessment builds a map of an individual's brain, and how those ideas apply to ADHD, anxiety, and depression. It is a clear primer, and it rewards a slow reading of the basics that many people skip.

What is neurofeedback, in Jeff Tarrant's definition?

Start with the word itself. Tarrant places neurofeedback inside a larger family. "Neurofeedback is really a specialized form of biofeedback," he explains, and he defines biofeedback as any system that measures some aspect of physiology and gives the person visual or auditory feedback about what the body is doing. The examples he gives are concrete: skin conductance, which is sweat gland activity on the fingertips; heart rate variability; muscle tension read by sensors stuck to the body; skin temperature; and brain blood flow.

Neurofeedback narrows that frame to one signal. Tarrant notes that people sometimes use the term for blood flow or other brain measures, but "it's almost always brain waves." The principle is the same across the family. Monitor the signal, communicate it in a form the person can perceive, and the person can learn to change it. The webinar's own description puts the core claim plainly: EEG biofeedback uses a brain-computer interface to measure brainwave data and display it, and that data is tied to visual or auditory feedback so that changes in activity are easy to see.

Why would a brain need to be retrained?

The reasoning Tarrant offers is about rigidity rather than damage. "One of the reasons that people tend to experience symptoms, whether it's anxiety or depression or something else," he says in substance, is that the brain "has become sort of stuck in a pattern that's no longer useful." The pattern may have started in a particular way, or it may simply be how a person was born, but over time the brain settles into a rhythm of engagement that repeats even when it stops serving the person. Neurofeedback, in his account, is a way of "creating more flexibility in the system," helping the brain move out of those stuck patterns and learn to do something different.

The teaching mechanism is older than the technology. Tarrant points to operant conditioning, the principle that behavior which is rewarded tends to recur. His illustration is a puppy: give a treat when it does what you like, and it does that thing more. Ignore or punish what you don't want, and it happens less. "Interestingly," he observes, the brain responds to the same basic behavioral mechanisms. Neurofeedback is essentially a way of rewarding a brain for producing the pattern you want, moment by moment, without any treats at all. The reward is the screen brightening.

He is also clear that the same method reaches beyond clinical concerns. Neurofeedback can be used to enhance cognitive performance and attention, and, he says, it is used a great deal to facilitate meditative states, because researchers have a sense of what the brain tends to do during different kinds of meditation and can monitor those patterns to help a person find them.

How does EEG actually measure what the brain is doing?

This is the most technically dense section of the webinar, and it is worth slowing down for. Tarrant begins with the cell. Neurons collect chemical messages through their dendrites, in the form of neurotransmitters such as serotonin and dopamine. The cell body weighs that input and decides whether to fire its own signal. That signal is electrical, travels down the axon, and then triggers the release of more chemicals to the next cell. "The brain communicates chemically and electrically," he says. "You've got to have both."

"What you're actually measuring is large groups of neurons firing together, so you're measuring patterns of electrical activity."

Jeff Tarrant, NeuroMeditation Institute webinar, about 8:50

A single neuron can fire thousands of times a second, but an EEG is not listening to single cells. Measuring one neuron at a time requires invasive electrodes inside the brain and a research hospital. What a scalp sensor records is the sum of large populations firing together. The raw trace that most people picture, the dense squiggle of a clinical or sleep-study EEG, is therefore not the usable signal. Tarrant explains that the meaningful information shows up only after filtering, when the activity is sorted into frequency ranges. That is when the work moves from "clusters" of activity to named bands: theta, and then faster rhythms beyond it, each associated with different states of alertness, drowsiness, or focus. The bands are the vocabulary of neurofeedback, and the system learns to reward the person when the vocabulary moves in the desired direction.

How is a brainmap made before training begins?

Training does not start with a screen. According to the webinar's description, it starts with a quantitative EEG assessment, or qEEG. Activity is recorded from 19 locations on the surface of the head and run through several analysis systems. The output is a set of "brainmaps" that compare an individual's activity against a normative database, which gives a practitioner an idea of where and how particular regions are behaving relative to a reference group.

The purpose is specificity. When the maps reveal patterns likely to be connected with particular concerns, such as rumination or difficulty paying attention, the practitioner builds an individualized program to train those patterns toward greater flexibility. Tarrant's webinar shows sensor placements such as Cz and Pz on the scalp as part of this picture, and he is candid that interpreting such data is not a matter of reading one number. The approach is probabilistic: a map suggests where to look, not what a person's diagnosis is.

What does the approach look like for ADHD and anxiety?

Tarrant uses ADHD as a worked example. He imagines a person who says they have ADHD and asks what the practitioner should do with that information. The answer runs through the brainmap rather than the label. Two people with the same diagnosis may show different patterns, so the training target depends on what the individual's EEG reveals. This is the logic of individualized protocols: the same symptom can come from different places in the system.

Anxiety receives the same treatment, with a caution attached. Tarrant describes one pattern that tends to be associated with anxiety, but he is careful to say that calling it a single cause is an oversimplification. The more accurate framing, in his telling, is that a pattern is a tendency the brain has fallen into, and the aim of training is to restore range and flexibility so the person can move between states rather than being locked in one. The webinar is also candid about the limits of the field. Tarrant warns at the outset that there are many kinds of neurofeedback, many companies, and many types of equipment, and that his talk is an overview that will resemble, he hopes, what most providers do.

Where has the field come from, and what does it look like now?

Tarrant's own career is the most vivid measure of change. He has worked in the field for about 25 years, and he remembers the early equipment as rudimentary. Comparing the first systems he used with what is available now, he says the difference is "night and day," and that it is "thank goodness" a matter of progress. The technology is more interesting and more useful than it was, and the protocols have grown more individualized as the maps and analysis systems have improved.

The webinar closes with a playback demonstration, so viewers can see what neurofeedback looks like on screen rather than hearing it described. That choice is itself a lesson. The method is easier to understand when you can watch the signal, the brightness, and the volume respond in real time. A reader who wants the concept rather than the sales pitch will find the demo the most useful part of the hour.

Where to go from here

If this introduction has you curious, the most useful next step is the full webinar, which runs about 53 minutes and includes the live playback demo that Tarrant builds toward. Watch it with the core ideas in mind: biofeedback as the parent category, operant conditioning as the learning engine, EEG bands as the vocabulary, and the qEEG brainmap as the starting point of an individualized program. Then look at the NeuroMeditation Institute website, listed in the video's description, to see how its approach is described in its own words. Keep in mind that this is a single introductory talk from 2022, and that Tarrant himself stresses that neurofeedback comes in many forms. Ask any provider how their assessment works, what their brainmaps compare against, and how they decide which patterns to train. Those questions will tell you more than any single video can.