AThe explanation
What neurofeedback is, described carefully.
Neurofeedback is a form of biofeedback that uses measured brain activity to provide feedback intended to support self-regulation. That sentence is short, and every part of it is worth unpacking, because each part is also where the misunderstandings start.
The definition, part by part
a.
‘a form of biofeedback’
Biofeedback means measuring something your body is doing that you would not normally perceive, such as heart rate, muscle tension or skin conductance, and presenting it back to you so that it becomes perceivable. Neurofeedback is the version of that idea applied to electrical activity from the brain. It belongs to an established family of approaches, not to a category of its own.
b.
‘measured brain activity’
The measurement is an electroencephalogram, or EEG: sensors placed against the scalp detect small voltage changes produced by populations of neurons. It is a recording taken from the outside of the head. It is not an image of the brain, it does not show structure, and it does not reveal thoughts.
c.
‘to provide feedback’
The recorded signal is processed and converted into something you can perceive in the moment: a sound that changes in volume or tone, an image that becomes clearer, a simple visual cue. The delay between what is happening and what you perceive is short, which is what makes it feedback rather than a report.
d.
‘intended to support self-regulation’
The word intended is doing deliberate work. The premise is that with repeated exposure to feedback, a person may become more familiar with their own states of attention and arousal, and better able to influence them. Whether that happens, and how much it matters in daily life, differs between people and is not something a provider can promise in advance.
BTwo words that get confused
EEG and qEEG are not the same thing.
EEG
The recording itself. Sensors on the scalp capture electrical activity over time. An EEG trace is raw material: lines on a screen that a trained reader can describe, and that software can process.
qEEG
Quantitative EEG, sometimes called brain mapping. It is a statistical treatment of an EEG recording, often a comparison against a reference database, usually displayed as a coloured map of the head.
The colours represent how a recording compares with a reference set. They are a picture of a statistical comparison. They are not a photograph of a brain, they do not establish a diagnosis, and a change in colour between two maps is not proof that a person is better.
A caution worth carrying
If anyone shows you two coloured brain maps side by side as evidence that treatment worked, be sceptical. Whether a quantitative analysis is appropriate at all, and what it can legitimately support, depends on the professional scope of the person doing it. Ask them to explain what the analysis is being used for, and what it cannot tell you.
CLimits
What this approach cannot do.
Stating limits is not modesty. It is the part of the explanation that lets you judge everything else.
It cannot diagnose.
A recording describes electrical activity during the minutes it was taken. Diagnosis is a clinical judgement made by a qualified professional using far more than that.
It cannot promise a result.
Responses differ between people and cannot be predicted in advance. Any provider quoting an expected outcome, a success rate, or a fixed number of sessions is describing marketing, not you.
It cannot replace care you already need.
Medical treatment, psychological therapy, medication decisions and educational support stay where they are. Training does not displace them.
It cannot rewrite who you are.
Language like rewiring, unlocking or optimising the brain is not used here, because it describes an idea of the brain rather than anything that is actually measured.
Next
Then read what actually happens, step by step.