EEG Neurofeedback & How It Can Help Stress, Anxiety, Emotional Resilience & Cognitive Performance
This article explains what EEG neurofeedback is, what it can be used for, and how it creates benefits. I discuss differences between some of the main forms of EEG neurofeedback, and compare it to peripheral biofeedback.
What Is Neurofeedback?
Neurofeedback is a form of brain training that works directly at the physiological level. It's aimed at improving brain performance and thereby such functions as:
- executive function: attention, focus and concentration, also impulse control and self-organisation
- emotional self-regulation or emotional resilience
- motivation, willpower and energy
Neurofeedback is a special form of biofeedback. Biofeedback is a training tool that measures physiological changes associated with how you're feeling, thinking and behaving. By feeding this information back in real time, biofeedback creates a context for learning to regulate your own body processes, and thereby influence your emotional resilience, etc.
Neurofeedback works specifically with measures of brain activity (as opposed to more "peripheral" measures such as muscle tension or heart rate variability). Later in the article I'll comment on the relative strengths of neurofeedback and peripheral biofeedback.
Most commonly neurofeedback is based on electroencephalography, or EEG, also refered to as brain waves. But in principle it can be used with any measure of brain activity. Other forms include:
- fMRI Neurofeedback - here the measure of brain activity comes from a magnetic resonance imaging scanner (generally only found in hospitals and research labs). It's an expensive form of neurofeedback but probably the most powerful because you can select any region of the brain to train.
- A recent TV documentary series by David Eagle showcased an fMRI neurofeedback study treating drug addiction.
- Hemoencephalography or HEG Neurofeedback - like fMRI this works by detecting changes in metabolic activity (i.e. energy consumption) associated with brain processing. However HEG sensors are much cheaper and more accessible (as I explain in this article on HEG neurofeedback). In HEG training the sensor is usually placed over the forehead where it monitors the prefrontal cortex or PFC, which plays an important role in executive function and emotional regulation. You can read more about HEG neurofeedback in this article.
The rest of this article will focus mostly on EEG neurofeedback.
What Is EEG?
EEG or electroencephalograph is simply an oscillating voltage measured from the scalp. The oscillation is complex, and it changes over time and across different parts of the head (or in other words in different parts of the brain from which it originates). Here's what a typical raw EEG looks like:
Most importantly for our purposes, the EEG varies in different states of mind. This gives rise to the idea that if we can somehow cause the EEG to change, then we can change the state of mind too, hopefully for the better - hopefully we can create a better mood or improved cognitive performance. In EEG neurofeedback we're trying to get the EEG to change through training or conditioning. More on that later.
EEG doesn't have a fixed frequency - it varies moment to moment, over a range of about 1 to 40 Hertz or cycles per second. (The brain's oscillations actually go well beyond this range at either end, but this is typically what's measured.) Another way to think of the osciallation is that it's a mix of different component frequencies. The components have names you might recognise, such as alpha and beta. Broadly speaking these components or bands tend to reflect mental state, or style of mental processing:
- Delta (1-4 Hz) rhythm is normally only present in deep sleep, but can be seen in some types of brain injury or depression cases.
- Alpha seems to be the brain's "idling rhythm", associated with relaxed awareness
- Theta is associated with an intuitive or dreamy processing style
- Beta is connected with awake thinking.
It's important to remember these are only rough approximations - e.g. alpha can vary a lot second to second, and you don't necessarily feel the difference in terms of relaxation level. Also, it depends where in the head you measure EEG to some extent.
Physiologically, the EEG voltage derives from millions of neurons acting in concert. It's thought that the "togetherness" or connectedness of the EEG across the scalp is important to brain function - for example research has shown that highly experienced meditators show a significantly higher level of synchronized gamma (about 40 Hz) across the whole brain.
How Neurofeedback Works
To recap: neurofeedback aims to create changes in mental and emotional functioning by training changes in the EEG.
The first step is to decide exactly what aspect of the EEG to train. Do you want to train increased alpha or decreased theta? And where in the head? The choice is known as the neurofeedback protocol, and it's a key part of neurofeedback. It's a daunting choice: the EEG contains such complexity that there's an almost limitless choice as to what to train. There are a number of ways of making the choice and this gives rise to a wide range of types of EEG neurofeedback. I'll return to this topic later.
Once the protocol has been defined, you then set up an EEG amplifier of some sort (and again there are a great number available, ranging widely in price) to read your brain waves. The amplifier typically connects to a computer (or tablet, etc.) and a neurofeedback software application will analyse your EEG, compute your desired parameter according to your protocol, and turn this calculation into real-time feedback.
In simple terms, this feedback tells you (or rather, your brain) whether you're doing it right or not, or getting closer to the desired state.
Suppose you're training for increased alpha. The simplest feedback might be a bell that rings whenever your alpha level exceeds a threshold (set within the software). This would be discrete feedback - either a "point is scored" or it isn't. An alternative is some sort of continuously varying feedback. The feedback can be presented in more elaborate and engaging forms - e.g. you play a game in which a space ship moves with a speed dependent on your level of alpha activity (this would be an example of continuous feedback).
In any case, the feedback serves as a kind of "reward" signal. The trainee is at least aware that it's a good thing when the reward happens, and they can hope for more even if they don't consciously know what to do. With repeated experience of feedback, the brain learns what it needs to do. In psychological terms, there is a process of conditioning.
Whatever form the feedback takes, it should be "real time", meaning that the gap between an actual EEG change (within the brain) and the software feedback of this change, should be as small as possible - a small fraction of a second - otherwise the brain does not learn (so effectively).
The Experience Of Feedback
Notice I said the brain learns, rather than you learn. This seems to be a key part of the process: most practitioners give the instruction to let the brain do it for you, in some sense. In neurofeedback, you don't "figure out" what you're supposed to be doing, in the normal problem-solving way. You might, after some experience of the training, "get it" - you develop a sense of what you're doing to gain the rewards, but it's not something you can really put into words. Indeed, some people never do get this sense that they've "got it" - but can still apparently benefit from the neurofeedback.
The Training Protocol
Recapping my earlier point, the training protocol is the choice of exactly what to train: what parameter within the whole complex phenomenon of EEG, and where on the head. This choice pretty much always has to be made in neurofeedback, and different choices give rise to different types of neurofeedback.
There are different ways of making the choice. In the first place, you can base the choice on some sort of assessment of the individual, or you can go for a "one size fits all" approach.
Neurofeedback Without Individual Assessment
One size fits all approaches have been criticized but they're not necessarily bad. Examples include:
- Simple consumer devices such as the Muse by Interaxon. The company has selected some general EEG parameter that they think reflects a meditative state. They claim their device helps meditation - they don't claim it treats medical disorders or produces universal improvements of brain performance. I think this is perfectly reasonable - though to my knowledge they haven't said what exactly within the EEG they're basing their feedback on.
- Open Focus training, as taught by Dr Les Fehmi. This is similar - Dr Fehmi is specifically training attention, a certain kind of attention that he calls "open focus", and he uses an EEG parameter called alpha synchrony as a brain correlate. Since attention is a high level mental function, it's reasonable to think that there's some brain process supporting it that's common to all.
- Neuroptimal brain training by Zengar Institute - the developer of this system calls it a "dynamic neurofeedback" system that trains brain flexibility and resilience, rather than some specific brain state. (Their "protocol" is proprietary.)
The alternative is to base the choice of protocol on some assessment of the individual - either using the trainee's symptoms, problems, and experiences of neurofeedback (e.g., as I understand it at least, the Othmer method to neurofeedback) or an objective assessment of the trainee's brain.
One of the most reputable forms of neurofeedback is QEEG-guided neurofeedback. A QEEG is a highly detailed "brain map", which is based on measuring EEG simultaneously from lots of points across the head. Essentially the approach is to look at how the individual brain deviates from "normal" (which is "average" of a large database of apparently healthy brains) and then train the brain to narrow that gap.
One criticism of QEEG-guided neurofeedback is that it trains "average" brain function which is not necessarily the same as optimal function. Other simpler assessments avoid this problem, e.g. Dr Paul Swingle's "clinical-Q" system, described in his book "Biofeedback for the Brain". I discuss EEG assessment in more detail in this article.
How EEG Neurofeedback Creates Change
Neurofeedback almost certainly induces neuroplastic change in the brain (i.e. functional change, and structural at the micro level). That's not necessarily a big claim - any repetitive, active behaviour does (e.g. playing a musical instrument or driving a London taxi). The difference is, with neurofeedback you're more precisely controlling the change process.
It could be said that with neurofeedback, and with biofeedback more generally, we're training specific skills - e.g. attentional control.
Another way of looking at it is that we're simply exercising the brain, as a means of improving "brain fitness" in some way - neurofeedback is a kind of weight-training for the brain. However if that were all, the changes probably wouldn't be as enduring as they are.
Some forms of neurofeedback, notably QEEG-guided neurotherapy, create the impression of creating very precise brain adaptations in an almost mechanical way - like fixing bugs in computer code, or as if the therapist is some sort of expert brain plumber who knows exactly which valve to tighten up.
I personally think a more general mechanism is more likely: I think the training proccess creates some sort of challenge for the brain, which then triggers a (natural) adaptive change in the brain over the days (and weeks?) following the training sessions. Again the weight training metaphor might help: weight training itself actually produces a mild level of damage to your muscles but it stimulates the body to repair and "heal" the muscles so that they come back stronger and better able to handle such challenges in the future. My guess is something like this happens in the brain with neurofeedback, and probably with other neurotherapy methods besides (e.g. tDCS). The healing ultimately originates within the brain. Perhaps neurotherapy works by stimulating (or "rebooting") the brain's natural self-regulation capacities.
I see problems like anxiety, depression and brain fog as loss of flexibility - the brain gets stuck in some unhelpful state. Recovery consists in re-regulating the brain, recovering adaptive capacity or flexibility.
LENS - Low Energy Neurofeedback System
One form of neurofeedback stands out as being very different from "traditional" EEG neurofeedback. It's known as LENS - the Low Energy Neurofeedback System. Perhaps the main difference is that the feedback is in some sense "subliminal" - the trainee is not consciously aware of it, and no consious volition or effort is required.
The actual form of the feedback is a pulsing electromagnetic signal transmitted to the brain via the same cables that read the EEG. This signal has extremely weak energy and pulses at a rate based on the brain's dominant frequency, which is varying moment to moment. It's a little like an electromagnetic echo.
With LENS there's no judgement to be made (by the therapist or even by the software) as to what the brain is doing well or badly, or what the brain should do more or less of. Like a mirror, LENS feedback simply reflects what's happening. And the brain only needs momentary exposure - literally seconds - so sessions are much shorter.
LENS developer Len Ochs warns of over-stimulating in cases of fragile or over-sensitive brains - this can lead to (short term) negative effects.
My own business was the first in the UK to offer LENS.
Results, Evidence & Research
There's pretty good evidence that EEG neurofeedback can lead to lasting improvements in mental and emotional wellbeing, and also cognitive performance.
EEG neurofeedback research has been going on since at least the 1950's.
In 2000 the medical journal Clinical Electroencephalography published a review of the evidence for neurofeedback. Neurologist and Harvard Medical School Professor Frank Duffy summarized findings with these comments: "The literature, which lacks any negative study of substance, suggests that EEG biofeedback therapy should play a major therapeutic role in many difficult areas. In my opinion, if any medication had demonstrated such a wide spectrum of efficacy, it would be universally accepted and widely used."
The International Society for Neurofeedback and Research (ISNR) has compiled a bibliography of neurofeedback research studies which you can check out here.
The Association for Applied Psychophysiology and Biofeedback (AAPB) has rated the efficacy of biofeedback and neurofeedback treatment of specific disorders such as anxiety, depression and ADHD, based on the available research evidence. You can review their findings here.
For the sake of balance it must be admitted that none of the neurofeedback research studies have been large, and a criticism has been leveled that many studies aren't well controlled or "blinded". In medical research it's considered that the best evidence comes from "double blinded" trials where neither the researchers nor the subjects of the study know whether they're getting the real, active therapy or some non-real or sham therapy (such as an inactive "placebo" pill). However I don't think this is a fair criticism because biofeedback and neurofeedback must be considered as "behavioural medicine" where the benefits result (at least in part) from some learning process. Double-blind trials are very appropriate for drugs research but how can you reasonably blind a behavioural or learning process? Imagine trying to test the efficacy of brushing your teeth without knowing whether you brushed your teeth or not.
Clearly neurofeedback is not a panacea, and it doesn't work for everyone who tries it. It's a way of optimizing brain performance, but doesn't necessarily address causal factors of problems (which might be for example heavy metal toxicity or gluten intolerance). In some ways neurofeedback is like pumping up your tyres but it might be better to fix any punctures first.
Safety of Neurofeedback
Because neurofeedback is a training or learning procedure, it's usually reported to be completely safe. Although neurofeedback almost certainly does induce change at the level of the brain, it's not invasive change coming from without but neuroplastic change, essentially coming from within the brain.
However I think it's naive to assume you can't do any harm with neurofeedback. I think a more reasonable assumption is that anything that can have an effect on the brain, might have a negative effect if used in the wrong way or the wrong circumstances. In the case of neurofeedback that might mean selecting an unhelpful training protocol, or training a brain that is too unstable in some sense. That said, it seems very unlikely to me that neurofeedback could produce permanent harm.
If you're thinking of trying neurofeedback I would suggest you'd better know what you're doing or find an experienced, qualified practitioner.
EEG Neurofeedback vs. Peripheral Biofeedback
My own practice is based much more on what's known as peripheral biofeedback rather than neurofeedback. Why? And what are the differences?
Recall that earlier, I suggested that neurofeedback and biofeedback work by a combination of (i) skills development (e.g. attentional control) and (ii) exercise that builds "fitness" in the brain and nervous system. I think peripheral biofeedback (such as the optimal breathing training I like to focus on) is more about the former (skills development), while neurofeedback is more about the latter (brain fitness training).
To put it another way, biofeedback is training at the level of the mind, while neurofeedback is training at the level of the brain. It may be that neurofeedback develops skills, but not necessarily "conscious mind" skills or volitional skills. Neurofeedback doesn't necessarily make you more self-aware or more aware of how emotions arise and affect you. It may be that neurofeedback will reduce your stress or anxiety level, but you won't necessarily know any more clearly what to do when a stressful situation arises.
More advantages of peripheral biofeedback over neurofeedback are:
Peripheral biofeedback generally takes far fewer sessions. Neurofeedback often takes 20-100 sessions, whereas I rarely take as many as 10 sessions with a client (assuming each session is about an hour long).
Biofeedback creates learning that is easier to transfer or generalise from the training context into real life contexts.
Of course these are my personal views and no doubt neurofeedback practitioners would take a different view.
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