✓ Fact checked by: Dr. Glen M Doniger, PhD
You're sitting on a sofa facing a screen. You're playing a game. On your head, there's a headset, and an electrode is attached to your scalp. The headset communicates with software on a mobile device programmed to respond to your brain's activity.
From an observer's perspective, you may appear to be simply relaxing and playing video games, but your brain is actually doing hard work. Based on your brain activity, you may be doing well at the game or, alternatively, your player may be struggling.
You’re doing EEG-based neurofeedback, typically referred to as simply neurofeedback, which is a non-invasive methodology that measures your brainwave activity and trains your brain using visual and auditory cues.
But what exactly does this mean? Let's break it down.
Neurofeedback Therapy Explained: Optimizing Your Brain Activity
Neurofeedback is a technique that leverages modern technology and scientific knowledge to train brainwaves. It is one of a broader group of biofeedback therapies relying on the principle that if a person can access information about their bodily functions in real time, they can learn to control them.
Biofeedback can be applied to a variety of bodily processes such as muscle tension, body temperature, or blood pressure, and a variety of conditions, including anxiety, migraines, and chronic pain.
Neurofeedback is a form of biofeedback based on a learning method called operant conditioning, which involves rewards and punishments for behavior. Through operant conditioning, an association is made between a behavior and a consequence (whether negative or positive).
The goal of neurofeedback is to train the brain to regulate itself and help you understand when your brain is in the desired state. Eventually, your brain may be able to maintain a more balanced state even when it's not receiving feedback.
For example, you may not be aware when your brain is in a focused state or notice when your mind is wandering. During neurofeedback training, visual and/or auditory feedback clue you in on exactly when your mind is wandering in real time, and you learn how to restore your focus to the activity at hand.
Brainwaves are patterns of electrical activity occurring in the brain. They are related to many crucial aspects of brain function, like thoughts, emotions, and behaviors.
Try to think of them as musical notes: the low-frequency waves are like a deep drum beat, while the higher frequency brainwaves are more like a subtle, high-pitched flute. As a symphony, the higher and lower frequencies link and cohere with each other through harmonics.
Depending on what you're doing at the time, a particular brainwave may be dominant over the others. And if your brainwaves are not balanced properly, you may experience both emotional and neuro-physical health concerns.
For example, if the slower brainwaves are dominant, you may feel tired, sluggish, or dreamy. The higher frequencies are dominant when you feel focused or hyper-alert.
5 Types of Brainwaves
The brainwaves recorded by the EEG are measured in frequency (speed of the waves expressed in hertz: number of waves per second) and in amplitude (height of the waves expressed in microvolts). In general, the amplitude decreases as the frequency increases.
Brainwaves are divided into frequency bands as follows:
Delta brainwaves (.5 to 3 Hz). Delta is a very slow, low-frequency brainwave generated in deep meditation and dreamless sleep. It tends to be the highest in amplitude and the slowest wave. Healing and regeneration occur when the brain is in this state. Feeling unrested when you wake up is probably a sign that you didn’t spend enough time in the stage of sleep characterized by delta waves.
Theta brainwaves (3 to 8 Hz) are slow waves that relate to dreamy, free-flowing, detached unconscious thought. They are dominant during “autopilot” states, or, in other words, instances of automatic tasks and sometimes in deep meditative states. Theta brainwaves are essential for processing information, and they are our gateway to learning, memory, and intuition.
Alpha brainwaves (8 to 12 Hz) are faster than theta but slower and higher in amplitude than beta brainwaves. They are typically dominant during meditative and mindful activities and represent non-arousal. During this state, the brain isn’t trying to solve any problems or process a lot of information. Alpha brainwaves help with mental coordination, calmness, alertness, mind/body integration and learning.
Beta brainwaves (12 to 38 Hz) are high-frequency waves of relatively low amplitude. They are amplified when your brain is alert and engaged in cognitive tasks that require a lot of attention and focus. They are dominant during instances of problem-solving, judgment, decision-making, or any other focused mental activity.
Beta brainwaves can be subdivided into three categories:
Lo-Beta (Beta1, 12-15Hz), called “sensorimotor rhythm” or “SMR” when recorded over the middle of the brain (sensorimotor strip), is dominant during meditative states and has been shown to be beneficial in reducing anxiety, increasing focus, and promoting overall well-being.
Beta (Beta2, 15-22Hz) is intense, focused brain activity when we are working on solving a problem or actively engaging with our environment.
Hi-Beta (Beta3, 22-38Hz) may reflect complex thought related to integrating new experiences, high anxiety, or excitement.
Gamma brainwaves (38 to 42 Hz) are the fastest (i.e, highest frequency) brainwaves with lowest amplitude. They are involved in combining information from different areas of the brain and are prominent when you’re both alert and highly focused. Gamma waves are dominant at times of very deep focus, like when you’re trying to solve a problem.
We cycle in and out of different brainwave states throughout the day and night. Even though all brainwave states are essential, they should be experienced appropriately — when engaged in certain activities, at certain times of day and for particular durations of time.
Neurofeedback teaches your brain to regulate your brainwaves so that you can achieve the desired brainwave state.
For example, alpha waves occur when you are relaxed. Beta waves are associated with alertness, but when maintained for too long, they may lead to fear and anxiety.
So, if you are anxious, learning how to increase alpha waves while reducing beta wave activity might be your goal.
A Brief History Lesson
Neurofeedback was pioneered in the 1960s by two researchers: Dr. Joseph Kamiya at the University of Chicago and Dr. Barry Sterman at UCLA.
Dr. Kamiya found that by using a simple reward system, people could control their brainwaves. He trained people to achieve an alpha state by rewarding them with the sound of a bell. This marked the first time that real-time feedback was provided to humans based on EEG monitoring – the first instance of neurofeedback training.
During the same period, Dr. Sterman found that cats in his lab could be trained to increase their brainwaves at a certain frequency when rewarded with food. Dr. Sterman called this frequency, which was in the low beta range (Beta1; 12-15 Hz; see above) and recorded over the middle part of the brain (sensorimotor strip), “sensorimotor rhythm”, or “SMR”.
A few years later, Dr. Sterman was doing an experiment for NASA on whether rocket fuel caused seizures, and he used the same cats as experimental subjects. During this study, he found that the cats who had undergone SMR training were significantly less likely to experience seizures than other cats. Dr. Sterman then applied this technique to humans who have epilepsy and found that 60% of the participants were able to reduce their epileptic seizures by 20-100% and that the results were enduring.
In the 1970s, Dr. Joel Lubar began to run controlled studies applying neurofeedback training to children, adolescents, and ultimately adults, to treat Attention Deficit Hyperactivity Disorder (ADHD).
Since then, a significant body of research on the efficacy of neurofeedback therapy for treating ADHD has emerged, with many studies showing significant and long-term improvements after neurofeedback therapy.
Neurofeedback has been around for more than 50 years! Its origins are fascinating, and there are hundreds of research studies in the scientific literature supporting its efficacy. In the past, neurofeedback was only available in specialized clinics, but today you can use it from the comfort of your home.
What Happens to Your Brain During a Neurofeedback Session?
"The brain electrical activity of human beings is the greatest potential resource for understanding the dynamics of all human behavior." - Barbara Brown, author of Stress and the Art of BiofeedBack
Inhibiting certain brainwave frequencies and enhancing others is usually done by placing electrodes on the scalp and then providing immediate feedback about the brain's activity. This awareness makes it possible to gradually recondition brain activity.
Let's say you're training for attention. EEG helps in detecting alertness in real time. So, each time you're in a mental state reflecting focus, you may get a visual or auditory reward, encouraging your brain to remain/enter this state more often. And that's how the brain self-regulates; it learns from positive or negative feedback.
Over time, the ability to regulate brainwaves can be applied in real-world situations. For example, you may find it easier to stay focused in stressful situations, like on a job interview or during an exam.
Neurofeedback Therapy for Attention Deficit Hyperactivity Disorder (ADHD)
Attention-deficit/hyperactivity disorder (ADHD) is a neuro-behavioral disorder characterized by an ongoing pattern of inattention and/or hyperactivity/impulsivity.
People with ADHD have different brainwave patterns from those who don't have the disorder.
They often have more theta (slow, mind-wandering waves) activity than usual, and less beta (fast, focused, problem-solving) activity than other people (see “5 Types of Brainwaves” above). Thus neurofeedback therapy for ADHD often aims to increase beta waves and diminish theta waves.
For ADHD, the usual recommendation for a full course of neurofeedback is 20–40 sessions twice or three times a week, with a session duration of 20–30 minutes.
People with ADHD may start to see results after 8–10 sessions, but the full course of sessions is recommended to ensure that results are long-lasting.
What Does Science Say About Neurofeedback for ADHD
ADHD is the most well-studied condition in neurofeedback research. Based on meta-analyses and large multicenter randomized controlled trials (RCTs), two frequency neurofeedback protocols researched for more than 40 years have been shown efficacious and specific for ADHD:
Theta-beta ratio (TBR) protocol, which aims to decrease theta and/or increase beta power in central and frontal locations. The goal is to reduce the high theta-beta ratios, high theta power, and/or low beta power characteristic of children and adults with ADHD.
Enhance SMR, which is known to heighten attention and has been applied to improve cognitive performance.
A series of meta-analyses have shown that the standard TBR and SMR protocols improve ADHD symptoms, especially inattention.
Notably, RCTs suggest that 30–40 sessions of TBR neurofeedback are as effective as methylphenidate (a central nervous system stimulant) in alleviating inattentive and hyperactivity symptoms and are even associated with superior academic performance (studies by Duric and colleagues, Meisel and colleagues).
Frequency neurofeedback for ADHD received a grade 1 (‘‘best support’’) rating from the American Academy of Pediatrics in 2013.
Neurofeedback Therapy for Anxiety: Repairing the Dysregulated Stress Response System
Anxiety is a feeling of fear and distress. It's a normal physical response when you are faced with severe stress or danger. However, it becomes a disorder if it’s prevalent almost all the time or if it becomes so intense that it interferes with your life.
“Anxiety disorders” is an umbrella term that includes generalized anxiety disorder (GAD), panic disorder, phobias, social anxiety disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD).
Prolonged symptom duration typically classifies anxiety as a chronic disorder, and in many cases these symptoms are frequent panic attacks, obsessive thoughts, a paralyzing phobia, or unrelenting worries.
Anxiety changes the brain by weakening the connections between the amygdala (a brain structure associated with emotional processes) and the ventrolateral prefrontal cortex (a region of the frontal lobes associated with response inhibition and goal-appropriate response selection).
In healthy brains, the ventrolateral prefrontal cortex and the amygdala work together to analyze and respond to social and environmental cues.
So, when you experience a potential threat, the amygdala sends signals throughout the brain, activating the ventrolateral prefrontal cortex, which helps your brain respond to the situation appropriately. Anxiety weakens the connection between the ventrolateral prefrontal cortex and the amygdala, making you less likely to respond to the threat rationally.
Research has shown that neurofeedback may help strengthen the connection between these parts of the brain. With the connection restored, the ventrolateral prefrontal cortex can effectively provide an appropriate response to potential threats, reducing the impulsive, hyperactive reactions commonly associated with anxiety.
In a study of highly-talented musicians performing under stressful conditions, only musicians who received alpha-theta (enhancement) neurofeedback training yielded enhanced musical performance under stress. In another study, adolescents with self-reported attention and anxiety symptoms found enhanced alpha and SMR along with improved symptoms (by visual analog scales) after neurofeedback training of alpha, theta, and SMR twice a week for five weeks.
Neurofeedback Therapy for Depression: Rebalancing the Brain
Depression is a mood disorder that causes a persistent feeling of sadness and loss of interest. Also called “major depressive disorder” or “clinical depression”, it affects how you feel, think and behave and can lead to a variety of emotional and physical problems.
There are different types of depressive disorders, and their symptoms can range from relatively minor (but still disabling) to very severe.
Neurofeedback for depression is based on well-established EEG research indicating that the left frontal area is more associated with positive affect, while the right frontal area is more involved with negative emotion.
A biological predisposition for depression exists when there is an asymmetry in brainwave activity, such that there is excessive left frontal alpha (8–12 Hz) reflecting less activation and failure to suppress the subcortical structures that mediate depression.
Research has shown that when the left frontal region is “stuck” in an alpha idling rhythm, there is both reduced positive affect and more withdrawal behavior.
And when there is increased left frontal beta (15–18 Hz), there is more activation and a greater sense of well-being.
In a recent study of major depressive disorder (MDD), most participants who received a 1-hour/week neurofeedback protocol were able to regulate their alpha asymmetry and show improvement in depressive symptoms after 6 weeks.
Studies have also shown that enhancing beta and inhibiting theta or alpha may reduce depressive symptoms.
Neurofeedback Therapy for PTSD: Regaining Control
PTSD (post-traumatic stress disorder) is an anxiety disorder caused by exposure to a traumatic event, often appearing after the event and characterized by feelings like guilt, isolation, irritability, difficulty sleeping, and difficulty concentrating.
Neurofeedback training for PTSD often starts with a training protocol to calm the patient physically and mentally. Neurofeedback experts then move on to "alpha-theta training," which encourages patients to enter a very relaxed state (see ‘5 Types of Brainwaves’ above).
This study, published in 1991, compared two groups of Vietnam veteran PTSD sufferers – one group received neurofeedback and the other didn't.
The neurofeedback group showed a significantly greater reduction in symptoms. Two-and-a-half years after the training, PTSD symptoms had returned in only 20% of the neurofeedback group, compared with 100% of the control group.
A recent systematic review and meta-analysis pooled data across four randomized controlled trials (RCTs) in PTSD and revealed a very large effect size for improvement in PTSD symptoms. The studies consistently favored neurofeedback in terms of symptom severity and number of patients achieving remission.
Specifically, PTSD symptoms were reduced by 34-66% in the neurofeedback group, but ranged from a reduction of 15% to an increase of 13% in the control groups.
The follow-up study reported a 46% symptom reduction and 51% symptom reduction at the one-month follow-up (compared with reductions of 13% and 14% at one-month follow-up in the control). At 1-month follow-up, 58% (11/19) of neurofeedback patients achieved remission as compared with only 11% (2/19) of controls.
Neurofeedback Training for Brain Injury Rehabilitation
Neurofeedback can also help with acquired brain injuries (ABI) or deterioration in brain function over time. These injuries can be:
Traumatic brain injuries (caused by a physical impact to the head).
Non-traumatic brain injuries (e.g., strokes, ruptured brain aneurysm, chemical brain injury).
Alzheimer's and Parkinson's diseases.
Neurofeedback cannot repair physical damage to the brain's structure, but it can strengthen and help generate new neural pathways to restore brain function.
In one study, 12 participants who experienced impairments of attention due to closed head injury engaged in ten neurofeedback sessions aimed at increasing beta activity over two weeks, while 9 participants trained with computer-based attention training.
All participants were tested before and after training with a set of attention tests.
Participants in the neurofeedback group improved significantly more on the attention tests than participants in the control group.
Neurofeedback Therapy for Peak Performance
Neurofeedback provides tools to improve brain efficiency and train neural networks in the same way you would build a muscle.
By strengthening specific neural connections and improving the brain's efficiency, less extraneous mental energy is expended maintaining composure or overanalyzing, for example.
Neurofeedback can also be used to promote stress recovery and improve sleep quality, which are essential to optimal brain performance and resilience.
Optimize Your Brain
Peak performance neurofeedback protocols aim to control arousal, attention, and motivation. The main goal of training is for you to complete a specific function or task with fewer errors and greater efficiency.
Twenty-three controlled studies reviewed here have shown neurofeedback-related gains in:
Sustained attention (the ability to focus on an activity or stimulus over a long period).
Orienting and executive attention (successfully directing attention to a target stimulus and the ability to regulate thoughts, emotions, and responses).
The P300b event-related potential (P300 is a shift in brain activity generated in response to specific stimuli and elicited in the process of decision making. It's an important signature of cognitive processes such as attention and working memory).
Reaction time (how fast you respond to a stimulus).
Complex psychomotor skills (a wide range of actions involving physical movement related to conscious cognitive processing).
Implicit procedural memory (a type of memory that enables you to perform many everyday physical activities, such as walking and riding a bike, without giving it a thought).
Recognition memory (the ability to identify as familiar a stimulus or situation you previously encountered).
Perceptual binding (the process of merging individual bits of sensory information into coherent representations; for example, reaching in the correct direction, or lifting a glass with the right amount of muscle tension and drinking the water it contains rather than trying to inhale it).
Mood and well-being.
Neurofeedback for Sleep
During sleep, pathways form between nerve cells (neurons) in your brain that help you remember new information you've learned.
When you're sleep-deprived, your brain can't perform its duties as well. And no matter how much work you've put in while you were awake, much of the value can be lost.
One study found that neurofeedback therapy resulted in increased total sleep time, increased REM sleep, and decreased periods of waking after sleep onset. Thus neurofeedback appears to be beneficial in alleviating symptoms of sleep disorders.
EEG-based neurofeedback has been offered in clinical settings for decades and for many different purposes. It's a form of biofeedback that uses EEG technology to read your brainwaves in real time and show visual or auditory feedback based on protocols determined by the neurofeedback expert.
In this article, we covered the basics of neurofeedback as well as the benefits of neurofeedback in alleviating symptoms of various brain disorders:
Brainwave Harmony: If your brainwaves are not balanced properly, you may experience both emotional and neuro-physical health concerns.
Neurofeedback for ADHD: Neurofeedback therapy for ADHD often aims to increase beta waves and diminish the frequency of theta waves.
Neurofeedback for Anxiety: Neurofeedback training that reduces arousal may be applied to reduce anxiety and create a generally relaxed state of well-being.
Neurofeedback for Depression: Neurofeedback can help alleviate the symptoms of depression by promoting better balance between left and right lobes of the brain.
Neurofeedback for PTSD: Through neurofeedback training, memories of the trauma (whether consciously remembered or not) may no longer be associated with negative emotions.
Brain Injury Rehabilitation: Neurofeedback cannot repair physical damage to the brain's structure, but it can help generate new neural pathways that restore brain function.
Neurofeedback for Peak Performance: You can use neurofeedback to promote stress recovery and improve sleep quality, essential elements for brain performance and resilience.
Neurofeedback for Sleep: Neurofeedback therapy may result in increased total sleep time, increased REM sleep, and decreased periods of waking after sleep onset.
Neurofeedback can help you perform at the top of your game in an increasingly challenging environment. It's at the cutting edge of mental health care! And by helping people worldwide to achieve optimal performance, little by little, neuron by neuron, this type of brain training is changing the world!
Visit our research overview article for a comprehensive summary of neurofeedback research in multiple conditions, with supporting scientific references.
Dr. Doniger is a cognitive neuroscientist with two decades of experience in the neurotech industry. He holds a PhD from New York University and has been involved in studies of visual perception, cognitive training, neurofeedback, and neurostimulation using behavioral and neuroimaging techniques in a variety of research and clinical settings.