Neurofeedback is a technique used to train brain wave patterns. It is potentially beneficial in several conditions that are difficult to treat, including chronic pain, depression, PMS, autism spectrum disorder, ADHD, sleep disorders, and PTSD. More recently, neurofeedback has been used by healthy users looking to enhance cognitive performance and boost their mood.
What is Neurofeedback?
Biofeedback training is a growing trend in healthcare, where people are hooked up to devices for measuring different aspects of bodily functions to see how these processes are taking place in real time. People can then be trained to learn to control the way these processes are carried out [1, 2].
Neurofeedback is a specific form of biofeedback training, which is based on the idea that people can consciously alter the way their brains function with training programs that help them to visualize and learn to change the patterns of electrical activity in their brain .
Types of Neurofeedback Training
All neurofeedback techniques involve measuring and visualizing activity patterns of the brain so that the patient can gradually learn how to change the way their brain works .
- Slow cortical potentials (SCP) [6, 7]
- Hemoencephalography (HEG) [8, 9]
- Brain wave training (BWT) or frequency band training [3, 4]
In slow cortical potentials training, patients learn to control the overall activity levels (excitability) of the cerebral cortex as it responds to different stimuli. The feedback uses electroencephalography (EEG) to measure the electrical activity of the brain [6, 7, 4, 10].
In hemoencephalography training, patients learn to consciously control the level of blood flow to different parts of the brain, which can enhance or suppress different mental processes depending on the brain area being targeted. Feedback is based on infrared light that measures oxygenated blood levels (near infrared) or that measures the heat generated by brain activation and oxygenated blood levels (passive infrared) [8, 9].
However, the most popular form of neurofeedback training is brain wave training (also known as frequency band training), of which there are multiple protocols (for each brain wave frequency). EEG is used to measure different patterns of electrical activity of the brain. This technique trains patients to increase or decrease the strength or speed of brain waves [3, 4].
What Are Brain Waves?
To understand how neurofeedback works, we first have to know what “brain waves” are and what they do.
Your brain is made up of billions of neurons, all of which are constantly firing together in different patterns or “waves” .
These frequencies can then be classified into different categories (frequency bands). Each of these frequency bands (alpha, beta, is associated with different particular cognitive and emotional processes in the brain [13, 14, 15, 4].
This means that if we can learn how to increase or decrease the strength or speed of certain brain waves, we can consciously control how our brains process and react to different sensations and events .
Mechanism of Action
Ordinarily, people cannot directly inﬂuence their brain wave patterns. However, when they can see their brain waves on a computer screen in real time, it gives them the ability to learn how to gradually inﬂuence and change them. The mechanism of action at work is operant conditioning – a learning process where the strength of a behavior is modified by reward or punishment [4, 16].
The first step in neurofeedback involves putting a series of electrodes onto a person’s scalp and forehead to create a brain map. These electrodes measure the electrical patterns taking place in the part of the brain where each electrode is placed .
Next, if conducting brain wave training or slow cortical potentials training, the brain’s electrical activity is categorized into brain waves based on their frequency (speed of oscillations). There are five well-known brain wave frequency types [3, 17]:
- Gamma (40.0 Hz and up)
- Beta (14.0 – 40.0 Hz)
- Alpha (7.5 – 14.0 Hz)
- Theta (4.0 – 7.5 Hz)
- Delta (0.5 – 4.0 Hz)
A visual representation of these brain waves called a quantitative electroencephalogram (qEEG), or brain map, is created. This brain map can then be compared to those from healthy individuals of a similar age and sex to identify the parts of the brain that are functioning abnormally .
During training sessions (typically 40 – 60 minutes), electrodes are placed on the scalp. The patient then receives some form of positive or negative sensory feedback when their brain waves become closer or further, respectively, to the desired pattern of activity. This feedback can be in the form of visual images, audio tones, or physical sensations [3, 4].
Health Benefits of Neurofeedback Therapy
1) Improves Cognitive Function
Neurofeedback can enhance neuroplasticity (the capacity of the brain to change and adapt) and, therefore, possibly slow or reverse the natural aging process .
For example, neurofeedback improved cognitive processing speed and executive function in elderly subjects .
Specific types of neurofeedback training, such as decreasing sensorimotor rhythm (SMR) beta rhythms, can improve reaction time .
2) Boosts Attention and Working Memory
Issues with working memory, the memory used when thinking, is often associated with issues with attention and short-term memory. By increasing brain wave activity (theta, alpha, or SMR), healthy individuals were able to improve their working memory and extend their attention span [23, 24, 25, 26, 27].
A study in 32 human subjects found that neurofeedback (EEG) improved attention and working memory in older patients, while younger subjects improved their concentration and attention (executive functioning). This suggests that neurofeedback may be an effective way to prevent age-related cognitive impairment [28, 29].
3) Improves Short- and Long-Term Memory
Using EEG neurofeedback to boost alpha wave strength was associated with increases in the accuracy of multiple types of memory (episodic, working, short-term). The stronger the boost in alpha waves, the more memory enhancement each subject showed (RCT with 50 healthy adults) [32, 33].
EEG neurofeedback training (SMR and upper alpha) improved verbal memory, short-term visual memory, and working memory in 70% of the subjects (17 stroke patients and 40 healthy control subjects). Neurofeedback was more effective than traditional cognitive training and can benefit patients suffering from brain damage .
4) Helps Improve Skills
EEG neurofeedback was used to promote brain waves associated with attention and relaxation, improving the performance of professional musicians when performing in stressful conditions (SB-pilot study). A follow-up study used alpha/theta EEG neurofeedback training to enhance the creativity, communication, and technical skill of novice musicians. SMR neurofeedback enhanced technique and communication [36, 37].
Neurofeedback training (alpha/theta) also improved musical performance in school children, who showed greater creativity and reported higher well-being. This suggests that neurofeedback might be a great learning tool in the classroom (RCT with 33 children) .
EEG neurofeedback also helped actors learn faster, as well as improved their creativity, the quality of their performance, and boosted their confidence .
Athletic performance can be enhanced by EEG neurofeedback. Both golfing accuracy (in 6 subjects) and dance performance were improved by neurofeedback (RCT with 24 dancers). It also improved reaction time and visual-spatial abilities, which are important for athletic performance (RCT with 41 people) [40, 41, 42].
Both alpha/theta and SMR neurofeedback improved surgical technique (RCT with 28 surgical trainees) .
5) Lowers Anxiety
Neurofeedback can also be used to alter and control emotional processes.
6) May Help Treat Depression
EEG neurofeedback treatment reduced depression symptoms even when this training was “disguised” by having participants use their own brain activity to control music .
Hemodynamic (HEG) neurofeedback (training to control blood flow in specific brain regions) has also been used to treat depression by enhancing responses to positive memories in the limbic system, a key brain network involved in processing and regulating emotions [52, 53, 54].
Similarly, a controlled study in 10 depression patients found that using neurofeedback to reduce the brain’s responses to negative information was also effective in improving depression symptoms .
7) Improves Sleep Quality
Using neurofeedback to increase a type of brain wave called the sensorimotor rhythm (SMR) has been shown to help people fall asleep faster and improve sleep quality in healthy humans (RCT with 38 subjects) .
Neurofeedback also improves sleep quality in insomniacs. 18 sessions of remote neurofeedback (administered over the internet) decreased both the time needed to fall asleep and increased total sleep time (RCT with 29 adults) .
Similarly, insomnia patients experienced improvements in sleep quality but only if the appropriate feedback therapy was used. A follow-up study also confirmed that these benefits lasted for up to 9 months. Patients who were tense and anxious only benefited from theta feedback, while relaxed patients only benefited from SMR feedback (RCT with 48 insomniacs, RCT with 16 insomniacs) [57, 58].
8) Effective for ADHD
Children with ADHD who had received fMRI neurofeedback treatment had increased activation in the anterior cingulate cortex, a part of the brain involved in selective attention. (RCT of 20 children with ADHD) .
In children with ADHD, 30 sessions of neurofeedback training (SCP) improved cognitive function, attention, and IQ; these effects were still seen 6 months after the treatment. This finding was confirmed in another study (SB-RCT of 38 children, study with 23 children with ADHD) [60, 61].
Neurofeedback training (alpha/theta) used to improve musical performance in school children also improved their sustained attention. 15 of the 33 children had ADHD, suggesting neurofeedback would be helpful for ADHD (RCT with 33 children) .
Intriguingly, neurofeedback training is just as effective as ADHD medication. 20 sessions produced improvements in attention and concentration equal to methylphenidate (commonly known as Ritalin) .
A study tested the effects of EEG neurofeedback combined with a 1-year program of Ritalin (average dose of 25 mg/3x a day), parent counseling, and academic support. All children received the program and 51 children also received neurofeedback. Although all of the children had improved symptoms, the neurofeedback group did not need to continue taking Ritalin to maintain the benefits (RCT with 100 children with ADHD, aged 6-19) .
9) Can Improve Learning Disabilities
After 2 months of EEG theta/alpha neurofeedback, learning disabled children had improved behavior and cognitive abilities (such as memory, attention, and attitude), as reported by their parents (study with 16 learning disabled children) .
Children with dyslexia who received 20 sessions of EEG neurofeedback training showed improvements in spelling but not reading ability (RCT with 19 children) .
30-35 sessions of EEG neurofeedback training helped 12 dyslexic children improve their reading speed and comprehension abilities by at least two whole grade levels .
10) May Help Developmental Disabilities
After receiving EEG neurofeedback, 22 of 23 children with mental retardation showed clinical improvements in behavior and 19 of 23 showed improvements in IQ. However, 2 children had a decline in IQ .
11) Beneficial for Autism Spectrum Disorders
A large-scale review of data from 150 patients with Asperger’s Syndrome found that EEG neurofeedback improved symptoms of Asperger’s. It also enhanced the patients’ attention, improved their levels of academic achievement, and boosted IQ by an average of 9 points .
Similarly, in several studies, neurofeedback training led to improved social behavior, communication skills, and executive control (review of 2 studies with 8 and 19 high-functioning autistic children, study of 7 autistic children) [70, 71].
12) Helps Recover From Head Injury
Head injury and brain trauma often lead to unique cognitive impairments that can be difficult to treat with usual medical techniques. Intriguingly, neurofeedback can potentially help patients recover cognitive function after a head injury [72, 73].
In a study of 27 patients with a variety of head-injury symptoms, customized neurofeedback training improved different individual symptoms and these benefits grew stronger with more training sessions. Similarly, beta EEG neurofeedback helped 12 head injury patients improve attention (RCT) [74, 72].
Similarly, an open trial of neurofeedback training in 26 head injury patients achieved symptom improvements of at least 50% in 88% of treated patients and enabled the majority of the patients to return to work .
25 sessions of EEG neurofeedback training improved symptoms of depression, fatigue, and cognitive functioning in 6 head injury patients. The patients also reported improved social and occupational functioning .
Brain injury can sometimes lead to a complete and incurable loss of certain senses, such as the sense of smell (anosmia). Interestingly, EEG-based neurofeedback training completely restored the sense of smell in two brain injury patients with anosmia .
13) May Help Minimize Symptoms After Stroke
A 43-year-old female stroke victim experienced improved cognitive functioning and mood following EEG neurofeedback .
Neurofeedback with physical therapy helped a 71-year-old female stroke victim regain her ability to speak and move .
In a 55-year-old male stroke victim, neurofeedback training improved stroke symptoms such as speech fluency, balance, coordination, attention, and concentration. It also reduced depression, anxiety, and ringing in the ears (tinnitus) .
14) Could Treat Addiction
Chronic alcoholism can drastically alter alpha, theta, and beta brain waves. Thus, normalizing these brain waves can help reduce symptoms and possibly treat addiction .
Neurofeedback training helped alcoholics stay sober in two studies (92% of 14 remained sober for 21 months, RCT: 77% of the treated group compared to 44% of the control group remained sober for 12 months in a study with 121 alcoholics) [81, 82].
Alcoholics who received 30 sessions of neurofeedback training self-reported improvements in depression symptoms .
Similarly, EEG neurofeedback training improved mental health symptoms (such as aggression and psychosis) and reduced the desire to use drugs in opioid addicts. In a follow-up study, neurofeedback improved physical symptoms, depression, and withdrawal. The desire to use drugs was reduced. In both studies, neurofeedback was used along with medication such as methadone or buprenorphine (2 RCT of 20 opioid addicts) [85, 86].
15) May Help Manage PTSD
A review paper examined 5 studies on the effect of neurofeedback on PTSD and determined neurofeedback is a likely potential treatment for PTSD (3 of 5 studies had positive results) 
16) Might Help Chronic Fatigue Syndrome
In a similar case study, EEG neurofeedback boosted cognitive ability, functional skill level, and quality of life in a patient with chronic fatigue syndrome .
Neurofeedback can be an effective way to alleviate migraines and headaches. A review paper reported that neurofeedback treatment can reliably reduce the frequency of headaches by 50%. However, children with tension headaches needed “reminder” training every 6-12 months to maintain these benefits .
A study of 4 different biofeedback treatments (including alpha neurofeedback) found all treatments to be effective in reducing the number of migraine headaches (but not intensity, disability, or length of headache, study with 42 patients). Alpha neurofeedback (and also two other biofeedback treatments) was effective in another study (study with 33 patients) [93, 94].
Neurofeedback therapy addressing overactivated brain cells (slow cortical potentials training) reduced migraine frequency in 10 children after 10 sessions (exploratory study with 30 children) .
Using EEG and hemoencephalography neurofeedback with hand warming biofeedback, 26 of 37 migraine patients reduced headache frequency by 50% for up to 14 months (average of 40 training sessions) .
18) Can Decrease Pain
Chronic pain is often difficult to treat; current treatments have several major drawbacks (such as the potential for patients to become addicted to painkillers). However, neurofeedback training may be a powerful and more effective alternative treatment for pain disorders. However, not many controlled studies have been performed [92, 97].
People with chronic pain experienced immediate relief from pain intensity following EEG neurofeedback. This reduction in pain intensity at a 3-month follow-up (study with 10 patients) .
Similarly, fMRI neurofeedback helped chronic pain patients reduce symptoms (RCT with 36 healthy controls and 12 patients with chronic pain) .
19) May Treat Fibromyalgia
In patients with fibromyalgia, neurofeedback can cause signiﬁcant improvements in mood, mental clarity, and sleep (a study of 30 patients) .
20) May Help With Weight Issues
A review study found that neurofeedback is a promising treatment for eating disorders, obesity, and food cravings .
A pilot study with 6 healthy overweight or obese males found that hemoencephalography neurofeedback helped increase self-control with food and reduced weight .
Similarly, another study found neurofeedback helped 8 overweight or obese males choose lower-calorie foods. However, it also increased secret snacking tendencies .
21) Alleviates Parkinson’s Syndromes
Neurofeedback improved balance (both standing and moving) in individuals with Parkinson’s disease after only 8 sessions (RCT with 16 patients) .
After 2 sessions of fMRI neurofeedback, people with Parkinson’s disease improved movement speed and other movement symptoms (RCT with 10 patients). Similarly, a trial combining fMRI with motor training had promising results (RCT with 30 patients) .
22) May Treat Epilepsy
Approximately 1/3 of epileptics don’t respond to conventional therapies. For those patients, (SMR or slow cortical potentials) neurofeedback can reduce seizure frequency, approximately 70% of the time .
Similarly, after being treated with neurofeedback, 25 out of 25 epilepsy patients became seizure free. 76% no longer needed anti-seizure medication .
However, a review evaluating neurofeedback studies suggested further research be conducted .
23) Might Help Treat Cerebral Palsy
Children born with cerebral palsy have abnormalities in overall brain activity that can be detected with EEG almost immediately after birth. By correcting these abnormalities with neurofeedback training, children with cerebral palsy can improve their speech, physical coordination, and emotion regulation abilities [111, 112].
Because cerebral palsy patients often have very unique sets of abnormalities in brain function, coming up with effective training programs for each patient can be tricky and time-consuming, somewhat limiting the potential of this treatment .
One study found alpha neurofeedback did not have an effect on cerebral palsy syndromes .
24) May Treat Schizophrenia
Neurofeedback improved schizophrenia symptoms in 47 out of 48 schizophrenia patients who did not respond to medication. This suggests that neurofeedback techniques may be a potential treatment for severe psychological disorders that are often difficult to manage effectively .
25) Treats Obsessive-Compulsive Disorder
In another study, two patients given neurofeedback training saw improvements in common behaviors of OCD (e.g. obsessive washing, grooming, and checking). One patient also saw improvements in depression and anxiety and even become more extroverted .
26) Might Treat Tourette’s Syndrome
Multiple studies have shown that using neurofeedback training to reduce theta brain waves and enhance activity in the sensorimotor cortex can give patients with Tourette’s syndrome better control over their movements. This can help reduce or even completely eliminate their motor “tics” (sudden and uncontrolled movements) [118, 119].
27) Helpful For Restless Leg Syndrome
Although the causes of restless leg syndrome are unknown, sufferers often have abnormal brain activity patterns in the alpha frequency range. The results of several individual case studies suggest that correcting these abnormalities with neurofeedback may be a way to improve sleep and quality of life in restless leg syndrome patients .
28) Can Treat Tinnitus
Tinnitus is associated with particular brain wave patterns in the temporal lobe. By training these abnormal patterns, neurofeedback can completely reverse or drastically improve tinnitus (two studies with 21 and 15 patients) [121, 122].
29) May Help Manage Symptoms of Diabetes
Two case studies of diabetic patients found that just 20 sessions of neurofeedback training not only improved their quality of life but also stabilized their blood sugar levels and allowed them to rely less on insulin to treat their symptoms. The mechanisms for these benefits is unclear .
Neurofeedback Side Effects
Under clinical circumstances, mild side effects can occur during neurofeedback training provided by a certified medical expert. A person may feel fatigued, disoriented, anxious, agitated or irritable. Others may experience a headache or have trouble falling asleep .
However, these side effects are nearly always temporary and are most likely due to excessively long training sessions, rather than the nature of neurofeedback treatment itself .
However, more serious side effects can occur if neurofeedback training is not overseen by a certified medical professional. Because brain wave activity is unique to the individual, neurofeedback treatment requires a personalized training program in order to be safe and effective [126, 127, 128].
Limitations and Caveats
Although many of the studies show very promising results for a very wide variety of conditions, the nature of neurofeedback training makes it difficult to run double-blind studies. Even when randomized controls are part of the study, some of the outcomes may be partially based on a placebo effect. More research needs to be conducted .
Neurofeedback is a largely unregulated practice so caution should be exercised in the prospect of undertaking it.