Neurofeedback

Neurofeedback (NFB), also called neurotherapy, neurobiofeedback or EEG biofeedback is a type of biofeedback that uses realtime displays of electroencephalography to illustrate brain activity, often with a goal of controlling central nervous system activity. Sensors are placed on the scalp to measure activity, with measurements displayed using video displays or sound.

Definition
Neurofeedback is a type of biofeedback that uses electroencephalography to provide a signal that can be used by a person to receive feedback about brain activity.

Training process


Some approaches believe that conscious understanding and mediation of that information is important for the training process; however, this claim has never actually been verified. Those approaches also believe that neurofeedback training can be understood as being based on a form of operant and/or classical conditioning. In that frame of reference, when brain activity changes in the direction desired by the trainer directing the training, a positive "reward" feedback is given to the individual, and if the change is in the opposite direction from what was intended, then either different feedback is given or the provision of otherwise attained "positive" feedback is inhibited (or blocked). These ideas can be applied in various combinations depending on the protocol decided upon by the trainer. Rewards/Reinforcements can be as simple as a change in pitch of a tone or as complex as a certain type of movement of a character in a video game. This experience could be called operant conditioning for internal states even though no research has yet demonstrated that clear operant response curves occur under those scenarios.

Nonetheless, a number of different brainwave goals have been proposed by different researchers in the field following on these general ideas. Usually, these goals are based upon extrapolations from research describing abnormal EEG patterns or on results from a quantitative EEG (QEEG - also known as brain mapping) upon the particular client being offered neurofeedback training. A popular goal is the increase of activity in the 12–18 Hz band (mu rhythm/ sensorimotor rhythm (SMR)) and a decrease in the 4–8 Hz and/or 22–28 Hz bands (theta and/or beta). The most common and well-documented use of neurofeedback is in the treatment of attention deficit hyperactivity disorder: multiple studies have shown neurofeedback to be useful in the treatment of ADHD. QEEG has been ambivalent with some studies showing that some forms of ADHD can be characterized by an abundance of slow brainwaves and a diminished quantity of fast wave activity; however, alternative patterns have also been described making the overall picture inconclusive at this time.

Some ADHD researchers are unconvinced by these studies, including the psychiatry professor and author of several books on ADHD, Russell Barkley. Barkley opines that neurotherapy's effectiveness in treating ADHD can be ascribed to either uncontrolled case studies or the placebo effect. In return, neurofeedback advocates note that Barkley has received research funds and personal remuneration from drug giant Eli Lilly and Company and other drug companies.

Other areas where neurofeedback has been researched include treatment of substance abuse, anxiety, depression, epilepsy, OCD, learning disabilities, bipolar disorder, conduct disorder, cognitive impairment, migraines, headaches, chronic pain,autism spectrum disorders, sleep dysregulation, PTSD and concussion.

Other approaches to understanding and providing neurofeedback training use non-linear dynamical control processes and joint time-frequency analyses to characterize the ongoing dynamics of EEG during the training process itself. These approaches understand the functioning of the CNS in a more integrated or comprehensive fashion, including the structural ideas of the Russian neuropsychologist Luria and neuropsychiatrist Karl Pribram.

Related technologies include hemoencephalography biofeedback (HEG).

History and application
In 1924, the German psychiatrist Hans Berger connected a couple of electrodes (small round discs of metal) to a patient's scalp and detected a small current by using a ballistic galvanometer. During the years 1929-1938 he published 14 reports about his studies of EEGs, and much of our modern knowledge of the subject, especially in the middle frequencies, is due to his research.

Berger analyzed EEGs qualitatively, but in 1932 G. Dietsch applied Fourier analysis to seven records of EEG and became the first researcher of what later is called QEEG (quantitative EEG).

Later, Joe Kamiya popularized neurofeedback in the 1960s when an article about the alpha brain wave experiments he had been conducting was published in Psychology Today in 1968. Kamiya’s experiment had two parts. In the first part, a subject was asked to keep his eyes closed and when a tone sounded to say whether he thought he was in alpha. He was then told whether he was correct or wrong. Initially the subject would get about fifty percent correct, but some subjects would eventually develop the ability to distinguish between states and be correct a highly significant percentage of the time. In the second part of the study, subjects were asked to go into alpha when a bell rang once and not go into the state when the bell rang twice. Once again some subjects were able to enter the state on command. Others, however, could not control it at all. Nevertheless, the results were significant and very attractive. Alpha states were connected with relaxation, and alpha training had the possibility to alleviate stress and stress-related conditions.

Despite these highly dramatic claims, the universal correlation of high alpha density to a subjective experience of calm cannot be assumed. Alpha states do not seem to have the universal stress-alleviating power indicated by early observations. However, this is not cause to reject the concept of biofeedback entirely. Many other biofeedback treatments have emerged, since Kamiya’s alpha experiments.

At one point, Martin Orne and others challenged the claim that alpha biofeedback actually involved the training of an individual to voluntarily regulate brainwave activity. James Hardt and Joe Kamiya, then at UC San Francisco's Langley Porter Neuropsychiatric Institute published a paper, proving the efficacy of EEG biofeedback training, and that it was not just related to visuo/motor eyes open or closed factors.

In the late sixties and early seventies, Barbara Brown, one of the most effective popularizers of Biofeedback, wrote several books on biofeedback, making the public much more aware of the technology. The books included New Mind New Body, with a foreword from Hugh Downs, and Stress and the Art of Biofeedback. Brown took a creative approach to neurofeedback, linking brainwave self regulation to a switching relay which turned on an electric train.

The work of Barry Sterman, Joel F. Lubar and others has indicated a high efficacy for beta training, involving the role of sensorimotor rhythmic EEG activity. This training has been used in the treatment of epilepsy, attention deficit disorder and hyperactive disorder,. The sensorimotor rhythm (SMR) is rhythmic activity between 12 and 16 hertz that can be recorded from an area near the sensorimotor cortex. SMR is found in waking states and is very similar if not identical to the sleep spindles that are recorded in the second stage of sleep.

For example Sterman has shown that both monkeys and cats who had undergone SMR training had elevated thresholds for the convulsant chemical monomethylhydrazine. These studies indicate that SMR is associated with an inhibitory process in the motor system and therefore increasing SMR through operant conditioning increases the ability to control seizures.

Neuroimaging studies have correlated ADHD with abnormal functioning in the anterior cingulate cortex (ACC) during tasks involving selective attention. In 2006, Johanne Levesque et al. published results from their fMRI study showing normalization of ACC activation during a selective-attention task in ADHD subjects who had undergone neurofeedback training. Subjects in the study were randomly assigned to either the neurofeedback treatment group or a no-treatment control group, and subjects from the latter showed no difference in ACC activation compared to their baseline.

A significant bibliography on the efficacy of EEG biofeedback documented in refereed journals is listed at isnr.org.

For years, EEG biofeedback was treated as a minor part of the field of biofeedback, particularly by the primary biofeedback organization, AAPB. In 1993, three different efforts, somewhat overlapping, dramatically increased the energy and influence of EEG biofeedback.

In February 1993, Rob Kall, president of Futurehealth, organized the first annual Winter Brain Meeting, in Key West Florida. The meeting brought together many of the leading figures in the field and it created a setting where the leaders could discuss and plan strategies for building greater influence and organization to move the field forward.

In April 1993, Ken Tachiki, Jim Smith and Bob Grove organized a meeting of leaders in the field of Neurofeedback on Catalina Island, immediately before the 1993 AAPB meeting. Further planning took place at this meeting and the beginnings of SSNR occurred. SSNR= Society for the Study of Neuronal Regulation. Since then, SSNR has evolved to become ISNR International Society for Neuronal Regulation, and is now known as the International Society for Neurofeedback & Research ISNR.

Immediately after the Catalina meeting, at the 1993 AAPB meeting, a new EEG section was formed, after plenty of lively discussion. It quickly grew to become the biggest section of the organization. Things were never the same at AAPB. Neurofeedback had become a mainstream part of the field, though it took a few years to fully integrate into the annual meeting and journals.

Within the last 5–10 years, neurofeedback has taken a new approach, in taking a second look at deep states. Alpha-theta training has been used in the treatment of alcoholism, other addictions as well as anxiety. This low frequency training differs greatly from the high frequency beta and SMR training that has been practiced for over thirty years and is reminiscent of the original alpha training of Elmer Green and Joe Kamiya. Beta and SMR training can be considered a more directly physiological approach, strengthening sensorimotor inhibition in the cortex and inhibiting alpha patterns, which slow metabolism. Alpha-theta training, however, derives from the psychotherapeutic model and involves accessing of painful or repressed memories through the alpha-theta state. The alpha-theta state is a term that comes from the representation on the EEG.

Neurofeedback in practice
A common professional neurofeedback therapy session today goes as follows:


 * 1) In an intake of about 90 minutes the patient will get a questionnaire and a first EEG reading. The questionnaire specifies the complaints and also helps to indicate if the referral to a specialist might be called for. In some cases but not all a full EEG will be recorded.
 * 2) If a full EEG is called for, the EEG recording is typically done on 19 - 21 sites on the scalp. It results in a brainmap ("quantative EEG"). This is a series of maps (for each frequency one) where for each measured spot the average level of activity is shown. The brainmap is compared to a database to determine spots of over- and under activity compared to the average people of the patient's age and sex. There are several commercial providers of such databases.
 * 3) The actual session itself involves placing sensors on the head. The feedback may involve, for example, a simple light or tone or game that will move and play when certain brain activity is detected by the system. For other brain activity the rewarding tone, or light or game is taken away.
 * 4) A typical course of sessions takes 20 to 40 visits. At the beginning of each session the patient reports the course of his complaints and also mentions other mental effects. On the basis of this report the therapy may be adjusted. In some cases a patient is allowed to take a feedback machine home and have most - but not all - sessions there.

See also: Psychophysiology, the study of the connections between neurobiology and psychology.

Neuroplasticity
In 2010, a study provided the first evidence of neuroplastic changes occurring directly after natural brainwave training. Half an hour of voluntary control of brain rhythms was shown to be sufficient to induce a lasting shift in cortical excitability and intracortical function. Ros et al. observed that the cortical response to transcranial magnetic stimulation (TMS) was significantly enhanced after neurofeedback, persisted for at least 20 minutes, and was correlated with an EEG time-course indicative of activity-dependent plasticity.