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Neurofeedback (NFB), also called neurotherapy, neurobiofeedback or EEG biofeedback (EEGBF) is a therapy technique that presents the user with realtime feedback on brainwave activity, as measured by sensors on the scalp, typically in the form of a video display, sound or vibration. The aim is to provide real-time information to the Central Nervous System (CNS) as to its current activity. 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 direct 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 [1] (Butnik 2005) (Masterpasqual et al 2003). 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 (Butnik 2005); however, alternative patterns have also been described making the overall picture inconclusive at this time. Some approaches believe that neurofeedback training is best done when it seeks to teach individuals to produce more normalized EEG patterns that optimize their functioning.[citation needed]

Some ADHD researchers are unconvinced by these studies, including the psychiatry professor and author of several books on ADHD, Russell Barkley. Barkely opines that neurotherapy's effectiveness in treating ADHD can be ascribed to either uncontrolled case studies or the placebo effect [2]. In return, neurofeedback advocates note that Barkely has received research funds and personal remuneration from drug giant Eli Lilly and Company and other drug companies [3] [4] [5].

Other areas where neurofeedback has been researched include treatment of substance abuse, anxiety, depression, epilepsy, OCD, learning disabilities, Bipolar Disorder, Conduct Disorder, anger and rage, cognitive impairment, migraines, headaches, chronic pain, autism spectrum disorders, sleep dysregulation, PTSD and MTBI.

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).


[edit] 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 (Kaiser 2005).

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). (Kaiser 2005)

Later, Joe Kamiya popularized neurofeedback in the 1960s when an article[1] 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. Neurofeedback appealed greatly to the social movements of the 1960s as well, when altered states were a lifestyle. For example, in 1973 Elmer Green took a portable psychophysiological lab to India to study Eastern holy men, all of whom possessed the incredible ability to control their heart rate, blood flow, and other autonomic functions, all of whom generated alpha waves continuously while doing so, according to Green’s EEG.[citation needed]

Despite these highly dramatic and compelling claims, the universal correlation of high alpha density to a subjective experience of calm cannot be assumed. Visuomotor activity seems to be of primary importance in alpha neurofeedback, and the ability to generate alpha with the eyes open and the lights on could develop different skills and results than if the procedure were carried out in total darkness or with the eyes closed.[citation needed] Alpha states do not seem to have the universal stress-alleviating power indicated by early observations.[2] 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.[3] James Hardt and Joe Kamiya, then at UC San Francisco's Langley Porter Neuropsychiatric Institute published a paper, [4] 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.[5] This training has been used in the treatment of epilepsy [6][7], attention deficit disorder and hyperactive disorder,[8] and other mood disorders[citation needed]. 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. Studies have shown that enhancement of sensorimotor activity through operant conditioning designed to increase SMR is an anticonvulsant process and is therefore an effective treatment for epilepsy. (citation needed)

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.[7] Most individuals treated with biofeedback in research studies have been sufferers of the most severe epilepsy for whom anticonvulsant drug therapy has proven ineffective.[citation needed] However, even among these most severe cases, beta and SMR training has been found to produce an average 70% reduction in seizures and to facilitate increased control of seizures in 82% of patients.[citation needed]

Lubar addressed attention disorders using essentially the same protocol.[citation needed] His research indicates that inhibition of motor function also inhibits input function, which is related to attention. Lubar’s protocol, which has been adopted by most practitioners as the standard protocol for treating patients with attention disorders, is to inhibit 2-10 Hz slow waves (alpha and theta) as well as 19-22 Hz waves and encouraging activity in the 12-19 Hz range.[citation needed] This procedure has been supported since alpha activity is known to decrease during cognitive functions and to be inversely related to metabolism.[citation needed] Lubar’s hypothesis for what is happening in an ADD brain is that there is a decreased metabolism and decreased blood flow to the subcalossol cortex. Alpha is inhibited to counter these problems.[citation needed] Lubar has published 10-year follow-ups on cases and found that in about 80% of patients biofeedback can substantially improve the symptoms of ADD and ADHD, and these changes are maintained.[citation needed] Currently, treatment for attention disorders is the most common application of EEG biofeedback.[citation needed] However, the treatment is also effective in the treatment of traumatic head injuries and sleep disorders as well as epilepsy.[citation needed]

Neuroimaging studies have correlated ADHD with abnormal functioning in the anterior cingulate cortex (ACC) during tasks involving selective attention. In 2006, Johanne Levesque and colleagues at the University of Montreal published results from their fMRI study showing normalization of ACC activation during a selective-attention task in ADHD subjects who had undergone neurofeedback training (Levesque, 2006). 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.

In 1974 the pioneer Canadian psychologist (holding Registration #1 as a registered psychologist[citation needed]) D.A. Quirk heard a presentation by Sterman and discussed with him the method. Quirk immediately conferred with his colleague, G.von Hilsheimer, Director of the Green Valley Psychiatric Hospital in Orange City Florida([citation needed]). Quirk and von Hilsheimer began applying EEG biofeedback, training the amplitude of 4-7 Hz (theta)down, whilst training the amplitude of 13-14 Hz (sensori-motor) up over the Fissure of Roland (Ten-20 locations C-3 and C-4). From 1974 until his retirement in 1995 Quirk trained 2700 felons incarcerated at the Ontario Correctional Institute near Toronto using temperature at the left ring finger, skin conductance (palm to palm), and EEG detected at Ten-20 sites C-3 and C-4.[citation needed] The three year recidivism rate for these felons was 15%, which compares well to the range of 40-70% widely reported in the correction literature.[citation needed]

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

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.

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 (first reported by Penniston in 1989[citation needed]) and other addictions as well as post-traumatic stress disorder, the dysphoric disorders of women, musicians, and psychopathic offenders.[citation needed] 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. During this therapy, when the alpha waves amplitude is crossed over by the rising amplitude of theta waves, the state is called the alpha-theta crossover state and is associated with resolution of traumatic memories.[citation needed]

The physiological mechanisms behind these therapies are very unclear. EEGs of alcoholics have revealed an inability to produce the alpha waves generally associated with feelings of relaxation and comfort.[citation needed] However, following the use of alcohol, theta and alpha waves increase.[citation needed] This can be expected considering the drowsiness and relaxation are common effects of alcohol. Therefore, alcoholics may be self-medicating their abnormal level of low frequency waves. Studies have demonstrated a high efficacy of alpha-theta therapy in treating alcoholism.[citation needed] Peniston and Kulkosky found that while alcoholics in a control group receiving standard treatment showed significant increases in beta-endorphin levels as a result of stress caused by abstinence from alcohol, alcoholics receiving the alpha-theta treatment did not. On four-year follow-ups only 20% of the traditionally treated group of alcoholics remained sober, compared with 80% of the experimental group who received neurofeedback training.[citation needed]

[edit] Low Energy Neurofeedback System (LENS)

The Low Energy Neurofeedback System (LENS) uses a device, under control of a computer program, to produce electromagnetic fields and apply them as brain stimuli. The stimuli are applied by EEG leads that serve as bi-directional conduits for both the stimuli and returning EEG signals. Treatment sessions are very short, typically only a few minutes (treatments that are too long or use incorrect settings can cause hyper-arousal, headache, irritability, nausea, etc). During treatment sessions, the subject is completely passive; there is no auditory or visual feedback.

LENS treatment is preceeded by a diagnostic Quantitative EEG (QEEG) brain map to identify zones of the brain at which the various brain waves deviate from the norm. Both electrode placement and system settings are determined by the condition being treated and the clinician's interpretation of the brain map. System settings must be adjusted by the clinician over the course of treatment to accommodate the effects of treatment. The number of treatments needed to achieve improvements for ADD/ADHD, depression, PTSD, and seizures is claimed to be fewer than for more tradional neural feedback methods.

At least two books detailing the concept and methodology of LENS are available commercially: "The Healing Power of Neurofeedback: The Revolutionary LENS Technique for Restoring Optimal Brain Function" by Stephen Larsen and Thom Hartmann (Paperback - May 2, 2006); and "Lens: The Low Energy Neurofeedback System," by D. Corydon Hammond (Paperback - Feb 13, 2007).

[edit] Neurofeedback in practice

A common professional neurofeedback therapy nowadays 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 filters out people with serious psychological problems. The EEG serves both for diagnosis and as a reference to check later whether there is progress. In about 20% of the patients neurofeedback has no effect.

2. The EEG recording is typically done on a few dozen points on the head. 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 underactivity compared to the average people of the patient's age and sex. There are several commercial providers of such databases.

3. On the basis of the complaints, the brainmap and the database results a therapy is chosen. This involves an electrode on a single spot on the head that needs to become more or less active for specific frequencies. During the therapy the patient gets feedback that helps them improve. This feedback may involve for example a simple light or tone, some game where "good" brainwaves are rewarded and "bad" ones punished or some image that becomes less sharp when the patient loses focus.

4. A typical therapy takes 20 to 40 sessions. Some forms of psychotherapy are considerably faster, so neurofeedback is not always the most efficient solution. 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.

[edit] See also

[edit] References

  • Butnik, Steven M. "Neurofeedback in adolescents and adults with attention deficit hyperactivity disorder." Journal of Clinical Psychology, May 2005. Vol. 61 Issue 5, p621-625
  • Evans, J.R., and Abarbnanel, A. An introduction to quantitative EEG and Neurofeedback. Academic Press: San Diego, 1999.
  • Hammond, Corydon D. "Neurofeedback Treatment of Depression and Anxiety." Journal of Adult Development, Vol 12, Nos. 2/3, August 2005
  • Kaiser, David A. "Basic Principles of Quantitative EEG." Journal of Adult Development, Vol. 12, Nos. 2/3, August 2005.
  • Levesque, Johanne and Mario Beauregard. "Effect of neurofeedback training on the neural substrates of selective attention in children with attention-deficit/hyperactivity disorder: A functional magnetic resonance imaging study." Neuroscience Letters, 394, 216-221.
  • Masterpasqual, Frank and Healey, Katherine N. "Neurofeedback in psychological practice." Professional Psychology: Research & Practice. Dec 2003, Vol. 34 Issue 6, p652-656
  • Trudeau, David L. "EEG Biofeedback for Addictive Disorders -- The State of the Art in 2004." Journal of Adult Development, Vol 12, Nos. 2/3, August 2005.
  • Vernon, D. (2005). Can neurofeedback training enhance performance? An evaluation of the evidence with implications for future research. Applied Psychophysiology and Biofeedback, 30(4), 347-364.
  1. ^ Kamiya, J. (1971). "Operant Control of the EEG Alpha Rhythm and Some of its Reported Effects on Consciousness". Biofeedback and Self-Control: an Aldine Reader on the Regulation of Bodily Processes and Consciousness. 
  2. ^ Hardt, J.V.; Kamiya, J. (1978). "Anxiety change through electroencephalographic alpha feedback seen only in high anxiety subjects". Science 201 (4350): 79–81. doi:10.1126/science.663641. PMID 663641. 
  3. ^ Paskewitz, D.A.; Orne, M.T. (1973). "Visual Effects on Alpha Feedback Training". Science 181 (4097): 360–363. doi:10.1126/science.181.4097.360. PMID 4719909. 
  4. ^ Hardt, J.V.; Kamiya, J. (1976). "Conflicting results in EEG alpha feedback studies". Applied Psychophysiology and Biofeedback 1 (1): 63–75. Retrieved on 2007-12-05. 
  5. ^ Sterman, M.B.; Clemente, C.D. (1962). "Forebrain inhibitory mechanisms: cortical synchronization induced by basal forebrain stimulation". Exp Neurol 6: 91–102. doi:10.1016/0014-4886(62)90080-8. Retrieved on 2007-12-05. 
  6. ^ Sterman, M.B.; Friar, L. (1972). "Suppression of seizures in an epileptic following sensorimotor EEG feedback training". Electroencephalogr Clin Neurophysiol 33 (1): 89–95. doi:10.1016/0013-4694(72)90028-4. Retrieved on 2007-12-05. 
  7. ^ a b Sterman, M.B. (2000). "Basic concepts and clinical findings in the treatment of seizure disorders with EEG operant conditioning". Clin Electroencephalogr 31 (1): 45–55. Retrieved on 2007-12-05. 
  8. ^ Lubar, J.F.; Swartwood, M.O.; Swartwood, J.N.; O'Donnell, P.H. (1995). "Evaluation of the effectiveness of EEG neurofeedback training for ADHD in a clinical setting as measured by changes in TOVA scores, behavioral ratings, and WISC-R performance". Applied Psychophysiology and Biofeedback 20 (1): 83–99. Retrieved on 2007-12-05. 

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