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NEUROFEEDBACK: A TOOL FOR IMPROVING COGNITIVE PERFORMANCE THROUGH CONSCIOUS TRAINING
Mirjana Di Paolo1, Milagros B. Buscaglia1; Milagros Medina1; Braian M. Beker1; Gustavo Aroca-Martínez2,3, Carlos G. Musso1,2
1Physiology Department. Instituto Universitario del Hospital Italiano de Buenos Aires,
Argentina
1Physiology Department. Instituto Universitario del Hospital Italiano de Buenos Aires, Argentina
2Facultad de Ciencias de la Salud. Universidad Simón Bolívar; 3Clínica de la Costa, Barranquilla, Colombia.
Email: carlos.musso @ hospitalitaliano.org.ar
Rev Electron Biomed / Electron J Biomed 2023;1:44-59.
Comment of the reviewer Dra. Victoria P. Musso-Enz. Cardiology Department. Hospital Italiano de Buenos Aires. Argentina
Comment of the reviewer Dr. Guido M. Musso-Enz. Teaching Assistant, Physiology Department. Catholic University of Argentina. Buenos Aires. Argentina
RESUMEN Mejorar el rendimiento cognitivo ha sido una búsqueda de larga data. Mientras tanto, la investigación sobre el entrenamiento de neurofeedback para mejorar el rendimiento cognitivo máximo ha sido un tema de creciente interés últimamente. Las intervenciones de neurofeedback ayudan a los sujetos a modular conscientemente sus propias ondas cerebrales para lograr cambios neuroplásticos que se correlacionan, según las funciones relacionadas con las ondas cerebrales, con beneficios positivos. Su investigación ha demostrado muchas mejoras en el rendimiento cognitivo basadas en mejoras en la función de la memoria, la creatividad, la atención y la concentración, al mismo tiempo que mejora el estado de ánimo y disminuye las emociones negativas. La siguiente revisión informa sobre la evidencia basada en el entrenamiento de neurofeedback para lograr un rendimiento cognitivo máximo.
PALABRAS CLAVE: Neurofeedback, biofeedback, mejora del desempeño, desempeño cognitivo, memoria, atención, creatividad, emociones.
ABSTRACT: Enhancing cognitive performance has been a long-time quest. Meanwhile, neurofeedback training research to improve peak cognitive performance, has been a subject of increasing interest lately. Neurofeedback interventions assists subjects in modulating their own brain waves consciously to achieve neuroplastic changes which correlate, based on brain waves related functions, to positive benefits. Its research has manifested many improvements in cognitive performance based on enhancements on memory function, creativity, focused attention and concentration while also improving mood and decreasing negative emotions. The following review reports neurofeedback training based-evidence for achieving peak cognitive performance.
KEY WORDS: neurofeedback; biofeedback; performance enhancement; cognitive performance; memory; focus; creativity; emotions
INTRODUCTION
The objective of clinical neurosciences has been recognizing and understanding nervous system mechanisms in order to improve neural processes related to behaviour and to enhance or restore cognitive or neurological functions1.
Neurofeedback, or Biofeedback, is a method which assists subjects to modulate their own brain waves consciously2-4. This process of learning to control their own electroencephalogram (EEG) bands activity through a range of trial-and-error procedures, has been used widely as a therapy for certain cognitive and behavioral disorders5,6.
One of the essential principles that neurofeedback depends on is the paradigm of brain neuroplasticity. Gulyaeva defines neuroplasticity as the "functional and structural brain alterations which enable adaptation to the environment, learning, memory, as well as rehabilitation after brain injuries"7.
The subjects receive real-time valuable information of their live brain activity through an EEG. So as they can understand the EEG-feedback, the data is presented to them as a sensorial interface of audio, visual or combined audio-visual information8.In some neurofeedback animations, the cortical activity is, for instance, represented by the speed or height of a feedback object, like a ball or a car. If the EEG activity is regulated in the way that is desired, the object falls, rises or advances faster. In other animations, the subject has to try to watch a movie or alter the color of an object on the screen by producing the neural activity of interest9-12.
Neurofeedback requires that the subject learns to alter some aspect of her/his cortical activity. This could include learning how to change the frequency, amplitude and/or coherence of different electrophysiological components of subject's own brain.
It needs an understanding of brain waves, the measurement of those brain waves at certain locations on the scalp and a subject learning to then alter these brain waves to generate a modification in cognitive processing by operant conditioning4.
The brain's activity can be objectified through a recording using scalp electrodes known as electroencephalogram. The measurement of brain waves is an assessment of electrical activity produced by the pyramidal cells of the brain.
The brain has been functionally divided by regions called Brodmann Areas; which have been associated to certain cortical functions. Broadly speaking, a single channel or electrode can be placed on a particular cortical area which corresponds to a specific Brodmann Area, manifesting the cognitive processes associated to that region4.
Brain EEG signals can be divided into frequency bands indicated in terms of frequency in Hertz, which is the number of waves per second. Five principal brain waves can be recognized by their frequency ranges: Delta, Theta, Alpha, Beta and Gamma3.
Certain EEG frequency patterns have been related to certain brain activities. Slow frequency waves are associated with resting states while faster frequency waves to cognitive challenges, such as performing a math exercise. Consequently, lower frequencies than 4 Hz (Delta waves) have been associated with sleep states and deep-unconsciousness; 4 to 7 Hz frequencies (Theta) to deep relaxation such as stage 1 sleep, meditation, hypnosis and unconsciousness, and Alpha waves (8-12 Hz) are manifested in peaceful and relaxed states. Faster waves such as Beta waves (13 to 30 Hz) correlate to concentration, sustained attention and neuronal excitability. Finally, Gamma waves (32 to 100 Hz) have been associated to learning, cognitive processing and problem solving tasks6,13,14.A summary of these associations can be found in
In this manner, the objective of neurofeedback training is to teach the subject what certain states of cortical arousal feel like and how to activate those states voluntarily15.Consequently, subjects are able to learn how to control their brain activities, to favorably enhance physical and cognitive performance and manage their own mental and physiological states through a neurofeedback device2,5,16-19.For example, if performance on a certain cognitive task is associated with a specific EEG frequency, the objective would be to train subjects to improve their control over that brain pattern, its generation and maintenance to cause the associated peak performance state on demand15,20.
Using Neurofeedback training to self-regulate EEG patterns for regaining or optimizing behavioral performance is turning into an establishment20.It has been used to treat patients since the 1970's to reduce symptoms or improve cognitive disorders, including Attention Deficit Hyperactivity Disorder (ADHD)9.
These days, Neurofeedback training can be used in at least three main ways: 1) like a therapeutic tool to normalize subject's deviating brain activity to influence symptoms, such as motor learning in post-stroke recovery, to treat addictive disorders, autism spectrum disorders and as a treatment for ADHD and epilepsy; 2) as so-called peak-performance training to improve cognitive performance in healthy subjects; and 3) like an experimental procedure to research the causal role of certain neural events (for instance brain oscillations) for cognition and behavior that is known as brain-state dependent stimulation17,21-23.
Cognitive performance has been defined as the brain's mental processes and abilities related to areas such as reasoning, problem solving, mood, decision making, attention, learning, memorization and creativity24.
In this article, we searched Medline, with no language restrictions, for studies from past 10 years on benefits and limitations of neurofeedback training for improving cognitive performance. The aim of this review is to describe the most recent evidence on neurofeedback training protocols and their impact on different brain cognitive functions.
2. NEUROFEEDBACK PROTOCOLS AND EEG CORRELATION
2.1 Alpha protocol
The rhythm that dominates the human electroencephalogram is the alpha rhythm, characterized by a range of 7.5-12.5 Hz. It has been associated to memory performance, cognitive demanding tasks, brain volume, intelligence, peaceful and relaxed states8,21,25.Alpha oscillations are inversely related to brain activity; meaning that, for example, if the left hemisphere is the predominant, alpha waves will predominate in right hemisphere26. Cortical inhibition is thought to be related to alpha rhythm, which may result in lower brain activity2.
Alpha bands can be subdivided into two groups based on their frequency: higher or lower power. Research has evidenced a relation between better cognitive activity during resting conditions, semantic memory and retrieval processes from long-term memory with higher alpha power (9.5-12 Hz); while in cognitive demanding tasks and attentional processes, a lower alpha frequency (6-8 Hz/8-10 Hz) predominated. Thus, the higher frequency alpha bands could correlate stronger with improved cognitive performance and enhanced memory function because of the presumed overlap of sensorimotor rhythm (12-15 Hz) and the high-frequency alpha band12,15,25.
Alpha protocols have manifested promising results for treating brain injuries, improving memory and mental performance in a 10.2 Hz frequency stimulation. Pain relief progress has been observed in various conditions along with stress and anxiety reduction in a 9 Hz and 10-30 Hz stimulation, respectively2,6. Cognition and memory enhancement have been manifested through alpha protocol neurofeedback. However, inter-individual differences were evidenced between the participants which still needs further research27.
2.2 Beta protocol
Attention, action and alertness have been associated to beta waves28. They can be classified based on their amplitude: sensorimotor rhythm (low beta waves of 12-15 Hz) which correlate to omission error reductions and improved perceptual sensitivity in tasks performance; and higher amplitude waves (15-18 Hz) which resulted in an opposite pattern during testing11. Some research suggested that low beta waves (sensorimotor rhythm) can lead to general improvements in high alertness, attention and concentration performance compared to higher amplitude frequencies3,12. Beta waves also appear to induce metabolic activity near the Rolandic fissure showing an increase in the somatosensory strips29.
Training in beta protocols has shown to reduce worries and over-thinking while manifesting improvements in alcoholism, insomnia and obsessive compulsive disorders. Hence, it has been suggested as a complementary tool to treat ADHD, enhance reading abilities and school performance3,6.
2.3 Theta protocol
Theta oscillations have a frequency range of 4-8 Hz. They together, along with alpha oscillations, compose the lowest frequency brainwaves6. Theta neurofeedback training can influence in a wide spectrum of cognitive processes which may vary from attentional focus to affective states17.
There is strong evidence that suggests an important role of theta waves in memory formation, including working, episodic and semantic memory formation22,23,28. Theta waves are typical of hippocampal activity but they generate oscillations that disseminate to other brain structures. This affirmation supports the hypothesis that theta waves would also engage in long-term plasticity; although the mechanism of action whereby theta communicates the hippocampus, the ventromedial prefrontal cortex and remote memory areas is not clear yet28. This interaction is suggested to impact positively in memory consolidation results15.
More theta functions have been associated recently in the memory field, such as information encoding, retrieval and consolidation through sleep. In addition, it has been correlated to attention, sustaining concentration, creativity and meditation practice12,30.
Interestingly enough, creative insights are believed to be related to a state of hypnagogia (a state of reverie and twilight, between waking and sleeping; related to theta rhythm). Theta rhythm neurofeedback has been proposed as a way to induce this state for producing creative breakthroughs31.
2.4 Alpha/Theta protocol
Alpha/theta protocol is one of the most applied neurofeedback protocols for stress reduction and usually employed to recover from traumatic experiences in post-traumatic stress disorders. Thus, it has been used as a complementary treatment for deep levels of depression, addiction and anxiety. Increases in creativity, relaxation, musical performance and trauma healing reactions have been observed6. Alpha/theta training has shown that slower rhythms in long-distance connectivity helps in memory associations together with sensory-motor integration32.
The objective of this protocol is to reach a "crossover" between theta over alpha waves associated with reduced anxiety, depression, drowsiness and re-experiencing biographical episodes. In order to do so, it is necessary to maintain low delta activity to avoid sleep and low beta activity to avoid anxiety manifestations6,17.
2.5 Beta-Gamma protocol
Little can be said about beta and gamma protocol since research is scarce. It has been used for testing long term memory and familiarity recognition memory30.
3. EXECUTIVE FUNCTIONS
According to Alvarez and Emory "executive functions are defined as the ability to maintain and shift tasks, planning, response inhibition, working memory, organizational skills, reasoning, problem-solving, impulse control and abstract thinking "33,34. The network responsible of this is the fronto-cingulate-parietal network that consists of the dorsolateral prefrontal cortex, the frontopolar cortex, the orbitofrontal cortex and the midcingulate cortex34.
Vernon reports that numerous neurofeedback protocols have been studied to evaluate their effect in improving executive functions: theta to increase attentional performance; alpha for short-memory performance; alpha/theta for creativity and well-being enhancemente and beta for attentional processing. Although very promising, most of them failed to establish a clear correlation between neurofeedback training and executive functions enhancement15.
However, when Zoefel's team studied upper alpha neurofeedback training, they reported an improvement of cognitive performance regarding to mental rotation activities compared to the control group35.
Childhood executive functions have shown to predict academic accomplishments and social development in adolescence. They are related to healthy behaviour and stress regulation, which is why authors have proposed public health research programs to enhance executive functions34.
A study manifested that semantic working memory can be improved by sensorimotor rhythm neurofeedback training or by individual upper alpha neurofeedback training. Moreover, increasing peak alpha frequency through neurofeedback training, can enhance the cognitive processing speed and executive function in the old-age patients11.
4. MEMORY
Working memory has been defined as a psychological process which empowers the brain to maintain current plans of action across time as well as the sensory information that is required to perform them4. It alludes to the capacity to hold information transiently in the mind in the service of comprehension, thinking and planning36. The active manipulation of temporarily stored information is of paramount importance for executing these functions while being a relatively slow process that lasts from considerable seconds to minutes. Consequently, it must be linked with slow components of event-related potentials, as a direct result of a specific sensory, cognitive or motor event, measured by electroencephalography4. Specific neurofeedback techniques have been used to enhance working memory, including alpha and theta protocols4.
In recent studies, theta oscillations have been found to play a critical role in the pairing and integration of extensively distributed neural circuits while also being linked to improvements in working memory, episodic memory and new information codification12,14. In addition, long range functional interaction in working memory of widely distributed regions and increased coupling of theta oscillations between frontal and parietal cortices during retention intermissions was also reported14. Research shows that working memory utilizes the posterior association cortex, (implicated in the storage of sensory information) and the prefrontal cortex (which updates the information)36. Vernon's team has proposed that, based on research that manifests that theta activity might connect these two regions together during a working memory task, enhancing selectively theta activity could produce beneficial effects on working memory. Although very attractive in theory, they failed to manifest this effect empirically36.
Reiner et al. embraced a system-level memory consolidation view. They proposed a two-stage process where firstly, memory formation occurs in the hippocampus. After that, a second level instance takes place with the development of neocortical structures; an hippocampus-independent process. Theta is suggested to regulate the transaction of information between the hippocampus and the neocortical areas for effective memory consolidation28. Elevating theta power may lead to better memory consolidation, and consequently leading to improved long-term memory formation15,28.
Previous research manifested that theta activity had an influence on the cellular mechanism of memory through its role in promoting long-term potentiation. Recent studies have evidentiated a link between recognition memory processes and theta activity, recorded from the scalp. A direct relationship between theta waves and working memory has been evidenced from data that, during the encoding phase of a recognition task, only words that were posteriously correctly recognised by subjects, presented a significant increase in theta activity36. Based on this promising association, training individuals for improving theta activity may influence working memory performance36. The use of relatively short theta neurofeedback training sessions (45 min) produced objective enhancement of memory consolidation. The implications of these results could translate into beneficial effects on individuals of several educational, clinical and social backgrounds since memory is of such importance to cognitive functions28.
Furthermore, the relationship between memory performance and alpha activity has been described by several studies in the last two decades. It has been reported that memory performance is positively associated to resting power in the alpha band11. Recent studies have shown that alpha power and alpha duration was increased throughout the Neurofeedback training in the Alpha training group, compared with the control group. The author's findings manifest the effect of alpha rhythm on both working memory and episodic memory; which correlated to improvements in working memory and attention2. Successful training of the frontoparietal alpha rhythm was displayed in terms of progressive changes in the mean relative alpha amplitude, the entire alpha duration, and the density function of continuous alpha episodes in the Alpha trained group37. This denoted a significant improvement in both working and episodic memory compared with that of the control group, suggesting that alpha neurofeedback training could have great benefits on memory enhancement37. One study by YuLeung To et al. focused on upper alpha band, as it is generally associated with semantic memory, and reported that in healthy individuals, a daily upper alpha frequency training for only 5 days enriched working memory test results4.
Regarding short-term memory, even though the baseline enhancement of alpha bands was not found in the neurofeedback training group, short term memory was enhanced meaningfully. First and foremost, the increase of the neurofeedback training group results in short-term memory were significantly higher than the control group, pointing out that neurofeedback training did have positive effect on this cognitive performance area. Another curious finding was that the increase of short-term memory performance was positively associated with the increase of the relative amplitude in the individual upper alpha band while training. It advocates that the individual upper alpha can be a promising parameter in future short-term memory neurofeedback training studies11. It has been proposed that with the appropriate protocols and suitable guidance, the participants can learn to increase the relative amplitude in individual alpha band during training11.
The potential role of theta rhythms engaged in the hippocampal/prefrontal cortex interplay and the reported empirical results on the effect of enhanced theta and alpha activity on memory consolidation, provide promising benefits of neurofeedback training for memory improvements.
5. FOCUS AND CONCENTRATION
Among the brain's most important cognitive functions, the capacity to focus attention, encode and sustain information have to be mentioned. Attention is a central constituent of cognitive ability. Measurements of neural activity have become powerful predictors of cognitive impairments in persons affected with diverse kinds of cognitive deficits. Lapses in attention can diminish memory and behavioral performance16.
The Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) interprets ADHD as a "constant pattern of inattention and/or hyperactivity-impulsiveness that is more frequent or severe than individuals with a comparable level of development normally shown", and it has been a repeatedly reported deficiency in executive functioning, working memory and response inhibition18,38. It is the most prevalent neurodevelopmental and psychiatric disorder of childhood. The general rate of prevalence is detailed between 3% and 7% of school age children and, of all ADHD cases, 40 to 60% prevails further into adolescence and adulthood9,39. ADHD main symptoms include impaired attention and/or hyperactivity/impulsivity; which in many cases leads to deterioration in different domains, including low academic performance, diminished occupational success, short social relationships, and higher risk-taking behavior9.
Traditional pharmacological treatments for ADHD can be easily put into practice and, while usually effective, their long-term therapeutic effects have been put into question and they are not free from adverse events like sleep problems, appetite reduction and growth deceleration. Moreover, psychosocial treatments, such as parental training and behavioral therapy seem to be producing the expected results during its delivery but their effects seem to be rarely maintained long-term. Considering the meaningful limitations of actual available interventions, it has become clear among clinicians that new treatment options for ADHD are needed13. Among non-pharmacological alternative treatment methods, since the early 1970s, neurofeedback has been contemplated as a promising ADHD treatment strategy. When applied to individuals with ADHD, neurofeedback aimed to decrease its symptoms by targeting aberrant patterns of brain activity, thought to underpin the condition9. It has manifested its capacity to enhance attention levels and alleviate the hyperactivity symptoms. Neurofeedback training offers a mechanism by which the patient can normalize the cortical activity profile through lowering slow wave activity and increasing fast wave activity25. However, since it is relatively recent, research consensus is still needed. Some studies suggested neurofeedback as a treatment alternative for children with ADHD whose parents opt for a nonpharmacological treatments25.
The reason for using neurofeedback to treat ADHD appeared from preceding observations which reported that children with ADHD, in their resting state, manifested extremely high amplitudes of low-frequency electroencephalogram oscillations (such as delta and theta bands) in comparison with healthy developing children. Employing pharmacotherapy in children with ADHD is useful to reduce these high amplitudes oscillations. Previous research studies proposed neurofeedback as a potential strategy to reduce the elevated low-frequency synchronization seen in ADHD1. Following studies in children with ADHD demonstrated that decreased low-frequency amplitudes, through neurofeedback training, were related with improvements in ADHD symptoms1,20.
A significant advantage of neurofeedback, as well as other neurotherapeutic approaches, over typical pharmacologic interventions is the potential sustained, long-term profits after the successful culmination of the intervention. Positive benefits on ADHD symptoms were found stable for over 6 months after training. In some, even after 2 years follow-up with a few booster sessions9.
Among children with ADHD, there have been distinguished three distinct electroencephalogram patterns. The first is characterized by slow wave activity overabundance and fast wave deficit. The second group presents significantly raised theta amplitude with decreased beta activity and finally, the third pattern exhibits excess beta activity. Based on these premises, in terms of electroencephalogram profile, children with ADHD cannot be categorized as an homogenous group and treatment strategies need to aim in working on these alterations18.
The suppression of theta wave (because of its relation with hyperactivity, impulsivity, and inattentiveness) with an enhancement of beta activity (related to cognitive tasks, concentration and focused attention) is likely to be the most common treatment protocol for improving ADHD symptoms. In addition, enhancing upper alpha power activity was also associated to improvements in ADHD symptoms in relation to processes such as intelligence, memory and perceptual performances9,25. Mohagheghi's team when comparing both protocols, theta suppression/beta enhancement and theta suppression/alpha enhancement, found that both were effective in reducing clinical symptoms of ADHD. However, alpha enhancement protocol seemed to suppress even more omission errors, which reflects inattentiveness, compared to beta suppression25. Possible factors may have produced the beneficial effects on both groups other than neurofeedback, including time with therapist during neurofeedback training, motivation for change and cognitive-behavioral training introduced under neurofeedback interventions25.
In addition, a 2009 meta-analysis of 15 controlled studies, evaluated neurofeedback for improving inattention, impulsivity and hyperactivity in ADHD. 11 of the studied research adopted a theta/beta protocol and Arns' team concluded that neurofeedback training is "efficacious and specific" while being clinically meaningful, with a huge effect on symptoms of inattention and impulsivity, and a reasonable effect size on hyperactivity symptoms39.
Regarding the sensorimotor rhythm protocol (12-15 Hz), the improvements of low beta ratio are associated with higher alertness, concentration and focused attention3,36.
A significant relevance of employing neurofeedback hinges decidedly on its potential to invoke long-term effects. Up to date, respecting alpha/theta training protocols, research is limited to provide an answer in this matter. But regarding sensorimotor rhythm and beta training in ADHD children, there is suggestive data of long-term efficacy. Whether neurofeedback training is justified in terms of time and money as a clinical and performance enhancement tool based on long term returns is an aspect of paramount importance32.
Even though research suggests a viable efficacy and specificity of neurofeedback training for ADHD improvements, more studies are needed to answer critical queries, including when and how to use neurofeedback in routinely clinical practice and whether is neurofeedback training useful for training healthy subjects which aim to improve their focused attention and concentration13.
6. EMOTIONS AND ATHLETE'S PERFORMANCE
Mood conditions such as anxiety and depression have been a subject of increasing interest the last couple of decades and complementary treatments have been evaluated to help in minimizing the effect of the symptoms in affected individuals. Recent studies have been done with the purpose of investigating whether neurofeedback training could have an impact in brain's connectivity in patients with depression by employing real-time functional magnetic resonance imaging along with neurofeedback interventions. Until now, previous investigations have suggested that patients with superior depressive disorders, when stimulated with positive stimuli, manifested diminished hemodynamic amygdala responses. Through active recall of happy autobiographical memories during neurofeedback procedures, amygdala responses increased, normalizing brain activity and improving depression symptoms. A positive association was found between symptoms reduction and connectivity. Patients which manifested most benefits in reducing symptoms, where also the ones that presented higher increase in connectivity17.
Quaedflieg et al. proposed an association between psychopathology and emotional responses in different subjects with frontal alpha asymmetry. They suggested neurofeedback as a validated tool to decrease stress in these individuals26. Thus, alpha enhancement to theta suppression neurofeedback training was shown to be the most indicated for improvements in the neuropsychology field. Through the implementation of this protocol, participants are helped to improve their tolerance to stress and anxiety3. Other complimentary evidence suggests an effective role of alpha enhancement and beta, delta and theta suppression protocols for chronic posttraumatic stress disorder based on alpha wave association to relaxed states40.
Regarding athletes, research has been done in order to explore a possible association between neurofeedback training and sport performance enhancement. When electroencephalograms of expert sportsmen were compared with amateur competitors, the former exhibited a dissimilar pattern of cortical activity. By the identification of this dissimilar pattern in the electroencephalogram of the expert group, neurofeedback could be useful to mimic those patterns in the amateur, potentially improving their performance in sports; although further studies are needed15. Another study, which analyzed psychophysiological state of athletes, reported some hemispheric asymmetries in the electroencephalogram just before the performance of a skill. But, in the preparatory period of the skill, studies have shown a significant increase in alpha activity in the left-temporal electroencephalogram15.
A study by Graczyk et al. in one individual athlete proposes that enhancement in sports including archery, physical balance in gymnastic, ice skating, skiing and other areas, could be achieved by training athletes in beta protocols. This has been explained by the authors since higher beta activity, which was achieved during the intervention, correlated to increased cortical metabolic activity in the areas located near the Rolandic fissure29. In people who suffered concussions and mild head injuries, neurofeedback training could be applied to enhance concentration and focus, improve cognitive function and also emotional control29.
7. CREATIVITY
Optimizing creativity to produce a masterpiece is probably a goal for many artists. Hypnagogia, a state of reverie and twilight, between waking and sleeping (related to theta rhythm), has been described by many inventors and artists (including Mozart, Edison and Dali) as a source of their major breakthroughs14,31.
Hypnagogia facilitates the retrieval, understanding and expression of newly formed cognitive associations between items stored in long-term memory. Cognitive associative tasks requires the integration of information in widely distributed networks. Since theta and low alpha were established as the carriers of long distance information from dispersed connections, it has been proposed training them via neurofeedback so as to enhance new neural network productions14. Hence, the proposed neurofeedback protocol is alpha/theta; where the objective is maximising the theta to alpha ratio in order to stimulate creativity, in addition to well-being14,15.
Raymond et al. found that dancers trained with alpha/theta neurofeedback protocols manifested an enhancement in dance performance after only 10 sessions of 20 minute duration each41. In addition, actors trained in sensorimotor rhythm manifested an increased "sense of flow in performance" which positively correlated to better expert opinion on their acting overall ratings compared to controls41.
Alpha/theta protocol training not only enhanced relaxation but creativity and emotional aspects of the participants. It was proposed that the areas responsible for this effects are the limbic and long distance circuitry. Studies have reported that an alpha/theta five week training is enough to produce successfully significant improvements in competitive university ballroom dancing14,30,31.
Regarding music skills, research has shown a higher production of alpha waves while listening to music in musicians than in non-musicians. This alpha activity suggests a reflect of the training or education that a musician receives15. Significant results were found in performance improvements on a number of musical criteria in musicians after learning to increase theta over alpha amplitudes42,43. These musical refinements were not evident after training in other neurofeedback protocols42.
8. CONCLUSIONS
Enhancing cognitive performance has been a long-time quest. Neurofeedback training has shown promising results for strengthening memory function; focused attention and concentration; improved creativity; decrease the effect of stress and enlarge more creative thinking abilities while improving mood and increasing positive emotions. These improved areas could transform individuals in more efficient beings in all areas of life, including education and work-related activities. A growing number of research have proposed neurofeedback training as a potential and non-pharmacological complementary treatment for numerous psychiatric and neurological disorders; associated to abnormal patterns of cortical activity11,13,27. Although a very promising tool, further research is needed to manifest its potential, limits and unify treatment methods and protocols used.
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CORRESPONDENCE:
Dr. Carlos Guido Musso
Physiology Department
Instituto Universitario del Hospital Italiano
Gral. Juan Domingo Perón 4190, PC 1199, Buenos Aires, Argentina
Buenos Aires, Argentina
Mail: carlos.musso @ hospitalitaliano.org.ar