Neural oscillations can be measured by electroencephalography (EEG) and these oscillations can be characterized by their frequency, amplitude and phase. The mechanistic properties of neural oscillations and their synchronization are able to explain various aspects of many cognitive functions such as motor control, memory, attention, information transfer across brain regions, segmentation of the sensory input and perception (Arnal and Giraud, 2012). The alpha band frequency is the dominant oscillation in the human brain. This oscillatory activity is found in the scalp EEG at frequencies around 8-13 Hz in all healthy adults (Makeig et al., 2002) and considerable interest has been generated in exploring EEG alpha oscillations with regard to their role in cognitive (Klimesch et al., 1993; Hanselmayr et al., 2005), sensorimotor (Birbaumer, 2006; Sauseng et al., 2009) and physiological (Lehmann, 1971; Niedermeyer, 1997; Kiyatkin, 2010) aspects of human life. The ability to voluntarily regulate the alpha amplitude can be learned with neurofeedback training and offers the possibility to control a brain-computer interface (BCI), a muscle independent interaction channel. BCI research is predominantly focused on the signal processing, the classification and the algorithms necessary to translate brain signals into control commands than on the person interacting with the technical system. The end-user must be properly trained to be able to successfully use the BCI and factors such as task instructions, training, and especially feedback can therefore play an important role in learning to control a BCI (Neumann and Kübler, 2003; Pfurtscheller et al., 2006, 2007; Allison and Neuper, 2010; Friedrich et al., 2012; Kaufmann et al., 2013; Lotte et al., 2013). The main purpose of this thesis was to investigate how end-users can efficiently be trained to perform alpha band modulation recorded over their sensorimotor cortex. The herein presented work comprises three studies with healthy participants and participants with schizophrenia focusing on the effects of feedback and training time on cortical activation patterns and performance. In the first study, the application of a realistic visual feedback to support end-users in developing a concrete feeling of kinesthetic motor imagery was tested in 2D and 3D visualization modality during a single training session. Participants were able to elicit the typical event-related desynchronisation responses over sensorimotor cortex in both conditions but the most significant decrease in the alpha band power was obtained following the three-dimensional realistic visualization. The second study strengthen the hypothesis that an enriched visual feedback with information about the quality of the input signal supports an easier approach for motor imagery based BCI control and can help to enhance performance. Significantly better performance levels were measurable during five online training sessions in the groups with enriched feedback as compared to a conventional simple visual feedback group, without significant differences in performance between the unimodal (visual) and multimodal (auditory–visual) feedback modality. Furthermore, the last study, in which people with schizophrenia participated in multiple sessions with simple feedback, demonstrated that these patients can learn to voluntarily regulate their alpha band. Compared to the healthy group they required longer training times and could not achieve performance levels as high as the control group. Nonetheless, alpha neurofeedback training lead to a constant increase of the alpha resting power across all 20 training session. To date only little is known about the effects of feedback and training time on BCI performance and cortical activation patterns. The presented work contributes to the evidence that healthy individuals can benefit from enriched feedback: A realistic presentation can support participants in getting a concrete feeling of motor imagery and enriched feedback, which instructs participants about the quality of their input signal can give support while learning to control the BCI. This thesis demonstrates that people with schizophrenia can learn to gain control of their alpha oscillations recorded over the sensorimotor cortex when participating in sufficient training sessions. In conclusion, this thesis improved current motor imagery BCI feedback protocols and enhanced our understanding of the interplay between feedback and BCI performance. / Die Wirksamkeit von Feedback und Trainingseffekten während der Alphaband Modulation über dem menschlichen sensomotorischen Cortex

Zugl.: Konstanz, Universiẗat, Diss., 2008.

Zugl.: Konstanz, Univ., Diss., 2008

No description available.

No description available.

This thesis investigated the modulation of approach-avoidance behavior using neurofeedback (NF), focusing specifically on Frontal Midline Theta (FMT) as a target oscillation. The main goal was to determine whether reducing FMT through NF could enhance approach behavior in conflict situations while increasing FMT would promote avoidance. To provide an overview of the current state of the art, the first study focused on a systematic review and meta-analysis of existing studies on FMT modulation by NF. The results indicated a medium effect size, suggesting the feasibility of FMT-NF. However, sub-analyses showed only successful upregulation of FMT, with no evidence supporting FMT downregulation. Although the synthesis was complicated by substantial variability in study design, the number of NF sessions emerged as a moderator of effect size. This comprehensive review provided guidance for future NF protocols and introduced new responder nomenclature to facilitate cross-study comparisons. The next study aimed to integrate the findings into an efficient NF protocol to inhibit FMT. Based on the previous review, we individualized the feedback band to the FMT peak frequency (ITF) elicited during an approach-avoidance task. However, pilot data revealed substantial ITF variability between sessions. Therefore, we analyzed data from an additional 151 participants, confirming that ITF is highly variable over time, with low reliability within and across sessions. This suggests that a single calibration is insufficient for multi-session NF. Lastly, based on the processes related to FMT and the lack of supporting evidence for its downregulation, we proposed the "FMT inhibition dilemma," which suggests that FMT is challenging to downregulate due to its association with cognitive effort during NF. Analysis of two distinct datasets showed that FMT activity increased during NF, even when attempts were made to inhibit it. This indicates a severe dilemma and the need for alternative NF protocols that reduce cognitive engagement or adjust feedback mechanisms. In summary, while FMT-targeted neurofeedback presents a promising avenue for influencing approach-avoidance behavior, there are significant methodological and theoretical challenges that need to be addressed. Key recommendations include embracing multi-session protocols, systematically reporting and investigating individual peak frequencies, and considering inherent processes of FMT when designing and aiming at FMT inhibition. The adoption of open science practices and rigorous replication are highlighted as critical to advancing the reliability and efficacy of neurofeedback research. / In dieser Arbeit wurde die Modulation von Annäherungs-Vermeidungs-Verhalten mittels Neurofeedback (NF) untersucht. Im Speziellen wurde sich dabei auf Frontal Midline Theta (FMT) als Modulationsziel konzentriert. Das Hauptziel war es, festzustellen, ob eine Verringerung der FMT-Aktivität durch NF das Annäherungsverhalten in Konfliktsituationen erhöhen könnte, während eine Erhöhung der FMT das Vermeidungsverhalten fördern würde. Um einen Überblick über den aktuellen Stand der Forschung zu erhalten, fokussiert die erste Studie eine systematische Überprüfung und Meta-Analyse bestehender Studien zur Modulation von FMT durch. Die Ergebnisse weisen auf eine mittlere Effektstärke hin, was auf ihre Durchführbarkeit von FMT-NF schließen lässt. Die Subanalysen zeigten jedoch nur eine erfolgreiche Hochregulierung von FMT, während es keine Belege für eine FMT-Runterregulierung gab. Obwohl die Synthese durch die erhebliche Variabilität der Studiendesigns erschwert wurde, erwies sich die Anzahl der NF-Sitzungen als Moderator der Effektstärke. In dieser umfassenden Übersicht liefern wir Leitlinien für künftige NF-Protokolle und führen eine neue Nomenklatur für Personen die auf NF ansprechen ein, um den künftigen Vergleich zwischen verschiedenen Studien zu erleichtern. Ziel der nächsten Studie war es, die Erkenntnisse in ein effizientes NF-Protokoll zur Verringerung von FMT zu integrieren. Auf der Grundlage der vorangegangenen Übersichtsarbeit haben wir das Feedbackband an die individuelle FMT-Spitzenfrequenz (ITF) angepasst, die während einer Annäherungs-Vermeidungs-Aufgabe ausgelöst wurde. Pilotdaten zeigten jedoch eine erhebliche ITF-Variabilität zwischen den Sitzungen. Daher analysierten wir die Daten von weiteren 151 Teilnehmern und bestätigten, dass die ITF im Laufe der Zeit sehr variabel ist, mit geringer Zuverlässigkeit innerhalb und zwischen den Sitzungen. Dies legt nahe, dass eine einzige Kalibrierung für eine NF-Intervention, die mehrere Sitzungen umfasst, unzureichend ist. Basierend auf den Prozessen, die mit FMT assoziert sind, und dem Mangel an unterstützenden Beweisen für die Herunterregulierung von FMT, schlugen wir das „FMT-Inhibitionsdilemma“ vor. Dieses besagt, dass es schwierig ist, FMT herunterzuregulieren, da es durch kognitive Anstrengung während der NF erhöht wird. Die Analyse von zwei verschiedenen Datensätzen zeigte, dass die FMT-Aktivität während der NF zunahm, selbst wenn versucht wurde, sie zu hemmen. Dies deutet auf ein schwerwiegendes Dilemma und die Notwendigkeit alternativer NF-Protokolle hin, die das kognitive Engagement reduzieren oder die Feedback-Mechanismen anpassen. Zusammenfassend lässt sich sagen, dass FMT-gezieltes Neurofeedback zwar einen vielversprechenden Weg zur Beeinflussung des Annäherungs-/Vermeidungsverhaltens darstellt, es jedoch erhebliche methodische und theoretische Herausforderungen gibt, die es zu bewältigen gilt. Zu den wichtigsten Empfehlungen gehören die Verwendung von Protokollen mit mehreren Sitzungen, die systematische Erfassung und Untersuchung individueller Spitzenfrequenzen und die Berücksichtigung inhärenter Prozesse der FMT bei der Entwicklung von FMT-Hemmungen. Die Integration von „Open-Science“ Praktiken und rigoroser Replikation werden als entscheidend für die Verbesserung der Zuverlässigkeit und Wirksamkeit der Neurofeedbackforschung hervorgehoben.

O neurofeedback é um processo psicofisiológico de aprendizagem por meio do qual o indivíduo obtém controle sobre a freqüência de suas ondas cerebrais. Este estudo objetivou avaliar o efeito do treinamento do ritmo beta inferior (12-15Hz) sobre o córtex sensoriomotor e a concomitante inibição do ritmo teta (4-8Hz) na mesma área, sobre o desempenho atencional, mnemônico e cognitivo de adultos normais de nível universitário. Formou-se um grupo experimental e um grupo controle com 11 sujeitos cada, com idade média de 25,7 anos, estudantes de uma instituição de ensino superior particular em São Paulo. Todos os sujeitos foram submetidos a pré e pós-testes de inteligência não-verbal (Matrizes Progressivas de Raven Escala Avançada), verbal (V-47), atenção (D2) e memória (Fator M Bateria Cepa). O experimento, que durou dois meses, submeteu os sujeitos experimentais a 36 sessões (em média) de treinamento em neurofeedback, com a duração de 15 minutos cada e freqüência de três vezes por semana. Os resultados indicaram uma melhora significante nos processos atencionais, mnemônicos (icônicos) e edutivos (inteligência não-verbal). Não foram obtidas melhoras significantes nos processos mnemônicos (ecóicos) e reprodutivos (inteligência verbal). A comparação do grupo experimental com o grupo controle indicou a não relevância do efeito aprendizagem (teste-reteste) nas tarefas utilizadas para a avaliação dos sujeitos / Neurofeedback is a psychophysiological process where visual stimuli and sounds are employed to reinforce voluntary control over EEG patterns. This study evaluated the effect of low beta (12-15Hz) increase and theta (4-8Hz) inhibit training over sensorimotor cortex on attention, memory and cognitive performance of young adults college students. Experimental and control groups were formed by 11 volunteers subjects each, aging 25,7 years on average. All subjects were submitted to pre and post evaluations of non-verbal (Ravens Advanced Progressive Matrices) and verbal intelligence (V-47 test), attention (D2 test) and memory (Fator M Bateria Cepa). The experiment was conducted along two months, subjects having an average of 36 sessions (15 minutes each), three times a week. Results provide strong evidences of significant improvement on attention, visual memory and non-verbal intelligence (eduction). However, it could not be found evidence of significant improvement on auditory memory or verbal intelligence (reproduction). The experimental and control comparision did not indicate test-retest effects on the experiment

O neurofeedback é um processo psicofisiológico de aprendizagem por meio do qual o indivíduo obtém controle sobre a freqüência de suas ondas cerebrais. Este estudo objetivou avaliar o efeito do treinamento do ritmo beta inferior (12-15Hz) sobre o córtex sensoriomotor e a concomitante inibição do ritmo teta (4-8Hz) na mesma área, sobre o desempenho atencional, mnemônico e cognitivo de adultos normais de nível universitário. Formou-se um grupo experimental e um grupo controle com 11 sujeitos cada, com idade média de 25,7 anos, estudantes de uma instituição de ensino superior particular em São Paulo. Todos os sujeitos foram submetidos a pré e pós-testes de inteligência não-verbal (Matrizes Progressivas de Raven Escala Avançada), verbal (V-47), atenção (D2) e memória (Fator M Bateria Cepa). O experimento, que durou dois meses, submeteu os sujeitos experimentais a 36 sessões (em média) de treinamento em neurofeedback, com a duração de 15 minutos cada e freqüência de três vezes por semana. Os resultados indicaram uma melhora significante nos processos atencionais, mnemônicos (icônicos) e edutivos (inteligência não-verbal). Não foram obtidas melhoras significantes nos processos mnemônicos (ecóicos) e reprodutivos (inteligência verbal). A comparação do grupo experimental com o grupo controle indicou a não relevância do efeito aprendizagem (teste-reteste) nas tarefas utilizadas para a avaliação dos sujeitos / Neurofeedback is a psychophysiological process where visual stimuli and sounds are employed to reinforce voluntary control over EEG patterns. This study evaluated the effect of low beta (12-15Hz) increase and theta (4-8Hz) inhibit training over sensorimotor cortex on attention, memory and cognitive performance of young adults college students. Experimental and control groups were formed by 11 volunteers subjects each, aging 25,7 years on average. All subjects were submitted to pre and post evaluations of non-verbal (Ravens Advanced Progressive Matrices) and verbal intelligence (V-47 test), attention (D2 test) and memory (Fator M Bateria Cepa). The experiment was conducted along two months, subjects having an average of 36 sessions (15 minutes each), three times a week. Results provide strong evidences of significant improvement on attention, visual memory and non-verbal intelligence (eduction). However, it could not be found evidence of significant improvement on auditory memory or verbal intelligence (reproduction). The experimental and control comparision did not indicate test-retest effects on the experiment

Seit vier Jahrzehnten werden verschiedene Neurofeedbackmethoden bei der Behandlung unterschiedlicher Störungen, unter anderem bei AD/HS-Kindern, eingesetzt. Die Grundlage der Anwendung von Neurofeedback bei dieser Störung besteht darin, dass die Kinder Auffälligkeiten in ihrem EEG zeigen. Dort treten im Vergleich zu unauffälligen Kindern vermehrt Theta-Gehirnwellen und weniger Beta-Gehirnwellen auf. Mittels Neurofeedback wird versucht, die Gehirnfunktionen zu korrigieren. Zahlreiche Einzellfallstudien bestätigen die Wirksamkeit dieser Therapiemethode bei der AD/HS-Behandlung. Bisher wurde jedoch keine Studie veröffentlicht, in der die Wirksamkeit von Neurofeedback mit einer Placebogruppe verglichen wurde. Ziel der vorliegenden Studie war es, die Wirksamkeit eines Theta/Beta-Neurofeedbacks (NF) bei der Behandlung von AD/HS-Kindern zu überprüfen und mit einem EMG-Biofeedback (BF) als Placebobedingung zu vergleichen. Es wurden 35 ADHS-Kinder (6 -14 Jahre; 26 Jungen und 9 Mädchen) untersucht. Nach Standarddiagnostik und Vergabe der AD/HS-Diagnose durch einen unabhängigen Psychotherapeuten wurden die Kinder per Zufall zwei Gruppen (NF: n = 18 bzw. BF: n = 17) zugeteilt. Alle Kinder beider Gruppen erhielten ein 30 Sitzungen umfassendes Training mittels Theta/Beta-Neurofeedback bzw. EMG-Biofeedback. Unmittelbar vor und nach dem Training wurden Intelligenz- bzw. Aufmerksamkeitsleistungen untersucht und Einschätzungen des Verhaltens von Eltern und Lehrern erhoben. Im Anschluss an das Training erfolgte eine erneute diagnostische Einschätzung durch einen unabhängigen Psychotherapeuten. Die EEG-Daten in der NF-Gruppe zeigen eine Reduktion der Theta/Beta-Quotienten im Laufe der NF-Sitzungen. Die EMG-Daten zeigen für die EMG-Biofeedback-Bedingung gleichfalls eine Reduktion der EMG-Amplitude. Die Ergebnisse der zweifaktoriellen Varianzanalysen mit Messwiederholung auf einem Faktor zeigen für die angewendeten diagnostischen Verfahren die erwarteten signifikanten Interaktionen zwischen Messzeitpunkt und Gruppe. Die Ergebnisse des t-Tests zeigen signifikante Verbesserungen in der Aufmerksamkeitsleistung, dem Intelligenzniveau und im Verhalten der Kinder aus der NF-Gruppe im Vergleich zu den Resultaten des Prä-Tests. Die EMG-Biofeedbackgruppe zeigt mit Ausnahme einer Erhöhung des Arbeitstempos in den Paper-Pencil-Aufmerksamkeitstests (die im CPT nicht repliziert werden konnte) keine signifikanten Verbesserungen relativ zum Prä-Test. Nach dem Training erhielten 55,6 % (n = 10) der AD/HS-Kinder aus der Neurofeedbackgruppe und 23,5 % (n = 4) der Kinder aus der EMG-Biofeedbackgruppe keine AD/HS-Diagnose nach den Kriterien der ICD-10. Der Chi-Quadrat-Test zeigt jedoch lediglich einen tendenziell bedeutsamen Unterschied (p = .086). Insgesamt bestätigen die Ergebnisse die Wirksamkeit des Neurofeedbacks bei der Behandlung von ADHS-Kindern im Vergleich mit einer Placebogruppe. Weitere Studien in diesem Bereich sind notwendig, um die Wirksamkeit des Neurofeedbacktrainings im Vergleich zu einer Placebomethode bei der ADHS-Behandlung zu untersuchen. / Neurofeedback (NF) has been introduced four decades ago as an alternative treatment for different disorders, one of these being Attention Deficit/Hyperactivity Disorder (AD/HD). As compared to a control group (non ADHD children), children diagnosed with ADHD show an increased frequency of Theta waves and a decreased frequency of Beta waves in their EEGs. A treatment consisting of NF-training attempts to correct these anomalies. There are numerous single case studies in this area but only a few controlled studies. Furthermore, there are no studies comparing the effect of NF in the treatment of ADHD with a placebo group. This study sets out to evaluate the effects of 30 (Theta/Beta) NF training sessions on ADHD symptoms and compare those with the effects of the placebo EMG-biofeedback (BF) training group. The subjects, consisting of 35 children both male (n = 26) and female (n = 9) between the ages of 6 and 14 diagnosed with ADHD by independent psychotherapists, were randomly assigned to either the treatment group (NF; n = 18) or the placebo group (BF; n = 17). In addition to the Theta/Beta quotient (in NF group) and EMG-Amplitude (in BF group) as seen during the sessions, pre and post measures of the subjects´ intelligence (Raven Test), paper-pencil attention test scores (bp/d2), Continuous Performance Task (CPT) as well as symptom ratings (MEF and FBB-HKS) from both teachers and parents were obtained. Finally, subjects were re-evaluated after treatment by independent psychotherapists. The results showed a significant decrease in the Theta/Beta quotient after the NF training and a significant decrease in the EMG-Amplitude after the BF-training. The results of an ANOVA with repeated measures showed significant differences between the treatment group (NF training) and the placebo (BF training) group in attention tests and symptom rating scores after treatment. Compared to the pre-test scores, subjects in the NF group showed significant improvements in attention scores, intelligence scores, and behaviour after the NF training sessions. The BF placebo group showed no significant improvements in any of the outcome variables except on the speed scale of the paper-pencil attention tests (this was incompatible with the results of CPT). Finally, 55.6% (n = 10) of the children in the NF training group were not diagnosed with ADHD (using ICD-10 criteria) at the time of the second evaluation. In the BF group, 23.5% (n = 4) were not diagnosed with ADHD by independent psychotherapists at the end of the BF training. The results indicate that NF training in comparing with a placebo method is an effective treatment method in the treatment of ADHD children. Further studies are necessary in comparing the effectiveness of NF training with more neutral placebo interventions in the treatment of children with ADHD.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-06-18T13:40:42Z No. of bitstreams: 1 priscillarezendesilva.pdf: 1039823 bytes, checksum: 1dd3ace224b869dc4a10c45288993628 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-06-27T12:00:30Z (GMT) No. of bitstreams: 1 priscillarezendesilva.pdf: 1039823 bytes, checksum: 1dd3ace224b869dc4a10c45288993628 (MD5) / Made available in DSpace on 2018-06-27T12:00:30Z (GMT). No. of bitstreams: 1 priscillarezendesilva.pdf: 1039823 bytes, checksum: 1dd3ace224b869dc4a10c45288993628 (MD5) Previous issue date: 2018-02-27 / Dentre os tratamentos propostos para transtornos mentais, a terapia de biofeedback é uma das muitas abordagens utilizadas. Tal terapia tem como objetivo auxiliar o indivíduo a assumir a responsabilidade pelo seu bem-estar, englobando responsabilidades pelas mudanças cognitivas, emocionais e comportamentais necessárias para a obtenção de mudanças fisiológicas saudáveis. Neste trabalho de revisão sistemática objetivou-se pesquisar e averiguar em quais psicopatologias o biofeedback e o neurofeedback têm sido utilizados, bem como verificar a existência de evidências de sua eficácia nesses quadros. Foi realizada uma pesquisa em cinco bases de dados eletrônicas (PubMed/Medline, SCOPUS, Web of Science, PsycInfo e Scielo), utilizando-se combinações booleanas do termo “biofeedback” (AND) com termos retirados da Classificação Estatística Internacional de Doenças e Problemas Relacionados à Saúde – 10 (CID-10). A seguir, novas combinações foram empregadas adicionando o termo “intervention” às combinações descritas. Um total de 14.350 estudos foram incluídos no conjunto de dados. Foram analisados estudos originais, cujo objetivo era investigar a eficácia do biofeedback no tratamento de psicopatologias, escritos em português e/ou inglês publicados entre os anos de 2012-2017. Após o cumprimento de várias etapas de seleção, foram incluídos 49 estudos no conjunto de dados final e analisados de acordo com a: descrição da amostra (patologia; idade; tipo de biofeedback), desenho (Randomização; Controle, Cegamento; cálculo do N, Follow-up, Registro, Tamanho de efeito, análise por intenção de tratar, Multicêntrico, Piloto), protocolo (número de sessões de treinamento e de intervenção, duração da sessão de intervenção, frequência das sessões e duração da pesquisa). As psicopatologias mais frequentes foram transtorno de déficit de atenção e hiperatividade, transtorno depressivo maior, transtorno do espectro autista, dependência de álcool, compulsão alimentar e estresse. A maioria (51,02%) dos estudos analisados não utilizou medidas de tamanho de efeito e apenas um quinto (20,42%) encontrou, efetivamente, algum efeito nas intervenções com biofeedback ou neurofeedback. Todos os 13 estudos nos quais foi apresentado algum efeito do bio ou neurofeedback continham importantes falhas metodológicas. Considerados todos os aspectos metodológicos e os vieses de cada uma das falhas, verifica-se que nenhum dos artigos conseguiu contemplar todos os requisitos metodológicos para que se pudesse afirmar a eficácia do tratamento através do biofeedback e o neurofeedback. São necessários estudos mais rigorosos para que se possa afirmar a aplicabilidade e a eficácia do biofeedback e neurofeedback no manejo de psicopatologias. / Among the proposed treatments for mental disorders, biofeedback therapy is one of many approaches. Such therapy aims to assist the individual to take responsibility for their well-being, encompassing responsibility for the cognitive, emotional, and behavioral changes necessary to effect healthy physiological changes. In this systematic review we aimed to investigate in which psychopathologies biofeedback and neurofeedback have been used, as well as to verify the existence of evidence of its effectiveness in these psychopathologies. A search was carried out in five electronic databases (PubMed / Medline, SCOPUS, Web of Science, PsycInfo and Scielo), using boolean combinations of the term "biofeedback" (AND) with terms derived from the International Classification of Diseases for Mortality and Morbidity Statistics- 10 (ICD-10). Next, new combinations were employed by adding the term "intervention" to the combinations described. A total of 14,350 studies were included in the data set. We analyzed original studies, whose objective was to investigate the efficacy of biofeedback in the treatment of psychopathologies, written in Portuguese and / or English and published between the years of 2012-2017. After completing several selection steps, 49 studies were included in the final data set and analyzed according to: sample description (pathology; age; type of biofeedback), design (Randomization; Control, Blinding; Statistic for sample size, Follow-up, size of effect, intention-to-treat, Multicenter, Pilot) and protocol (number of training sessions, number of intervention sessions, duration of intervention session, frequency of sessions and duration of research). Biofeedback and neurofeedback were found mostly used in attention deficit hyperactivity disorder, major depressive disorder, autism spectrum disorder, alcohol dependence, binge eating, and stress. Most (51.02%) of the studies analyzed did not use effect size measures and only one fifth (20.42%) did indeed find any effect on interventions with biofeedback or neurofeedback. All 13 studies that found some bio or neurofeedback effect contained important methodological flaws. Considering all the methodological aspects and biases of each one of the failures, it was verified that none of the studies was able to contemplate all the methodological requirements so that the effectiveness of the treatment with the biofeedback and the neurofeedback could be affirmed. More rigorous studies are needed to establish the applicability and efficacy of biofeedback and neurofeedback in the management of psychopathologies.