An Exploratory Study of Intensive Neurofeedback Training for Schizophrenia

A Systematic Review of the Effects of EEG Neurofeedback on Patients with Schizophrenia

Schizophrenia is a neuropsychiatric disorder affecting approximately 1 in 300 people worldwide. It is characterized by a range of symptoms, including positive symptoms (delusions, hallucinations, and formal thought disorganization), negative symptoms (anhedonia, alogia, avolition, asociality, and blunted affect), and cognitive impairments (impaired memory, attention, executive function, and processing speed). Current treatments, such as psychopharmacology and psychotherapy, often do not fully address these symptoms, leading to impaired everyday functionality. In recent years, there has been a growing interest in neuromodulation due to computer and engineering science making extraordinary computational advances. Those put together have reinitiated the spark in the field of neurofeedback (NF) as a means for self-regulation and neuromodulation with the potential to alleviate the daily burden of schizophrenia. We review, in a systematic way, the primary reports of electroencephalogram (EEG)-based NF as a therapeutical tool for schizophrenia. The main body of research consists mostly of case studies and case reports. The results of a few randomized controlled studies, combined with case studies/series, underscore the potential use of NF as an add-on treatment option for improving the lives of suffering individuals, being sustained by the changes in brain function and symptomatology improvement. We aim to provide important evidence of neuromodulation using NF in patients with schizophrenia, summarizing the effects and conclusions found in several clinical trials.

The Influence of an Alpha Band Neurofeedback Training in Heart Rate Variability in Athletes

Neurofeedback training is a technique which has seen a widespread use in clinical applications, but has only given its first steps in the sport environment. Therefore, there is still little information about the effects that this technique might have on parameters, which are relevant for athletes' health and performance, such as heart rate variability, which has been linked to physiological recovery. In the sport domain, no studies have tried to understand the effects of neurofeedback training on heart rate variability, even though some studies have compared the effects of doing neurofeedback or heart rate biofeedback training on performance. The main goal of the present study was to understand if alpha-band neurofeedback training could lead to increases in heart rate variability. 30 male student-athletes, divided into two groups, (21.2 ± 2.62 year 2/week protocol and 22.6 ± 1.1 year 3/week protocol) participated in the study, of which three subjects were excluded. Both groups performed a pre-test, a trial session and 12 neurofeedback sessions, which consisted of 25 trials of 60 s of a neurofeedback task, with 5 s rest in-between trials. The total neurofeedback session time for each subject was 300 min in both groups. Throughout the experiment, electroencephalography and heart rate variability signals were recorded. Only the three sessions/week group revealed significant improvements in mean heart rate variability at the end of the 12 neurofeedback sessions (p = 0.05); however, significant interaction was not found when compared with both groups. It is possible to conclude that neurofeedback training of individual alpha band may induce changes in heart rate variability in physically active athletes.

Review of Neuropsychological and Electrophysiological Correlates of Callous-unemotional Traits in Children: Implications for EEG Neurofeedback Intervention

Conduct disorder is a significant psychiatric disorder of childhood and adolescence. The Diagnostic and Statistical Manual of Mental Disorders, fifth version (DSM-5), added the limited prosocial specifier to identify those individuals who exhibit a more severe pattern of behavior characterized by a callous and unemotional (CU) interpersonal style across multiple settings and relationships. This review has attempted to summarize the relevant research focusing on the significance of CU interpersonal style in the development of psychopathy. The primary focus was on the electrophysiological and neuropsychological correlates of CU traits and their implication on the treatment protocol using neurofeedback training for children with such traits. The source of the literature search was PubMed, which majorly uses the MEDLINE database. The keywords used included CU traits, conduct disorder, child psychopathy, empathy, electrophysiology, criminal behavior, neuropsychology, neurofeedback training, and so on. Studies from the last 15 years were considered for the review. This review revealed that children with conduct disorder and high-CU traits with a combination of reactive and proactive aggression are more likely to develop psychopathy. Evidence suggests that these children have distinct forms of electrophysiological and neuropsychological correlates. However, research in this area is still not conclusive as they yield variation in findings. Studies on the efficacy of neurofeedback training on reducing symptoms such as impulsivity, hostility, and psychopathy indicate that neurofeedback training can be a promising treatment alternative for children with severe conduct disorder.

Session Frequency Matters in Neurofeedback Training of Athletes

Neurofeedback training has been an increasingly used technique and is taking its first steps in sport. Being at an embryonic stage, it is difficult to find consensus regarding the applied methodology to achieve the best results. This study focused on understanding one of the major methodological issues-the training session frequency. The aim of the investigation was to understand if there are differences between performing two sessions or three sessions per week in enhancement of alpha activity and improvement of cognition; and in case there are differences, infer the best protocol. Forty-five athletes were randomly assigned to the three-session-training-per-week group, the two-session-training-per-week group and a control group. The results showed that neurofeedback training with three sessions per week was more effective in increase of alpha amplitude during neurofeedback training than two sessions per week. Furthermore, only the three-session-per-week group showed significant enhancement in N-back and oddball performance after training. The findings suggested more condensed training protocol lead to better outcomes, providing guidance on neurofeedback protocol design in order to optimize training efficacy.

Improving treatments for psychotic disorders: beyond cognitive behaviour therapy for psychosis

More effective treatments for people with psychotic disorders are urgently required. Here, we make three suggestions for progress: 1. Targeting the disorders' core phenomenological features ('phenomenological phenotype'), 2. Addressing social disconnection, isolation and loneliness, and 3. Leveraging 'hot' cognitions and using symptom capture approaches that combine psychotherapy with advances in technology and neuroscience.

On the use of pairwise distance learning for brain signal classification with limited observations

The increasing access to brain signal data using electroencephalography creates new opportunities to study electrophysiological brain activity and perform ambulatory diagnoses of neurological disorders. This work proposes a pairwise distance learning approach for schizophrenia classification relying on the spectral properties of the signal. To be able to handle clinical trials with a limited number of observations (i.e. case and/or control individuals), we propose a Siamese neural network architecture to learn a discriminative feature space from pairwise combinations of observations per channel. In this way, the multivariate order of the signal is used as a form of data augmentation, further supporting the network generalization ability. Convolutional layers with parameters learned under a cosine contrastive loss are proposed to adequately explore spectral images derived from the brain signal. The proposed approach for schizophrenia diagnostic was tested on reference clinical trial data under resting-state protocol, achieving 0.95 ± 0.05 accuracy, 0.98 ± 0.02 sensitivity and 0.92 ± 0.07 specificity. Results show that the features extracted using the proposed neural network are remarkably superior than baselines to diagnose schizophrenia (+20pp in accuracy and sensitivity), suggesting the existence of non-trivial electrophysiological brain patterns able to capture discriminative neuroplasticity profiles among individuals. The code is available on Github: https://github.com/DCalhas/siamese_schizophrenia_eeg.

A Systematic Review of the Potential Use of Neurofeedback in Patients With Schizophrenia

Schizophrenia (SCZ) is a neurodevelopmental disorder characterized by positive symptoms (hallucinations and delusions), negative symptoms (anhedonia, social withdrawal) and marked cognitive deficits (memory, executive function, and attention). Current mainstays of treatment, including medications and psychotherapy, do not adequately address cognitive symptoms, which are essential for everyday functioning. However, recent advances in computational neurobiology have rekindled interest in neurofeedback (NF), a form of self-regulation or neuromodulation, in potentially alleviating cognitive symptoms in patients with SCZ. Therefore, we conducted a systematic review of the literature for NF studies in SCZ to identify lessons learned and to identify steps to move the field forward. Our findings reveal that NF studies to date consist mostly of case studies and small sample, single-group studies. Despite few randomized clinical trials, the results suggest that NF is feasible and that it leads to measurable changes in brain function. These findings indicate early proof-of-concept data that needs to be followed up by larger, randomized clinical trials, testing the efficacy of NF compared to well thought out placebos. We hope that such an undertaking by the field will lead to innovative solutions that address refractory symptoms and improve everyday functioning in patients with SCZ.

Electrophysiological Markers of Motivation in Psychosis

Motivation is associated with electrophysiological markers, such as awake state delta oscillation and frontal alpha asymmetry, as well as event-related potentials, such as error-related negativity, feedback-related negativity, and prepulse inhibition. These indicators provide an objective measure of motivational deficits in psychiatric conditions, and response to treatment. Also, these modalities of brain activities are drawing attention as a target of neurofeedback training. The aim of this article is to provide a brief overview on electrophysiological findings relevant to the understanding of the mechanisms underlying impaired motivation in psychiatric disorders and clinical practice.

Neurofeedback Training for Psychiatric Disorders Associated with Criminal Offending: A Review

BACKGROUND

Effective treatment interventions for criminal offenders are necessary to reduce risk of criminal recidivism. Evidence about deviant electroencephalographic (EEG)-frequencies underlying disorders found in criminal offenders is accumulating. Yet, treatment modalities, such as neurofeedback, are rarely applied in the forensic psychiatric domain. Since offenders usually have multiple disorders, difficulties adhering to long-term treatment modalities, and are highly vulnerable for psychiatric decompensation, more information about neurofeedback training protocols, number of sessions, and expected symptom reduction is necessary before it can be successfully used in offender populations.

METHOD

Studies were analyzed that used neurofeedback in adult criminal offenders, and in disorders these patients present with. Specifically aggression, violence, recidivism, offending, psychopathy, schizophrenia, attention-deficit hyperactivity disorder (ADHD), substance-use disorder (SUD), and cluster B personality disorders were included. Only studies that reported changes in EEG-frequencies posttreatment (increase/decrease/no change in EEG amplitude/power) were included.

RESULTS

Databases Psychinfo and Pubmed were searched in the period 1990-2017 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, resulting in a total of 10 studies. Studies in which neurofeedback was applied in ADHD (N = 3), SUD (N = 3), schizophrenia (N = 3), and psychopathy (N = 1) could be identified. No studies could be identified for neurofeedback applied in cluster B personality disorders, aggression, violence, or recidivism in criminal offenders. For all treatment populations and neurofeedback protocols, number of sessions varied greatly. Changes in behavioral levels ranged from no improvements to significant symptom reduction after neurofeedback training. The results are also mixed concerning posttreatment changes in targeted EEG-frequency bands. Only three studies established criteria for EEG-learning.

CONCLUSION

Implications of the results for the applicability of neurofeedback training in criminal offender populations are discussed. More research focusing on neurofeedback and learning of cortical activity regulation is needed in populations with externalizing behaviors associated with violence and criminal behavior, as well as multiple comorbidities. At this point, it is unclear whether standard neurofeedback training protocols can be applied in offender populations, or whether QEEG-guided neurofeedback is a better choice. Given the special context in which the studies are executed, clinical trials, as well as single-case experimental designs, might be more feasible than large double-blind randomized controls.