Modulatory dynamics mark the transition between anesthetic states of unconsciousness.

Unconsciousness maintained by GABAergic anesthetics, such as propofol and sevoflurane, is characterized by slow-delta oscillations (0.3 to 4 Hz) and alpha oscillations (8 to 14 Hz) that are readily visible in the electroencephalogram. At higher doses, these slow-delta-alpha (SDA) oscillations transition into burst suppression. This is a marker of a state of profound brain inactivation during which isoelectric (flatline) periods alternate with periods of the SDA patterns present at lower doses. While the SDA and burst suppression patterns have been analyzed separately, the transition from one to the other has not. Using state-space methods, we characterize the dynamic evolution of brain activity from SDA to burst suppression and back during unconsciousness maintained with propofol or sevoflurane in volunteer subjects and surgical patients. We uncover two dynamical processes that continuously modulate the SDA oscillations: alpha-wave amplitude and slow-wave frequency modulation. We present an alpha modulation index and a slow modulation index which characterize how these processes track the transition from SDA oscillations to burst suppression and back to SDA oscillations as a function of increasing and decreasing anesthetic doses, respectively. Our biophysical model reveals that these dynamics track the combined evolution of the neurophysiological and metabolic effects of a GABAergic anesthetic on brain circuits. Our characterization of the modulatory dynamics mediated by GABAergic anesthetics offers insights into the mechanisms of these agents and strategies for monitoring and precisely controlling the level of unconsciousness in patients under general anesthesia.

Musical Auditory Alpha Wave Neurofeedback: Validation and Cognitive Perspectives.

Neurofeedback through visual, auditory, or tactile sensations improves cognitive functions and alters the activities of daily living. However, some people, such as children and the elderly, have difficulty concentrating on neurofeedback for a long time. Constant stressless neurofeedback for a long time may be achieved with auditory neurofeedback using music. The primary purpose of this study was to clarify whether music-based auditory neurofeedback increases the power of the alpha wave in healthy subjects. During neurofeedback, white noise was superimposed on classical music, with the noise level inversely correlating with normalized alpha wave power. This was a single-blind, randomized control crossover trial in which 10 healthy subjects underwent, in an assigned order, normal and random feedback (NF and RF), either of which was at least 4 weeks long. Cognitive functions were evaluated before, between, and after each neurofeedback period. The secondary purpose was to assess neurofeedback-induced changes in cognitive functions. A crossover analysis showed that normalized alpha-power was significantly higher in NF than in RF; therefore, music-based auditory neurofeedback facilitated alpha wave induction. A composite category-based analysis of cognitive functions revealed greater improvements in short-term memory in subjects whose alpha-power increased in response to NF. The present study employed a long period of auditory alpha neurofeedback and achieved successful alpha wave induction and subsequent improvements in cognitive functions. Although this was a pilot study that validated a music-based alpha neurofeedback system for healthy subjects, the results obtained are encouraging for those with difficulty in concentrating on conventional alpha neurofeedback.Trial registration: 2018077NI, date of registration: 2018/11/27.

Electroencephalography as a Non-Invasive Biomarker of Alzheimer's Disease: A Forgotten Candidate to Substitute CSF Molecules?

Biomarkers for disease diagnosis and prognosis are crucial in clinical practice. They should be objective and quantifiable and respond to specific therapeutic interventions. Optimal biomarkers should reflect the underlying process (pathological or not), be reproducible, widely available, and allow measurements repeatedly over time. Ideally, biomarkers should also be non-invasive and cost-effective. This review aims to focus on the usefulness and limitations of electroencephalography (EEG) in the search for Alzheimer's disease (AD) biomarkers. The main aim of this article is to review the evolution of the most used biomarkers in AD and the need for new peripheral and, ideally, non-invasive biomarkers. The characteristics of the EEG as a possible source for biomarkers will be revised, highlighting its advantages compared to the molecular markers available so far.

Alpha and beta cortical activity during guitar playing: task complexity and audiovisual stimulus analysis.

PURPOSE: Some studies have explored the relationship between music and cortical activities; however, there are just few studies investigating guitar performance associated with different sensory stimuli. Our aim was to evaluate alpha and beta activity during guitar playing. MATERIALS AND METHOD: Twenty healthy right-handed people participated in this study. Cortical activity was measured by electroencephalogram (EEG) during rest and 4 tasks (1: easy music with an auditory stimulus; 2: easy music with an audiovisual stimulus; 3: complex music with an auditory stimulus; 4: complex music with an audiovisual stimulus). The peak frequency (PF), median frequency (MF) and root mean square (RMS) of alpha and beta EEG signals were assessed. RESULTS: A higher alpha PF at the T3-P3 was observed, and this difference was higher between rest and task 3, rest and task 4, tasks 1 and 3, and tasks 1 and 4. For beta waves, a higher PF was observed at C4-P4 and a higher RMS at C3-C4 and O1-O2. At C4-P4, differences between rest and tasks 2 and 4 were observed. The RMS of beta waves at C3-C4 presented differences between rest and task 3 and at O1-O2 between rest and task 2 and 4. CONCLUSION: The action observation of audiovisual stimuli while playing guitar can increase beta wave activity in the somatosensory and motor cortexes; and increase in the alpha activity in the somatosensory and auditory cortexes and increase in the beta activity in the bilateral visual cortexes during complex music execution, regardless of the stimulus type received. Abbreviations: bpm: beats per minute; C: central; EEG: electroencephalogram; F: frontal; Hz: hertz; LABCOM: Laboratory of Motor Control and Biomechanics; MD: mean difference; MF: median frequency; O: occipital; P: parietal; PF: peak frequency; R: rest; RMS: root mean square; T: temporal; T1: task 1; T2: task 2; T3: task 3; T4: task 4; UFTM: Federal University of Triângulo Mineiro.

A novel training-free externally-regulated neurofeedback (ER-NF) system using phase-guided visual stimulation for alpha modulation.

The efficacy of neurofeedback is a point of great controversy, because a certain proportion of users cannot properly regulate their brain activities and thereby fail to benefit from neurofeedback. To address the neurofeedback inefficacy problem, the present study is aimed to design and implement a new neurofeedback system that can more effectively and consistently regulate users' brain activities than the conventional way of training users to voluntarily regulate brain activities. The new neurofeedback system delivers external visual stimuli continuously at a specific alpha phase, which is real-time decoded from ongoing alpha wave, to regulate the alpha wave. Experimental results show that the proposed training-free externally-regulated neurofeedback (ER-NF) system can achieve consistent (effective in almost all sessions for almost all users), flexible (either increasing or decreasing peak alpha frequency and alpha power), and immediate (taking or losing effect immediately after stimulation is on or off) modulation effects on alpha wave. Therefore, the ER-NF system holds great potential to be able to more reliably and flexibly modulate cognition and behavior.

Effects of 8 weeks of modified hatha yoga training on resting-state brain activity and the p300 ERP in patients with physical disability-related stress.

[Purpose] We examined the effects of Hatha yoga on EEG and ERP in patients with physical disability-related stress. [Participants and Methods] Eighteen male and female injured workers with high stress levels, aged between 18 to 55 years, were evenly divided into two groups: untrained (CG) and trained (TG) modified hatha yoga groups. A modified Hatha yoga protocol was designed for this population by two certified yoga instructors, approved by a physical therapist, and conducted for one hour, three times weekly for 8 weeks. [Results] The results indicated a significant increase in alpha EEG activity over the frontal, central, and parietal electrodes and the delta EEG activity over the centroparietal electrode from pre- to post-training in TG. In addition, significantly faster auditory reaction time for target stimuli, as well as lower P300 peak latency of ERP in auditory oddball paradigm were obtained in TG after 8 weeks of yoga training compare to CG. [Conclusion] Changes in brain activity and ERP components following yoga training would support the psychophysiological effects of hatha yoga as an adjunct to routine rehabilitation.

Simultaneous EEG-fMRI at ultra-high field: artifact prevention and safety assessment.

The simultaneous recording of scalp electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) can provide unique insights into the dynamics of human brain function, and the increased functional sensitivity offered by ultra-high field fMRI opens exciting perspectives for the future of this multimodal approach. However, simultaneous recordings are susceptible to various types of artifacts, many of which scale with magnetic field strength and can seriously compromise both EEG and fMRI data quality in recordings above 3T. The aim of the present study was to implement and characterize an optimized setup for simultaneous EEG-fMRI in humans at 7 T. The effects of EEG cable length and geometry for signal transmission between the cap and amplifiers were assessed in a phantom model, with specific attention to noise contributions from the MR scanner coldheads. Cable shortening (down to 12 cm from cap to amplifiers) and bundling effectively reduced environment noise by up to 84% in average power and 91% in inter-channel power variability. Subject safety was assessed and confirmed via numerical simulations of RF power distribution and temperature measurements on a phantom model, building on the limited existing literature at ultra-high field. MRI data degradation effects due to the EEG system were characterized via B0 and B1(+) field mapping on a human volunteer, demonstrating important, although not prohibitive, B1 disruption effects. With the optimized setup, simultaneous EEG-fMRI acquisitions were performed on 5 healthy volunteers undergoing two visual paradigms: an eyes-open/eyes-closed task, and a visual evoked potential (VEP) paradigm using reversing-checkerboard stimulation. EEG data exhibited clear occipital alpha modulation and average VEPs, respectively, with concomitant BOLD signal changes. On a single-trial level, alpha power variations could be observed with relative confidence on all trials; VEP detection was more limited, although statistically significant responses could be detected in more than 50% of trials for every subject. Overall, we conclude that the proposed setup is well suited for simultaneous EEG-fMRI at 7 T.

Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders.

Theanine (n-ethylglutamic acid), a non-proteinaceous amino acid component of green and black teas, has received growing attention in recent years due to its reported effects on the central nervous system. It readily crosses the blood-brain barrier where it exerts a variety of neurophysiological and pharmacological effects. Its most well-documented effect has been its apparent anxiolytic and calming effect due to its up-regulation of inhibitory neurotransmitters and possible modulation of serotonin and dopamine in selected areas. It has also recently been shown to increase levels of brain-derived neurotrophic factor. An increasing number of studies demonstrate a neuroprotective effects following cerebral infarct and injury, although the exact molecular mechanisms remain to be fully elucidated. Theanine also elicits improvements in cognitive function including learning and memory, in human and animal studies, possibly via a decrease in NMDA-dependent CA1 long-term potentiation (LTP) and increase in NMDA-independent CA1-LTP. Furthermore, theanine administration elicits selective changes in alpha brain wave activity with concomitant increases in selective attention during the execution of mental tasks. Emerging studies also demonstrate a promising role for theanine in augmentation therapy for schizophrenia, while animal models of depression report positive improvements following theanine administration. A handful of studies are beginning to examine a putative role in attention deficit hyperactivity disorder, and theoretical extrapolations to a therapeutic role for theanine in other psychiatric disorders such as anxiety disorders, panic disorder, obsessive compulsive disorder (OCD), and bipolar disorder are discussed.

[Neurofeedback in the treatment of cognitive impairment in patients with early cerebral small vessel disease]. / Neirotrening metodom biologicheskoi obratnoi svyazi v korrektsii kognitivnykh narushenii u bol'nykh rannei tserebral'noi mikroangiopatiei.

OBJECTIVE: To compare the effectiveness of neurofeedback (NFB) at infra-low and alpha frequencies in the treatment of cognitive impairment in patients with early cerebral small vessel disease (cSVD). MATERIAL AND METHODS: The study included 71 patients (average age 52.8±6.3 years, men 15%, women 85%) with early cSVD and 21 healthy volunteers (average age 53.2±4.8 years, men 29%, women 71%). All participants were assessed for clinical manifestations and cognitive functions, brain MRI, and EEG. cSVD patients were randomized by an envelope method with double-blind placebo control. Three groups of neurofeedback were formed: infra-low waves (n=25), alpha waves (n=22), simulated neurofeedback using EEG (placebo) (n=24). Fifteen sessions of 30 minutes were conducted 2-5 times a week. The cognitive profile and EEG were assessed immediately and 6-8 weeks after completion of the neurofeedback course. RESULTS: Patients with early cSVD had subjective (65%) and moderate (35%) cognitive impairment with predominant deviations in the components of executive brain functions (EBF). Neurofeedback using infra-low waves significantly improved EBF in the components of productivity, switching and inhibition, non-verbal delayed memory immediately after the course, maintaining the effect for at least 6-8 weeks, which was accompanied by an increase in the power (µB2) of the alpha rhythm in the occipital regions. Neurofeedback using alpha waves showed improvement in the Stroop test (interference index) in the delayed period. CONCLUSION: In patients with early cSVD and deterioration of EBF, it is preferable to conduct biofeedback neurotraining at infra-low frequencies to treat cognitive impairment and create a cognitive reserve. An increase in the power of the alpha rhythm in the occipital regions during the course can be considered a prognostic marker of its effectiveness.

Association of Fear and Anxiety Scales in Pediatric Dental Patients Using Brainwave Entrainment: A Randomized Controlled Trial.

Background Dental fear and anxiety are significant issues among pediatric patients, often complicating dental treatments. Various tools measure these emotional responses, including subjective scales such as the Visual Facial Anxiety Scale (VFAS) and Children Fear Scale (CFS), and objective scales such as Venham's Anxiety Scale (VAS) and Frankl Behavior Rating Scale (FBRS). This study explores the association between these measures in children subjected to brainwave entrainment (BWE) therapy. This study aimed to evaluate the association between subjective and objective fear and anxiety measures in pediatric dental patients within both the brainwave entrainment (BWE) intervention group and control group. Methods This randomized controlled trial included pediatric participants aged seven to 12 years reporting to the department for dental treatment. Participants were randomized into two following groups: an experimental group receiving BWE therapy and a control group receiving traditional behavioral management. Fear and anxiety levels were measured using subjective and objective scales before and after the intervention. Data were analyzed using Spearman's correlation to examine the associations between these scales, with statistical significance set at p<0.05. Results Post-intervention analysis revealed significant correlations between subjective and objective measures of fear and anxiety in both groups. In the BWE group (N=126), there was a moderate positive correlation between the VFAS and VAS (rho=0.540, p<0.001) and a strong negative correlation between the CFS and FBRS (rho=-0.666, p<0.001). The control group (N=126) showed stronger correlations, rho=0.778 for anxiety scales and rho=-0.817 for fear and behavior scales (p<0.001). Combined data analysis from both groups (N=252) confirmed strong correlations. Conclusion This study found a significant association between subjective and objective measures of fear and anxiety in pediatric dental patients within both the brainwave entrainment (BWE) intervention group and control group. Thereby proving that self-reporting behavioral scales are useful for quickly assessing anxiety in pediatric dental settings.

Neurofeedback training and motor learning: the enhanced sensorimotor rhythm protocol is better or the suppressed alpha or the suppressed mu?

A large number of previous studies have examined how different neurofeedback-based techniques may influence motor learning. However, only a few studies attempted to compare the effects of these different techniques on motor learning. Therefore, the present study attempts to examine the effects of neurofeedback training on motor learning in novice golfers, using three protocols, namely enhanced sensorimotor rhythm (SMR) at Cz, suppressed alpha waves at Fz, and suppressed mu waves at Cz. The participants were 64 adults (32 females; mean age = 22.31 ± 2.25 years). The study consisted of a pretest stage (day 1), intervention (6 sessions, over two weeks, 3 sessions per week), short-term retention (one day after intervention), and long-term retention (two weeks after intervention); in the pretest and short-term and long-term retention, motor performance for golf putting (12 trials) as well as amplitudes of SMR wave at Cz, alpha at Fz, and Mu at Cz were recorded. During each intervention session, the participants in three neurofeedback groups and a sham group first performed neurofeedback training (enhanced SMR at Cz, suppressed alpha at Fz, and suppressed Mu at Cz) for 20 min. Then, the participants in all groups performed three blocks of 12 trials consisting of golf putting training. The results indicated no difference between the sham and the experimental groups in the acquisition stage, as individuals in all groups experienced similar improvement in putting accuracy. However, in the short-term retention, all the three neurofeedback groups outperformed the sham group, although in the long-term retention, only the SMR group and the Alpha group showed a better performance than the sham group while the Mu group did not exhibit a notably better performance than the sham group. Our results also showed significant variations in the amplitudes of the SMR, alpha, and mu waves depending on the neurofeedback intervention provided, while no significant variation was observed in the sham group. Based on these results, it is recommended that coaches should make further use of enhanced SMR at Cz or suppressed alpha at Fz as their neurofeedback interventions to facilitate longer-term motor learning in golfers.

A low- dose of caffeine suppresses EEG alpha power and improves working memory in healthy University males.

The effects of a low dose of caffeine, administered in the morning, on brain wave activity and cognitive function were investigated in 25 healthy university Southeast Asian men (mean age ±standard deviation: 21 ± 2 years). Participants received a placebo (PLA) or a 50 mg caffeinated drink (CAF) under randomized, double-blind crossover conditions, with 1 week between conditions. Brain wave activity was assessed using electroencephalography (EEG) from a 5 min eyes-closed resting state. Cognitive function, i.e., visuomotor processing speed, working memory, and attention were assessed using the trail-making test A (Trails A) and B (Trails B), and digit span Forwards (DF), respectively. All tests were examined before drinking (BD), 30 min after drinking (AD), and 35 min after 5-min isokinetic exercise (AE). [Results] The CAF showed a significant decrease in the percentage changes from baseline (%∆) of alpha wave activity over the midline electrodes, i.e., frontal, central, and occipital areas after AD (p<0.05). Data from cognitive function tests were significantly improved after AD (p<0.05). A significant inverse correlation between the diminished alpha wave activity over the midline central and occipital cortical regions and the Trails B positive scores were observed (p<0.05). [Conclusion] The diminishment in resting alpha wave activity and improvement of cognitive function on working memory assessed by the Trails B following caffeine consumption would support the stimulant effects of low-dose caffeine as a morning wake-up drink in young adults.

Comparing the demographics and laboratory biomarkers of the COVID-19 Omicron wave and the Alpha wave in a predominantly Afro-Caribbean patient population in New York City.

BACKGROUND: There is a knowledge gap of specific characteristics linked to disease severity of the different COVID-19 waves, especially in underserved populations. We compared the demographic and clinical factors associated with SARS-CoV-2-infected patients admitted to the intensive care unit (ICU) during the Omicron and Alpha waves. METHODS: An observational study comparing two COVID-19 waves was conducted in Brooklyn, NY. Twenty-seven ICU admitted patients with a positive COVID-19 test result during the period of November 1, 2021, to January 31, 2022, ("Omicron wave") were compared to 271 COVID-19 patients who received ICU consults during the Alpha wave, the period from March 28, 2020, to April 30, 2020. RESULTS: The Omicron wave had a 55.6% mortality rate compared to a 67.2% mortality rate in the Alpha wave. For the non-survivors, there were more females (66.7%) in the Omicron wave, while the trend was reversed in the Alpha wave (38.5%). Most of the patients seen were Black (> 85%) in both waves. A bivariate comparison of the two waves found that patients in the Omicron wave had overall significantly lower ALT levels (p = 0.03) and higher monocyte % (p = 0.005) compared to the patients in the Alpha wave. In the multivariate analysis, adjusting for age and sex, increasing levels of HCO3- were significantly associated with reduced mortality in the Omicron wave (OR: 0.698; 95% CI: 0.516 - 0.945; p = 0.02). Also, multivariable analyses using both waves combined found that neutrophil % was significantly associated with increased mortality (OR: 1.05; 95% CI: 1.02 - 1.09; p = 0.006) while lymphocyte % was significantly associated with reduced mortality (OR: 0.946; 95% CI: 0.904 - 0.990; p = 0.018). CONCLUSIONS: The COVID-19-positive ICU patients in the Omicron wave experienced less severe outcomes than those of the Alpha wave. In contrast to the Alpha variant, the Omicron variant exhibited enhanced infectivity and disease severity in females.

Pros and cons in tinnitus brain: Enhancement of global connectivity for alpha and delta waves.

Interactions among cortical areas of tinnitus brain remained unclear. Weaker alpha and stronger delta activities in tinnitus have been noted over auditory cortices. However, the interplay between a single substrate with whole brain within alpha/delta band remained unknown. Thirty-one patients with chronic tinnitus were recruited. Thirty-four healthy volunteers served as controls. Magnetoencephalographic measurements of spontaneous activities were performed. The strength of alpha/delta activities was analyzed. By dividing cortices into 38 regions of interest (ROIs), measurements of connectivity were performed using amplitude envelope correlation (AEC). Global connectivity was calculated by adding and averaging connectivity of single ROI with every other region. There were no significant differences in mean power of alpha and delta band between groups, despite the trend of stronger alpha and weaker delta band in controls. The global connectivity of alpha wave was significantly stronger in tinnitus for left frontal pole, and of delta wave for bilateral pars orbitalis, bilateral superior temporal, bilateral middle temporal, right pars triangularis, right transverse temporal, right inferior temporal, and right supra-marginal. The global connectivity of alpha/delta waves was enhanced for tinnitus in designated ROIs of frontal/temporal/parietal lobes. The underlying mechanism(s) might be associated with augmentation/modulation of tinnitus perception. Our results corroborated the evolving consensus about neural correlates inside frontal/temporal/parietal lobes as essential elements of hubs for central processing of tinnitus. Further study to explore the resolution of effective connectivity between those ROIs and respective substrates by using AEC will be necessary for the evaluation of pathogenetic scenario for tinnitus.

Prediction of dispositional dialectical thinking from resting-state electroencephalography.

This study aims to explore the possibility of predicting the dispositional level of dialectical thinking using resting-state electroencephalography signals. Thirty-four participants completed a self-reported measure of dialectical thinking, and their resting-state electroencephalography was recorded. After wave filtration and eye movement removal, time-frequency electroencephalography signals were converted into four frequency domains: delta (1-4 Hz), theta (4-7 Hz), alpha (7-13 Hz), and beta (13-30 Hz). Functional principal component analysis with B-spline approximation was then applied for feature reduction. Five machine learning methods (support vector regression, least absolute shrinkage and selection operator, K-nearest neighbors, random forest, and gradient boosting decision tree) were applied to the reduced features for prediction. The model ensemble technique was used to create the best performing final model. The results showed that the alpha wave of the electroencephalography signal in the early period (12-15 s) contributed most to the prediction of dialectical thinking. With data-driven electrode selection (FC1, FCz, Fz, FC3, Cz, AFz), the prediction model achieved an average coefficient of determination of 0.45 on 200 random test sets. Furthermore, a significant positive correlation was found between the alpha value of standardized low-resolution electromagnetic tomography activity in the right dorsal anterior cingulate cortex and dialectical self-scale score. The prefrontal and midline alpha oscillations of resting electroencephalography are good predictors of the dispositional level of dialectical thinking, possibly reflecting these brain structures' involvement in dialectical thinking.

Preserved action recognition in children with autism spectrum disorders: Evidence from an EEG and eye-tracking study.

Individuals with Autism Spectrum Disorder (ASD) have difficulties recognizing and understanding others' actions. The goal of the present study was to determine whether children with and without ASD show differences in the way they process stimuli depicting Biological Motion (BM). Thirty-two children aged 7-16 (16 ASD and 16 typically developing (TD) controls) participated in two experiments. In the first experiment, electroencephalography (EEG) was used to record low (8-10 Hz) and high (10-13 Hz) mu and beta (15-25 Hz) bands during the observation three different Point Light Displays (PLD) of action. In the second experiment, participants answered to action-recognition tests and their accuracy and response time were recorded, together with their eye-movements. There were no group differences in EEG data (first experiment), indicating that children with and without ASD do not differ in their mu suppression (8-13 Hz) and beta activity (15-25 Hz). However, behavioral data from second experiment revealed that children with ASD were less accurate and slower than TD children in their responses to an action recognition task. In addition, eye-tracking data indicated that children with ASD paid less attention to the body compared to the background when watching PLD stimuli. Our results indicate that the more the participants focused on the PLDs, the more they displayed mu suppressions. These results could challenge the results of previous studies that had not controlled for visual attention and found a possible deficit in MNS functions of individuals with ASD. We discuss possible mechanisms and interpretations.

Efficacy of an Integrative Treatment for Tinnitus Combining Music and Cognitive-Behavioral Therapy-Assessed With Behavioral and EEG Data.

Chronic tinnitus is a prevalent condition that could cause severe negative impact on an individual's life. However, there has not been an established treatment due to a limited understanding of the pathophysiology of this multifarious disorder. In this study, we tested the efficacy of an integrative treatment, combining music therapy with cognitive-behavioral therapy (CBT). We collected three groups of patients receiving three different treatments: Music-CBT, music therapy and CBT. We used both subjective (i.e., questionnaires) and objective (i.e., resting-state EEG data) measurements to assess the behavioral and neural changes brought upon by the treatments. Analyses of the subjective measurements found a significant improvement of scale scores in Music-CBT and CBT, but not in the Music group. Analysis of the EEG data further showed increased powers in alpha and theta band after the Music-CBT treatment, and increased gamma power after CBT, whereas no significant difference was found for the music therapy. Further source localization analysis of alpha and theta changes in the Music-CBT group found that primary sources of the changes were located at auditory processing regions such as superior temporal gyrus, and higher emotional and cognitive processing regions such as ventromedial prefrontal cortex (vMPFC), lateral prefrontal cortex and parahippocampus. These results indicated that Music-CBT was effective in improving tinnitus symptoms on both a behavioral and neural level, which is more robust than the music therapy or CBT alone.

Dual-Task Training Affect Cognitive and Physical Performances and Brain Oscillation Ratio of Patients With Alzheimer's Disease: A Randomized Controlled Trial.

This study aimed to investigate the effect of 12 weeks of dual-task training on cognitive status, physical performance, and brain oscillation of patients with Alzheimer's disease (AD). Twenty-six AD patients were randomly assigned to two groups, the training group (TG) and control group (CG). TG executed progressive combined exercises with visual stimulation twice a week for 12 weeks. Training included muscle endurance, balance, flexibility, and aerobic exercises with eyes closed and opened. Brain oscillation on electroencephalography (EEG) and a series of physical, cognitive, and mental tests were taken before and post-intervention. There was a significant improvement after training protocol in cognitive function, particularly in short-term and working memory, attention, and executive function (p < 0.01). Besides, there were substantial improvements in depression status (GDS scale), aerobic fitness (6 min walking), flexibility (chair sit and reach) functional ability (chair stand, timed up and go test), strength (knee extensions, preacher biceps curl, handgrip) in TG compared to CG. These signs of progress were associated with a significant increase (p < 0.05) in the frequency of brain oscillation and a decrease in the theta/alpha ratio. In addition to physical performance, the regular combined training with visual stimulation improves brain health as indicated by improving cognitive function and reducing the theta/alpha ratio. Clinical Trial Registration: Iranian Registry of Clinical Trials (IRCT) https://www.irct.ir/, identifier IRCT20190504043468N1-August 5, 2020.

The influence of mental fatigue on brain activity: Evidence from a systematic review with meta-analyses.

The occurrence of mental fatigue during tasks like driving a vehicle increases risk of injury or death. Changes in electroencephalographic (EEG) activity associated with mental fatigue has been frequently studied and considered a promising biomarker of mental fatigue. This is despite differences in methodologies and outcomes in prior research. A systematic review with meta-analyses was conducted to establish the influence of mental fatigue on EEG activity spectral bands, and to determine in which regions fatigue-related EEG spectral changes are likely to occur. A high-yield search strategy identified 21 studies meeting inclusion criteria for investigating the change in EEG spectral activity in non-diseased adults engaged in mentally fatiguing tasks. A medium effect size (using Cohen's g) of 0.68 (95%CI: 0.24-1.13) was found for increase in overall EEG activity following mental fatigue. Further examination of individual EEG spectral bands and regions using network meta-analyses indicated large increases in theta (g = 1.03; 95%CI: 0.79-1.60) and alpha bands (g = 0.85; 95%CI: 0.47-1.43), with small to moderate changes found in delta and beta bands. Central regions of the scalp showed largest change (g = 0.80; 95%CI: 0.46-1.21). Sub-group analyses indicated large increases in theta activity in frontal, central and posterior sites (all g > 1), with moderate changes in alpha activity in central and posterior sites. Findings have implications for fatigue monitoring and countermeasures with support for change in theta activity in frontal, central and posterior sites as a robust biomarker of mental fatigue and change in alpha wave activity considered a second line biomarker to account for individual variability.

Electroencephalographic monitoring during sevoflurane anaesthesia in an amyotrophic lateral sclerosis patient with locked-in state.

Recently, the cognitive abilities of patients with amyotrophic lateral sclerosis (ALS) have been found to be impaired along with the neurodegeneration of motor neurons. Electroencephalography (EEG) of end-stage ALS patients has reportedly shown specific features based on neuronal network modulations, differing from EEG of other patients with cognitive failure and dementia. However, EEG of end-stage ALS patients during anaesthesia has not yet been reported. A 64-year-old male ALS patient with locked-in state (LIS), supported by tracheostomy positive-pressure ventilation (TPPV) and enteral nourishment for 9years, underwent scheduled general anaesthesia for repair of a fractured mandible. He could blink and open his eyes, but seldom opened or closed his eyes on instruction. Sevoflurane anaesthesia was induced under continuous EEG monitoring with bispectral index (BIS), which is commonly used to examine the level of anaesthesia. Prominent alpha oscillations with lower peak frequency and high amplitude appeared during anaesthesia, differing from the characteristics of EEG seen in patients with general cognitive failure. Conversely, BIS reflected the sevoflurane concentration in this ALS patient, similar to healthy individuals, and BIS monitoring was useful for estimating the depth of anaesthesia. The prominent alpha oscillation revealed in this rare case report may suggest modulation of the functional neuronal network system during anaesthesia in patients with progressive ALS, in a manner quite different from typical dementia patients. EEG abnormalities in the present ALS patient did not influence the availability of BIS monitoring.