Self-regulation of the brain’s Beta rhythm using a brain-computer interface improves inhibitory control

Neural oscillations, or brain rhythms, fluctuate in a manner reflecting ongoing behavior. Whether these fluctuations are instrumental or epiphenomenal to the behavior remains elusive. Attempts to experimentally manipulate neural oscillations exogenously using non-invasive brain stimulation have shown some promise, but difficulty with tailoring stimulation parameters to individuals has hindered progress in this field. We demonstrate here using electroencephalography (EEG) neurofeedback in a brain-computer interface that human participants (n=44) learned over multiple sessions across a 6-day period to self-regulate their Beta rhythm (13-20 Hz) over the right inferior frontal cortex (rIFC). This Beta modulation had observable consequences on cognitive behavior: changes in an individual’s inhibitory control performance before and after training were predicted by the magnitude of their training-related change in Beta over rIFC. This was not the case for a control group (n=38) who underwent training of their Alpha rhythm (8-12 Hz). The present data support the view that the right frontal Beta rhythm is a key component of the brain’s inhibitory control system. Most importantly, we introduce causality to this relationship for the first time, as experimental modulation of rIFC Beta activity had a measurable impact upon behavior.

Neuropsychological features of patients of reproductive age diagnosed with breast cancer at the stage of surgical treatment using xenon-oxygen therapy

Purpose of the study. To study functional changes in the neuropsychological status of reproductive age patients with newly diagnosed breast cancer and to assess the possibility of using xenon-oxygen therapy to correct disorders.Patients and methods. This study included 60 reproductive age patients with newly diagnosed breast cancer who were undergoing surgical treatment at the Department of Bone, Skin, Soft Tissue and Breast Tumors of the National Medical Research Centre for Oncology of the Ministry of Health of Russia from 2018 to 2020. The main group included 30 patients with breast cancer diagnosed at the surgical stage of combined treatment, who underwent a rehabilitation course of xenon-oxygen therapy in the early postoperative period. The control group was formed from patients with the same diagnosis, without the use of this therapy. The functional state of the central nervous system in all patients was assessed by the parameters of the electroencephalography (EEG) bioelectrical activity. For the final assessment of the physiological and psychological state of the patients, a standardized questionnaires of the quality of life – ESAS, MOS-SF‑36, were used. Statistical data processing was performed using the Statistica 10 software package. Results. During the study, statistically significant differences were found in the assessment of subjective indicators, so in the group of patients using xenon-oxygen therapy, there was an improvement in well-being by 2.6 times, a decrease in depression by 2.3 times, a decrease in symptoms of nausea by 3 times, anxiety 1.9 times (p < 0.05). Against the background of an improvement in the psychophysiological state, the EEG showed a significant increase in the power of slow delta and theta rhythms, an increase in the power of the alpha rhythm and a decrease in the power of the beta rhythm, while in the patients of the control group only a decrease in the power of the beta rhythm was noted.Conclusion. The early postoperative period in patients with newly diagnosed breast cancer is characterized by the formation of a depressive symptom complex. The use of a course of xenon-oxygen therapy contributes to the normalization of the subjective feeling of physical and psychological health, increasing vital and social activity. Changes in the indicators of brain bioelectric activity and an improvement in psychophysiological state occur against the background of changes in brain activity caused by the normalizing effect of xenon.

AGE FEATURES OF BETA RHYTHMS EEG IN CHILDREN AGED 4-15 IN A STATE OF STABLE VISUAL ATTENTION

One of the reliable parameters for assessing the bioelectrical activity of the brain in children is the relative power (RP) of the EEG. Previous results have shown that EEG RP systematically changes not only depending on age, but also with various developmental disorders. The beta rhythm RP is of particular interest when performing tasks requiring the involvement of cognitive functions. In connection with the above, the purpose of the present study was to identify and analyze the RP of beta1 and beta2 EEG rhythms in a state of stable visual attention (SVА) in children 4–15 years old. The study involved 159 children (82 girls and 77 boys) aged 4–15 years with a normal level of physical and mental development. In the present study, children were required to observe and reproduce the movements of a computer mouse. At the same time, at certain moments, an image of a stationary computer mouse was presented, which was accompanied by a request to look at the computer screen, in connection with which both voluntary and involuntary attention of the subjects was activated. The use of the SVА situation makes it possible to analyze the nature of differences in the EEG pattern of children, taking into account the data on the neurophysiological mechanisms of attention. The greatest increase in the RP of the EEG beta1 rhythm found in the age range of 7–12. For the beta2 rhythm, the greatest increase discovered in the period of 10–15 years. The obtained values of the RP of the beta1 and beta2 rhythms of the EEG, recorded in the state of stable visual attention, in children of different ages can be used as reference data in the relevant research areas, as well as in the development of correction protocols for the cognitive functions and psychoemotional state using EEG biofeedback. The age-related dynamics of the beta rhythm RP can serve as an indicator of the maturation of cortical inhibition processes in children, which underlie the formation of voluntary cognitive functions and conscious purposeful behavior.

Relationships between calciemia and calciuria and EEG and HRV parameters in patients with chronic pyelonephritis

Background. This article launches a new project "Relationships between parameters of electrolytes exchange and EEG&HRV in people without kidney disease and patients with chronic pyelonephritis". Calcium was chosen as the first swallow. Material and methods. The object of observation were 48 males and 15 females 24-76 years old, who came to the spa Truskavets’ (Ukraine) for the treatment of chronic pyelonephritis in remission. We recorded simultaneosly EEG (“NeuroCom Standard”) and electrocardiogram ("CardioLab+HRV") in II lead to assess the parameters of HRV. Calcium and creatinine concentration was determined in blood plasma and daily urine. Results. The observed sample is characterized by moderate and mild expressed urinary syndrome, ie represents the urological contingent of the Truskavets’ spa. It was stated normal or moderately reduced plasma calcium levels in combination with a very wide range of calcium urinary excretion. A very strong canonical correlation was found between calciumemia and EEG/HRV parameters (r=0,910). The correlation with the parameters of the beta rhythm of the EEG and VLF/ULF components of the HRV is positive, while with the parameters of the alpha rhythm of the EEG is negative. The canonical correlation between calciumuria and EEG/HRV parameters is moderate (r=0,571). There was a positive correlation with other parameters of the beta rhythm of the EEG and a negative correlation with the parameters of the delta rhythm of the EEG and LF/VLF components of HRV. Conclusion. Parameters of calcium exchange and EEG/HRV are closely related, however the question of the causal nature of correlations remains open.

OPTIMIZATION OF PROFESSIONAL ACTIVITY IN OPERATORS OF MORNING CHRONOTYPE BASED ON BIOELECTRICAL FEATURES OF BRAIN

Biorhythmological features and electroencephalography parameters in operators of morning chronotype demonstrate a significant mutual influence. In particular, frequency of the low-frequency beta-rhythm in left central leads and the total result of Ostberg-Stepanova test have an inverse correlation of average strength (rs = -0,697), which reflects the expressed ability of these operators to perform stereotypical, routine mental operations. In addition, total result of Ostberg – Stepanova test has a strong inverse correlation with frequency of low-frequency beta-rhythm in right central (rs = -0,704) and right temporal leads (rs = -0,738). This indicates that «pronounced larks» have the ability to quickly and efficiently perform repetitive mental operations, especially those associated with the impact of non-verbal auditory stimuli.

Brain Oscillatory Activity during Tactile Stimulation Correlates with Cortical Thickness of Intact Areas and Predicts Outcome in Comatose Patients

This study reports a correlation between EEG and structural brain changes in patients after severe traumatic brain injury in a coma. The novelty of our approach was based on the combination of structural visualization (MRI) and functional neuroimaging (EEG) during tactile stimulation. The structural morphometry indicated a decrease of whole-brain cortical thickness, the gray-matter volume of the cortex, and subcortical structures in comatose patients compared to healthy subjects. In resting-state EEG, coma patients had significantly higher power of the slow-wave activity of 2-6 Hz and significantly less power of the alpha and beta rhythm. Importantly, coma patients showed a significant decrease of theta-rhythm power in tactile stimulation compared to the resting state, and this EEG pattern was not found in the control group. The decrease of the theta-rhythm power significantly correlated with the better outcome from a coma. Spectral changes in EEG in response to tactile stimuli showed no association with brain morphometric measures in healthy controls. In patients, decreasing theta-rhythm power correlated positively with the volume of whole-brain gray matter, right putamen, and insula; and negatively with the volume of damaged brain tissue. Increasing beta-rhythm power, specific tactile EEG response for a healthy brain, correlated with the cortical thickness of the somatosensory Paracentral and Precentral area. The observed decrease of gray-matter volume indicates brain atrophy in coma patients, which could be associated with neurodegeneration induced by injury. Our results also demonstrate that slow-wave desynchronization, as a nonspecific response to tactile stimulation, can serve as a sensitive index of morphometric changes after brain injury and coma outcome.