Dynamics of the Adolescent EEG Parameters with Changes in the CNS Functional State (Relaxation) Influenced by Rhythmic Acoustic Stimulation

Age-related specific features of the regulation of the CNS functional state (relaxation) were studied in adolescents between the ages of 14 and 15 years using 6-Hz rhythmic stimulation. The dynamics of the EEG findings (spectral power density, coherence functions) in the quiet wakefulness–relaxation–initial-state cycle was analyzed. The dynamics of the functional state was controlled by changes in the electrodermal resistance (EDR). The data showed that the studied group of adolescents was heterogeneous by the effectiveness of self-regulation: the majority was characterized by marked shifts whose distribution character was close to normal; the others, by mild EDR changes. It was shown that, with the use of rhythmic stimulation, relaxation shifts were more marked than those induced by common psychotherapeutic techniques. The basic relaxation changes in the EEG parameters are related to changes in the coherence function values, i.e., increases in its values, especially those of distant relations (with the focus) of significant connections in the frontal regions. The rate of the occurrence of relaxation changes in the coherence values is substantially higher in the low-frequency band (5 to 7 Hz) than in the EEG -band, constituting 20 to 50% in terms of different relations. The revealed specific features of the relaxation dynamics of the EEG parameters are analyzed in the age-related aspect. The influence of higher structures of the CNS and puberty-related rearrangements in the system of neuroendocrine regulation on the effectiveness of the regulatory function is discussed.     

The effect of BFB training on the efficiency of voluntary relaxation in junior schoolchildren

Psychophysiological features of schoolchildren seven to eight and nine to ten years of age (their autonomic balance and brain functional state) were studied; the effect of biofeedback (BFB) training on the regulatory influence of relaxation was evaluated (BFB signal—electrical skin resistance). Before and after BFB training, the electrophysiological experiment, i.e., relaxation testing, was performed without BFB in three situations: background, relaxation, and the state after relaxation. The EEG of various cortical areas was recorded, and the electrical skin resistance was determined. The short-term memory test was used to determine changes in the functional state at the behavioral level. Short-term training (five sessions) often enhanced the efficiency of voluntary relaxation and improved the postrelaxation mnestic function only in the group of 9- to 10-year-old children. The effect of training on the relaxation of the regulation depended on the individual psychophysiological features of children.     

Efficiency of biofeedback training of functional state regulation depending on individual psychophysiological characteristics

The psychophysiological characteristics of the subjects (emotional stability, autonomic lability, tension of autonomic regulation of cardiac activity, and EEG characteristics) were estimated. The efficiency of relaxation regulation training with the use of biofeedback (with the electrocutaneous impedance as a BF signal) was studied. Before and after BF training, an electrophysiological experiment was carried out, namely, a “relaxation test” without BF support. The test consisted of three situations: background, relaxation, and the state after coming out of relaxation. During the test, EEGs of different cortical areas (α bands) and autonomic indices were recorded. A short-term memory test was carried out with the purpose of controlling changes in the functional status. It has been shown that even a short training cycle of five sessions in most cases provided relaxation and improvement in self-regulation, accompanied by improvement of the mnestic activity. The effect of individual psychophysiological characteristics on the success of BF training has been established. A high autonomic lability, a high level of nonspecific cortex activity, as well as a dysfunction of the frontal-thalamic system, should be regarded as factors preventing effective self-regulation training.     

Rhythmic Acoustic Stimulation as a Method for Regulating the Functional State of the CNS in Young Schoolchildren

The author studied the dynamics of EEG (spectral power density and coherence functions) and autonomic (electrodermal resistance, EDR) indices in young schoolchildren with changes in the functional state of the CNS caused by rhythmic sensory stimulation (acoustic signals with frequencies of 6 and 9 Hz). Both of these signals influenced the CNS and may be used to achieve relaxation. Their comparison demonstrated both similar postrelaxation shifts (increased coherence of distant connections) and frequency-specific phenomena (more numerous significant changes in the respective frequency ranges). Thus, the signal frequency determines the pattern of physiological shifts, influencing the relaxation quality. Low-frequency (6 Hz) stimulation caused more pronounced changes in the CNS, reflected in enhanced EDR, and a stronger increase in the short-term memory volume. The author discusses the frequency-specific neurophysiological mechanisms of the effect of stimulation on the functional state of the brain.     

The age-related features of influence biofeedback training on efficiency of functional state voluntary regulation in young schoolchildren

The aim of the study was to assess an impact of biofeedback training (5 sessions) onto the voluntary regulation of the brain functional state (relaxation) in two groups of children of 7-8 and 9-10 years old. EEG alpha-band spectral coherence and skin resistance were measured during pre-relaxation, relaxation and post-relaxation phases before and after training. Short-term memory test was used to evaluate behavioral changes in functional state regulation before and after training. The group of children of 9-10 y.o. was the only group that showed any significant relaxation-related changes of spectral coherence in alpha-band after training. Besides, that group showed a significant post-relaxation improvement in short-term memory volume. We found a number of individual psychophysiological indices that influenced an efficiency of the biofeedback training.     

Influence of Short-Term Relaxation on the Organization of the Brain Electrical Activity of Young Schoolchildren in the State of Quiet Wakefulness

Relaxation-induced changes in characteristics of the functional state of the nervous system (EEG parameters and electrodermal resistance (EDR)) were studied in 30 schoolchildren aged 9–10 years. A multichannel EEG was recorded from the occipital, parietal, temporo-parieto-occipital, central, and frontal areas of both brain hemispheres in three test conditions: quiet wakefulness, R, and recovery of the initial state. Simultaneously, the EDR was monitored. EEG amplitude spectra and coherence were calculated. Prior to and after relaxation, a cognitive test to determine the extent of short-term auditory verbal memory was performed. While changes in the EDR were reversible, relaxation-induced changes in the EEG parameters persisted after relaxation in many subjects. Changes in EEG coherence between distant derivations were most stable. Since short-term auditory verbal memory improved after relaxation, the postrelaxation changes in the EEG parameters were considered to reflect positive changes arising in the brain function and increasing the efficiency of cognitive processes.     

Correlates of the Perception of Local Rhythmical Thermal Influences of Various Intensities

The effects of local (nasolabial triangle) rhythmical thermal influences synchronized with the breathing rhythm on the functional state were studied. When thermal stimuli were weak, the functional state of subjects was determined by the perception and identification of the stimuli. The rhythm dominated in the EEG, and the autonomic status of the subjects did not differ much from the baseline. With increasing intensity of the thermal stimuli, the natural mechanisms of self-regulation were triggered, parasympathetic effects on the heart increased, and slow ( and ) waves appeared in the EEG. Thermal stimuli with a high intensity caused a psychophysiological state similar to that of altered consciousness. The EEG was characterized by dominance of waves, and the autonomic activity involved an increased parasympathetic component, the functional activity was reduced, and the subjects noted somnolence and a feeling of heaviness and warmth in the limbs.     

Changes in EEG Power Spectra During Biofeedback of Slow Cortical Potentials in Epilepsy

The goal of the study was to explore parallel changes in EEG spectral frequencies during biofeedback of slow cortical potentials (SCPs) in epilepsy patients. Thirty-four patients with intractable focal epilepsy participated in 35 sessions of SCP self-regulation training. The spectral analysis was carried out for the EEG recorded at the same electrode site (Cz) that was used for SCP feedback. The most prominent effect was the increase in the 2 power (6.0–7.9 Hz) and the relative power decrement in all other frequency bands (particularly 1, 2, and 2) in transfer trials (i.e., where patients controlled their SCPs without continuous feedback) compared with feedback trials. In the second half of the training course (i.e., sessions 21–35) larger power values in the , , and bands were found when patients were required to produce positive versus negative SCP shifts. Both across-subject and across-session (within-subject) correlations between spectral EEG parameters, on the one hand, and SCP data, on the other hand, were low and inconsistent, contrary to high and stable correlations between different spectral variables. This fact, as well as the lack of considerable task-dependent effects during the first part of training, indicates that learned SCP shifts did not directly lead to the specific dynamics of the EEG power spectra. Rather, these dynamics were related to nonspecific changes in patients' brain state.     

Dynamics of spatial synchronization of EEG parameters during relaxation and their relationship with regulation of heart rate

EEG parameters were analyzed in a wide frequency range for the estimation of the possible functional importance of different EEG components in the formation of relaxation. Sixty-five subjects aged 17–20 years were involved in the investigation. The relaxation session with monopolar EEG recording and autonomic parameters recording was carried out for each subject. During the relaxation significant changes were observed in all analyzed EEG ranges. Two types of changes of EEG coherence in the wakefulness-relaxation shift of state were distinguished, and correlation of the type of dynamics with the LF/HF ratio, showing the balance of sympathetic and parasympathetic parts of the autonomic nervous system, was found.     

Electrophysiological Indices of Response Inhibition in a Go/NoGo Task Predict Self-Control in a Social Context

Recent research demonstrates that response inhibition—a core executive function—may subserve self-regulation and self-control. However, it is unclear whether response inhibition also predicts self-control in the multifaceted, high-level phenomena of social decision-making. Here we examined whether electrophysiological indices of response inhibition would predict self-control in a social context. Electroencephalography was recorded as participants completed a widely used Go/NoGo task (the cued Continuous Performance Test). Participants then interacted with a partner in an economic exchange game that requires self-control. Results demonstrated that greater NoGo-Anteriorization and larger NoGo-P300 peak amplitudes—two established electrophysiological indices of response inhibition—both predicted more self-control in this social game. These findings support continued integration of executive function and self-regulation and help extend prior research into social decision-making processes.     

Mapping of Changes in EEG Spectrum Power during a Session of Biofeedback Training of the β1 Rhythm

Changes in EEG spectrum power from 19 electrode sites were studied in 19 children with attention disorders during one session of EEG–biofeedback (EEG–BFB). EEG–BFB was aimed at increasing the relative power of the ₁ rhythm (15–18 Hz) in sites Fz–C ₃ with a bipolar electrode assembly. Comparison of the EEG spectrum powers at relaxation versus training periods in one BFB session revealed significant changes in the left parasagittal frontoparietal area (F ₃, Fz, C ₃, C ₄, P ₃).     

Interhemispheric EEG Coherence during Rehabilitation of Patients after Severe Craniocerebral Injury

Dynamic clinical and EEG examinations (78 observations) were carried out in 17 patients suffering from severe craniocerebral injury during the course of their rehabilitation. Successful recovery of functions to the point of social and family readaptation was reached in 61% of patients (group I), and in 39% of patients the results were poor (group II). The complex of EEG coherence parameters (six rhythmic bands, mean coherence levels for 26 intrahemispheric and 8 interhemispheric derivation pairs, and the asymmetry coefficient of the EEG coherence) was analyzed in patients in comparison with normal values (20 right-handers). The rehabilitation was most efficient in cases when a certain dynamic sequence of patterns of interhemispheric relations of the EEG coherence was observed. First, a stable formation of right-hemispheric dominance was observed (most expressed in the centrofrontal areas in the range). This asymmetry pattern was phenomenologically associated with the recovery of the emotional sphere and positive dynamics in the motor and autonomic spheres. Later on, formation of the left-hemispheric dominance of the EEG coherence was observed (in the frontotemporal areas in the – ranges. This pattern was associated with complication of the cognitive functions. In the most severe forms of brain damage, the rehabilitation process was accompanied by changes in the interhemispheric EEG coherence with the elements of stealing from one of the hemispheres, which was correlated with clinical dynamics. Different types of the dynamics of reactive changes in the EEG coherence were revealed in patients of the two groups: successive formation of a generalized and then local modally specific reaction to afferent stimuli was observed in group I, while the generalized type of reactivity persisted in group II until the end of rehabilitation. It is suggested that the different sequence of formation of the interhemispheric EEG coherence reflects the involvement of different brain regulation systems in different orders into the integrative activity, i.e., some specific features of the rehabilitation process.     

A Chinese Mind-Body Exercise Improves Self-Control of Children with Autism: A Randomized Controlled Trial

Self-control problems commonly manifest as temper outbursts and repetitive/rigid/impulsive behaviors, in children with autism spectrum disorders (ASD), which often contributes to learning difficulties and caregiver burden. The present study aims to compare the effect of a traditional Chinese Chan-based mind-body exercise, Nei Yang Gong, with that of the conventional Progressive Muscle Relaxation (PMR) technique in enhancing the self-control of children with ASD. Forty-six age- and IQ-matched ASD children were randomly assigned to receive group training in Nei Yang Gong (experimental group) or PMR (control group) twice per week for four weeks. The participants’ self-control was measured by three neuropsychological tests and parental rating on standardized questionnaires, and the underlying neural mechanism was assessed by the participants’ brain EEG activity during an inhibitory-control task before and after intervention. The results show that the experimental group demonstrated significantly greater improvement in self-control than the control group, which concurs with the parental reports of reduced autistic symptoms and increased control of temper and behaviors. In addition, the experimental group showed enhanced EEG activity in the anterior cingulate cortex, a region that mediates self-control, whereas the PMR group did not. The present findings support the potential application of Chinese Chan-based mind-body exercises as a form of neuropsychological rehabilitation for patients with self-control problems.Chinese Clinical Trial Registry; Registration No.: ChiCTR-TRC-12002561; URL: www.chictr.org.     

Biological Principles of Individual Differences in the Temperament of Children in the Second Half of the First Year of Life. Communication III: Psychophysiological Principles of Excitability and Activity

Correlations between individual differences in EEG characteristics of attention control systems and temperamental traits of children at the age of 11 months were studied. A sample of 88 healthy mono- and dizygotic twins at the ages of 10 to 11.5 months was examined. The EEG was recorded in the state of sustained attention to visual stimulus. Temperamental features were estimated by the Balleyguier's Questionnaire. Dependence of the scores on each of the basic temperamental traits (excitability, activity, and sociability) on the amplitudes of spectral frequency bands in 12 EEG leads was determined. To this end, the standard and stepwise linear regression techniques and multivariate discriminant analysis with training and test samples were applied. The intrapair correlations in mono- and dizygotic twins were compared in order to analyze the nature of individual differences in spectral characteristics of the EEG range. The main results are as follows. In 11-year-old children in the state of attention, the interindividual variability of spectral amplitudes in the band of the EEG recorded from the main cortical areas is caused, predominantly, by genetic factors. The extent of excitability inversely depends on the level of synchronization in the basic range (6.8–7.6 Hz), which includes both the rhythm in the retrosplenial cortical leads and the rhythms in the anterocentral cortical areas during sustained attention. The degree of passiveness is directly correlated with the level of synchronization in the higher subrange (8.4–8.8 Hz) of the rhythm in the anterocentral cortical areas during visual attention. It is suggested that certain individual differences in the temperament of one-year-old children are genetically determined by specific features of the inhibitory control over the functional state of the brain cortex.     

EEG Spectral Characteristics in Junior Schoolchildren with Learning Problems

EEG spectral characteristics were studied in two age groups (7–8.5 and 8.5–10 years) of mentally healthy children and children with learning problems at rest and during performance of a Raven test. It was shown that slow frequencies are more pronounced in the EEG of 7- to 8.5-year-old children with learning problems than in EEG of healthy children of the same age group. An immature form of EEG activation, i.e., an increase not only in the but also in the frequencies during activity, was characteristic of these children. The reaction of the activation of the definitive type develops between the 8.5–10 years of age. This reaction is correlated with an increase in the efficiency of the sensory perceptive and sensorimotor activity. The distinctive feature of children with learning problems between 8.5–10 years of age is a greater expression of slow frequencies in the baseline EEG of the frontal (in particular, left frontal) areas of the cortex. The obtained results are considered as a reflection of a retardation of the functional maturation of the brain structures responsible for the deficit of involuntary and voluntary attention and the disorder of a systemic organization of perception and analytical–synthetic brain activity as compared to the normal age characteristics. Possible neurophysiological mechanisms responsible for learning problems in junior schoolchildren are discussed on the basis of the obtained results and evidence from the literature.     

EEG spatial organization and activation of creative processes

Characteristic features of the spatino-temporal EEG organization of 24 right-handed children (aged from 8 to 13 years) were studied after stimulation of creative activity by the method of self-regulation of the brain functional state (Russian Inventor's Certificate no. 2157707, 01.06.1999). The multiparametric analysis of baseline recordings derived from 24 cortical points made it possible to find the most probable pattern of changes in the spatial synchronization of biopotentials, including increase in activity in the right anterior and left posterior cortical regions. These changes were accompanied by a rise in the information-energy parameter (the ratio between coherence and spectral power of potentials). This phenomenon may testify to a transition to the "economic" condition of information processing. Differences in EEG frequency characteristics corresponding to different levels of imagination and creative intuition were revealed.     

Concentration and Mindfulness Meditations: Unique Forms of Consciousness?

Electroencephalographic (EEG) recordings from 19 scalp recording sites were used to differentiate among two posited unique forms of mediation, concentration and mindfulness, and a normal relaxation control condition. Analyzes of all traditional frequency bandwidth data (i.e., delta 1–3 Hz; theta, 4–7 Hz; alpha, 8–12 Hz; beta 1, 13–25 Hz; beta 2, 26–32 Hz) showed strong mean amplitude frequency differences between the two meditation conditions and relaxation over numerous cortical sites. Furthermore, significant differences were obtained between concentration and mindfulness states at all bandwidths. Taken together, our results suggest that concentration and mindfulness meditations may be unique forms of consciousness and are not merely degrees of a state of relaxation.     

Relations of the Topographic EEG Organization to Temperament Traits

EEG mapping in six frequency bands was examined in relation to Keirsey and Eysenck temperament scales in 46 males 17–20 years old at rest. An analysis of the amplitude and coherence of the EEG (16-channel recording) revealed a positive correlation between interhemispheric coherence in and bands, and neuroticism as well as sensation scales. Extraversion correlated negatively with coherence, predominantly focused in the left frontal cortex in ₂band. Combinations of these temperament traits were associated with specific patterns of EEG amplitude and coherence. The most pronounced changes in EEG were found in subjects with high sensation and judgment, which were characterized by increased amplitudes and coherence in _{1, 2}bands, as well as increased interhemispheric coherence in the frontal cortex. Such a consistent interaction of neuronal assembles within the baseline EEG suggest that certain behavioral strategies are associated with specific temperament types.     

Dynamics of the EEG parameters in younger schoolchildren during change in the CNS functional state (relaxation) under the action of rhythmical auditory stimulation

The article is devoted to the problem of neurophysiological mechanisms of relaxation. Formation of the relaxation state under the influence of auditory rhythmic stimulation (RS) was studied using spectral and coherent EEG characteristics and electrodermal resistance. Notable shifts of the coherence (Coh) function of biopotentials during transition to the state of relaxation induced by the RS were established, namely, an increase in the distant Coh of the frontal area. A pronounced RS influence on the regulation of the CNS functional state was shown. On the basis of the results of the study and their comparison with the published data, a conclusion is drawn about the crucial role of the frontal areas in the regulation of cortical activation during relaxation and about the physiological justification of the application of the rhythmical auditory stimulation for the formation of the relaxation state its informational value.     

Deactivation of Brain Areas During Self-Regulation of Slow Cortical Potentials in Seizure Patients

This study investigates the neurophysiological basis of EEG feedback for patients with epilepsy. Brain areas are identified that become hemodynamically deactivated when epilepsy patients, trained in EEG self-regulation, generate positive slow cortical potentials (SCPs). Five patients were trained in producing positive SCPs, using a training protocol previously established to reduce seizure frequency in patients with drug refractory epilepsy. Patients attempted to produce positive SCP shifts in a functional magnetic resonance imaging (fMRI) scanner. Two patients were able to reliably produce positive SCP shifts. When these successful regulators were prompted to produce positive SCPs, blood oxygen level-dependent (BOLD) response indicated deactivation, in comparison to a control state, around the recording electrode, frontal lobe, and thalamus. Unsuccessful regulators’ BOLD response indicated no deactivation in cortical areas proximal to the active electrode. No thalamic deactivation was found in poor regulators. Decreased seizure frequency from SCP training may be the result of positively reinforced inhibition in cortical areas proximal to active electrode placement, the frontal cortex, and the thalamus.