Spectral analysis in cyclic changes of human sleep evaluation.

Background. The method of anterior decompression (discectomy) for monosegmental stenosis of the cervical spinal canal is subjectively assessed as highly effective by both neurosurgeons and the vast majority of patients. However, the objective criteria for the early effectiveness of this intervention have not been sufficiently studied to date. Aim of the study to evaluate the dynamics of electroencephalography parameters in the preoperative and early postoperative period in patients with monosegmental stenosis of the cervical spine. Materials and methods. Electroencephalography studies were conducted on 22 patients of the neurosurgery department, before and after surgical treatment under code A16.23.085.001. The spectral composition of the bioelectrical activity of the brain (alpha, beta, delta and theta rhythms), as well as the coherence of oscillations in selected leads, were studied. Results. In the preoperative period, a disorganized type of electroencephalogramm was recorded in the examined group according to the classification of E.A. Zhirmunskaya; there was a decrease in the index and amplitude of the alpha rhythm in the parietal-occipital leads; predominance of high-amplitude beta activity in the frontal-central leads; presence of diffuse delta activity of the average index and theta activity of the average index, localized in leads P3, P4, C3, C4. On the 5th day after the operation, an organized type of electroencephalography was recorded on the encephalogram; a well-modulated alpha rhythm was observed, with a frequency in the range from 9 to 10 Hz, and an amplitude of 70 to 80 microvolts. Low-amplitude beta rhythm activity was recorded in the frontocentral leads. Low-amplitude delta and theta rhythms were recorded in the parieto-occipital leads and had a low index. Overall, the obtained data indicated positive dynamics in the restoration of cortical rhythms. Conclusion. The positive dynamics of cerebral cortex biorhythms in the early postoperative period allows the use of the electroencephalography method to objectify the results of surgical treatment, and in the future for the purposes of neurorehabilitation.

Alpha and theta oscillations during the cognitive reappraisal of aversive pictures: A spatio-temporal qEEG investigation

To assess spatial working memory disorders in patients with mild depressive disorders and determine their neurophysiological correlates. Thirty patients (right-handed) with ICD-10 diagnosis Mood Disorders (F31.3, F32.0, F33.0, F34.1), aged 37±8 years, were examined before treatment. A control group included 30 mentally and somatically healthy individuals (32±7 years old). The study of spatial working memory was carried out using the Corsi Block-Tapping test. EEG was recorded and the values of the spectral power of theta, alpha and beta rhythms were analyzed. A decrease in the level of working memory that was correlated with higher values of theta rhythm power in the frontal and occipital regions and alpha rhythm in the frontal cortex was observed in affective disorders with mild depressive symptoms.

Sleep deficits in diabetic rats: restoration following chronic intravenous or intracerebroventricular infusions of insulin

The objective of the present study was to evaluate the effect on the electroencephalogram (EEG) of a chewing gum with and without our prepared new flavor. Electroencephalograms were obtained after the following three tests: chewing pure gumbase with sucrose (standard gumbase), chewing flavored standard gum and the inhalation of flavored aromatic oil. As the control, we used the pre-stimulus control EEG record without a stimulus. We examined the relationship between the pre-stimulus control record and the post-stimulus record using the changes of power in four bands. Chewing the standard gumbase led to an increase in the alpha wave and a decrease in the beta wave. Chewing the flavored standard gum and inhaling the flavored aromatic oil each increased the alpha and beta waves. In addition, chewing the flavored standard gum led to a change in the ratio of theta wave in the frontal area. The difference in the theta, alpha and beta bands in chewing gum with and without the added flavor suggested that the flavor as well as chewing could induce concentration with a harmonious high arousal state in brain function.

Sleep is essential for health and regulated by genetic and environmental factors. We performed genome-wide association studies of device-measured sleep duration, efficiency, and REM/NREM phases in 80,013 UK Biobank participants using accelerometer measurements separately validated against polysomnography. We identified 20 autosomal loci, 12 of which were novel, and report the first genome-wide significant signals for REM and NREM sleep duration. MEIS1 showed strong opposing effects on REM and NREM durations and is intolerant to loss-of-function mutations, suggesting a regulatory role. Functional enrichment implicated chromatin remodelling, lipid metabolism, and metal ion homeostasis; tissue enrichment highlighted regions including the hypothalamus and frontal cortex. Sex-stratified analyses identified distinct loci: FOXP2 and NRXN3 in females and LRP1B, NPBWR2, and PABPC4 in males. Mendelian randomization supported associations between shorter sleep duration and higher cardiometabolic risk. Our findings highlight novel sex- and phase-specific regulators of human sleep architecture, offering biological insights and potential therapeutic targets.

Electroencephalographic study of parasomnia: Sleep-talking, enuresis and bruxism

Source analysis of EEG oscillations using high-resolution EEG and MEG

Introductions: Medical students are required to lifelong learning. Electroencephalog-raphy is a neuroscience tool that can be used to record brain wave activity related to a person's cognitive function. Objective: This study was conducted to see the relationship between self-regulated learning and cognitive function with quantitative electroencepha-logram (qEEG) parameters. Methods: This study used an observa-tional analytic approach to assess self-regulated learning and cog-nitive function using the MSLQ and MoCA-INA questionnaires. qEEG recording to see brain wave activity was done when the eyes were open and closed and seen in alpha and beta waves. The sam-ple of this study amounted to 32 respondents who were willing to carry out each research procedure. Results: The study findings reveal a significant correlation between SRL and qEEG parameters. In the open-eye condition, such a correla-tion exists in the frontal and central regions with regard to alpha waves (P = 0.046 and P = 0.047). In contrast, in the closed-eye condition, it exists in the occipital, central, and parietal regions with alpha waves (P = 0.005, P = 0.021, and P = 0.049) and the central region with beta waves (P = 0.030). There is a significant correla-tion between cognitive function and qEEG parameters observed in both open and closed-eye conditions within the frontal region beta waves (P = 0.024, P = 0.044, and P = 0.021). Conclusions: There is a relationship between SRL and cognitive function with alpha and beta wave activity on qEEG recording.

This study explores the integration of dhikr spiritual practices with neurofeedback technology to improve self-regulated learning (SRL) skills in Muslim students. Using a mixed method approach, the study involved 30 Muslim students (aged 18-25 years) who underwent a dhikr intervention with neurofeedback for 4 weeks. Brain activity was measured using a 14-channel EEG device, while SRL ability was measured by the Motivated Strategies for Learning Questionnaire (MSLQ) through pre-test, post-test, and follow-up. The results of EEG analysis showed a significant increase in alpha (8-13 Hz) and theta (4-8 Hz) waves, as well as a decrease in beta (13-30 Hz) and gamma (>30 Hz) waves during and after the practice of dhikr. MSLQ measurements showed significant improvements in almost all components of SRL, especially metacognitive ability (d=1.07), self-efficacy (d=0.84), and business regulation (d=0.82). Correlation analysis revealed a strong positive association between increased alpha and theta waves and increased SRL scores. Thematic analysis of semi-structured interviews identified five main themes: increased internal awareness, mental calmness, strengthening of spiritual connections, transfer to learning activities, and the facilitative role of neurofeedback visualization. These findings suggest that the integration of dhikr with neurofeedback has the potential to be an innovative approach to developing SRL abilities while strengthening the religious identity of Muslim students, offering an educational model that integrates cognitive and spiritual aspects.

BackgroundHighly structured electroencephalography (EEG) oscillations can occur in adults during etomidate-induced general anesthesia, but the link between these two phenomena is poorly understood. Therefore, in the present study, we investigated the electroencephalogram dynamics of etomidate-induced loss of consciousness (LOC) in order to understand the neurological mechanism of etomidate-induced LOC.MethodsThis study is a prospective observational study. Etomidate-induced anesthesia was performed on eligible patients undergoing elective surgery. We analyzed EEG data from 20 patients who received etomidate for the induction of general anesthesia. We used power spectra and coherence methods to process and analyze the EEG data. Our study was based on 4-channel EEG recordings.ResultsCompared with the baseline (awake period), etomidate induced an increase in power in delta, theta, alpha and beta waves during LOC. Compared with the awake period, the delta-wave (1–4 Hz), alpha-wave(8–13 Hz), and theta-wave(4–8 Hz) coherence increased significantly during LOC, while the slow-wave (< 1 Hz) coherence decreased. However, the delta wave (1.0–4.0 Hz) during etomidate-induced LOC was more coherent than during the awake period (1.86–3.17 Hz, two-group test for coherence, p < 0.001).ConclusionsThe neural circuit mechanism of etomidate-induced LOC is closely related to the induction of oscillation in delta, theta, alpha and beta waves and the enhancement of delta-wave coherence.Trial registrationChiCTR1800017110

The goal of this study was to determine whether the cortical responses elicited by whole‐body balance perturbations were similar to established cortical markers of action monitoring. Postural changes imposed by balance perturbations elicit a robust negative potential (N1) and a brisk increase of theta activity in the electroencephalogram recorded over midfrontal scalp areas. Because action monitoring is a cognitive function proposed to detect errors and initiate corrective adjustments, we hypothesized that the possible cortical markers of action monitoring during balance control (N1 potential and theta rhythm) scale with perturbation intensity and the eventual execution of reactive stepping responses (as opposed to feet‐in‐place responses). We recorded high‐density electroencephalogram from eleven young individuals, who participated in an experimental balance assessment. The participants were asked to recover balance following anteroposterior translations of the support surface at various intensities, while attempting to maintain both feet in place. We estimated source‐resolved cortical activity using independent component analysis. Combining time‐frequency decomposition and group‐level general linear modeling of single‐trial responses, we found a significant relation of the interaction between perturbation intensity and stepping responses with multiple cortical features from the midfrontal cortex, including the N1 potential, and theta, alpha, and beta rhythms. Our findings suggest that the cortical responses to balance perturbations index the magnitude of a deviation from a stable postural state to predict the need for reactive stepping responses. We propose that the cortical control of balance may involve cognitive control mechanisms (i.e., action monitoring) that facilitate postural adjustments to maintain postural stability.

Time series of pain sensation thresholds are analyzed by the time series analysis technique. Mechanical stimulus, indentation of a needle on the skin, was used for pain stimulus. Subjects were healthy male and female humans. Stimulation was done for one minute, and time series of pain sensation thresholds were obtained. First, the trends of pain thresholds for 50 minutes were analyzed by regression analysis. First-order coefficients of first-order regression showed, on average, that pain thresholds tend to increase about 0.2 or 0.3% per minute. Second, frequency of the time series of pain thresholds was analyzed. Autocorrelation functions suggested that there exists periodicity in pain thresholds. To confirm this, alternative stimulation with a pin and cylindrical needle was done. Cross correlation showed that these were highly correlated, and it was considered that there are periodical factors in pain thresholds. The periods of the peak value of the power spectrum of pain threshold time series were obtained from fifty experiments. This showed that pain thresholds fluctuate periodically during about 10 minutes. As periodicity of pain thresholds was found, factors which produce this phenomenon were investigated. From the gate control theory, it was supposed that such fluctuations of pain threshold were caused by the inhibitory effects of touch or pressure sensation. To investigate these effects, pain thresholds and touch thresholds were measured simultaneously. Cross correlation and the coherence showed that there was a positive correlation between pain and touch sensation. This suggests that the periodicity is not caused by peripheral inhibition effects in the spinal cord but is caused by the higher central nervous system. In order to infer the conditions of the brain, several physiological parameters were measured. They were alpha rhythm・beta rhythm・theta rhythm from EEG, EMG, heart rate and skin temperature. Experiments were performed for 100 minutes. A two-dimensional autoregressive model was introduced to the analysis. Each physiological parameter was regarded as the input signal, and the pain threshold was regarded as the output of the system. For evaluation the relative power contribution was used, which is the ratio of the contribution of input signal to the spectrum of the output. For all physiological parameters, the relative power contribution was less than 50%. When focused on the main period of pain threshold which is about 10 minutes, the relative power contribution of theta rhythm had its peak at this period though values were low. From this result, as theta rhythm appears at the early stage of the sleep, there is a possibility that some periodicity of drowsiness causes the fluctuation of the pain threshold.

Previous studies have brought us to consider the variations in frequency of the basic alpha rhythm of the electroencephalograms, as an important and significant factor. Regarding the problem of the aging processus, we have looked for an eventual relationship between this fact and the variations in question. For this, we isolated a group of tracings showing no pathological pattern, or belonging to a group of control with no consumption of neuroleptics and able to be part of a “normal” existence. These 879 selected tracings have shown the alpha rhythm in all cases, and in 262 subjects its association with theta rhythm. They may be divided into 5 groups by decades: 1 test-group from 30 to 39 years (349 tracings). 1 group of comparison from 50 to 59 years (270 tracings). 1 group of comparison from 60 to 69 years (166 tracings). 1 group of comparison from 70 to 79 years (72 tracings). 1 group of comparison from 80 to 89 years (22 tracings). Even if these groups diminish in number with advancing age, as in all populations studied under this aspect, they remain sufficient in number to be compared under histographic form, grouping the different frequencies of alpha rhythm or according to their average frequencies. The first observation issued from this comparison is the decrease of alpha frequency with age. Among the four groups, the first group only can be compared to the test-group from 30 to 39 years of age. From 60 …. years of age, we see a profile clearly diverted to the left, whereas the averages diminish. The presence of theta rhythm in a tracing favors the reduction in the frequency of alpha rhythm as it is seen if we select in each group, the tracings composed of alpha rhythm (pure alpha rhythm) and those composed of both (alpha + theta). In what concerns reactivity, we have observed that during the aging processus: — the blocking is less and less adequate; — hyperventilation is more and more active; — theta rhythm increases; — the photic stimulation follows less the cerebral rhythm but its action increases the “irritative pattern” or in the appearance of theta rhythm. Moreover, the morphology of the tracing changes and the “choppy” rhythms become more and more abundant. In conclusion: The E.E.G. evolves in one way towards a decrease of the alpha frequency, which is considered as a minor but constant indication of “cerebral distress” and in another way, towards a pattern of reactivity showing, either a decrease of physiological responses, or an increase in pathological elements (vascular types, in particular).

Electroencephalogram (EEG) signal has been studied as a biological signal input for human-computer interaction. This research defines a control signal - focus value R to measure the concentration degree of human brain. According to frequency band, human brain waves have been classified to, such as alpha wave, beta wave, theta wave, delta wave. The focus value R is the ratio of beta wave's and theta wave's total power on frequency domain. The research then attests to the reasonable representing of brain concentration with R. To conclude, the research utilizes the self-controlled brain concentration degrees (the levels an individual can pay attention) into a human-computer interface application (HCI) like music control, which can be used for the disabled like Parkinson's disease patients to change music volume and switch as they like.