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Abstract Background The main objective of this research was to analyze the characteristics of electrical activity in the brain during REM (Rapid Eye Movements) sleep, by using an experimental model a pathology that affects the frontal lobes, such as brain tumors. In addition to determining the impact of variables such as the frontal area (dorsolateral, medial and orbital), laterality and size of the lesion; as well as the demographic and clinical characteristics of the patients evaluated. Methods By using polysomnographic recordings, 10 patients were evaluated. We obtained power spectra through a homemade program. For quantitative EEG (Electroencephalogram) (qEEG) analysis, the Fast Fourier Transform (FFT) algorithm was used to obtain the spectral power of each participant, channel, and frequency band. Results Sleep architecture and spectral power was found to be modified in patients compared to normative values. Other sociodemographic and clinical characteristics of the patients were also influenced, such as age range and antiepileptic drugs. Conclusions Brain tumors in the frontal lobe can modify the rhythmogenesis of REM sleep, possibly due to changes of brain plasticity as an effect of the pathology. In addition to this, through this study we were able to show the association between neuroanatomical and functional changes, on the characteristics of brain electrical activity in patients with frontal brain tumor. Finally, this qEEG analysis technique allows, on the one hand, to deepen the knowledge and relationship between psychophysiological processes and, on the other hand, to be able to guide therapeutic decisions.

Background: The main objective of this research was to analyze the characteristics of electrical activity in the brain during REM (Rapid Eye Movements) sleep, by using an experimental model a pathology that affects the frontal lobes, such as brain tumors. In addition to determining the impact of variables such as the frontal area (dorsolateral, medial and orbital), laterality and size of the lesion; as well as the demographic and clinical characteristics of the patients evaluated. Methods: By using polysomnographic recordings, 10 patients were evaluated. We obtained power spectra through a homemade program. For quantitative EEG (Electroencephalogram) (qEEG) analysis, the Fast Fourier Transform (FFT) algorithm was used to obtain the spectral power of each participant, channel, and frequency band. Results: Sleep architecture and spectral power was found to be modified in patients compared to normative values. Other sociodemographic and clinical characteristics of the patients were also influenced, such as age range and antiepileptic drugs. Conclusions: Brain tumors in the frontal lobe can modify the rhythmogenesis of REM sleep, possibly due to changes of brain plasticity as an effect of the pathology. In addition to this, through this study we were able to show the association between neuroanatomical and functional changes, on the characteristics of brain electrical activity in patients with frontal brain tumor. Finally, this qEEG analysis technique allows, on the one hand, to deepen the knowledge and relationship between psychophysiological processes and, on the other hand, to be able to guide therapeutic decisions. [ABSTRACT FROM AUTHOR]

Background: It has been demonstrated that in young and healthy individuals, there is a strong association between the amplitude of EEG-derived motor activity-related cortical potential or EEG spectral power (ESP) and voluntary muscle force. This association suggests that the motor-related ESP may serve as an index of central nervous system function in controlling voluntary muscle activation Therefore, it may potentially be used as an objective marker to track changes in functional neuroplasticity due to neurological disorders, aging, and following rehabilitation therapies. To this end, the relationship between the band-specific ESP—combined spectral power of EEG oscillatory and aperiodic (noise) components—and voluntary elbow flexion (EF) force has been analyzed in elder and young individuals. Methods: 20 young (22.6 ± 0.87 year) and 28 elderly (74.79 ± 1.37 year) participants performed EF contractions at 20%, 50%, and 80% of maximum voluntary contraction (MVC) while high-density EEG signals were recorded. Both the absolute and relative ESPs were computed for the EEG frequency bands of interest. Results: The MVC force generated by the elderly was foreseeably lower than that of the young participants. Compared to young, the elderly cohort's (1) total ESP was significantly lower for the high (80% MVC) force task; (2) relative ESP in beta band was significantly elevated for the low and moderate (20% MVC and 50% MVC) force tasks; (3) absolute ESP failed to have a positive trend with force for EEG frequency bands of interest; and (4) beta-band relative ESP did not exhibit a significant decrease with increasing force levels. Conclusions: As opposed to young subjects, the beta-band relative ESP in elderly did not significantly decrease with increasing EF force values. This observation suggests the use of beta-band relative ESP as a potential biomarker for age-related motor control degeneration. [ABSTRACT FROM AUTHOR]

This report presents a study of differences in the perception of own and others' faces using an integrated approach to the analysis of EEG data. A paradigm was developed in which healthy volunteers were offered a series of pre-processed and unified photographs of their own and other's faces. Data analysis used event-related potentials, EEG spectral power analysis, and non-linear EEG indicators such as fractal dimension, envelope frequency, and Hjorth complexity. Perception of one's own face, as compared with perception of another person's face, was found to be associated with greater slow-wave activity power and lower α and β rhythm power, a smaller-amplitude P100 component, a greater-amplitude late positive component, and greater values for all nonlinear EEG parameters studied. The results obtained here, along with the EEG data analysis techniques used, will be used in the future to study self-identification pathology in patients with brain lesions. [ABSTRACT FROM AUTHOR]

Daisy Duan,1 Chenjuan Gu,2 Vsevolod Y Polotsky,2 Jonathan C Jun,2 Luu V Pham2 1Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; 2Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USACorrespondence: Luu V PhamPulmonary and Critical Care Medicine, 5501 Hopkins Bayview Circle, Asthma and Allergy Center, Johns Hopkins Sleep Disorders Center, Baltimore, MD, 21224, USATel +1 410-550-0741Fax +1 410-550-3374Email luu.pham@jhmi.eduPurpose: Eating time and sleep habits are important modifiable behaviors that affect metabolic health, but the relationship between food intake and sleep remains incompletely understood. Observational data suggest that late food intake is associated with impaired sleep quality. We examined the effect of routine dinner (RD, 5 hours before bedtime) vs late dinner (LD, 1 hour before bedtime) on sleep architecture in healthy volunteers.Participants and Methods: This was a post hoc analysis of a randomized crossover study of RD vs LD with a fixed sleep opportunity in a laboratory setting. On each of the two visits, 20 healthy adult volunteers (10 women) received an isocaloric meal followed by overnight polysomnography. Sleep architecture over the course of the night was assessed using visual sleep staging and EEG spectral power analysis and was compared between RD and LD. We modeled the proportions of spectral power in alpha, beta, delta, and theta bands as functions of dinner timing, time of night, and their interaction with mixed-effect spline regression.Results: Conventional sleep stages were similar between the 2 visits. LD caused a 2.5% initial increase in delta power and a reciprocal 2.7% decrease in combined alpha and beta power (p< 0.0001). These effects diminished as sleep continued with a reversal of these patterns in the latter part of the night.Conclusion: Contrary to the existing literature, shifting dinner timing from 5 hours before sleep to 1 hour before sleep in healthy volunteers did not result in significant adverse changes in overnight sleep architecture. In fact, LD was associated with deeper sleep in the beginning of the night and lighter sleep in the latter part of the night in healthy volunteers. This novel manifestation of postprandial hypersomnia may have therapeutic potential in patients with sleep disorders.Keywords: late eating, dinner timing, sleep architecture, EEG spectral power

• The wake-sleep transition is characterized by progressive local EEG modifications. • Sleep deprivation enhances the EEG changes that characterize the sleep onset. • The local EEG features of the sleep onset can be promoted by tCS protocols. • tCS can also be used to reduce sleepiness, but electrophysiological evidence is scarce. The sleep onset (SO) process is characterized by gradual electroencephalographic (EEG) changes. The interest for the possibility to manipulate the electrophysiological pattern of the wake-sleep transition is recently growing. This review aims to describe the EEG modifications of the SO process in healthy humans and the evidence about their experimental manipulation. We provide an overview of the electrophysiological changes during the wake-sleep transition, considering several methods to study the EEG signals. We then describe the impact of sleep deprivation (SD) on the electrophysiology of SO. Finally, we discuss the evidence about the possibility to modulate the local EEG activity through transcranial current stimulation protocols with the aim to promote, hinder, or manipulate the electrophysiological mechanisms of the wake-sleep transition. The reviewed findings highlight the local nature of the EEG processes during the SO and their intensification and speedup after SD. The evidence about the possibility to non-invasively affect the EEG pattern of the wake-sleep transition may have important implications for clinical conditions that would benefit from its prevention or promotion. [ABSTRACT FROM AUTHOR]

Studies of 12 subjects using Fourier analysis addressed the EEG amplitude-frequency spectrum at a constant level of normobaric hypoxia (breathing an oxygen-nitrogen mix containing 8% oxygen for 25 min). Cluster analysis of the 16-channel EEG identified two groups of subjects differing in terms of relative spectral power (SP) in the EEG δ range averaged over the period of hypoxia. Six of the subjects of the group 1 (n = 7), with greater relative SP in the δ range during hypoxia showed dominance o δ activity in all subsequent 1-min segments and all leads starting after 6 min of hypoxia. Subjects of group 2 (n = 5) showed dominant α activity in the occipital leads overall for the 25 min of hypoxia. In sequential 1-min segments, the dominance of α activity in some subjects of this group changed to a dominance of δ and θ activity. These studies showed that the dynamics of the EEG amplitude-frequency spectrum at a constant level of hypoxia do not always correspond to sequential "slowing" of the EEG described in increasing hypoxia. [ABSTRACT FROM AUTHOR]

Study Objectives: Limited channel electroencephalography (EEG) investigations in obstructive sleep apnea (OSA) have revealed deficits in slow wave activity (SWA) and spindles during sleep and increased EEG slowing during resting wakefulness. High-density EEG (Hd-EEG) has also detected local parietal deficits in SWA (delta power) during NREM. It is unclear whether effective continuous positive airway pressure (CPAP) treatment reverses regional SWA deficits, and other regional sleep and wake EEG abnormalities, and whether any recovery relates to improved overnight memory consolidation., Methods: A clinical sample of men with moderate-severe OSA underwent sleep and resting wake recordings with 256-channel Hd-EEG before and after 3 months of CPAP. Declarative and procedural memory tasks were administered pre- and post-sleep. Topographical spectral power maps and differences between baseline and treatment were compared using t-tests and statistical nonparametric mapping (SnPM)., Results: In 11 compliant CPAP users (5.2 ± 1.1 hours/night), total sleep time did not differ after CPAP but N1 and N2 sleep were lower and N3 was higher. Centro-parietal gamma power during N3 increased and fronto-central slow spindle activity during N2 decreased (SnPM < 0.05). No other significant differences in EEG power were observed. When averaged specifically within the parietal region, N3 delta power increased after CPAP (p = 0.0029) and was correlated with the change in overnight procedural memory consolidation (rho = 0.79, p = 0.03). During resting wakefulness, there were trends for reduced delta and theta power., Conclusions: Effective CPAP treatment of OSA may correct regional EEG abnormalities, and regional recovery of SWA may relate to procedural memory improvements in the short term., (© The Author(s) 2023. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The study aimed to reveal task-related differences in story creation with and without the mental effort of overcoming self-induced stereotypes. Eighteen right-handed subjects (19.3 ± 1.1 years old) created stories. The subjects reported the formation of story plot stereotypes (as we call them: self-induced) during self-regulated creative production, which had to be overcome with the instruction to continue the story. Creative task fulfillment (without formed stereotypes—first stage of creation) was characterized by a decrease in the wave percentages of 9−10 Hz, 10−11 Hz and 11−12 Hz frequencies and EEG desynchronization (decreases in EEG spectral power) in the theta (4−8 Hz), alpha1 (8−10 Hz) and alpha2 (10−13 Hz) frequency bands in comparison with the REST (random episodic silent thought) state. The effortful creation task (with overcoming of self-induced stereotypes-second stage of creation) was characterized by increases in waves with frequencies of 9−10 Hz, 10−11 Hz, 11−12 Hz in temporal, occipital areas and pronounced EEG synchronization in alpha1,2 frequency bands in comparison with the free creation condition. It was also found, that the participants with the higher originality scores in psychological tests demonstrated increased percentage of high frequencies (11−12 Hz in comparison with those who had lower originality scores. Obtained results support the role of alpha and theta frequency bands dynamics in creative cognition.

Although shyness is a ubiquitous phenomenon and long viewed as a maladaptive characteristic, we know relatively little about the possible brain mechanism(s) underlying and maintaining shyness. Using a prospective longitudinal study, we examined frontal brain maturation in shy children. We collected measures of resting regional EEG spectral power approximately every six months for two years in young school-age children and characterized frontal brain maturation using a growth curve analysis of proportion of spectral power in relative faster-to-slower EEG frequencies. We found that children classified as low in shyness exhibited a significant linear growth in the proportion of overall frontal alpha power relative to delta power across assessments relative to children classified as high in shyness. High shy children displayed no growth in the proportion of overall frontal alpha power relative to delta power across assessments. These preliminary results indicate that high shy children exhibited delayed frontal brain maturation compared to low shy children. We interpret these findings within the context of a proximate explanation, suggesting links between delayed frontal maturation and emotion dysregulatory processes related to an approach-avoidance conflict. We also speculate on an ultimate explanation in which delayed frontal brain maturation may reflect neoteny (i.e., the prolongation and extension of childhood), which may have supported an adaptive function of shyness across human evolution. [ABSTRACT FROM AUTHOR]

Background: Foot reflexotherapy is a noninvasive complementary therapy that has gained considerable application in several fields of human endeavor. The therapy is used to relieve the symptoms of several ailments. For instance, foot reflexotherapy when applied to the cortical areas of the left or right foot relieves pain and stress. However, the electrophysiological mechanisms of the effect of foot reflexotherapy on cortical activity are not completely understood. While it has been shown that foot reflexotherapy exert positive effects on brain functions, little is known about the effects of this therapy on cortical activities as recorded with electroencephalogram (EEG) in healthy humans. Cortical activity is widely investigated with EEG, a noninvasive recording that is used to study brain activity in different functional states and conditions.Aim: The aim of this study was to investigate the effect of foot reflexotherapy on EEG rhythms in healthy humans.Material and Methods: EEG recording before and after reflexological therapy was carried out in seven healthy right-handed males who volunteered for the study.Results: Analysis of EEG data revealed activation offrontal cortex that resulted to significant increase in beta and gamma spectral powers after foot reflexotherapy (p ˂ 0.05).Conclusion: Foot reflexotherapy is associated with increase in spectral powers in beta and gamma frequency bands. Therefore cortical beta and gamma waves of the EEG could be used as measures of functional activation of the brain, related to foot reflexotherapy. [ABSTRACT FROM AUTHOR]

Stress and anxiety are states which sportsmen are continuously exposed to. Our study aimed to evaluate neuroelectrical peripheral and central nervous system responses of sportsmen (SPR) and sedentary individuals (SED) during concentration grid test (CGT) employed under time pressure. Forty three SPR and 33 SED participated in the study. Neuroelectrical responses were simultaneously obtained during baseline and CGT. All responses were observed to increase under stress in both SED and SPR. The SPR’s stress related peripheral responses were lower than SED’s. When central values were evaluated a stress related increase according to baseline was observed in all frequency powers in all of the participants. Statistical comparison of increase rates revealed a significantly greater increase in beta in SED compared to SPR. Beta has been associated to alertness and cortical arousal. As SED exhibit greater beta increase under stress compared to SPR their state of cortical arousal and alertness may be interpreted to be higher than SPR. However the SPR’s weak increase in beta and their lower peripheral responses taken together may imply that they are better in stress management. In fact according to their performance scores the SPR’s higher level of performance under stress compared to SED shows that they are better at maintaining and focusing their attention under stress than SED. [ABSTRACT FROM AUTHOR]

Recently, Electroencephalogram (EEG)-based computer-aided (CAD) techniques have shown their promise as decision-making tools to diagnose major depressive disorder (MDD) or simply depression. Although the research results have motivated the use of CAD techniques to help assist psychiatrists in clinics yet their clinical translation has been less clear and remains a research topic. In this paper, a proposed machine learning (ML) scheme was tested and validated with resting-state EEG data involving 33 MDD patients and 30 healthy controls. The EEG-derived measures such as power of different EEG frequency bands and EEG alpha interhemispheric asymmetry were investigated as input features to the proposed ML scheme to discriminate the MDD patients and healthy controls, and to prove their feasibility for diagnosing depression. The acquired EEG data were subjected to noise removal and feature extraction. As a result, a data matrix was constructed by the columns-wise concatenation of the extracted features. Furthermore, the z-score standardization was performed to standardize each column of the data matrix according to its mean and variance. The data matrix may have redundant and irrelevant features; therefore, to determine the most significant features, a weight was assigned to each feature based on its ability to separate the target classes according to the criterion, i.e., receiver operating characteristics (roc). Hence, only the most significant features were used for testing and training the classifier models: Logistic regression (LR), Support vector machine (SVM), and Naïve Bayesian (NB). Finally, the classifier models were validated with 10-fold cross-validation that has provided the performance metrics such as test accuracy, sensitivity, and specificity. As a result of the investigations, most significant features such as EEG signal power and EEG alpha interhemispheric asymmetry from the brain areas such as frontal, temporal, parietal and occipital were found significant. In addition, the proposed ML framework proved automatic identification of aberrant EEG patterns specific to disease conditions and provide high classification results i.e., LR classifier (accuracy = 97.6%, sensitivity = 96.66%, specificity = 98.5%), NB classification (accuracy = 96.8%, sensitivity = 96.6%, specificity = 97.02%), and SVM (accuracy = 98.4%, sensitivity = 96.66%, specificity = 100%). In conclusion, the proposed ML scheme along with the EEG signal power and EEG alpha interhemispheric asymmetry are proved suitable as clinical diagnostic tools for MDD. [ABSTRACT FROM AUTHOR]

The goal of these studies was to use quantitative (q)EEG techniques on data from children with Angelman syndrome (AS) using spectral power analysis, and to evaluate this as a potential biomarker and quantitative method to evaluate therapeutics. Although characteristic patterns are evident in visual inspection, using qEEG techniques has the potential to provide quantitative evidence of treatment efficacy. We first assessed spectral power from baseline EEG recordings collected from children with AS compared to age-matched neurotypical controls, which corroborated the previously reported finding of increased total power driven by elevated delta power in children with AS. We then retrospectively analyzed data collected during a clinical trial evaluating the safety and tolerability of minocycline (3 mg/kg/d) to compare pretreatment recordings from children with AS (4-12 years of age) to EEG activity at the end of treatment and following washout for EEG spectral power and epileptiform events. At baseline and during minocycline treatment, the AS subjects demonstrated increased delta power; however, following washout from minocycline treatment the AS subjects had significantly reduced EEG spectral power and epileptiform activity. Our findings support the use of qEEG analysis in evaluating AS and suggest that this technique may be useful to evaluate therapeutic efficacy in AS. Normalizing EEG power in AS therefore may become an important metric in screening therapeutics to gauge overall efficacy. As therapeutics transition from preclinical to clinical studies, it is vital to establish outcome measures that can quantitatively evaluate putative treatments for AS and neurological disorders with distinctive EEG patterns.

The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e. the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 sec before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals.

Objective To evaluate the spectral power of the cortical bands in patients with first episode schizophrenia and schizoaffective disorder at rest and during the performance of a mental arithmetic task. Methods We analyzed EEG spectral power (SP) in the resting state and subsequently while counting down from 200 in steps of 7, in 32 first episode schizophrenia patients (SZ), 32 patients with first episode schizoaffective disorder (SA) and healthy controls (HC, n = 40). Behavioral parameters such as accuracy and counting speed were also evaluated. Results Both SZ and SA patients were slower in counting than HC, no difference was obtained in the accuracy and counting speed in the patient groups. In the resting state patients showed elevated midline theta power, off-midline anterior beta 2 power and decreased central/posterior alpha power. The SA group occupied an intermediate position between the schizophrenia patients and controls. In task performance patients lacked a typical increase of midline theta , left anterior beta 2 , and anterior gamma power; however, schizoaffective patients demonstrated a growing trend of power in the gamma band in left anterior off-midline sites similar to HC. Moreover, alpha power was less inhibited in schizoaffective patients and more pronounced in schizophrenia patients indicating distinct inhibitory mechanisms in these psychotic disorders. Conclusions Patients with SA demonstrate less alteration in the spectral power of bands at rest than SZ, and present spectral power changes during cognitive task performance close to the controls. Significance Our study contributes to the present evidence on the neurophysiological distinction between schizophrenia and schizoaffective disorder. [ABSTRACT FROM AUTHOR]

The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e., the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 s before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals. [ABSTRACT FROM AUTHOR]

We present here a comparative analysis of spectral power and mean coherence of the theta and gamma rhythms in healthy boys and boys with early childhood autism aged 5-7 years (mean age 6 years 1 month) in the state of rest and on cognitive loading (counting). In contrast to the situation in patients, the background theta rhythm in healthy children showed a marked fronto-occipital gradient. In early childhood autism, the spectral power of the theta rhythm in baseline conditions had lower values than in healthy children, while baseline gamma rhythm power was greater. In healthy children, cognitive loading led to decreases in spectral power and mean coherence in the theta rhythm and increases in these measures of the gamma rhythm. In patients with early childhood autism, cognitive loading produced no marked changes from baseline in either rhythm. In healthy children, counting shifted the focus of theta-rhythm activity to the right occipital area, which did not occur in patients with early childhood autism. [ABSTRACT FROM AUTHOR]

Robotics is rapidly emerging as a viable approach to enhance motor recovery after disabling stroke. Current principles of cognitive motor learning recognize a positive relationship between reward and motor learning. Yet no prior studies have established explicitly whether reward improves the rate or efficacy of robotics-assisted rehabilitation or produces neurophysiologic adaptations associated with motor learning. We conducted a 3 wk, 9-session clinical pilot with 10 people with chronic hemiparetic stroke, randomly assigned to train with an impedance-controlled ankle robot (anklebot) under either high reward (HR) or low reward conditions. The 1 h training sessions entailed playing a seated video game by moving the paretic ankle to hit moving onscreen targets with the anklebot only providing assistance as needed. Assessments included paretic ankle motor control, learning curves, electroencephalograpy (EEG) coherence and spectral power during unassisted trials, and gait function. While both groups exhibited changes in EEG, the HR group had faster learning curves (p = 0.05), smoother movements (p

Expert sport stars reliably execute their skills with remarkable precision and accuracy. To provide an insight into the mechanisms that underpin the superior performance of experts compared to novices, this article critically reviews experiments that have examined cortical activity (i.e., movement related cortical potentials; EEG spectral power) and cardiac activity (i.e., dynamic changes in heart rate) during preparation for action in self-paced aiming sports. It suggests that decelerations in heart rate and task-specific changes in EEG activity during preparation for action can explain superior expert performance. These psychophysiological responses are interpreted in terms of preparatory information processing and response programming, before suggestions for future research into the psychophysiology of preparation for action are outlined. [ABSTRACT FROM AUTHOR]

We report here a comparative analysis of spectral power and mean coherence in the alpha, beta, and gamma rhythms in children aged 5-7 years, both normal and with early childhood autism, at rest and in conditions of a cognitive task (counting). In baseline conditions, both healthy children and those with autism showed a marked frontal-occipital alpha gradient. The cognitive task led to increases in the spectral power of the alpha1 range and its displacement into the left hemisphere without any alteration of alpha2; the task also produced a marked increase in spectral power in the alpha3 range. In healthy children, the cognitive task, as compared with baseline conditions, produced significant increases in the spectral power and coherence of the rapid rhythms in the central and frontal areas of the left hemisphere. In patients with early childhood autism, there was a right-sided predominance of spectral power in the alpha range both in baseline conditions and during the cognitive task. Baseline gamma-range spectral power in early childhood autism had greater values than in normal children and did not change during the cognitive task. [ABSTRACT FROM AUTHOR]

The spectral powers (SPs) of the θ and α EEG rhythms were studied at different stages of visual set in children from five to seven years of age. Children with a plastic set had a greater α band SP than those with a rigid set. At the set formation stage, children with a rigid set displayed an increase in the SP of the θ band, which is a manifestation of an 'immature' activation reaction. Children with a plastic set exhibited an increase in the α band SP in the occipital lobes of both hemispheres. The dynamics of the SP of the EEG rhythms differed in children younger and older than six years. At the set formation stage, children from five to six years of age exhibited the above-mentioned 'immature' activation reaction, while those from six to seven years of age showed an increase in the α band SP in the occipital lobes. At the set actualization stage, an increase in the α band SP was observed in the right caudal areas, while the set extinction stage was marked by a bilateral depression of the α band in the frontal lobes. The importance of the involvement of specific cortical areas in visual perception and the formation of a plastic set is discussed. [ABSTRACT FROM AUTHOR]

Abstract: Several studies support an association between electroencephalogram (EEG) voltage and alcohol dependence. However, the distribution of EEG variants also appears to differ depending on an individual''s ethnic heritage, suggesting significant genetic stratification of this EEG phenotype. The present study''s aims were to investigate the incidence of EEG alpha variants and spectral power in the alpha frequency range in Mexican American young adults based on gender, and personal and family history of alcohol dependence. Clinical ratings (high-, medium-, and low alpha voltage variants) and spectral characteristics of the EEG in the alpha frequency range (7.5–12Hz) were investigated in young adult (age 18–25 years) Mexican American men (n =98) and women (n =138) who were recruited from the community. Nineteen percent (n =45) of the participants had a low-voltage alpha EEG variant, 18% had a high-voltage variant, and 63% had a medium-voltage variant. There were no significant differences in the distribution of the EEG variants based on family history of alcohol dependence. There was a significant relationship between gender and the three alpha variants (χ 2 =9.7; df =2; P <.008), and there were no male participants with alcohol dependence with high alpha variants (χ 2 =5.8; df =2; P <.056). Alcohol dependence, but not a family history of alcohol dependence, was associated with lower spectral power in the alpha frequency range in the right (F =4.4; df =1,96; P <.04) and left (F =5.3; df =1.96; P <.02) occipital areas in the men but not in the women. In conclusion, in this select population of Mexican American young adults, male gender and alcohol dependence are associated with an absence of high-voltage alpha variants and lower alpha power in the EEG. These data suggest that EEG low voltage, a highly heritable trait, may represent an important endophenotype in male Mexican Americans that may aid in linking brain function with genetic factors underlying alcohol dependence in this ethnic group. [Copyright &y& Elsevier]

Background: Although the association between sleep and alcohol has been of interest to scientists for decades, the effects of alcohol on sleep and sleep electroencephalogram (EEG) have not been extensively studied in women. Our specific aim was to determine whether sleep stage variables and/or spectral characteristics of the sleep EEG are altered by alcohol administration in women. Methods: Changes of sleep and the sleep EEG were investigated after administration of a moderate dose of alcohol (0.49 g/kg) in the hour before bedtime compared with placebo in young healthy women. After approximately 2 weeks at home on a fixed 8.5- or 9-hour stabilization sleep schedule, sleep was continuously recorded by polysomnography for 3 consecutive nights [adaptation, placebo, alcohol (mean breath alcohol concentration 0.043 g/% before bedtime)] in the laboratory in 7 women (ages 22–25, mean=23.5, SD=1 year). Sleep stages were scored according to conventional criteria. Electroencephalogram power spectra of the bipolar derivations Fz/Cz (anterior) and Pz/Oz (posterior) were calculated using a fast Fourier transform routine. Results: Only few changes in sleep and the sleep EEG were observed. Across the entire night rapid eye movement (REM) sleep decreased, while minutes of stage 4 sleep were increased in the first 2-hour interval on alcohol nights compared with placebo nights. Spectral analysis of the EEG showed increased power in the α range (9–11 Hz) during all-night non-REM (NREM) sleep in anterior derivations after alcohol compared with placebo. Differences in spectral EEG power were also present in 2-hour intervals of NREM sleep; in particular, EEG power was increased on the alcohol night for frequency bins within the α range in anterior derivations and within the δ range (3–4 Hz) in posterior derivations during the initial part of the night. Conclusions: A moderate dose of alcohol just before bedtime resulted in a short-lived increase in sleep intensity. A limitation of the study, however, was that only a single dose of alcohol was used to examine the effects of alcohol on sleep. [ABSTRACT FROM AUTHOR]

Background. Both non-suicidal self-injuries (NSSIs) and suicidal attempts (SAs) in adolescence represent significant risk factors for consequent suicide, but neurophysiological markers and predictors of these two forms of auto-aggressive behavior have been studied insufficiently. Objective. The aim of the study was to identify the differences of electroencephalographic (EEG) frequency and spatial parameters between depressive female adolescents with solely NSSI, and with combined NSSI + SA behavior in their history. Methods. The study included 45 female depressive in-patients aged 16-25 years. Baseline resting EEG spectral power, asymmetry, and coherence were analyzed in 8 narrow frequency sub-bands. Results. In the NSSI + SA subgroup (n = 24), the spectral power of parietal-occipital alpha-2 (9-11 Hz) was higher than in the NSSI subgroup, its focus was localized in the right hemisphere, and alpha-3 (11-13 Hz) spectral power was higher than alpha-1 (8-9 Hz). In the NSSI subgroup (n = 21) alpha-1 spectral power was higher than alpha-3, and foci of alpha-2 and alpha-3 were localized in the left hemisphere. EEG coherence was also higher in the NSSI + SA subgroup than in the NSSI subgroup, especially in frontal-central-parietal regions. Conclusions. The spatial distribution of the EEG frequency components in the NSSI + SA subgroup reflects the greater activation of the left hemisphere that is more typical for the EEG of individuals with an increased risk for suicide. In the NSSI subgroup, the right hemisphere is relatively more activated, and EEG coherence is lower, which is more typical for EEG in depressive disorders. The results obtained suggested the use of EEG to clarify the degree of suicidal risk in depressive female adolescents with NSSI.

Idiopathic generalized epilepsies (IGE) are characterized by generalized interictal epileptiform discharges (IEDs) on a normal background electroencephalography (EEG). However, the yield of IEDs can be low. Approximately 20% of patients with IGE fail to achieve seizure control with antiepileptic drug (AED) treatment. Currently, there are no reliable prognostic markers for early identification of drug-resistant epilepsy (DRE). We examined spectral power of the interictal EEG in patients with IGE and healthy controls, to identify potential diagnostic and prognostic biomarkers of IGE. A 64-channel EEG was recorded under standard conditions in patients with well-controlled IGE (WC-IGE, n = 19), drug-resistant IGE (DR-IGE, n = 18), and age-matched controls (n = 20). After preprocessing, fast Fourier transform was performed to obtain 1D frequency spectra for each EEG channel. The 1D spectra (averaged over channels) and 2D topographic maps (averaged over canonical frequency bands) were computed for each participant. Power spectra in the 3 cohorts were compared using one-way analysis of variance (ANOVA), and power spectra images were compared using T-contrast tests. A post hoc analysis compared peak alpha power between the groups. Compared with controls, participants with IGE had higher interictal EEG spectral power in the delta band in the midline central region, in the theta band in the midline, in the beta band over the left hemisphere, and in the gamma band over right hemisphere and left central regions. There were no differences in spectral power between cohorts with WC-IGE and DR-IGE. Peak alpha power was lower in WC-IGE and DR-IGE than controls. Electroencephalography spectral power analysis could form part of a clinically useful diagnostic biomarker for IGE; however, it did not correlate with response to AED in this study. • A 64 channel EEG was recorded 19 patients with well controlled IGE, 18 with drug resistant EEG and 20 control subjects. • Spectral power of interictal EEG was compared between the 3 groups • Compared to controls, patients with IGE had higher interictal EEG spectral power in the delta, theta, beta and gamma bands • There were no differences in spectral power between the well controlled and drug resistant IGE cohorts • EEG spectral power analysis could be useful in the diagnosis of IGE, but did not correlate with response to AED in this study [ABSTRACT FROM AUTHOR]

The study aimed to reveal task-related differences in story creation with and without the mental effort of overcoming self-induced stereotypes. Eighteen right-handed subjects (19.3 ± 1.1 years old) created stories. The subjects reported the formation of story plot stereotypes (as we call them: self-induced) during self-regulated creative production, which had to be overcome with the instruction to continue the story. Creative task fulfillment (without formed stereotypes—first stage of creation) was characterized by a decrease in the wave percentages of 9–10 Hz, 10–11 Hz and 11–12 Hz frequencies and EEG desynchronization (decreases in EEG spectral power) in the theta (4–8 Hz), alpha1 (8–10 Hz) and alpha2 (10–13 Hz) frequency bands in comparison with the REST (random episodic silent thought) state. The effortful creation task (with overcoming of self-induced stereotypes-second stage of creation) was characterized by increases in waves with frequencies of 9–10 Hz, 10–11 Hz, 11–12 Hz in temporal, occipital areas and pronounced EEG synchronization in alpha1,2 frequency bands in comparison with the free creation condition. It was also found, that the participants with the higher originality scores in psychological tests demonstrated increased percentage of high frequencies (11–12 Hz in comparison with those who had lower originality scores. Obtained results support the role of alpha and theta frequency bands dynamics in creative cognition. [ABSTRACT FROM AUTHOR]

The study aimed to reveal task-related differences in story creation with and without the mental effort of overcoming self-induced stereotypes. Eighteen right-handed subjects (19.3 ± 1.1 years old) created stories. The subjects reported the formation of story plot stereotypes (as we call them: self-induced) during self-regulated creative production, which had to be overcome with the instruction to continue the story. Creative task fulfillment (without formed stereotypes-first stage of creation) was characterized by a decrease in the wave percentages of 9-10 Hz, 10-11 Hz and 11-12 Hz frequencies and EEG desynchronization (decreases in EEG spectral power) in the theta (4-8 Hz), alpha1 (8-10 Hz) and alpha2 (10-13 Hz) frequency bands in comparison with the REST (random episodic silent thought) state. The effortful creation task (with overcoming of self-induced stereotypes-second stage of creation) was characterized by increases in waves with frequencies of 9-10 Hz, 10-11 Hz, 11-12 Hz in temporal, occipital areas and pronounced EEG synchronization in alpha1,2 frequency bands in comparison with the free creation condition. It was also found, that the participants with the higher originality scores in psychological tests demonstrated increased percentage of high frequencies (11-12 Hz in comparison with those who had lower originality scores. Obtained results support the role of alpha and theta frequency bands dynamics in creative cognition.

Study Objectives: Sleep disordered breathing (SDB) in children has significant effects on daytime functioning and cardiovascular control; attributed to sleep fragmentation and repetitive hypoxia. Associations between electroencephalograph (EEG) spectral power, autonomic cardiovascular control and cerebral oxygenation have been identified in adults with SDB. To date, there have been no studies in children. We aimed to assess associations between EEG spectral power and heart rate variability as a measure of autonomic control, with cerebral oxygenation in children with SDB., Methods: One hundred sixteen children (3-12 years) with SDB and 42 controls underwent overnight polysomnography including measurement of cerebral oxygenation. Power spectral analysis of the EEG derived from C4-M1 and F4-M1, quantified delta, theta, alpha, and beta waveforms during sleep. Multiple regression tested whether age, SDB severity, heart rate (HR), HR variability (HRV), and cerebral oxygenation were determinants of EEG spectral power., Results: There were no differences in EEG spectral power derived from either central or frontal regions for any frequency between children with different severities of SDB so these were combined. Age, HR, and HRV low frequency power were significant determinants of EEG spectral power depending on brain region and sleep stage., Conclusion: The significant findings of this study were that age and autonomic control, rather than cerebral oxygenation and SDB severity, were predictive of EEG spectral power in children. Further research is needed to elucidate how the physiology that underlies the relationship between autonomic control and EEG impacts on the cardiovascular sequelae in children with SDB., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Study Objectives: The CACNA1C gene encodes the alpha 1C (α1C) subunit of the Cav1.2 voltage-dependent L-type calcium channel (LTCC). Some of the other voltage-dependent calcium channels, e.g., P-/Q-type, Cav2.1; N-type, Cav2.2; E-/R-type, Cav2.3; and T-type, Cav3.3 have been implicated in sleep modulation. However, the contribution of LTCCs to sleep remains largely unknown. Based on recent genome-wide association studies, CACNA1C emerged as one of potential candidate genes associated with both sleep and psychiatric disorders. Indeed, most patients with mental illnesses have sleep problems and vice versa., Design: To investigate an impact of Cav1.2 on sleep-wake behavior and electroencephalogram (EEG) activity, polysomnography was performed in heterozygous Cacna1c (HET) knockout mice and their wild-type (WT) littermates under baseline and challenging conditions (acute sleep deprivation and restraint stress)., Measurements and Results: HET mice displayed significantly lower EEG spectral power than WT mice across high frequency ranges (beta to gamma) during wake and rapid eye movement (REM) sleep. Although HET mice spent slightly more time asleep in the dark period, daily amounts of sleep did not differ between the two genotypes. However, recovery sleep after exposure to both types of challenging stress conditions differed markedly; HET mice exhibited reduced REM sleep recovery responses compared to WT mice., Conclusions: These results suggest the involvement of Cacna1c (Cav1.2) in fast electroencephalogram oscillations and REM sleep regulatory processes. Lower spectral gamma activity, slightly increased sleep demands, and altered REM sleep responses found in heterozygous Cacna1c knockout mice may rather resemble a sleep phenotype observed in schizophrenia patients., (© 2015 Associated Professional Sleep Societies, LLC.)