scholarly journals Radiofrequency signal affects alpha band in resting electroencephalogram

2015 ◽  
Vol 113 (7) ◽  
pp. 2753-2759 ◽  
Author(s):  
Rania Ghosn ◽  
Lydia Yahia-Cherif ◽  
Laurent Hugueville ◽  
Antoine Ducorps ◽  
Jean-Didier Lemaréchal ◽  
...  
Keyword(s):  
Salivary Cortisol ◽  
Spectral Power ◽  
Electrode Impedance ◽  
Alpha Band ◽  
Double Blind ◽  
Eyes Closed ◽  
Before And After ◽  
Sham Exposure ◽  
Eyes Open ◽  
Young Subjects

The aim of the present work was to investigate the effects of the radiofrequency (RF) electromagnetic fields (EMFs) on human resting EEG with a control of some parameters that are known to affect alpha band, such as electrode impedance, salivary cortisol, and caffeine. Eyes-open and eyes-closed resting EEG data were recorded in 26 healthy young subjects under two conditions: sham exposure and real exposure in double-blind, counterbalanced, crossover design. Spectral power of EEG rhythms was calculated for the alpha band (8–12 Hz). Saliva samples were collected before and after the study. Salivary cortisol and caffeine were assessed by ELISA and HPLC, respectively. The electrode impedance was recorded at the beginning of each run. Compared with the sham session, the exposure session showed a statistically significant ( P < 0.0001) decrease of the alpha band spectral power during closed-eyes condition. This effect persisted in the postexposure session ( P < 0.0001). No significant changes were detected in electrode impedance, salivary cortisol, and caffeine in the sham session compared with the exposure one. These results suggest that GSM-EMFs of a mobile phone affect the alpha band within spectral power of resting human EEG.

scholarly journals Modulation of magnetoencephalography alpha band activity by radiofrequency electromagnetic field depicted in sensor and source space

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jasmina Wallace ◽  
Lydia Yahia-Cherif ◽  
Christophe Gitton ◽  
Laurent Hugueville ◽  
Jean-Didier Lemaréchal ◽  
...  
Keyword(s):  
High Performance ◽  
Spectral Power ◽  
Heart Rate Variability Analysis ◽  
Alpha Band ◽  
Control Parameters ◽  
Double Blind ◽  
Eyes Closed ◽  
Significant Difference ◽  
Cortical Regions ◽  
Band Activity

AbstractSeveral studies reported changes in spontaneous electroencephalogram alpha band activity related to radiofrequency electromagnetic fields, but findings showed both an increase and a decrease of its spectral power or no effect. Here, we studied the alpha band modulation after 900 MHz mobile phone radiofrequency exposure and localized cortical regions involved in these changes, via a magnetoencephalography (MEG) protocol with healthy volunteers in a double-blind, randomized, counterbalanced crossover design. MEG was recorded during eyes open and eyes closed resting-state before and after radiofrequency exposure. Potential confounding factors, known to affect alpha band activity, were assessed as control parameters to limit bias. Entire alpha band, lower and upper alpha sub-bands MEG power spectral densities were estimated in sensor and source space. Biochemistry assays for salivary biomarkers of stress (cortisol, chromogranin-A, alpha amylase), heart rate variability analysis and high-performance liquid chromatography for salivary caffeine concentration were realized. Results in sensor and source space showed a significant modulation of MEG alpha band activity after the radiofrequency exposure, with different involved cortical regions in relation to the eyes condition, probably because of different attention level with open or closed eyes. None of the control parameters reported a statistically significant difference between experimental sessions.

scholarly journals Gender Differences in Postural Stability among 13-Year-Old Alpine Skiers

2020 ◽  
Vol 17 (11) ◽  
pp. 3859 ◽  
Author(s):  
Agnieszka D. Jastrzębska
Keyword(s):  
Gender Differences ◽  
Postural Balance ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Body Sway ◽  
Foot Pressure ◽  
Eyes Closed ◽  
Before And After ◽  
Eyes Open ◽  
Alpine Skiers

This experiment examined changes in body sway after Wingate test (WAnT) in 19 adolescents practicing alpine skiing, subjected to the same type of training load for 4–5 years (10 girls and nine boys). The postural examinations were performed with eyes open (EO), eyes closed (EC), and sway reverenced vision (SRV) in the medial-lateral (ML) and anterior-posterior (AP) planes. The displacement of center of foot pressure (CoP), range of sway (RS), mean sway velocity (MV), way length, and surface area were measured in bipedal upright stance before and after the WAnT to assess the influence of fatigue on postural balance. There were no significant differences in WAnT parameters between girls and boys. Relative peak power (RPP), relative total work (RWtot) were (girls vs. boys) 8.89 ± 0.70 vs. 9.57 ± 1.22 W/kg, p < 0.05 and 227.91 ± 14.98 vs. 243.22 ± 30.24 W/kg, p < 0.05 respectively. The fatigue index (FI) was also on similar level in both genders; however, blood lactate concentration (BLa) was significantly higher in boys (10.35 ± 1.16 mM) than in girls (8.67 ± 1.35 mM) p = 0.007. In the EO examination, statistically significant differences between resting and fatigue conditions in the whole group and after the division into girls and boys were found. In fatigue conditions, significant gender differences were noted for measurements in the ML plane (sway path and RS) and RS in the AP plane. Comparison of the three conditions shows differences between EO vs. EC and SRV in AP plane measured parameters, and for RS in ML plane in rest condition in girls. The strong correlations between FI and CoP parameters mainly in ML plane in the whole group for all examination conditions were noted. By genders, mainly RS in ML plane strongly correlates with FI (r > 0.7). No correlation was found between BLa and CoP parameters (p > 0.06). The presented results indicate that subjecting adolescents of both genders to the same training may reduce gender differences in the postural balance ability at rest but not in fatigue conditions and that girls are significantly superior in postural balance in the ML plane than boys. It was also shown that too little or too much information may be destructive to postural balance in young adolescents.

scholarly journals EEG Data Quality: Determinants and Impact in a Multicenter Study of Children, Adolescents, and Adults with Attention-Deficit/Hyperactivity Disorder (ADHD)

2021 ◽  
Vol 11 (2) ◽  
pp. 214
Author(s):  
Anna Kaiser ◽  
Pascal-M. Aggensteiner ◽  
Martin Holtmann ◽  
Andreas Fallgatter ◽  
Marcel Romanos ◽  
...  
Keyword(s):  
Data Quality ◽  
Large Scale ◽  
Linear Models ◽  
Spectral Power ◽  
Control Group ◽  
Continuous Performance Task ◽  
Related Data ◽  
Eyes Closed ◽  
Eeg Data ◽  
Eyes Open

Electroencephalography (EEG) represents a widely established method for assessing altered and typically developing brain function. However, systematic studies on EEG data quality, its correlates, and consequences are scarce. To address this research gap, the current study focused on the percentage of artifact-free segments after standard EEG pre-processing as a data quality index. We analyzed participant-related and methodological influences, and validity by replicating landmark EEG effects. Further, effects of data quality on spectral power analyses beyond participant-related characteristics were explored. EEG data from a multicenter ADHD-cohort (age range 6 to 45 years), and a non-ADHD school-age control group were analyzed (ntotal = 305). Resting-state data during eyes open, and eyes closed conditions, and task-related data during a cued Continuous Performance Task (CPT) were collected. After pre-processing, general linear models, and stepwise regression models were fitted to the data. We found that EEG data quality was strongly related to demographic characteristics, but not to methodological factors. We were able to replicate maturational, task, and ADHD effects reported in the EEG literature, establishing a link with EEG-landmark effects. Furthermore, we showed that poor data quality significantly increases spectral power beyond effects of maturation and symptom severity. Taken together, the current results indicate that with a careful design and systematic quality control, informative large-scale multicenter trials characterizing neurophysiological mechanisms in neurodevelopmental disorders across the lifespan are feasible. Nevertheless, results are restricted to the limitations reported. Future work will clarify predictive value.

Reliability of Force-Platform Measures of Postural Sway and Expertise-Related Differences

2011 ◽  
Vol 20 (4) ◽  
pp. 442-456 ◽  
Author(s):  
Zohreh Meshkati ◽  
Mehdi Namazizadeh ◽  
Mahyar Salavati ◽  
Masood Mazaheri
Keyword(s):  
Outcome Measures ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Intraclass Correlation ◽  
Specific Property ◽  
Force Platform ◽  
Quiet Standing ◽  
Eyes Closed ◽  
Before And After ◽  
Eyes Open

Context:Although reliability is a population-specific property, few studies have investigated the measurement error associated with force-platform parameters in athletic populations.Objective:To investigate the skill-related differences between athletes and nonathletes in reliability of center-of-pressure (COP) summary measures under eyes-open (EO) and eyes-closed (EC) conditions.Design:Test–retest reliability study.Setting:COP was recorded during double-leg quiet standing on a Kistler force platform before and after a fatiguing treadmill exercise, with EO and EC.Participants:31 male participants including 15 athletes practiced in karate and 16 nonathletes.Main Outcome Measures:Standard deviation (SD) of amplitude, phase-plane portrait, SD of velocity, mean total velocity, and area were calculated from 30-s COP data. Intraclass correlation coefficient (ICC), standard error of measurement, and coefficient of variation (CV) were used as estimates of reliability and precision.Results:Higher ICCs were found for COP measures in the athlete (compared with the nonathlete) group, postfatigued (compared with prefatigued) condition, and EC (compared with EO) tests. CVs smaller than 15% were obtained for most of the COP measures. SD of velocity in the anteroposterior direction showed the highest reliability in most conditions.Conclusions:Tests with EC and to a lesser extent tests performed in the athlete group and in the postfatigued condition showed better reliability.

scholarly journals The impact of modern jazz dance on the electrical brain activity

2018 ◽  
Author(s):  
Johanna Wind ◽  
Wolfgang Schöllhorn
Keyword(s):  
Brain Activity ◽  
Brain Activation ◽  
Brain Areas ◽  
Eyes Closed ◽  
Gamma Frequency ◽  
Electrical Brain Activity ◽  
Modern Jazz ◽  
Before And After ◽  
Eyes Open ◽  
The Impact

AbstractDance as one of the earliest cultural assets of mankind is practised in different cultures, mostly for wellbeing or for treating psycho-physiological disorders like Parkinson, depression, autism. However, the underlying neurophysiological mechanisms are still unclear and only few studies address the effects of particular dance styles. For a first impression, we were interested in the effects of modern jazz dance (MJD) on the brain activation that would contribute to the understanding of these mechanisms. 11 female subjects rehearsed a MJD choreography for three weeks (1h per week) and passed electroencephalographic (EEG) measurements in a crossover-design thereafter. The objectives were to establish the differences between dancing physically and participating just mentally with or without music. Therefore, each subject realized the four following test conditions: dancing physically to and without music, dancing mentally to and without music. Each of the conditions were performed for 15 minutes. Before and after each condition, the EEG activities were recorded under resting conditions (2 min. eyes-open, 2 min. eyes-closed) followed by a subsequent wash-out phase of 10 minutes.The results of the study revealed no time effects for the mental dancing conditions, either to or without music. An increased electrical brain activation was followed by the physical dancing conditions with and without music for the theta, alpha-1, alpha-2, beta and gamma frequency band across the entire scalp. Especially the higher frequencies (alpha-2, beta, gamma) showed increased brain activation across all brain areas. Higher brain activities for the physical dancing conditions were identified in comparison to the mental dancing condition. No statistically significant differences could be found as to dancing to or without music. Our findings demonstrate evidence for the immediate influence of modern jazz dance and its sweeping effects on all brain areas for all measured frequency bands, when dancing physically. In comparison, dancing just mentally does not result in similar effects.

Effects of lifetime ethanol consumption on postural control: A computerized dynamic posturography study

2002 ◽  
Vol 12 (1) ◽  
pp. 53-64
Author(s):  
Saad Ahmad ◽  
John W. Rohrbaugh ◽  
Andrey P. Anokhin ◽  
Erik J. Sirevaag ◽  
Joel A. Goebel
Keyword(s):  
Alcohol Consumption ◽  
Postural Control ◽  
Spectral Power ◽  
Support Surface ◽  
Dependent Manner ◽  
Dynamic Posturography ◽  
Eyes Closed ◽  
Sensory Organization ◽  
Computerized Dynamic Posturography ◽  
Eyes Open

The relationship between lifetime alcohol consumption and postural control was investigated in 35 subjects with no clinically-detectable neurologic abnormalities, using computerized dynamic posturography (CDP) procedures. The estimated total number of lifetime alcoholic drinks was positively correlated with anteroposterior sway spectral power within the 2–4 Hz and 4–6 Hz frequency bands, in three Sensory Organization Test (SOT) conditions: eyes closed with stable support surface (SOT 2), eyes open with sway-referenced support (SOT 4), and eyes closed with sway-referenced support (SOT 5). All correlations remained significant after controlling for subject age, and were increased after excluding nine drug-abusing subjects. In contrast to the strong findings for frequency-based measures, no correlation was observed using conventional amplitude-based sway measures. These results suggest that 1) alcohol consumption compromises postural control in an exposure-dependent manner, and 2) sway frequency analysis reveals pathological processes not manifested in conventional CDP measures of sway amplitude.

scholarly journals Effect of a “T-Band” Kick Training Protocol on Postural Sway

1998 ◽  
Vol 7 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Andrew G. Baker ◽  
William G. Webright ◽  
David H. Perrin
Keyword(s):  
Postural Sway ◽  
Stability Index ◽  
Control Group ◽  
Eyes Closed ◽  
Before And After ◽  
Proprioceptive Training ◽  
Eyes Open ◽  
Potential Benefits ◽  
Experimental Group ◽  
Training Protocol

The purpose of this study was to examine the effects of a resistive tubing kick training protocol on postural sway in uninjured collegiate wrestlers. An experimental group (n= 10) performed a progressive resistive tubing kick training protocol three times per week for 6 weeks. A control group (n= 9) performed no resistive tubing training during the 6 weeks. Postural sway (stability index) was assessed before and after the 6-week training period. ANOVAs demonstrated no significant interactions, although significant main effects were found for group and eye condition. The experimental group demonstrated less postural sway than the control group regardless of training, and postural sway was greater with the eyes closed than with the eyes open. Resistive tubing kick training does not significantly improve postural sway in healthy collegiate wrestlers. Further research should examine the potential benefits of proprioceptive training using a greater intensity of training and/or using subjects who have a greater potential for improvement.

scholarly journals The Difference of Brain Functional Connectivity between Eyes-Closed and Eyes-Open Using Graph Theoretical Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Bo Tan ◽  
Xianxian Kong ◽  
Ping Yang ◽  
Zhenlan Jin ◽  
Ling Li
Keyword(s):  
Functional Connectivity ◽  
Alpha Band ◽  
Topological Parameters ◽  
Eyes Closed ◽  
Synchronization Likelihood ◽  
Functional Brain Networks ◽  
Eyes Open ◽  
The Difference ◽  
Path Lengths ◽  
Brain Functional Connectivity

To study the differences in functional brain networks between eyes-closed (EC) and eyes-open (EO) at resting state, electroencephalographic (EEG) activity was recorded in 21 normal adults during EC and EO states. The synchronization likelihood (SL) was applied to measure correlations between all pairwise EEG channels, and then the SL matrices were converted to graphs by thresholding. Graphs were measured by topological parameters in theta (4–7 Hz), alpha (8–13 Hz), and beta (14–30 Hz) bands. By changing from EC to EO states, mean cluster coefficients decreased in both theta and alpha bands, but mean shortest path lengths became shorter only in the alpha band. In addition, local efficiencies decreased in both theta and alpha bands, while global efficiencies in the alpha band increased inversely. Opening the eyes decreased both nodes and connections in frontal area in the theta band, and also decreased those in bilateral posterior areas in the alpha band. These results suggested that a combination of the SL and graph theory methods may be a useful tool for distinguishing states of EC and EO. The differences in functional connectivity between EC and EO states may reflect the difference of information communication in human brain.

scholarly journals The importance of computerized dynamic posturography in vestibular rehabilitation of patients with unilateral peripheral vestibular deficiency

2015 ◽  
Vol 5 (19) ◽  
pp. 173-178
Author(s):  
Anamaria Andreia Ulmeanu ◽  
Andreea Didilescu ◽  
Raluca Enache ◽  
Gabriela Musat ◽  
Codrut Sarafoleanu
Keyword(s):  
Maximum Amplitude ◽  
Vestibular Rehabilitation ◽  
Deficiency Syndrome ◽  
Rehabilitation Program ◽  
Time Interval ◽  
Dynamic Posturography ◽  
Eyes Closed ◽  
Computerized Dynamic Posturography ◽  
Before And After ◽  
Eyes Open

Abstract OBJECTIVE. To evaluate the importance of computerized dynamic posturography in vestibular rehabilitation of patients with unilateral peripheral vestibular deficiency syndrome. MATERIAL AND METHODS. The study was conducted on a group of 30 patients (33-78 years; mean age (± SD) = 55.8 ± 12.12) diagnosed with unilateral peripheral vestibular deficiency syndrome, which benefited from VR on a posturography platform. Assessment of the patients was made using the Sensory Organization Test before and after eight sessions of rehabilitation. We analyzed the results obtained with eyes open (EO) and eyes closed (EC) on static and foam platform. The following variables were evaluated: Romberg coefficient, statokinesigram (SKG), maximum amplitude of the degree of deviation in anterior/posterior and medial/lateral planes, SKG and the time interval of the game rehabilitation program. RESULTS. The statistical analysis of the data revealed a strong correlation (p<0.05) for the studied parameters, especially when the test was performed with the eyes closed on foam platform. The analysis of the Romberg coefficient did not show statistically significant results (p>0.05) and the measured values were outside the range of normality even at the end of the rehabilitation program. SKG and the time interval reference of the game showed significant improvement of the parameters (p<0.05); at the end of the rehabilitation sessions, 93.33% of the patients showed full recovery of their deficit. CONCLUSION. Computerized dynamic posturography has a particularly important role in the evaluation, monitoring and rehabilitation of the patients with peripheral vestibular deficiency.

scholarly journals Correlation between Post-Acute Electroconvulsive Therapy Alpha-Band Spectrum Power Increase and Improvement of Psychiatric Symptoms

2021 ◽  
Vol 11 (12) ◽  
pp. 1315
Author(s):  
Hideyuki Iwanaga ◽  
Takefumi Ueno ◽  
Naoya Oribe ◽  
Manabu Hashimoto ◽  
Jun Nishimura ◽  
...  
Keyword(s):  
Electroconvulsive Therapy ◽  
Rating Scale ◽  
Psychiatric Symptoms ◽  
Spectral Power ◽  
Band Spectrum ◽  
Alpha Band ◽  
Brief Psychiatric Rating Scale ◽  
Before And After ◽  
Psychiatric Rating ◽  
Psychiatric Rating Scale

The results of quantitative electroencephalography (qEEG) studies on electroconvulsive therapy (ECT) have been inconsistent, and indicators of the efficacy of ECT have not been clearly identified. In this study, we examined whether qEEG could be used as an indicator of the effect of ECT by measuring it during the course of treatment. We analyzed qEEG data before and after acute-phase ECT in 18 patients with schizophrenia, mood disorders, and other psychiatric disorders. We processed the qEEG data and compared the spectral power between the data acquired before and after ECT. The spectral power increased significantly after ECT in the delta, theta, and alpha bands. There was a strong significant correlation between the increase in the spectral power of the alpha band after acute ECT and improvement in the Brief Psychiatric Rating Scale score. Our results suggest that an increase in the alpha-band spectral power may be useful as an objective indicator of the treatment effect of acute ECT.

Sign in / Sign up

Export Citation Format

Share Document