scholarly journals Topography and asymmetry of visual EEG reactivity in healthy school-age children

2002 ◽  
Vol 130 (1-2) ◽  
pp. 13-18
Author(s):  
Dusan Ristanovic ◽  
Zarko Martinovic ◽  
Vesna Jovanovic-Cupic
Keyword(s):  
Power Spectra ◽  
Asymmetry Index ◽  
School Age Children ◽  
Total Power ◽  
School Age ◽  
Alpha Band ◽  
Theta Band ◽  
Eeg Power Spectra ◽  
Eyes Closed ◽  
Eyes Open

In order to quantify the visual reactivity of EEC to opening the eyes, the topography of EEG power spectra in a sample of 72 healthy subjects aged from 7-15 years, was studied. The EEGs were recorder at 14 scalp sites under eyes closed (ECL) and eyes open (EOP). It has been established that the absolute powers in total and in alpha band were significant- ly higher in all derivations under ECL as compared with EOP condition. Except for the frontal derivations, absolute power in theta band under ECL condition was significantly higher than that under EOP condition. Changes in delta and beta powers were seldom significant. In beta 2 band no EEG blocking was noticed in anterior area. Opening the eyes significantly influenced the values of asymmetry index in alpha band and total power. In all frequency bands and under both conditions, the differences of powers between the hemi spheres were found mainly in the prefrontal and laterofrontal areas. The results showed that the visual blocking of EEG was mostly due to a higher degree of EEG desynchronization after opening the eyes.

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 Hypoarousal non-stationary ADHD biomarker based on echo-state networks

2018 ◽  
Author(s):  
D. Ibanez-Soria ◽  
A. Soria-Frisch ◽  
J. Garcia-Ojalvo ◽  
Jacobo Picardo ◽  
Gloria García-Banda ◽  
...  
Keyword(s):  
Neurodevelopmental Disorder ◽  
High Rate ◽  
Theta Band ◽  
Hyperactivity Disorder ◽  
Eyes Closed ◽  
Echo State Networks ◽  
High Prevalence ◽  
Eyes Open ◽  
Very High ◽  
Better Than

ABSTRACTAttention-Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity and impulsivity. It is one of the most commonly diagnosed neurodevelopmental and psychiatric disorders of childhood and therefore presents a very high prevalence rate. However the high rate of ADHD misdiagnosis makes the discovery of neurophysiological ADHD biomarkers an important clinical challenge. This study proposes a novel non-stationary ADHD biomarker based on Echo State Networks to quantify EEG dynamical changes between low attention/arousal states (resting with eyes closed, or EC) and normal attention/arousal states (resting with eyes open, or EO). Traditionally, EEG biomarkers have revealed an increase in stationary power in the theta band along with a decrease in beta, with these frequencies largely accepted to be altered in the ADHD population. We successfully verify the hypothesis that measured differences between these two conditions are altered in the ADHD population. Statistically significant differences between a group of ADHD subjects and an aged-matched control population were obtained in theta and beta rhythms. Our network discriminates between EO/EC EEG regimes in the ADHDs better than in controls, suggesting that differences in EEG patterns between low and normal arousal/attention states are larger in the ADHD population.

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.

Eeg Spectral Analysis in Schizophrenia

1980 ◽  
Vol 136 (5) ◽  
pp. 445-455 ◽  
Author(s):  
G. W. Fenton ◽  
P. B. C. Fenwick ◽  
J. Dollimore ◽  
T. L. Dunn ◽  
S. R. Hirsch
Keyword(s):  
Power Spectra ◽  
Alpha Power ◽  
Eeg Spectral Analysis ◽  
Eyes Closed ◽  
Beta Power ◽  
Eyes Open ◽  
Schizophrenic Patients ◽  
Patient Groups ◽  
Schizophrenic Group ◽  
Normal Controls

SummaryFour channels of EEG (T4-T6, P4-02, T3-T5, P3-01) were recorded from several groups of control subjects and schizophrenia patients on analogue tape. They were later digitized and analysed by computer; power spectra were computed for 30 second epochs of EEG per channel; eyes closed, eyes open. No difference between normal controls and neurotic in-patients was apparent. An acute schizophrenic group had less alpha power, this change being confined largely to the temporal areas. A chronic outpatient sample showed less alpha and beta power, while chronic long-stay schizophrenic patients had an excess of delta power. The changes in both chronic patient groups were diffuse rather than local.

scholarly journals Evidence that alpha blocking is due to increases in system-level oscillatory damping not neuronal population desynchronisation

2019 ◽  
Author(s):  
David T. J. Liley ◽  
Suresh D. Muthukumarswamy
Keyword(s):  
Moving Average ◽  
Nmda Antagonist ◽  
Neuronal Population ◽  
System Level ◽  
Oscillatory Activity ◽  
Alpha Band ◽  
Eyes Closed ◽  
Alpha Blocking ◽  
Time Series Modelling ◽  
Eyes Open

AbstractThe attenuation of the alpha rhythm following eyes-opening (alpha blocking) is among the most robust features of the human electroencephalogram with the prevailing view being that it is caused by changes in neuronal population synchrony. To further study the basis for this phenomenon we use theoretically motivated fixed-order Auto-Regressive Moving-Average (ARMA) time series modelling to study the oscillatory dynamics of spontaneous alpha-band electroencephalographic activity in eyes-open and eyes-closed conditions and its modulation by the NMDA antagonist ketamine. We find that the reduction in alpha-band power between eyes-closed and eyes-open states is explicable in terms of an increase in the damping of stochastically perturbed alpha-band relaxation oscillatory activity. These changes in damping are putatively modified by the antagonism of NMDA-mediated glutamatergic neurotransmission but are not directly driven by changes in input to cortex nor by reductions in the phase synchronisation of populations of near identical oscillators. These results not only provide a direct challenge to the dominant view of the role that thalamus and neuronal population de-/synchronisation have in the genesis and modulation of alpha electro-/magnetoencephalographic activity but also suggest potentially important physiological determinants underlying its dynamical control and regulation.

scholarly journals Associations between EEG functional brain connectivity and a cognitive reserve proxy in healthy older adults

2019 ◽  
Author(s):  
Bahar Moezzi ◽  
Louise M. Lavrencic ◽  
Mitchell R. Goldsworthy ◽  
Scott Coussens ◽  
Hannah A.D. Keage
Keyword(s):  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Cognitive Reserve ◽  
Medium Effect ◽  
Theta Band ◽  
Healthy Older Adults ◽  
Eyes Closed ◽  
Medium Effect Size ◽  
Eyes Open ◽  
The Right

AbstractCognitive reserve is a concept that explains individual differences in vulnerability to cognitive impairment due to age and dementia-related brain changes. Mechanisms underlying the cognitive reserve effect are poorly understood. We investigated associations between a comprehensive cognitive reserve proxy (Lifetime Experiences Questionnaire/LEQ) and functional connectivity of the prefrontal cortex across the whole scalp, covarying for the level of current cognitive functioning (Addenbrookes Cognitive Examination Revised/ACE-R), using multiblock parallel and orthogonalized partial least squares regression. EEG data were collected from 34 healthy older adults (63 to 83 years) in eyes-open and eyes-closed resting-states, and during 0-back and 1-back tasks. Functional connectivity was estimated using imaginary coherence in the theta and alpha frequency bands, as these bands have been heavily implicated in cognitive ageing, attention and executive function. We found three clusters of electrodes where the absolute values of the regression coefficient were above threshold when covarying for ACE-R: (1) a cluster approximating the right frontocentral region during the eyes-open condition in the theta band with seed electrodes approximating the left prefrontal cortex with positive associations of medium effect size; (2) a cluster approximating the right parietotemporal region during the 0-back task in the theta band with seed electrodes approximating the right prefrontal cortex with negative associations of medium to large effect sizes; and (3) a cluster approximating the occipitoparietal region in the eyes-closed condition in the alpha band with seed electrodes approximating the left prefrontal cortex with negative associations of medium effect size. These relationships between a cognitive reserve proxy and functional connectivity, within key networks and frequency bands associated with attention and executive function, may reflect greater neural capacity and efficiency.

scholarly journals Globally elevated excitation-inhibition ratio in children with autism spectrum disorder and below-average intelligence

2021 ◽  
Author(s):  
Viktoriya O Manyukhina ◽  
Andrey O Prokofyev ◽  
Ilia A Galuta ◽  
Dzerassa E Goiaeva ◽  
Tatiana S Obukhova ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Treatment Effectiveness ◽  
Rank Order ◽  
Power Spectra ◽  
Autism Spectrum ◽  
Beta Activity ◽  
Spectral Slope ◽  
Eyes Closed ◽  
Children With Asd ◽  
Eyes Open

BACKGROUND: An altered balance of neuronal excitation and inhibition (E-I balance) might be implicated in the co-occurrence of autism and intellectual disability, but this hypothesis has never been tested. E-I balance changes can be estimated from the spectral slope of the aperiodic 1/f neural activity. Herein, we used magnetoencephalography (MEG) to test whether the 1/f slope would differentiate ASD children with and without intellectual disability. METHODS: MEG was recorded at rest with eyes open/closed in 49 boys with ASD aged 6-15 years with a broad range of IQs, and in 49 age-matched typically developing (TD) boys. The cortical source activity was estimated using the LCMV beamformer approach. We then extracted the 1/f slope by fitting a linear function in to the log-log-scale power spectra in the high-frequency range. RESULTS: The grand averaged 1/f slope was steeper in the eyes closed than in the eyes open condition, but had high rank-order stability between them. In line with the previous research, the slope flattened with age. Children with ASD and below-average (<85) IQ had flatter slopes than either TD or ASD children with average IQ. These group differences could not be explained by differences in signal-to-noise ratio or periodic (alpha and beta) activity. CONCLUSIONS: The atypically flattened spectral slope of aperiodic activity in children with ASD and below-average IQ suggests a shift of the global E-I balance toward hyper-excitation. The spectral slope can provide an accessible non-invasive biomarker of the E-I ratio for translational research and making objective judgments about treatment effectiveness.

A Contribution by Multidimensional Methods to Choosing Descriptive Data for EEG by Spectral Analysis

1976 ◽  
Vol 15 (04) ◽  
pp. 229-236 ◽  
Author(s):  
M. Chavance ◽  
Dominique Samson-Dollfus
Keyword(s):  
Spectral Analysis ◽  
Power Spectra ◽  
Principal Component ◽  
Partial Reduction ◽  
Descriptive Data ◽  
Normal Children ◽  
Simple Arithmetic ◽  
Eyes Closed ◽  
Eyes Open ◽  
Multidimensional Methods

One of the main difficulties in automatic analysis of EEG tracings is the reduction of data; spectral analysis allows only a partial reduction. Principal component analysis is used to determine amongst a group of quantitative variables those which best describe a given sample of power spectra. The tracings come from normal children (10 to 12 years of age) recorded on four leads (fronto-central right and left, centro-occipital right and left) in five experimental situations (resting with eyes closed, during five minutes of hyperventilation, resting with eyes open, and during simple arithmetic and vocabulary tests, eyes closed). It is shown that four variables are enough to describe the spectra.

scholarly journals Alpha blocking and 1/fβ spectral scaling in resting EEG can be accounted for by a sum of damped alpha band oscillatory processes

2021 ◽  
Author(s):  
Rick Evertz ◽  
Damien G. Hicks ◽  
David T. J. Liley
Keyword(s):  
Resting State ◽  
Power Spectra ◽  
Alpha Band ◽  
Relaxation Rates ◽  
Physiological Basis ◽  
Eeg Power Spectra ◽  
Alpha Blocking ◽  
Eeg Power ◽  
Band Activity ◽  
Oscillatory Processes

The dynamical and physiological basis of alpha band activity and 1/fβ noise in the EEG are the subject of continued speculation. Here we conjecture, on the basis of empirical data analysis, that both of these features may be economically accounted for through a single process if the resting EEG is conceived of being the sum of multiple stochastically perturbed alpha band damped linear oscillators with a distribution of dampings (relaxation rates). The modulation of alpha-band and 1/fβ noise activity by changes in damping is explored in eyes closed (EC) and eyes open (EO) resting state EEG. We aim to estimate the distribution of dampings by solving an inverse problem applied to EEG power spectra. The characteristics of the damping distribution are examined across subjects, sensors and recording condition (EC/EO). We find that there are robust changes in the damping distribution between EC and EO recording conditions across participants. The estimated damping distributions are found to be predominantly bimodal, with the number and position of the modes related to the sharpness of the alpha resonance and the scaling (β) of the power spectrum (1/fβ). The results suggest that there exists an intimate relationship between resting state alpha activity and 1/fβ noise with changes in both governed by changes to the damping of the underlying alpha oscillatory processes. In particular, alpha-blocking is observed to be the result of the most weakly damped distribution mode becoming more heavily damped. The results suggest a novel way of characterizing resting EEG power spectra and provides new insight into the central role that damped alpha-band activity may play in characterising the spatio-temporal features of resting state EEG.

Sign in / Sign up

Export Citation Format

Share Document