Sample records for eeg alpha phenotypes

  1. EEG alpha phenotypes: linkage analyses and relation to alcohol dependence in an American Indian community study

    Microsoft Academic Search

    Cindy L Ehlers; Ian R Gizer; Evelyn Phillips; Kirk C Wilhelmsen

    2010-01-01

    BACKGROUND: Evidence for a high degree of heritability of EEG alpha phenotypes has been demonstrated in twin and family studies in a number of populations. However, information on linkage of this phenotype to specific chromosome locations is still limited. This study's aims were to map loci linked to EEG alpha phenotypes and to determine if there was overlap with loci

  2. HTR3B is associated with alcoholism with antisocial behavior and alpha EEG power--an intermediate phenotype for alcoholism and co-morbid behaviors.

    PubMed

    Ducci, Francesca; Enoch, Mary-Anne; Yuan, Qiaoping; Shen, Pei-Hong; White, Kenneth V; Hodgkinson, Colin; Albaugh, Bernard; Virkkunen, Matti; Goldman, David

    2009-02-01

    Alcohol use disorders (AUD) with co-morbid antisocial personality disorder (ASPD) have been associated with serotonin (5-HT) dysfunction. 5-HT3 receptors are potentiated by ethanol and appear to modulate reward. 5-HT3 receptor antagonists may be useful in the treatment of early-onset alcoholics with co-morbid ASPD. Low-voltage alpha electroencephalogram (EEG) power, a highly heritable trait, has been associated with both AUD and ASPD. A recent whole genome linkage scan in one of our samples, Plains American Indians (PI), has shown a suggestive linkage peak for alpha power at the 5-HT3R locus. We tested whether genetic variation within the HTR3A and HTR3B genes influences vulnerability to AUD with comorbid ASPD (AUD+ASPD) and moderates alpha power. Our study included three samples: 284 criminal alcoholic Finnish Caucasians and 234 controls; two independent community-ascertained samples with resting EEG recordings: a predominantly Caucasian sample of 191 individuals (Bethesda) and 306 PI. In the Finns, an intronic HTR3B SNP rs3782025 was associated with AUD+ASPD (P=.004). In the Bethesda sample, the same allele predicted lower alpha power (P=7.37e(-5)). Associations between alpha power and two other HTR3B SNPs were also observed among PI (P=.03). One haplotype in the haplotype block at the 3' region of the gene that included rs3782025 was associated with AUD+ASPD in the Finns (P=.02) and with reduced alpha power in the Bethesda population (P=.00009). Another haplotype in this block was associated with alpha power among PI (P=.03). No associations were found for HTR3A. Genetic variation within HTR3B may influence vulnerability to develop AUD with comorbid ASPD. 5-HT3R might contribute to the imbalance between excitation and inhibition that characterize the brain of alcoholics. PMID:19185213

  3. HTR3B is associated with alcoholism with antisocial behavior and alpha EEG power—an intermediate phenotype for alcoholism and co-morbid behaviors

    PubMed Central

    Ducci, Francesca; Enoch, Mary-Anne; Yuan, Qiaoping; Shen, Pei-Hong; White, Kenneth V.; Hodgkinson, Colin; Albaugh, Bernard; Virkkunen, Matti; Goldman, David

    2009-01-01

    Alcohol use disorders (AUD) with co-morbid antisocial personality disorder (ASPD) have been associated with serotonin (5-HT) dysfunction. 5-HT3 receptors are potentiated by ethanol and appear to modulate reward. 5-HT3 receptor antagonists may be useful in the treatment of early-onset alcoholics with co-morbid ASPD. Low-voltage alpha electroencephalogram (EEG) power, a highly heritable trait, has been associated with both AUD and ASPD. A recent whole genome linkage scan in one of our samples, Plains American Indians (PI), has shown a suggestive linkage peak for alpha power at the 5-HT3R locus. We tested whether genetic variation within the HTR3A and HTR3B genes influences vulnerability to AUD with comorbid ASPD (AUD + ASPD) and moderates alpha power. Our study included three samples: 284 criminal alcoholic Finnish Caucasians and 234 controls; two independent community-ascertained samples with resting EEG recordings: a predominantly Caucasian sample of 191 individuals (Bethesda) and 306 PI. In the Finns, an intronic HTR3B SNP rs3782025 was associated with AUD + ASPD (P = .004). In the Bethesda sample, the same allele predicted lower alpha power (P = 7.37e-5). Associations between alpha power and two other HTR3B SNPs were also observed among PI (P = .03). One haplotype in the haplotype block at the 3? region of the gene that included rs3782025 was associated with AUD + ASPD in the Finns (P = .02) and with reduced alpha power in the Bethesda population (P = .00009). Another haplotype in this block was associated with alpha power among PI (P = .03). No associations were found for HTR3A. Genetic variation within HTR3B may influence vulnerability to develop AUD with comorbid ASPD. 5-HT3R might contribute to the imbalance between excitation and inhibition that characterize the brain of alcoholics. PMID:19185213

  4. Relations between PET-derived measures of thalamic glucose metabolism and EEG alpha power

    E-print Network

    Wisconsin at Madison, University of

    , Madison, USA Abstract Electroencephalogram ~EEG! alpha power has been demonstrated to be inversely related, Positron emission tomography, Alpha, Thalamus Alpha electroencephalogram ~EEG! power is a commonly used

  5. Relationship of genetically transmitted alpha EEG traits to anxiety disorders and alcoholism

    SciTech Connect

    Enoch, M.A.; Rohrbaugh, W.; Harris, C.R. [Washington School of Medicine, St. Louis, MO (United States)] [and others

    1995-10-09

    We tested the hypothesis that a heritable EEG trait, the low voltage alpha (LV), is associated with psychiatric disorders. Modest to moderate evidence for genetic linkage of both panic disorder and the low voltage alpha trait to the same region of chromosome 20q has recently been reported, raising the issue of whether there is a phenotypic correlation between these traits. A total of 124 subjects including 50 unrelated index subjects and 74 relatives were studied. Alpha EEG power was measured and EEG phenotypes were impressionistically classified. Subjects were psychiatrically interviewed using the SADS-L and blind-rated by RDC criteria. Alcoholics were four times more likely to be LV (including so-called borderline low voltage alpha) than were nonalcoholic, nonanxious subjects. Alcoholics with anxiety disorder are 10 times more likely to be LV. However, alcoholics without anxiety disorder were similar to nonalcoholics in alpha power. An anxiety disorder (panic disorder, phobia, or generalized anxiety) was found in 14/17 LV subjects as compared to 34/101 of the rest of the sample (P < 0.01). Support for these observations was found in the unrelated index subjects in whom no traits would be shared by familial clustering. Lower alpha power in anxiety disorders was not state-dependent, as indicated by the Spielberger Anxiety Scale. Familial covariance of alpha power was 0.25 (P < 0.01). These findings indicate there may be a shared factor underlying the transmissible low voltage alpha EEG variant and vulnerability to anxiety disorders with associated alcoholism. This factor is apparently not rare, because LV was found in approximately 10% of unrelated index subjects and 5% of subjects free of alcoholism and anxiety disorders. 43 refs., 1 fig., 3 tabs.

  6. EEG alpha power and alpha power asymmetry in sleep and wakefulness.

    PubMed

    Benca, R M; Obermeyer, W H; Larson, C L; Yun, B; Dolski, I; Kleist, K D; Weber, S M; Davidson, R J

    1999-07-01

    Asymmetry of waking electroencephalography (EEG) alpha power in frontal regions has been correlated with waking emotional reactivity and the emotional content of dream reports. Little is known regarding alpha asymmetry during sleep. The present study was performed to compare alpha power and alpha power asymmetry in various brain regions across states of sleep and wakefulness. Waking and sleep EEG were recorded in a group of patients undergoing polysomnographic evaluation for possible sleep disorders. Alpha EEG asymmetry in frontal and temporal regions was significantly correlated in waking versus sleep, particularly during rapid eye movement (REM) sleep. These results suggest that patterns of frontal alpha asymmetry are stable across sleep and waking and may be related to emotional reactivity during dreaming. During sleep, alpha power was highest during slow-wave sleep and lowest during REM sleep. Implications of these data for understanding the functional significance of alpha power during waking and sleeping are considered. PMID:10432792

  7. EEG Alpha Rhythms and Susceptibility to Hypnosis

    Microsoft Academic Search

    Perry London; JOSEPH T. HART; MORRIS P. LEIBOVITZ

    1968-01-01

    DESPITE a rich literature of anecdotal and clinical material on the relationship of hypnosis to physiological functions, especially to events in the central nervous system, the research findings are highly equivocal. Most relevant studies have been concerned with shifts in brain wave patterns, as measured by the electroencephalogram (EEG). The studies have attempted to identify the underlying processes which accompany

  8. EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis

    Microsoft Academic Search

    Wolfgang Klimesch

    1999-01-01

    Evidence is presented that EEG oscillations in the alpha and theta band reflect cognitive and memory performance in particular. Good performance is related to two types of EEG phenomena (i) a tonic increase in alpha but a decrease in theta power, and (ii) a large phasic (event-related) decrease in alpha but increase in theta, depending on the type of memory

  9. EEG alpha phase shifts during transition from wakefulness to drowsiness.

    PubMed

    Kalauzi, Aleksandar; Vuckovic, Aleksandra; Boji?, Tijana

    2012-12-01

    Phases of alpha oscillations recorded by EEG were typically studied in the context of event or task related experiments, rarely during spontaneous alpha activity and in different brain states. During wake-to-drowsy transition they change unevenly, depending on the brain region. To explore their dynamics, we recorded ten adult healthy individuals in these two states. Alpha waves were treated as stable frequency and variable amplitude signals with one carrier frequency (CF). A method for calculating their CF phase shifts (CFPS) and CF phase potentials (CFPP) was developed and verified on surrogate signals as more accurate than phase shifts of Fourier components. Probability density estimate (PDE) of CFPS, CFPP and CF phase locking showed that frontal and fronto-temporal areas of the cortex underwent more extensive changes than posterior regions. The greatest differences were found between pairs of channels involving F7, F8, F3 and F4 (PDE of CFPS); F7, F8, T3 and T4 (CFPP); F7, F8, F3, F4, C3, C4 and T3 (decrease in CF phase locking). A topographic distribution of channels with above the average phase locking in the wake state revealed two separate regions occupying anterior and posterior brain areas (with intra regional and inter hemispheric connections). These regions merged and became mutually phase locked longitudinally in the drowsy state. Changes occurring primarily in the frontal and fronto-temporal regions correlated with an early decrease of alertness. Areas of increased phase locking might be correlated with topography of synchronous neuronal assemblies conceptualized within neural correlates of consciousness. PMID:22580156

  10. Changes in EEG alpha power during simulated driving: a demonstration

    Microsoft Academic Search

    Mark A Schier

    2000-01-01

    The aim was to assess the suitability of EEG-based techniques to recording activity during a driving simulation task. To achieve this, an inexpensive driving simulator (comprising a steering wheel, pedals and gear shift) were made to function with a personal computer running ‘Need for Speed’ simulation software. Simulators of this type are both inexpensive and relatively realistic. The EEG was

  11. Neuronal generators of posterior EEG alpha reflect individual differences in prioritizing personal spirituality

    PubMed Central

    Tenke, C. E.; Kayser, J.; Miller, L.; Warner, V.; Wickramaratne, P.; Weissman, M. M.; Bruder, G. E.

    2013-01-01

    Prominent posterior EEG alpha is associated with depression and clinical response to antidepressants. Given that religious belief was protective against depression in a longitudinal study of familial risk, we hypothesized that individuals who differed by strength of spiritual beliefs might also differ in EEG alpha. Clinical evaluations and self-reports of the importance of religion or spirituality (R/S) were obtained from 52 participants, and again at 10-y followup when EEG was measured. EEG alpha was quantified using frequency PCA of current source densities (CSD-fPCA). Participants who rated R/S as highly important at initial assessment showed greater alpha compared to those who did not. Those who rated R/S important in both sessions showed greater alpha than those who changed their ratings. EEG differences were particularly well-defined for participants with lifetime depression. Findings extend the view of alpha as a marker for affective processes, suggesting an association with the ontogenesis of spirituality. PMID:23998996

  12. Enhanced EEG alpha time-domain phase synchrony during Transcendental Meditation: Implications for cortical integration theory

    Microsoft Academic Search

    Russell Hebert; Dietrich Lehmann; Gabriel Tan; Fred Travis; Alarik Arenander

    2005-01-01

    Information transfer and integration in the brain that leads to high-level cognitive processes requires neuronal coordination. High phase synchronization (zero-lag) in fast frequencies is implicated in integrating sensory events. Alpha EEG activity, long regarded as a passive “idling” frequency, is now being implicated in this integrative function. As an example, in brain pathology decreased alpha phase synchrony is correlated with

  13. Neonatal EEG\\/Sleep State Analyses: A Complex Phenotype of Developmental Neural Plasticity

    Microsoft Academic Search

    Mark S. Scher; Kenneth A. Loparo

    2009-01-01

    Computer analyses of EEG\\/sleep states can be used as physiologic biomarkers of developmental neural plasticity. Frequency- and time-dependent signal processing strategies of cerebral and noncerebral measures can help test current theories of neuronal network maturation in terms of segregation and integration of short-distance versus long-distance neuronal connections throughout the neuroaxis. Specific phenotypic expressions of adaptive or maladaptive neuronal connectivity are

  14. Alpha and beta EEG power reflects L-dopa acute administration in parkinsonian patients

    PubMed Central

    Melgari, Jean-Marc; Curcio, Giuseppe; Mastrolilli, Francesca; Salomone, Gaetano; Trotta, Laura; Tombini, Mario; di Biase, Lazzaro; Scrascia, Federica; Fini, Rita; Fabrizio, Emma; Rossini, Paolo Maria; Vernieri, Fabrizio

    2014-01-01

    Aim: To evaluate the effect of an acute L-dopa administration on eye-closed resting state electroencephalographic (EEG) activity of cognitively preserved Parkinsonian patients. Methods: We examined 24 right-handed patients diagnosed as uncomplicated probable Parkinson’s disease (PD). Each patient underwent Unified Parkinson’s Disease Rating Scale (UPDRS)-part-III evaluation before and 60 min after an oral load of L-dopa-methyl-ester/carbidopa 250/25 mg. Resting condition eyes-closed EEG data were recorded both pre- and post L-dopa load. Absolute EEG power values were calculated at each scalp derivation for Delta, Theta, Alpha and Beta frequency bands. UPDRS scores (both global and subscale scores) and EEG data (power values of different frequency bands for each scalp derivation) were submitted to a statistical analysis to compare Pre and Post L-Dopa conditions. Finally, a correlation analysis was carried out between EEG spectral content and UPDRS scores. Results: Considering EEG power spectral analysis, no statistically significant differences arose on Delta and Theta bands after L-dopa intake. Conversely, Alpha and Beta rhythms significantly increased on centro-parietal scalp derivations, as a function of L-dopa administration. Correlation analysis indicated a significant negative correlation between Beta power increase on centro-parietal areas and UPDRS subscores (Rigidity of arms and Bradykinesia). A minor significant negative correlation was also found between Alpha band increase and resting tremor. Conclusions: Assuming that a significant change in EEG power spectrum after L-dopa intake may be related to dopaminergic mechanisms, our findings are consistent with the hypothesis that dopaminergic defective networks are implicated in cortical oscillatory abnormalities at rest in non-demented PD patients. PMID:25452725

  15. Dipole estimation of alpha EEG during alcohol ingestion in males genotypes for ALDH2.

    PubMed

    Hara, K; Terasaki, O; Okubo, Y

    2000-01-01

    Using a dipole tracing method based on the two-dipole model, the purpose of the present study was to investigate alcohol-induced changes in the alpha band of electroencephalogram (EEG) and its equivalent current dipoles (ECDs) in 12 healthy male volunteers, who were genetically typed for mitochondrial aldehyde dehydrogenase-2 (ALDH2). The alpha power and the mean interval dipolarity, which represents the goodness of fit of alpha EEG with the two-dipole model, increased at 30 min after 0.75 ml/kg of alcohol ingestion, when breath alcohol concentration showed its peak. However, the location of ECDs and distribution of alpha EEG did not change after alcohol ingestion. These findings indicate that alcohol enhances alpha EEG but does not change the location of its electrical sources. Interestingly, the time course of alcohol-induced EEG changes differed significantly according to the aversive flushing reaction after its intake. From 60 to 120 min, the non-flushing group which had homozygous ALDH2* 1 (active type) displayed significant increase not only in the alpha power but also in the interval dipolarity compared to the baseline, whereas the flushing group with heterozygous ALDH2*1/2*2 (inactive type) did not exhibit this significant increase. The difference in the time course was discussed from the viewpoint of the protective effect of ALDH2*2 allele against the risk for alcoholism. These results suggest that the dipole tracing method could provide an alternative neurophysiological marker for the risk for alcoholism. PMID:10954050

  16. A Study on EEG Alpha Wave-based Brain-Computer Interface Remote Control System

    Microsoft Academic Search

    Li Penghai; Wan Baikun

    2007-01-01

    This study designs a electroencephalography or EEG alpha wave-based brain-computer interface (BCI) TV remote control system comprising BCI interface control panel, signal acquisition system, signal processing platform and interface control circuit. The specific constitution, function, mechanism and key techniques of each part are explained in detail. To test effect of the system and determine relevant parameters, we designed and conducted

  17. Spontaneous Slow Fluctuation of EEG Alpha Rhythm Reflects Activity in Deep-Brain Structures: A Simultaneous EEG-fMRI Study

    PubMed Central

    Omata, Kei; Hanakawa, Takashi; Morimoto, Masako; Honda, Manabu

    2013-01-01

    The emergence of the occipital alpha rhythm on brain electroencephalogram (EEG) is associated with brain activity in the cerebral neocortex and deep brain structures. To further understand the mechanisms of alpha rhythm power fluctuation, we performed simultaneous EEGs and functional magnetic resonance imaging recordings in human subjects during a resting state and explored the dynamic relationship between alpha power fluctuation and blood oxygenation level-dependent (BOLD) signals of the brain. Based on the frequency characteristics of the alpha power time series (APTS) during 20-minute EEG recordings, we divided the APTS into two components: fast fluctuation (0.04–0.167 Hz) and slow fluctuation (0–0.04 Hz). Analysis of the correlation between the MRI signal and each component revealed that the slow fluctuation component of alpha power was positively correlated with BOLD signal changes in the brain stem and the medial part of the thalamus and anterior cingulate cortex, while the fast fluctuation component was correlated with the lateral part of the thalamus and the anterior cingulate cortex, but not the brain stem. In summary, these data suggest that different subcortical structures contribute to slow and fast modulations of alpha spectra on brain EEG. PMID:23824708

  18. EEG alpha blocking correlated with perception of inner light during zen meditation.

    PubMed

    Lo, Pei-Chen; Huang, Ming-Liang; Chang, Kang-Ming

    2003-01-01

    According to the experimental results and practitioners' subjective experience, we report some hypotheses that may account for meditative phenomena during the practice of Zen-Buddhism. Orthodox Zen-Buddhist practitioners, aiming to prove the most original true-self, discover and uncover the inner energy or light on the way towards their goal. Perception of the inner light can be comprehended as resonance. Uncovering the inner energy optimizes physiological and mental health. In the meditation experiment, a significant correlation was observed between perception of the inner light and electroencephalographic (EEG) alpha blockage. We further examined this phenomenon by recording the EEG from subjects during a blessing that the subjects did not know being given. During the blessing period, significant alpha blocking was observed in experimental subjects who had been practicing meditation for years in preparation for being in resonance with the inner light. This report provides a new insight into the debate that meditation benefits our health. PMID:14587885

  19. Prestimulus EEG alpha oscillations modulate task-related fMRI BOLD responses to auditory stimuli.

    PubMed

    Walz, Jennifer M; Goldman, Robin I; Carapezza, Michael; Muraskin, Jordan; Brown, Truman R; Sajda, Paul

    2015-06-01

    EEG alpha-band activity is generally thought to represent an inhibitory state related to decreased attention and play a role in suppression of task-irrelevant stimulus processing, but a competing hypothesis suggests an active role in processing task-relevant information - one in which phase dynamics are involved. Here we used simultaneous EEG-fMRI and a whole-brain analysis to investigate the effects of prestimulus alpha activity on the event-related BOLD response during an auditory oddball task. We separately investigated the effects of the posterior alpha rhythm's power and phase on activity related to task-relevant stimulus processing and also investigated higher-level decision-related processing. We found stronger decision-related BOLD activity in areas late in the processing stream when subjects were in the high alpha power state prior to stimulus onset, but did not detect any effect in primary sensory regions. Our phase analysis revealed correlates in the bilateral thalamus, providing support for a thalamo-cortical loop in attentional modulations and suggesting that the cortical alpha rhythm acts as a cyclic modulator of task-related responses very early in the processing stream. Our results help to reconcile the competing inhibition and active-processing hypotheses for ongoing alpha oscillations and begin to tease apart the distinct roles and mechanisms underlying their power and phase. PMID:25797833

  20. A novel EEG for alpha brain state training, neurobiofeedback and behavior change.

    PubMed

    Stinson, Bruce; Arthur, David

    2013-08-01

    Mindfulness meditation, with the resulting alpha brain state, is gaining a strong following as an adjunct to health, so too is applying self-affirmation to stimulate behavior change through subconscious re-programming. Until recently the EEG technology needed to demonstrate this has been cumbersome and required specialist training. This paper reports a pilot study using a remote EEG headband, which through a sophisticated algorithm, provides a real-time EEG readout unencumbered by conventional artifacts. In a convenience sample of 13, the difference in brain waves was examined while the subjects were occupied in an 'attention' and an 'alpha mind state' exercise. There was a significant difference in the mean scores for theta, delta, beta and gamma brain waves. Alpha brain waves remained static suggesting an ability of the headset to discriminate a mindful state and to provide real-time, easy to interpret feedback for the facilitator and subject. The findings provide encouragement for research applications in health care activities providing neurobiofeedback to subjects involved in mindfulness behavior change activities. PMID:23890456

  1. Attention and the EEG Alpha Rhythm in Learning Disabled Children

    ERIC Educational Resources Information Center

    Fuller, Peter W.

    1978-01-01

    Parieto-occipital electroencephalograms were recorded during resting baseline intervals, during an initial instruction period, and during active performance on mental arithmetic and immediate recall tasks to determine if 10 learning disabled boys (10-12 years old) would show less alpha attenuation than 11 normal controls. (Author/CL)

  2. EEG Alpha Rhythm Frequency and Intelligence in Normal Adults.

    ERIC Educational Resources Information Center

    Anokhin, Andrey; Vogel, Friedrich

    1996-01-01

    Scores on Raven's Progressive Matrices correlated positively with electroencephalogram-recorded alpha rhythm frequency (AF) in 101 healthy male adults, as did one test of verbal ability and one of mental performance. However, AF did not show significant relationships with general intelligence or spatial and arithmetic abilities. (SLD)

  3. EEG Alpha and Beta Activity in Normal and Deaf Subjects.

    ERIC Educational Resources Information Center

    Waldron, Manjula; And Others

    Electroencephalogram and task performance data were collected from three groups of young adult males: profoundly deaf Ss who signed from an early age, profoundly deaf Ss who only used oral (speech and speedreading) methods of communication, and normal hearing Ss. Alpha and Beta brain wave patterns over the Wernicke's area were compared across…

  4. Dynamics of alpha control: preparatory suppression of posterior alpha oscillations by frontal modulators revealed with combined EEG and event-related optical signal.

    PubMed

    Mathewson, Kyle E; Beck, Diane M; Ro, Tony; Maclin, Edward L; Low, Kathy A; Fabiani, Monica; Gratton, Gabriele

    2014-10-01

    We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously, we proposed that alpha (8-12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top-down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently recorded EEG, while participants performed a visual target detection task. The pretarget alpha oscillations measured with EEG and EROS from posterior areas were larger for subsequently undetected targets, supporting alpha's inhibitory role. Using EROS, we localized brain correlates of these awareness-related alpha oscillations measured at the scalp to the cuneus and precuneus. Crucially, EROS alpha suppression correlated with posterior EEG alpha power across participants. Sorting the EROS data based on EEG alpha power quartiles to investigate alpha modulators revealed that suppression of posterior alpha was preceded by increased activity in regions of the dorsal attention network and decreased activity in regions of the cingulo-opercular network. Cross-correlations revealed the temporal dynamics of activity within these preparatory networks before posterior alpha modulation. The novel combination of EEG and EROS afforded localization of the sources and correlates of alpha oscillations and their temporal relationships, supporting our proposal that top-down control from attention networks modulates both posterior alpha and awareness of visual stimuli. PMID:24702458

  5. Relation of EEG alpha background to cognitive fuction, brain atrophy, and cerebral metabolism in Down's syndrome. Age-specific changes

    SciTech Connect

    Devinsky, O.; Sato, S.; Conwit, R.A.; Schapiro, M.B. (National Institute of Neurological Disorders and Stroke, Bethesda, MD (USA))

    1990-01-01

    We studied 19 young adults (19 to 37 years old) and 9 older patients (42 to 66 years old) with Down's syndrome (DS) and a control group of 13 healthy adults (22 to 38 years old) to investigate the relation of electroencephalographic (EEG) alpha background to cognitive function and cerebral metabolism. Four of the older patients with DS had a history of mental deterioration, disorientation, and memory loss and were demented. Patients and control subjects had EEGs, psychometric testing, quantitative computed tomography, and positron emission tomography with fludeoxyglucose F 18. A blinded reader classified the EEGs into two groups--those with normal alpha background or those with abnormal background. All the control subjects, the 13 young adult patients with DS, and the 5 older patients with DS had normal EEG backgrounds. In comparison with the age-matched patients with DS with normal alpha background, older patients with DS with decreased alpha background had dementia, fewer visuospatial skills, decreased attention span, larger third ventricles, and a global decrease in cerebral glucose utilization with parietal hypometabolism. In the young patients with DS, the EEG background did not correlate with psychometric or positron emission tomographic findings, but the third ventricles were significantly larger in those with abnormal EEG background. The young patients with DS, with or without normal EEG background, had positron emission tomographic findings similar to those of the control subjects. The mechanism underlying the abnormal EEG background may be the neuropathologic changes of Alzheimer's disease in older patients with DS and may be cerebral immaturity in younger patients with DS.

  6. Is Resting Anterior EEG Alpha Asymmetry a Trait Marker for Depression? Findings for Healthy Adults and Clinically Depressed Patients

    Microsoft Academic Search

    Stefan Debener; André Beauducel; Doreen Nessler; Burkhard Brocke; Hubert Heilemann

    2000-01-01

    Several lines of evidence suggest that asymmetric ante- rior brain activation is related to affective style, linking left hemisphere activation to positive affect and right hemisphere activation to negative affect. However, pre- vious reports of left frontal hypoactivation in depressed patients were not confirmed in recent studies. This study evaluated additional characteristics of resting EEG alpha (8-13 Hz) asymmetry in

  7. [EEG correlates of geno-phenotypical features of the brain development in children of the native and newcomers' population of the Russian North-East].

    PubMed

    Soroko, S I; Bekshaev, S S; Rozhkov, V P

    2012-01-01

    Traditional and original methods of EEG analysis were used to study the brain electrical activity maturation in 156 children and adolescents from 7 to 17 years old who represented the native (Koryaks and Evenks) and newcomers' populations living in severe climatic and geographic conditions of the Russian North-East. New data revealing age-, sex- and ethnic-related features in quantitative EEG parameters are presented. Markers are obtained that characterize alterations in the structure of interaction between different EEG rhythms. The results demonstrate age-dependent transformation of this structure separated in time for both different cortical areas and different EEG frequency bands. These alterations show time lag from 2 to 3 years in children of native population compared to the newcomers. The revealed differences are assumed to reflect geno-phenotypical features of morpho-functional CNS development in children of the native and newcomers' population that depend on strong adaptation tension for extreme environmental conditions. PMID:22586927

  8. TNF-alpha promotes an odontoblastic phenotype in dental pulp cells.

    PubMed

    Paula-Silva, F W G; Ghosh, A; Silva, L A B; Kapila, Y L

    2009-04-01

    Dental pulp cells can differentiate toward an odontoblastic phenotype to produce reparative dentin beneath caries lesions. However, the mechanisms involved in pulp cell differentiation under pro-inflammatory stimuli have not been well-explored. Thus, we hypothesized that the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) could be a mediator involved in dental pulp cell differentiation toward an odontoblastic phenotype. We observed that TNF-alpha-challenged pulp cells exhibited increased mineralization and early and increased expression of dentin phosphoprotein (DPP), dentin sialoprotein (DSP), dentin matrix protein-1, and osteocalcin during a phase of reduced matrix metalloproteinase (MMP) expression. We investigated whether these events were related and found that p38, a mitogen-activated protein kinase, differentially regulated MMP-1 and DSP/DPP expression and mediated mineralization upon TNF-alpha treatment. These findings indicate that TNF-alpha stimulates differentiation of dental pulp cells toward an odontoblastic phenotype via p38, while negatively regulating MMP-1 expression. PMID:19407154

  9. Human alpha-N-acetylgalactosaminidase (alpha-NAGA) deficiency: new mutations and the paradox between genotype and phenotype.

    PubMed Central

    Keulemans, J L; Reuser, A J; Kroos, M A; Willemsen, R; Hermans, M M; van den Ouweland, A M; de Jong, J G; Wevers, R A; Renier, W O; Schindler, D; Coll, M J; Chabas, A; Sakuraba, H; Suzuki, Y; van Diggelen, O P

    1996-01-01

    Up to now eight patients with alpha-NAGA deficiency have been described. This includes the newly identified patient reported here who died unexpectedly aged 1 1/2 years of hypoxia during convulsions; necropsy was not performed. Three patients have been genotyped previously and here we report the mutations in the other five patients, including two new mutations (S160C and E193X). The newly identified patient is consanguineous with the first patients reported with alpha-NAGA deficiency and neuroaxonal dystrophy and they all had the alpha-NAGA genotype E325K/E325K. Clinical heterogeneity among patients with alpha-NAGA deficiency is extreme. Two affected sibs, homozygotes for E325K, are severely affected and have the signs and symptoms of infantile neuroaxonal dystrophy, but prominent vacuolisation is lacking. The mildly affected patients (two families, three patients) at the opposite end of the clinical spectrum have clear vacuolisation and angiokeratoma but no overt neurological manifestations. Two of them are homozygous for the stop mutation E193X, leading to complete loss of alpha-NAGA protein. These observations are difficult to reconcile with a simple genotype-phenotype correlation and we suggest that factors or genes other than alpha-NAGA contribute to the clinical heterogeneity of the eight patients with alpha-NAGA deficiency. At the metabolic level, the patients with alpha-NAGA deficiency are similar. The major abnormal urinary oligosaccharides are sialylglycopeptides of the O linked type. Our enzymatic studies indicated that these compounds are not the primary lysosomal storage products. Images PMID:8782044

  10. Phenotypic classification of male pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency

    SciTech Connect

    Sinnecker, G.H.G; Hiort, O.; Kruse, K.; Dibbelt, L. [Medical Univ. of Luebeck (Germany)] [and others] [Medical Univ. of Luebeck (Germany); and others

    1996-05-03

    Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5{alpha}-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause masculinization defects of varying degree. The classical syndrome, formerly described as pseudovaginal perineoscrotal hypospadias, is characterized by a predominantly female phenotype at birth and significant virilization without gynecomastia at puberty. We investigated nine patients with steroid 5{alpha}-reductase 2 deficiency (SRD). T/DHT-ratios were highly increased in the classical syndrome, but variable in the less severe affected patients. Mutations in the SRD5A2 gene had been characterized using PCR-SSCP analysis and direct DNA sequencing. A small deletion was encountered in two patients, while all other patients had single base mutations which result in amino acid substitutions. We conclude that phenotypes may vary widely in patients with SRD5A2 gene mutations spanning the whole range from completely female to normal male without distinctive clinical signs of the disease. Hence, steroid 5{alpha}-reductase deficiency should be considered not only in sex reversed patients with female or ambiguous phenotypes, but also in those with mild symptoms of undermasculinization as encountered in patients with hypospadias and/or micropenis. A classification based on the severity of the masculinization defect may be used for correlation of phenotypes with enzyme activities and genotypes, and for comparisons of phenotypes between different patients as the basis for clinical decisions to be made in patients with pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency. 22 refs., 2 figs., 2 tabs.

  11. Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention: high-resolution EEG investigation of meditation.

    PubMed

    Aftanas, L I; Golocheikine, S A

    2001-09-01

    EEG spectral power and coherence estimates in the individually defined delta, theta, alpha-1, alpha-2, and alpha-3 bands were used to identify and characterize brain regions involved in meditative states, in which focused internalized attention gives rise to emotionally positive "blissful" experience. Blissful state was accompanied by increased anterior frontal and midline theta synchronization as well as enhanced theta long-distant connectivity between prefrontal and posterior association cortex with distinct "center of gravity" in the left prefrontal region (AF3 site). Subjective scores of emotional experience significantly correlated with theta, whereas scores of internalized attention with both theta and alpha lower synchronization. Our results propose selective associations of theta and alpha oscillating networks activity with states of internalized attention and positive emotional experience. PMID:11524157

  12. Pupil Dilation and EEG Alpha Frequency Band Power Reveal Load on Executive Functions for Link-Selection Processes during Text Reading.

    PubMed

    Scharinger, Christian; Kammerer, Yvonne; Gerjets, Peter

    2015-01-01

    Executive working memory functions play a central role in reading comprehension. In the present research we were interested in additional load imposed on executive functions by link-selection processes during computer-based reading. For obtaining process measures, we used a methodology of concurrent electroencephalographic (EEG) and eye-tracking data recording that allowed us to compare epochs of pure text reading with epochs of hyperlink-like selection processes in an online reading situation. Furthermore, this methodology allowed us to directly compare the two physiological load-measures EEG alpha frequency band power and pupil dilation. We observed increased load on executive functions during hyperlink-like selection processes on both measures in terms of decreased alpha frequency band power and increased pupil dilation. Surprisingly however, the two measures did not correlate. Two additional experiments were conducted that excluded potential perceptual, motor, or structural confounds. In sum, EEG alpha frequency band power and pupil dilation both turned out to be sensitive measures for increased load during hyperlink-like selection processes in online text reading. PMID:26076026

  13. Pupil Dilation and EEG Alpha Frequency Band Power Reveal Load on Executive Functions for Link-Selection Processes during Text Reading

    PubMed Central

    Scharinger, Christian; Kammerer, Yvonne; Gerjets, Peter

    2015-01-01

    Executive working memory functions play a central role in reading comprehension. In the present research we were interested in additional load imposed on executive functions by link-selection processes during computer-based reading. For obtaining process measures, we used a methodology of concurrent electroencephalographic (EEG) and eye-tracking data recording that allowed us to compare epochs of pure text reading with epochs of hyperlink-like selection processes in an online reading situation. Furthermore, this methodology allowed us to directly compare the two physiological load-measures EEG alpha frequency band power and pupil dilation. We observed increased load on executive functions during hyperlink-like selection processes on both measures in terms of decreased alpha frequency band power and increased pupil dilation. Surprisingly however, the two measures did not correlate. Two additional experiments were conducted that excluded potential perceptual, motor, or structural confounds. In sum, EEG alpha frequency band power and pupil dilation both turned out to be sensitive measures for increased load during hyperlink-like selection processes in online text reading. PMID:26076026

  14. An empirical study on the relations between EEG alpha-beta entropy & EQ- IQ test scores

    Microsoft Academic Search

    Sarah Vakili; Nima Tehranchian; Maryam Tajziehchi; Iman Mohammad Rezazadeh; Xiangyu Wang

    2012-01-01

    In this paper, the relationship between the subjects' brain waves and the relative Emotional Quotient (EQ) and Intelligence Quotient (IQ) has been investigated. In this study, the intensity of correlation between the entropy of Alpha and Beta brain waves and the IQ and EQ has been evaluated over thirty healthy subjects (15 males, 15 females, and aged 21–25 year old)

  15. EEG alpha power as an intermediate measure between brain-derived neurotrophic factor Val66Met and depression severity in patients with major depressive disorder.

    PubMed

    Zoon, Harriët F A; Veth, C P M; Arns, Martijn; Drinkenburg, W H I M; Talloen, Willem; Peeters, Pieter J; Kenemans, J L

    2013-06-01

    Major depressive disorder has a large impact on patients and society and is projected to be the second greatest global burden of disease by 2020. The brain-derived neurotrophic factor (BDNF) gene is considered to be one of the important factors in the etiology of major depressive disorder. In a recent study, alpha power was found to mediate between BDNF Met and subclinical depressed mood. The current study looked at a population of patients with major depressive disorder (N = 107) to examine the association between the BDNF Val66Met polymorphism, resting state EEG alpha power, and depression severity. For this purpose, repeated-measures analysis of variance, partial correlation, and multiple linear models were used. Results indicated a negative association between parietal-occipital alpha power in the eyes open resting state and depression severity. In addition, Met/Met patients showed lower global absolute alpha power in the eyes closed condition compared with Val-carriers. These findings are in accordance with the previously uncovered pathway between BDNF Val66Met, resting state EEG alpha power, and depression severity. Additional research is needed for the clarification of this tentative pathway and its implication in personalized treatment of major depressive disorder. PMID:23733090

  16. Appearance of high-frequency alpha band with disappearance of low-frequency alpha band in EEG is produced during voluntary abdominal breathing in an eyes-closed condition

    Microsoft Academic Search

    Masaki Fumoto; Ikuko Sato-Suzuki; Yoshinari Seki; Yuko Mohri; Hideho Arita

    2004-01-01

    This study examined the effects of voluntary abdominal breathing (VAB) on the electroencephalogram (EEG) in 22 healthy subjects. VAB was characterized by prolonged rhythmic contraction of abdominal muscles for 20min in an eyes-closed condition. The breathing rate was instructed to be very slow, i.e., 3–4 breaths\\/min (inspiratory time for 6–8s and expiratory time for 9–12s). A low-frequency alpha band appeared

  17. Reciprocal dynamics of EEG alpha and delta oscillations during spontaneous blinking at rest: a survey on a default mode-based visuo-spatial awareness.

    PubMed

    Bonfiglio, Luca; Sello, Stefano; Carboncini, Maria Chiara; Arrighi, Pieranna; Andre, Paolo; Rossi, Bruno

    2011-04-01

    By means of a narrowband wavelet analysis (0.5-6Hz), EEG delta event-related oscillations (EROs), both time- and phase-locked to spontaneous blinking (delta blink-related oscillations or delta BROs), have recently been demonstrated. On the basis of their spatiotemporal characteristics, delta BROs have been proposed as being involved in an automatic mechanism of maintaining awareness in a visuo-spatial context. The aim of the present study was: a) to investigate whether spontaneous blinking was also able to modulate alpha oscillations and, if so, b) whether this modulation was consistent with delta BROs, in order c) to acquire additional information for a better understanding of the cognitive phenomena underlying blinking. Using a broadband (0.5-100 Hz) continuous wavelet transform (CWT), we analysed a total of 189 three-second EEG epochs time-locked to the blinks of seven healthy volunteers. The EEG signals were submitted both to band-pass filtered cross-trial averaging (to obtain frequency-specific BROs) and to alpha event-related synchronization/desynchronization (i.e., blink-related synchronization/desynchronization, BRS/BRD). The alpha oscillations showed: a) an early BRS; b) a BRD in the same temporal window of the delta BROs and, c) a late BRS. We postulate that: a) the early BRS represents the short-term memory maintenance of the last visually perceived trace of the surroundings; b) the alpha BRD is associated with the comparison between the newly perceived image of the environment and its mnestic representation, and, lastly, c) the late BRS is connected with neuronal recovery phenomena. PMID:21238505

  18. "I am resting but rest less well with you." The moderating effect of anxious attachment style on alpha power during EEG resting state in a social context.

    PubMed

    Verbeke, Willem J M I; Pozharliev, Rumen; Van Strien, Jan W; Belschak, Frank; Bagozzi, Richard P

    2014-01-01

    We took EEG recordings to measure task-free resting-state cortical brain activity in 35 participants under two conditions, alone (A) or together (T). We also investigated whether psychological attachment styles shape human cortical activity differently in these two settings. The results indicate that social context matters and that participants' cortical activity is moderated by the anxious, but not avoidant attachment style. We found enhanced alpha, beta and theta band activity in the T rather than the A resting-state condition, which was more pronounced in posterior brain regions. We further found a positive correlation between anxious attachment style and enhanced alpha power in the T vs. A condition over frontal and parietal scalp regions. There was no significant correlation between the absolute powers registered in the other two frequency bands and the participants' anxious attachment style. PMID:25071516

  19. Time course and specificity of sensory-motor alpha modulation during the observation of hand motor acts and gestures: a high density EEG study

    PubMed Central

    Streltsova, Alena; Berchio, Cristina; Gallese, Vittorio

    2010-01-01

    The main aim of the present study was to explore, by means of high-density EEG, the intensity and the temporal pattern of event-related sensory-motor alpha desynchronization (ERD) during the observation of different types of hand motor acts and gestures. In particular, we aimed to investigate whether the sensory-motor ERD would show a specific modulation during the observation of hand behaviors differing for goal-relatedness (hand grasping of an object and meaningless hand movements) and social relevance (communicative hand gestures and grasping within a social context). Time course analysis of alpha suppression showed that all types of hand behaviors were effective in triggering sensory-motor alpha ERD, but to a different degree depending on the category of observed hand motor acts and gestures. Meaningless gestures and hand grasping were the most effective stimuli, resulting in the strongest ERD. The observation of social hand behaviors such as social grasping and communicative gestures, triggered a more dynamic time course of ERD compared to that driven by the observation of simple grasping and meaningless gestures. These findings indicate that the observation of hand motor acts and gestures evoke the activation of a motor resonance mechanism that differs on the basis of the goal-relatedness and the social relevance of the observed hand behavior. PMID:20680250

  20. Prestimulus oscillations in the alpha band of the EEG are modulated by the difficulty of feature discrimination and predict activation of a sensory discrimination process.

    PubMed

    Roberts, Daniel M; Fedota, John R; Buzzell, George A; Parasuraman, Raja; McDonald, Craig G

    2014-08-01

    Recent work has demonstrated that the occipital-temporal N1 component of the ERP is sensitive to the difficulty of visual discrimination, in a manner that cannot be explained by simple differences in low-level visual features, arousal, or time on task. These observations provide evidence that the occipital-temporal N1 component is modulated by the application of top-down control. However, the timing of this control process remains unclear. Previous work has demonstrated proactive, top-down modulation of cortical excitability for cued spatial attention or feature selection tasks. Here, the possibility that a similar top-down process facilitates performance of a difficult stimulus discrimination task is explored. Participants performed an oddball task at two levels of discrimination difficulty, with difficulty manipulated by modulating the similarity between target and nontarget stimuli. Discrimination processes and cortical excitability were assessed via the amplitude of the occipital-temporal N1 component and prestimulus alpha oscillation of the EEG, respectively. For correct discriminations, prestimulus alpha power was reduced, and the occipital-temporal N1 was enhanced in the hard relative to the easy condition. Furthermore, within the hard condition, prestimulus alpha power was reduced, and the occipital-temporal N1 was enhanced for correct relative to incorrect discriminations. The generation of ERPs contingent on relative prestimulus alpha power additionally suggests that diminished alpha power preceding stimulus onset is related to enhancement of the occipital-temporal N1. As in spatial attention, proactive control appears to enhance cortical excitability and facilitate discrimination performance in tasks requiring nonspatial, feature-based attention, even in the absence of competing stimulus features. PMID:24405187

  1. Transforming Growth Factor Alpha (TGF?) Transforms Astrocytes to a Growth Supportive Phenotype after Spinal Cord Injury

    PubMed Central

    White, Robin E.; Rao, Meghan; Gensel, John C.; McTigue, Dana M.; Kaspar, Brian K.; Jakeman, Lyn B.

    2011-01-01

    Astrocytes are both detrimental and beneficial for repair and recovery after spinal cord injury (SCI). These dynamic cells are primary contributors to the growth-inhibitory glial scar, yet they are also neuroprotective and can form growth-supportive bridges upon which axons traverse. We have shown that intrathecal administration of transforming growth factor alpha (TGF?) to the contused mouse spinal cord can enhance astrocyte infiltration and axonal growth within the injury site, but the mechanisms of these effects are not well understood. The present studies demonstrate that the epidermal growth factor receptor (EGFR) is upregulated primarily by astrocytes and glial progenitors early after SCI. TGF? directly activates the EGFR on these cells in vitro, inducing their proliferation, migration, and transformation to a phenotype that supports robust neurite outgrowth. Overexpression of TGF? in vivo by intraparenchymal adeno-associated virus injection adjacent to the injury site enhances cell proliferation, alters astrocyte distribution and facilitates increased axonal penetration at the rostral lesion border. To determine if endogenous EGFR activation is required after injury, SCI was also performed on Velvet (C57BL/6J-EgfrVel/J) mice, a mutant strain with defective EGFR activity. The affected mice exhibited malformed glial borders, larger lesions, and impaired recovery of function, indicating that intrinsic EGFR activation is necessary for neuroprotection and normal glial scar formation after SCI. By further stimulating precursor proliferation and modifying glial activation to promote a growth permissive environment, controlled stimulation of EGFR at the lesion border may be considered in the context of future strategies to enhance endogenous cellular repair following injury. PMID:22016551

  2. Tonic pain and continuous EEG: Prediction of subjective pain perception by alpha-1 power during stimulation and at rest

    Microsoft Academic Search

    Rony-Reuven Nir; Alon Sinai; Ruth Moont; Eyal Harari; David Yarnitsky

    ObjectivePain neurophysiology has been chiefly characterized via event-related potentials (ERPs), which are exerted using brief, phase-locked noxious stimuli. Striving for objectively characterizing clinical pain states using more natural, prolonged stimuli, tonic pain has been recently associated with the individual peak frequency of alpha oscillations. This finding encouraged us to explore whether alpha power, reflecting the magnitude of the synchronized activity

  3. Lung fibroblast alpha-smooth muscle actin expression and contractile phenotype in bleomycin-induced pulmonary fibrosis.

    PubMed Central

    Zhang, H. Y.; Gharaee-Kermani, M.; Zhang, K.; Karmiol, S.; Phan, S. H.

    1996-01-01

    The emergence of the myofibroblast phenotype (characterized by alpha-smooth muscle actin expression) in wound healing and in tissues undergoing fibrosis is thought to be responsible for the increased contractility of the affected tissues. In bleomycin-induced pulmonary fibrosis, the myofibroblast is also responsible for the observed increase in collagen gene expression. To evaluate further these phenotypic changes in lung fibroblasts, contractile and other phenotypic properties of fibroblasts isolated from lungs of rats with bleomycin-induced fibrosis were compared with those of normal rats using in vitro models. Pulmonary fibrosis was induced in rats by endotracheal injection on day 0, and 7 and 14 days later the animals were sacrificed and lung fibroblasts isolated. Using immunofluorescence, < 10% of fibroblasts from control animals express alpha-smooth muscle actin when cultured as a monolayer. In contrast, 19% and 21% of cells from day 7 and day 14 bleomycin-treated animals, respectively, expressed this actin and with greater intensity than in control lung cells. This increase in actin expression was associated with enhanced contractility when evaluated using a three-dimensional cell culture model consisting of fibroblast-populated collagen gels. This enhanced contractility was abolished by treatment with antibody to transforming growth factor-beta (TGF-beta), whereas exogenous TGF-beta 1 and serum-stimulated contraction of control lung fibroblasts. TGF-beta 1 gene expression was greater in cells from bleomycin-treated animals than those from control lungs. These results show that cells with the myofibroblast phenotype are more abundant in fibrotic lung, and that these cells possess greater contractile capacity in vitro at least partly by virtue of their enhanced endogenous TGF-beta 1 gene expression. Images Figure 4 Figure 5 Figure 9 PMID:8579115

  4. COMT polymorphism modulates the resting-state EEG alpha oscillatory response to acute nicotine in male non-smokers

    PubMed Central

    Bowers, H.; Smith, D.; de la Salle, S.; Choueiry, J.; Impey, D.; Philippe, T.; Dort, H.; Millar, A.; Daigle, M.; Albert, P. R.; Beaudoin, A.; Knott, V.

    2015-01-01

    Performance improvements in cognitive tasks requiring executive functions are evident with nicotinic acetylcholine receptor (nAChR) agonists, and activation of the underlying neural circuitry supporting these cognitive effects is thought to involve dopamine neurotransmission. As individual difference in response to nicotine may be related to a functional polymorphism in the gene encoding catechol-O-methyltransferase (COMT), an enzyme that strongly influences cortical dopamine metabolism, this study examined the modulatory effects of the COMT Val158Met polymorphism on the neural response to acute nicotine as measured with resting-state electroencephalographic (EEG) oscillations. In a sample of 62 healthy non-smoking adult males, a single dose (6 mg) of nicotine gum administered in a randomized, double-blind, placebo-controlled design was shown to affect ? oscillatory activity, increasing power of upper ? oscillations in frontocentral regions of Met/Met homozygotes and in parietal/occipital regions of Val/Met heterozygotes. Peak ? frequency was also found to be faster with nicotine (vs. placebo) treatment in Val/Met heterozygotes, who exhibited a slower ? frequency compared to Val/Val homozygotes. The data tentatively suggest that interindividual differences in brain ? oscillations and their response to nicotinic agonist treatment are influenced by genetic mechanisms involving COMT. PMID:26096691

  5. The alpha2beta1 integrin mediates the malignant phenotype on type I collagen in pancreatic cancer cell lines.

    PubMed

    Grzesiak, J J; Bouvet, M

    2006-05-01

    Pancreatic cancer is characterised by a hallmark desmoplastic response that includes upregulated expression of the extracellular matrix, and type I collagen in particular. Recent studies indicate that pancreatic cancer cells stimulate type I collagen synthesis in adjacent stellate cells, and that this upregulated type I collagen expression promotes the malignant phenotype in tumour cells as defined by increased proliferation, resistance to chemically induced apoptosis, and increased tumorigenesis. The integrin specificity of this interaction between type I collagen and tumour cells was not identified, however. In the present study, we examined eight pancreatic cancer cell lines for adhesion, proliferation, and migration, on types I and IV collagen, fibronectin, laminin, and vitronectin, as well as integrin expression. Our results indicate, for the overwhelming majority of cell lines, that type I collagen promotes the strongest adhesion, proliferation, and migration relative to the other substrates tested. Utilising function-blocking monoclonal antibodies directed against particular integrin subunits in cell adhesion and migration inhibition assays, we demonstrate further that the malignant phenotype on type I collagen is mediated specifically by the alpha2beta1 integrin. These results identify alpha2beta1 integrin-mediated adhesion to type I collagen as a potential therapeutic target in the treatment of pancreatic cancer. PMID:16622460

  6. Phenotype and gene distribution of alpha-1-antitrypsin in a North Italian population.

    PubMed

    Klasen, E C; D'Andrea, F; Bernini, L F

    1978-01-01

    A group of 202 unrelated Italians were screened for alpha1-antitrypsin using agarose-acrylamide electrophoresis and isoelectric focusing. The S and F gene frequencies were comparable to those found among Greeks and North European populations but they differed considerably from the frequencies found among Spaniards and Portuguese. The other gene frequencies appeared to be comparable to other populations, studied. PMID:308033

  7. [Computerized EEG and personality].

    PubMed

    Ramírez Pérez, A; Martínez López-Coterilla, M; Fajardo López, A; Lardelli Claret, A

    1989-01-01

    The ordinary EEG, on only showing qualitative malfunction of abnormal graphoelements in the tracings, proves itself insufficient to go into the analysis of psychological and psycho-pathological problems. Since computerised studies of EEG permit quantitative comparisons, we tried to apply them in correlation with the characteristics of the personality classified also with quantitative criteria, such as those offered in the personality inventory 16 PF; from which have been chosen the so-called factors of the second order, and the subjectivity-objectivity factors. The test was carried out on 100 voluntary subjects from Almeria (Spain), all with High School grades, between 18 and 40 years of age, of both sexes, all right-handed, without neuro-psychiatric history, and with normal ordinary EEGs. From the statistical analysis of the results one could deduce that there are significant specific relationships from the computerised EEG, with those secondary polar values of 16 PF: high and low anxiety, extroversion-introversion. Subjects with low anxiety presented a significant increase of the alpha band opposed to the subjects with high anxiety. There is a significant differences in power of the frontal areas between extrovert and introvert subjects. The extroverted subjects have a greater power of the right side and the introverted subjects a greater power of the left. PMID:2698596

  8. CRB2 mutations produce a phenotype resembling congenital nephrosis, Finnish type, with cerebral ventriculomegaly and raised alpha-fetoprotein.

    PubMed

    Slavotinek, Anne; Kaylor, Julie; Pierce, Heather; Cahr, Michelle; DeWard, Stephanie J; Schneidman-Duhovny, Dina; Alsadah, Adnan; Salem, Fadi; Schmajuk, Gabriela; Mehta, Lakshmi

    2015-01-01

    We report five fetuses and a child from three families who shared a phenotype comprising cerebral ventriculomegaly and echogenic kidneys with histopathological findings of congenital nephrosis. The presenting features were greatly elevated maternal serum alpha-fetoprotein (MSAFP) or amniotic fluid alpha-fetoprotein (AFAFP) levels or abnormalities visualized on ultrasound scan during the second trimester of pregnancy. Exome sequencing revealed deleterious sequence variants in Crumbs, Drosophila, Homolog of, 2 (CRB2) consistent with autosomal-recessive inheritance. Two fetuses with cerebral ventriculomegaly and renal microcysts were compound heterozygotes for p.Asn800Lys and p.Trp759Ter, one fetus with renal microcysts was a compound heterozygote for p.Glu643Ala and p.Asn800Lys, and one child with cerebral ventriculomegaly, periventricular heterotopias, echogenic kidneys, and renal failure was homozygous for p.Arg633Trp in CRB2. Examination of the kidneys in one fetus showed tubular cysts at the corticomedullary junction and diffuse effacement of the epithelial foot processes and microvillous transformation of the renal podocytes, findings that were similar to those reported in congenital nephrotic syndrome, Finnish type, that is caused by mutations in nephrin (NPHS1). Loss of function for crb2b and nphs1 in Danio rerio were previously shown to result in loss of the slit diaphragms of the podocytes, leading to the hypothesis that nephrosis develops from an inability to develop a functional glomerular barrier. We conclude that the phenotype associated with CRB2 mutations is pleiotropic and that the condition is an important consideration in the evaluation of high MSAFP/AFAFP where a renal cause is suspected. PMID:25557780

  9. Intravenous administration of alpha-1-proteinase inhibitor in patients of PiZ and PiM phenotype. Preliminary report

    SciTech Connect

    Moser, K.M.; Smith, R.M.; Spragg, R.G.; Tisi, G.M.

    1988-06-24

    Nine patients with moderate pulmonary emphysema, six of PiZ phenotype and three of PiM phenotype, have received a single intravenous infusion of alpha-1-proteinase inhibitor (human) (A1PI), in a dose of 60 mg/kg over a 30-minute period. They also received a tracer dose (300 microCi) of /sup 131/I-labeled A1PI. No active or passive immunization against hepatitis was given. No acute toxicity was observed. Compared with baseline data, significant elevations of serum A1PI (measured both antigenically and as anti-elastase activity) occurred, with a serum half-life approximating 110 hours. Bronchoalveolar lavage fluid, obtained 48 hours after infusion, reflected a significant increase in A1PI concentration versus baseline bronchoalveolar lavage fluid values. Serial gamma camera images of the lungs confirmed persistence of enhanced lung radioactivity for several days. Urinary desmosine excretion did not change following A1PI infusion. During the period of follow-up thus far, no patient has had chronic toxicity, results of liver function tests have been stable, and there has been no development of hepatitis B antigen or antibodies to hepatitis B surface or core antigens.

  10. A short-term treatment with tumor necrosis factor-alpha enhances stem cell phenotype of human dental pulp cells

    PubMed Central

    2014-01-01

    Introduction During normal pulp tissue healing, inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-?) or interleukins, act in the initial 48 hours (inflammatory phase) and play important roles not only as chemo-attractants of inflammatory cells and stem/progenitor cells but also in inducing a cascade of reactions toward tissue regeneration or reparative dentin formation or both. Previous reports have shown that inflammatory cytokines regulate the differentiation capacity of dental pulp stem/progenitor cells (DPCs), but none has interrogated the impact of these cytokines on the stem cell phenotype of stem/progenitor cells. This study investigated the effects of a short-term treatment with TNF-? on the stem cell phenotype and differentiation ability of human DPCs. Methods An in vivo mouse model of pulp exposure was performed for analysis of expression of the mesenchymal stem cell marker CD146 in DPCs during the initial stage of inflammatory response. For in vitro studies, human DPCs were isolated and incubated with TNF-? for 2 days and passaged to eliminate TNF-? completely. Analysis of stem cell phenotype was performed by quantification of cells positive for mesenchymal stem cell markers SSEA-4 (stage-specific embryonic antigen 4) and CD146 by flow cytometry as well as by quantitative analysis of telomerase activity and mRNA levels of OCT-4 and NANOG. Cell migration, colony-forming ability, and differentiation toward odontogenesis and adipogenesis were also investigated. Results The pulp exposure model revealed a strong staining for CD146 during the initial inflammatory response, at 2 days after pulp exposure. In vitro experiments demonstrated that a short-term (2-day) treatment of TNF-? increased by twofold the percentage of SSEA-4+ cells. Accordingly, STRO-1, CD146, and SSEA-4 protein levels as well as OCT-4 and NANOG mRNA levels were also significantly upregulated upon TNF-? treatment. A short-term TNF-? treatment also enhanced DPC function, including the ability to form cell colonies, to migrate, and to differentiate into odontogenic and adipogenic lineages. Conclusions A short-term treatment with TNF-? enhanced the stem cell phenotype, migration, and differentiation ability of DPCs. PMID:24580841

  11. TNF-alpha impairs regulation of muscle oxidative phenotype: implications for cachexia?

    PubMed

    Remels, A H V; Gosker, H R; Schrauwen, P; Hommelberg, P P H; Sliwinski, P; Polkey, M; Galdiz, J; Wouters, E F M; Langen, R C J; Schols, A M W J

    2010-12-01

    Chronic obstructive pulmonary disease (COPD) is characterized by weight loss, muscle wasting (in advanced disease ultimately resulting in cachexia), and loss of muscle oxidative phenotype (oxphen). This study investigates the effect of inflammation (as a determinant of muscle wasting) on muscle oxphen by using cell studies combined with analyses of muscle biopsies of patients with COPD and control participants. We analyzed markers (citrate synthase, ?-hydroxyacyl-CoA dehydrogenase, and cytochrome c oxidase IV) and regulators (PGC-1?, PPAR-?, and Tfam) of oxphen in vastus lateralis muscle biopsies of patients with advanced COPD and healthy smoking control participants. Here 17 of 73 patients exhibited elevated muscle TNF-? mRNA levels. In these patients, significantly lower mRNA levels of all oxidative markers/regulators were found. Interestingly, these patients also had a significantly lower body mass index and tended to have less muscle mass. In cultured muscle cells, mitochondrial protein content and myosin heavy chain isoform I (but not II) protein and mRNA levels were reduced on chronic TNF-? stimulation. TNF-? also reduced mitochondrial respiration in a nuclear factor kappaB (NF-?B) -dependent manner. Importantly, TNF-?-induced NF-?B activation decreased promoter transactivation and transcriptional activity of regulators of mitochondrial biogenesis and muscle oxphen. In conclusion, these results demonstrate that TNF-? impairs muscle oxphen in a NF-?B-dependent manner. PMID:20807714

  12. Preserved functional autonomic phenotype in adult mice overexpressing moderate levels of human alpha?synuclein in oligodendrocytes

    PubMed Central

    Tank, Jens; da Costa?Goncalves, Andrey C.; Kamer, Ilona; Qadri, Fatimunnisa; Ubhi, Kiren; Rockenstein, Edward; Diedrich, André; Masliah, Eliezer; Gross, Volkmar; Jordan, Jens

    2014-01-01

    Abstract Mice overexpressing human alpha?synuclein in oligodendrocytes (MBP1???syn) recapitulate some key functional and neuropathological features of multiple system atrophy (MSA). Whether or not these mice develop severe autonomic failure, which is a key feature of human MSA, remains unknown. We explored cardiovascular autonomic regulation using long?term blood pressure (BP) radiotelemetry and pharmacological testing. We instrumented 12 MBP1???syn mice and 11 wild?type mice aged 9 months for radiotelemetry. Animals were tested with atropine, metoprolol, clonidine, and trimethaphan at 9 and 12 months age. We applied spectral and cross?spectral analysis to assess heart rate (HR) and BP variability. At 9 months of age daytime BP (transgenic: 101 ± 2 vs. wild type: 99 ± 2 mmHg) and HR (497 ± 11 vs. 505 ± 16 beats/min) were similar. Circadian BP and HR rhythms were maintained. Nighttime BP (109 ± 2 vs. 108 ± 2 mmHg) and HR (575 ± 15 vs. 569 ± 14 beats/min), mean arterial BP responses to trimethaphan (?21 ± 8 vs. ?10 ± 5 mmHg, P = 0.240) and to clonidine (?8 ± 3 vs. ?5 ± 2 mmHg, P = 0.314) were similar. HR responses to atropine (+159 ± 24 vs. +146 ± 22 beats/min), and to clonidine (?188 ± 21 vs. ?163 ± 33 beats/min) did not differ between strains. Baroreflex sensitivity (4 ± 1 vs. 4 ± 1 msec/mmHg) and HR variability (total power, 84 ± 17 vs. 65 ± 21 msec²) were similar under resting conditions and during pharmacological testing. Repeated measurements at 12 months of age provided similar results. In mice, moderate overexpression of human alpha?synuclein in oligodendrocytes is not sufficient to induce overt autonomic failure. Additional mechanisms may be required to express the autonomic failure phenotype including higher levels of expression or more advanced age. PMID:25428949

  13. Topographic EEG brain mapping during Yogic Flying.

    PubMed

    Orme-Johnson, D W; Gelderloos, P

    1988-02-01

    Voluntary focal activity typically disrupts EEG alpha activity. This experiment tested the hypothesis that the alpha wave would not be disrupted during "Yogic Flying" (YF), a TM-Sidhi technique that produces movement of the body such as hopping, because the technique operates at a self-referral level in which attention remains in a settled, inwardly directed state. In 23 subjects YF was compared with voluntary jumping in the same subjects which mimicked the movements of YF. The percentage of relative power of alpha was significantly higher for YF in virtually all EEG derivations, supporting the hypothesis. The effect appeared to be of similar magnitude in all cortical areas. PMID:3372156

  14. ER-alpha and ER-beta expression in differentiated thyroid cancer: relation with tumor phenotype across the TNM staging and peri-tumor inflammation.

    PubMed

    Magri, Flavia; Capelli, Valentina; Gaiti, Margherita; Villani, Laura; Zerbini, Francesca; La Manna, Luigi; Rotondi, Mario; Chiovato, Luca

    2015-06-01

    Thyroid cancer may express estrogen receptors (ERs) and various grades of peri-tumor inflammation. The aim of the study was to evaluate the expression of ERs in relation to the TNM stage and peri-tumor inflammatory infiltrate in differentiated thyroid cancers. 127 patients (109 females, 18 males) with differentiated thyroid cancer (T1 = 91, T2 = 18, T3 = 11, T4 = 7) were evaluated. In tumors and in the correspondent extra-tumor parenchyma, ERs expression was evaluated by immunohistochemistry. In 114 tumors and correspondent peri-tumor tissues, the presence of inflammatory infiltration was also recorded. ER-alpha expression was higher in clinical than in incidental tumors of the T1 subgroup (p = 0.037), and was associated with capsular invasion in T2 tumors (p < 0.0001). ER-beta expression was negatively associated with vascular invasion in T1 (p = 0.005) and T2 tumors (p = 0.015). No significant relationship between ERs expression and tumor phenotype emerged in T3 and T4 subgroups. Tumors without inflammatory cell infiltrate showed a higher expression of both ER-alpha (p = 0.035) and ER-beta (p = 0.026) than the ones with inflammatory infiltrate. The relationship between tumor phenotype and ERs expression did not vary in the presence or absence of peri-tumor inflammatory infiltration. ER-alpha positivity and ER-beta negativity are associated with a more aggressive phenotype in both T1 and T2 thyroid cancers, suggesting that tumor biology may be more relevant than tumor size for cancer risk assessment. Inflammatory status is also associated with ERs expression, but not with tumor growth or phenotype. PMID:25338203

  15. Comparison between spectral and fractal EEG analyses of sleeping newborns

    Microsoft Academic Search

    A. P. Accardo; M. Affinito; M. Carrozzi; S. Cisint; F. Bouquet

    1998-01-01

    Spectral parameters (power spectrum in the delta, theta, alpha, beta1 and beta2 bands) and the fractal dimension were estimated for each two seconds frame of the EEG sleep time series at the awake condition or during one of the four EEG sleep states: active sleep (two stages: mixed and low voltage irregular) and quiet sleep (two stages: quiet sleep high

  16. Prognostic Value of EEG in Post-Anoxic Coma after Cardiac Arrest

    Microsoft Academic Search

    Giuseppe Scollo-Lavizzari; Claudio Bassetti

    1987-01-01

    The authors themselves studied 26 patients. The EEGs were classified in terms of increasing severity in 5 categories. Incorporating over 400 cases from the literature, the authors correlated the initial EEG findings with the clinical outcome following cardiac arrest. Grade I EEG findings (normal alpha with theta-delta activity) imply a very good prognosis. A complete remission can be expected in

  17. The Utility of EEG Band Power Analysis in the Study of Infancy and Early Childhood

    Microsoft Academic Search

    Joni N. Saby; Peter J. Marshall

    2012-01-01

    Research employing electroencephalographic (EEG) techniques with infants and young children has flourished in recent years due to increased interest in understanding the neural processes involved in early social and cognitive development. This review focuses on the functional characteristics of the alpha, theta, and gamma frequency bands in the developing EEG. Examples of how analyses of EEG band power have been

  18. The Effects of Mobile Phone Usage on Human Brainwave Using EEG

    Microsoft Academic Search

    Zunairah Hj Murat; Ros Shilawani S. AbdulKadir; Roshakimah Mohd Isa; Mohd Nasir Taib

    2011-01-01

    The aim of this research is to investigate any effects of mobile phone usage on human brainwaves using electroencephalograph (EEG) particularly on alpha wave. EEG signals were recorded from thirty samples that make calls from a mobile phone to another party without conversation. The mobile phone is strapped to the right ear. The EEG recording took place before, during and

  19. Effets des RF sur le systme nerveux central chez l'homme : EEG, sommeil, cognition, vascularisation

    E-print Network

    Boyer, Edmond

    of EEG alpha waves, mainly during sleep, look consistent. It would however be important to define more, vascularisation Effects of RF on the central nervous system in human: EEG, sleep, cognition, vascularisation, sommeil, cognition, vascularisation Key words: RF, central nervous system, EEG, sleep, cognition

  20. Lateralisation effect in comprehension of emotional facial expression: A comparison between EEG alpha band power and behavioural inhibition (BIS) and activation (BAS) systems

    Microsoft Academic Search

    Michela Balconi; Guido Mazza

    2010-01-01

    Asymmetry in comprehension of facial expression of emotions was explored in the present study by analysing alpha band variation within the right and left cortical sides. Second, the behavioural activation system (BAS) and behavioural inhibition system (BIS) were considered as an explicative factor to verify the effect of a motivational\\/emotional variable on alpha activity. A total of 19 participants looked

  1. The Mozart Effect: A quantitative EEG study.

    PubMed

    Verrusio, Walter; Ettorre, Evaristo; Vicenzini, Edoardo; Vanacore, Nicola; Cacciafesta, Mauro; Mecarelli, Oriano

    2015-09-01

    The aim of this study is to investigate the influence of Mozart's music on brain activity through spectral analysis of the EEG in young healthy adults (Adults), in healthy elderly (Elderly) and in elderly with Mild Cognitive Impairment (MCI). EEG recording was performed at basal rest conditions and after listening to Mozart's K448 or "Fur Elise" Beethoven's sonatas. After listening to Mozart, an increase of alpha band and median frequency index of background alpha rhythm activity (a pattern of brain wave activity linked to memory, cognition and open mind to problem solving) was observed both in Adults and in Elderly. No changes were observed in MCI. After listening to Beethoven, no changes in EEG activity were detected. This results may be representative of the fact that said Mozart's music is able to "activate" neuronal cortical circuits related to attentive and cognitive functions. PMID:26036835

  2. Feline large granular lymphocyte (LGL) lymphoma with secondary leukemia: primary intestinal origin with predominance of a CD3/CD8(alpha)(alpha) phenotype.

    PubMed

    Roccabianca, P; Vernau, W; Caniatti, M; Moore, P F

    2006-01-01

    Clinicopathologic and immunophenotypic characteristics of large granular lymphocyte (LGL) neoplasia in 21 cats were examined. All cats were domestic short (19) or long hair (2) with a mean age of 9.3 years at diagnosis. Increased peripheral blood LGL counts were present in 18/21 cats. Neutrophilia (12/21 cats) and increased serum liver enzymes (7/12), total and direct bilirubin (7/13), BUN (5/14), and creatinine (2/14) were observed. Cats usually presented with advanced disease and none survived longer than 84 days (mean 18.8 days) postdiagnosis. Cytologically, LGLs had a mature (6/21), immature (13/21), or mixed (2/21) morphology. Necropsy lesions consisted of neoplastic lymphoid infiltrates in the jejunum, ileum, and duodenum in decreasing order of frequency. In the small intestine, mucosal ulceration (9/13) and epitheliotropism of neoplastic cells (9/13) were common. Neoplastic infiltrates were also present in the mesenteric lymph nodes (13/13), liver (12/13), spleen (8/13), kidneys (5/7), and bone marrow (5/7). A T cell phenotype (CD3epsilon+) characterized LGL neoplasia in 19/21 cases. A CD8alphaalpha+ cytotoxic/suppressor phenotype was present in 12/19 T cell tumors, 2 had a CD4+CD8alphaalpha phenotype, 3 had a CD4-CD8- phenotype, and 2 were CD4+ helper T cells. CD8beta chain expression was not detected in any instance. In two cats, a B or T cell origin could not be established. CD103 was expressed by 11 of 19 (58%) of the lymphomas tested. The immunophenotypic features shared by neoplastic LGLs in the cat and feline intestinal intraepithelial lymphocytes (IELs) support a small intestinal IEL origin for feline LGL lymphoma. PMID:16407483

  3. Fluctuations between sleep and wakefulness: wake-like features indicated by increased EEG alpha power during different sleep stages in nightmare disorder.

    PubMed

    Simor, Péter; Horváth, Klára; Ujma, Péter P; Gombos, Ferenc; Bódizs, Róbert

    2013-12-01

    Although a growing body of research indicates that frequent nightmares are related to impaired sleep regulation, the pathophysiology of nightmare disorder is far from being fully understood. We examined the relative spectral power values for NREM and REM sleep separately in 19 individuals with nightmare disorder and 21 healthy controls, based on polysomnographic recordings of the second nights' laboratory sleep. Nightmare subjects compared to controls exhibited increased relative high alpha (10-14.5Hz) and fronto-central increases in high delta (3-4Hz) power during REM sleep, and a trend of increased fronto-central low alpha (7.75-9Hz) power in NREM sleep. These differences were independent of the confounding effects of waking emotional distress. High REM alpha and low NREM alpha powers were strongly related in nightmare but not in control subjects. The topographical distribution and spectral components of REM alpha activity suggest that nightmare disordered subjects are characterized by wake-like electroencephalographic features during REM sleep. PMID:23831546

  4. Temporal relationships between independent EEG frequency modulations

    E-print Network

    Makeig, Scott

    Temporal relationships between independent EEG frequency modulations Julie Onton1 and Scott Makeig1 was found across subjects between all lower frequency modulations (delta, theta, alpha, and beta) and the broadband gamma modulations, suggesting that within single cortical source domains, when low-frequency power

  5. The preliminary study on the effect of nasyid music and rock music on brainwave signal using EEG

    Microsoft Academic Search

    Ros Shilawani S. Abdul Kadir; Mohd Hafizi Ghazali; Zunairah Hj. Murat; Mohd Nasir Taib; Husna Abdul Rahman; Siti Armiza Mohd Aris

    2010-01-01

    This preliminary study analyzes the effect of nasyid music and rock music on brainwave signal particularly focusing on alpha wave. EEG data were recorded from 30 students from Faculty of Electrical Engineering, UiTM age 18 to 27 years old. Students were interviewed before EEG recording to find out their music preference. Using EEG, the brainwave signal of the sample is

  6. Mobile EEG in epilepsy.

    PubMed

    Askamp, Jessica; van Putten, Michel J A M

    2014-01-01

    The sensitivity of routine EEG recordings for interictal epileptiform discharges in epilepsy is limited. In some patients, inpatient video-EEG may be performed to increase the likelihood of finding abnormalities. Although many agree that home EEG recordings may provide a cost-effective alternative to these recordings, their use is still not introduced everywhere. We surveyed Dutch neurologists and patients and evaluated a novel mobile EEG device (Mobita, TMSi). Key specifications were compared with three other current mobile EEG devices. We shortly discuss algorithms to assist in the review process. Thirty percent (33 out of 109) of Dutch neurologists reported that home EEG recordings are used in their hospital. The majority of neurologists think that mobile EEG can have additional value in investigation of unclear paroxysms, but not in the initial diagnosis after a first seizure. Poor electrode contacts and signal quality, limited recording time and absence of software for reliable and effective assistance in the interpretation of EEGs have been important constraints for usage, but in recent devices discussed here, many of these problems have been solved. The majority of our patients were satisfied with the home EEG procedure and did not think that our EEG device was uncomfortable to wear, but they did feel uneasy wearing it in public. PMID:24060755

  7. Perturbations of Drosophila alpha-actinin cause muscle paralysis, weakness, and atrophy but do not confer obvious nonmuscle phenotypes

    PubMed Central

    1992-01-01

    We have investigated accumulation of alpha-actinin, the principal cross- linker of actin filaments, in four Drosophila fliA mutants. A single gene is variably spliced to generate one nonmuscle and two muscle isoforms whose primary sequence differences are confined to a peptide spanning the actin binding domain and first central repeat. In fliA3 the synthesis of an adult muscle-specific isoform is blocked in flight and leg muscles, while in fliA4 the synthesis of nonmuscle and both muscle-specific isoforms is severely reduced. Affected muscles are weak or paralyzed, and, in the case of fliA3, atrophic. Their myofibrils, while structurally irregular, are remarkably normal considering that they are nearly devoid of a major contractile protein. Also surprising is that no obvious nonmuscle cell abnormalities can be discerned despite the fact that both the fliA1- and fliA4-associated mutations perturb the nonmuscle isoform. Our observations suggest that alpha- actinin stabilizes and anchors thin filament arrays, rather than orchestrating their assembly, and further imply that alpha-actinin function is redundant in both muscle and nonmuscle cells. PMID:1734023

  8. EEG Correlates of Self-Referential Processing

    PubMed Central

    Knyazev, Gennady G.

    2013-01-01

    Self-referential processing has been principally investigated using functional magnetic resonance imaging (fMRI). However, understanding of the brain functioning is not possible without careful comparison of the evidence coming from different methodological domains. This paper aims to review electroencephalographic (EEG) studies of self-referential processing and to evaluate how they correspond, complement, or contradict the existing fMRI evidence. There are potentially two approaches to the study of EEG correlates of self-referential processing. Firstly, because simultaneous registration of EEG and fMRI has become possible, the degree of overlap between these two signals in brain regions related to self-referential processing could be determined. Second and more direct approach would be the study of EEG correlates of self-referential processing per se. In this review, I discuss studies, which employed both these approaches and show that in line with fMRI evidence, EEG correlates of self-referential processing are most frequently found in brain regions overlapping with the default network, particularly in the medial prefrontal cortex. In the time domain, the discrimination of self- and others-related information is mostly associated with the P300 ERP component, but sometimes is observed even earlier. In the frequency domain, different frequency oscillations have been shown to contribute to self-referential processing, with spontaneous self-referential mentation being mostly associated with the alpha frequency band. PMID:23761757

  9. Over the last decade a wealth of research into alpha activity has shown that it is intimately linked to attention and it is now

    E-print Network

    Yeung, Nick

    electroencephalogram (EEG) alpha activity. On a trial-by-trial basis, we investigate the relationship between Group, Honeywell Labs, Redmond,WA, USA Parieto-occipital electroencephalogram (EEG) alpha power

  10. Novel active comb-shaped dry electrode for EEG measurement in hairy site.

    PubMed

    Huang, Yan-Jun; Wu, Chung-Yu; Wong, Alice May-Kuen; Lin, Bor-Shyh

    2015-01-01

    Electroencephalography (EEG) is an important biopotential, and has been widely applied in clinical applications. The conventional EEG electrode with conductive gels is usually used for measuring EEG. However, the use of conductive gel also encounters with the issue of drying and hardening. Recently, many dry EEG electrodes based on different conductive materials and techniques were proposed to solve the previous issue. However, measuring EEG in the hairy site is still a difficult challenge. In this study, a novel active comb-shaped dry electrode was proposed to measure EEG in hairy site. Different form other comb-shaped or spike-shaped dry electrodes, it can provide more excellent performance of avoiding the signal attenuation, phase distortion, and the reduction of common mode rejection ratio. Even under walking motion, it can effectively acquire EEG in hairy site. Finally, the experiments for alpha rhythm and steady-state visually evoked potential were also tested to validate the proposed electrode. PMID:25137719

  11. Phenotypic alterations in human saphenous vein culture induced by tumor necrosis factor-alpha and lipoproteins: a preliminary development of an initial atherosclerotic plaque model

    PubMed Central

    2013-01-01

    Background Atherosclerosis is a chronic progressive inflammatory disease of blood vessels particularly the arteries. The development of atherosclerotic plaques or atherogenesis is a complex process that is influenced by cardiovascular risk factors such as vascular inflammation and dyslipidemia. This study demonstrates the ability of tumor necrosis factor-alpha (TNF-?) and low density lipoproteins (LDL) to induce atherosclerotic plaque in human saphenous vein (HSV) organ culture. Methods Normal HSV segments, from male patients who had coronary bypass graft, were cultured in DMEM containing 5% heat inactivated fetal bovine serum. TNF-? (5 ng/ml) was applied in combination with native LDL (nLDL) or oxidized LDL (oxLDL) at the dose of 50 ?g/ml for 14 days. The phenotypic changes of the organ cultures characteristic of initial atherosclerotic plaques were evaluated. The effect of anti-atherogenic agent, 17-? estradiol (E2), was also determined. Results Histologic, histomorphometric, and immunohistochemical examinations revealed that HSV rings stimulated with TNF-? + nLDL or TNF-? + oxLDL can exhibit the essential morphological features of atherogenesis, including fibrous cap formation, cholesterol clefts, evident thickening of the intimal layer, increased proliferation of smooth muscle cells (SMC) and migration to the subendothelial layer, significant SMC foam cell formation, and increased expression of adhesion molecules in the vascular wall. Addition of E2 (50 nM) to the culture significantly modulated the critical changes. Consistently, mRNA profiling of the HSV model revealed that 50 of 84 genes of atherosclerosis were up-regulated. Conclusions Phenotypic changes characteristic of the initial development of atherosclerotic plaques can be induced in HSV organ culture. PMID:24010774

  12. Predictable Internal Brain Dynamics in EEG and Its Relation to Conscious States 

    E-print Network

    Yoo, Jaewook; Kwon, Jaewook; Choe, Yoonsuck

    2014-06-03

    for synchronous, and coherent sinusoidal oscillations in EEG brain signals (Nunez et al., 2001; Gerrard and Malcolm, 2007). Therefore, alpha waves are probably most predictable neural oscillations in EEG brain signals. In our FFT power spectral analysis results... be tuned more to shorter IPIs as the EEG signals generally tend to show high-frequency bursts followed by occa- sional pause of low-frequency intervals. The IPI distribution itself (Figure 6) shows that, for all cases, the distributions are positively...

  13. Identifying periods of drowsy driving using EEG.

    PubMed

    Brown, Timothy; Johnson, Robin; Milavetz, Gary

    2013-01-01

    Drowsy driving is a significant contributor to death and injury crashes on our nation's highways. Predictive neurophysiologic/physiologic solutions to reduce these incidences have been proposed and developed. EEG based metrics were found to be promising in initial studies, but remain controversial in their efficacy, primarily due to failures to develop replication studies within the simulation settings used for development, and real-world validation. This analysis sought to address these short comings by assessing the utility of the B-Alert algorithms, in a replication study of driving and drowsiness. Data were collected on the National Advanced Driving Simulator from 72 volunteer drivers exposed to three types of roadways at three times of day representing different levels of drowsiness. EEG metrics, collected using the B-Alert X10 Wireless Headset were evaluated to determine their utility in future predictive studies. The replication of the B-Alert algorithms was a secondary focus for this analysis, resulting in highly variable start times within each time of day segment, leading to EEG data being confounded by the diurnal variations that occur in the basal EEG signal. Regardless of this limitation, the analysis revealed promising outcomes. The EEG based algorithms for sleep onset, drowsiness, as well as fatigue related power spectral bandwidths (i.e. lateral central, and parietal alpha) varied with time of day of the drives. Interestingly, EEG metrics of cognitive workload were also sensative to the terrain of the drives. The replicaiton of the B-Alert algorithms were a secondary focuse in the study design, Taken together, these data indicate great potential of carefully designed studies to utilize neurophysiologic metrics to identify time of day and task and road conditions that may be at greatest risk during fatigued/drowsy periods. PMID:24406950

  14. Widespread EEG changes precede focal seizures.

    PubMed

    Perucca, Piero; Dubeau, François; Gotman, Jean

    2013-01-01

    The process by which the brain transitions into an epileptic seizure is unknown. In this study, we investigated whether the transition to seizure is associated with changes in brain dynamics detectable in the wideband EEG, and whether differences exist across underlying pathologies. Depth electrode ictal EEG recordings from 40 consecutive patients with pharmacoresistant lesional focal epilepsy were low-pass filtered at 500 Hz and sampled at 2,000 Hz. Predefined EEG sections were selected immediately before (immediate preictal), and 30 seconds before the earliest EEG sign suggestive of seizure activity (baseline). Spectral analysis, visual inspection and discrete wavelet transform were used to detect standard (delta, theta, alpha, beta and gamma) and high-frequency bands (ripples and fast ripples). At the group level, each EEG frequency band activity increased significantly from baseline to the immediate preictal section, mostly in a progressive manner and independently of any modification in the state of vigilance. Preictal increases in each frequency band activity were widespread, being observed in the seizure-onset zone and lesional tissue, as well as in remote regions. These changes occurred in all the investigated pathologies (mesial temporal atrophy/sclerosis, local/regional cortical atrophy, and malformations of cortical development), but were more pronounced in mesial temporal atrophy/sclerosis. Our findings indicate that a brain state change with distinctive features, in the form of unidirectional changes across the entire EEG bandwidth, occurs immediately prior to seizure onset. We postulate that these changes might reflect a facilitating state of the brain which enables a susceptible region to generate seizures. PMID:24260523

  15. Identifying Periods of Drowsy Driving Using EEG

    PubMed Central

    Brown, Timothy; Johnson, Robin; Milavetz, Gary

    2013-01-01

    Drowsy driving is a significant contributor to death and injury crashes on our nation’s highways. Predictive neurophysiologic/physiologic solutions to reduce these incidences have been proposed and developed. EEG based metrics were found to be promising in initial studies, but remain controversial in their efficacy, primarily due to failures to develop replication studies within the simulation settings used for development, and real-world validation. This analysis sought to address these short comings by assessing the utility of the B-Alert algorithms, in a replication study of driving and drowsiness. Data were collected on the National Advanced Driving Simulator from 72 volunteer drivers exposed to three types of roadways at three times of day representing different levels of drowsiness. EEG metrics, collected using the B-Alert X10 Wireless Headset were evaluated to determine their utility in future predictive studies. The replication of the B-Alert algorithms was a secondary focus for this analysis, resulting in highly variable start times within each time of day segment, leading to EEG data being confounded by the diurnal variations that occur in the basal EEG signal. Regardless of this limitation, the analysis revealed promising outcomes. The EEG based algorithms for sleep onset, drowsiness, as well as fatigue related power spectral bandwidths (i.e. lateral central, and parietal alpha) varied with time of day of the drives. Interestingly, EEG metrics of cognitive workload were also sensative to the terrain of the drives. The replicaiton of the B-Alert algorithms were a secondary focuse in the study design, Taken together, these data indicate great potential of carefully designed studies to utilize neurophysiologic metrics to identify time of day and task and road conditions that may be at greatest risk during fatigued/drowsy periods. PMID:24406950

  16. Initial investigation of brainwave synchronization after five sessions of Horizontal Rotation intervention using EEG

    Microsoft Academic Search

    Z. H. Murat; M. N. Taib; Z. M. Hanafiah; S. Lias; R. S. S. A. Kadir; H. A. Rahman

    2009-01-01

    This research investigates the effects of five sessions of Horizontal Rotation (HR) on human brainwaves synchronization using EEG. EEG signals were captured from 42 participants before and after undergoing HR using two-channel bipolar connection in a controlled environment. The signals were filtered and classified into the four frequency bands; Delta, Theta, Alpha and Beta. Graphs were plotted and paired T-test

  17. Quantitative EEG Markers in Mild Cognitive Impairment: Degenerative versus Vascular Brain Impairment

    PubMed Central

    Moretti, D. V.; Zanetti, O.; Binetti, G.; Frisoni, G. B.

    2012-01-01

    We evaluated the relationship between brain rhythmicity and both the cerebrovascular damage (CVD) and amygdalohippocampal complex (AHC) atrophy, as revealed by scalp electroencephalography (EEG) in a cohort of subjects with mild cognitive impairment (MCI). All MCI subjects underwent EEG recording and magnetic resonance imaging. EEGs were recorded at rest. Relative power was separately computed for delta, theta, alpha1, alpha2, and alpha3 frequency bands. In the spectral band power the severity of CVD was associated with increased delta power and decreased alpha2 power. No association of vascular damage was observed with alpha3 power. Moreover, the theta/alpha1 ratio could be a reliable index for the estimation of the individual extent of CV damage. On the other side, the group with moderate hippocampal atrophy showed the highest increase of alpha2 and alpha3 power. Moreover, when the amygdalar and hippocampal volumes are separately considered, within amygdalohippocampal complex (AHC), the increase of theta/gamma ratio is best associated with amygdalar atrophy whereas alpha3/alpha2 ratio is best associated with hippocampal atrophy. CVD and AHC damages are associated with specific EEG markers. So far, these EEG markers could have a prospective value in differential diagnosis between vascular and degenerative MCI. PMID:22900229

  18. EEG correlates of emotions in dream narratives from typical young adults and individuals with autistic spectrum disorders.

    PubMed

    Daoust, Anne-Marie; Lusignan, Félix-Antoine; Braun, Claude M J; Mottron, Laurent; Godbout, Roger

    2008-03-01

    The relationship between emotional dream content and Alpha and Beta REM sleep EEG activity was investigated in typical individuals and in Autistic Spectrum Disorders (ASD). Dream narratives of persons with ASD contained fewer emotional elements. In both groups, emotions correlated positively with slow Alpha (8.0-10.0 Hz) spectral power over parieto-occipital and left central regions, as well as with a right occipital EEG asymmetry. Slow Alpha activity in ASD individuals was lower over midline and parasagittal areas and higher over lateral areas compared to controls. Both groups displayed a right-biased slow Alpha activity for midparietal and occipital (significantly higher in control) sites. Results indicate that Alpha EEG activity may represent a neurophysiological substrate associated with emotional dream content. Distinctive Alpha EEG patterns and asymmetries suggest that dream generation implies different brain connectivity in ASD. PMID:18047484

  19. Stability of EEG inter- and intrahemispheric correlation in women.

    PubMed

    Corsi-Cabrera, M; Solís-Ortiz, S; Guevara, M A

    1997-03-01

    EEG correlation and coherence analyses have been used to study functional relationships between cortical regions, and found to vary as a function of physiological conditions, sex hormones and cognitive processes. However, the utility of serial EEG studies is dependent upon the within-subject reliability of repeated EEG recordings. The present study was undertaken to assess the within-subject and within-group stability of EEG correlations in a group of young women (n = 9). EEG was recorded during relaxed wakefulness at F3, F4, C3, C4, P3, P4, O1 and O2 for 11 sessions, during 1 month. Ten artifact free 2-s epochs of EEG from each session were digitally filtered by means of a fast Fourier transform into 6 broad bands, and correlation coefficients between the EEG activity of every pair of derivations and bands were calculated in the time domain. All EEG features were submitted to principal component analysis and the first 5 components did not show significant differences between sessions (ANOVAs) for any band or pair of derivations. Alpha and beta showed higher variability whereas slow bands showed very little variability. The within-subject stability was assessed calculating multiple correlation coefficients between all EEG features of the eleven sessions of each subject: R-values ranged from 0.85 to 0.97. Present results indicate that the pattern of functional relationships between cortical regions during resting wakefulness is a stable characteristic for each woman at least over a 1 month period and that there are no significant group differences over sessions when menstrual phases are randomly distributed between women. PMID:9129580

  20. EEG manifestations of nondual experiences in meditators.

    PubMed

    Berman, Amanda E; Stevens, Larry

    2015-01-01

    The holistic experiential benefits of meditation among a widely ranging population have been well established within the empirical literature. What remain less clear are the underlying mechanisms of the meditative process. A large impediment to this clarity is attributable to the lack of a unified and comprehensive taxonomy, as well as to the absence of clear differentiation within the literature between method of practice and resulting state. The present study discusses and then attempts to identify within our sample a theoretically universal culminating meditative state known as Nondual Awareness, which is differentiated from the method or practice state. Participants completed an in-lab meditation, during which neurological patterns were analyzed using electroencephalography (EEG). Analyses indicated significantly higher EEG power among slower wave frequencies (delta, theta, alpha) during the reported nondual events. These events appear neurologically distinct from meditation sessions as a whole, which interestingly demonstrated significant elevation within the gamma range. PMID:25460236

  1. Inter- and intra-individual probability maps in EEG cartography by use of nonparametric Fisher tests.

    PubMed

    Etévenon, P; Bertaut, A; Mitermite, F; Eustache, F; Lepaisant, J; Lechevalier, B; Zarifian, E

    1989-01-01

    The three types of non-parametric permutation Fisher tests have been applied to inter-individual group studies and further to intra-individual multiple EEG recording sequences, providing computations of EEG probability maps testing two ordinal hypotheses. Two examples of previous group studies with "EEG local cerebral activation" are given: mental computation in a group of 20 controls and caffeine effects versus placebo in a group of 10 controls. For the intra-individual study, two successive recordings of 2.3 min eyes closed (EC1 and EC2), obtained at 50 min intervals, were compared by paired exact permutation Fisher tests (over 15 or 42 synchronous EEG sequences). These tests were applied to descriptive spectral parameters: RMS and % amplitudes, mean frequencies, resonance coefficient, for raw unfiltered EEG and delta, theta, alpha, alpha 1, alpha 2, beta 1, beta 2 frequency bands. Two hypotheses were tested for each of the computed 31 parameters, providing two probability maps indicating if the parameter was greater or lower in the first EEG recording or in the second. The second EEG sequence, EC2, was "EEG activated" compared to the first sequence EC1 if the following were present: decreased amplitudes mainly in raw EEG, low activity and alpha bands; increased frequencies mainly, in raw EEG, delta and beta 1 fast activities; increased fast activity percentages; decreased coefficient of resonance. The effect of choice of reference was also evaluated: probability maps for a frontal reference were different than other probability maps obtained after computation of average reference or source derivation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2641478

  2. Atypical Alpha Asymmetry in Adults with ADHD

    ERIC Educational Resources Information Center

    Hale, T. Sigi; Smalley, Susan L.; Hanada, Grant; Macion, James; McCracken, James T.; McGough, James J.; Loo, Sandra K.

    2009-01-01

    Introduction: A growing body of literature suggests atypical cerebral asymmetry and interhemispheric interaction in ADHD. A common means of assessing lateralized brain function in clinical populations has been to examine the relative proportion of EEG alpha activity (8-12 Hz) in each hemisphere (i.e., alpha asymmetry). Increased rightward alpha

  3. [EEG synchronisation in autistic children. Analysis of coherency].

    PubMed

    Luschekina, E A; Haerdinova, O Yu; Novototsky-Vlasov, V Yu; Luschekin, V S; Strelets, V B

    2015-01-01

    EEG study of 5-7 years boys with autism revealed lower values of coherence in background delta, theta and alpha bands and higher values of coherence in background beta 1, beta 2 and gamma bands. Healthy boys showed higher values of beta and gamma coherence during cognitive task. Autistic persons demonstrated higher values of theta coherence during cognitive task. PMID:25966574

  4. Volumetric Differences in Mapped Hippocampal Regions Correlate with Increase of High Alpha Rhythm in Alzheimer's Disease

    PubMed Central

    Moretti, D. V.; Prestia, A.; Fracassi, C.; Geroldi, C.; Binetti, G.; Rossini, P. M.; Zanetti, O.; Frisoni, G. B.

    2011-01-01

    Objective. The increase of high alpha relative to low alpha power has been recently demonstrated as a reliable EEG marker of hippocampal atrophy conversion of patients with mild cognitive impairment (MCI) in Alzheimer's disease (AD). In the present study we test the reliability of this EEG index in subjects with AD. Methods. Correlation between EEG markers and volumetric differences in mapped hippocampal regions was estimated in AD patients. Results. Results show that the increase of alpha3/alpha2 power ratio is correlated with atrophy of mapped hippocampal regions in Alzheimer's disease. Conclusions. The findings confirm the possible diagnostic role of EEG markers. PMID:21760984

  5. Maternal dexamethasone and EEG hyperactivity in preterm fetal sheep.

    PubMed

    Davidson, Joanne O; Quaedackers, Josine S L T; George, Sherly A; Gunn, Alistair Jan; Bennet, Laura

    2011-08-01

    Maternal treatment with synthetic corticosteroids such as dexamethasone (DEX)significantly reduces neonatal morbidity and mortality, but its effects on the fetal brain remain unclear. In this study we evaluated the effects of DEX on EEG activity in preterm fetal sheep. Ewes at 103 days gestation received two intramuscular injections of DEX (12 mg, n = 8) or saline vehicle (n = 7) 24 h apart. Fetal EEG activity was recorded from 6 h before until 120 h after the first injection (DEX-1). DEX-1 was associated with a marked transient rise in total EEG power, maximal at 12 h (P < 0.001), with a relative increase in delta and reduced theta, alpha and beta activity, resolving by 24 h. Continuous EEG records showed a shift to larger but less frequent transient waveforms (P < 0.001). Unexpectedly, evolving epileptiform activity, consistent with electrographic and clinical seizures, developed from 178 ± 44 min after DEX-1.Similar but smaller changes were seen after the second injection. Following the injections, total power returned to control values, but the proportion of alpha activity progressively increased vs. controls (P < 0.001), with reduced interburst interval duration and number (P < 0.001). No histological neural injury or microglial activation was seen. In summary, exposure to maternal dexamethasone was associated with dramatic, evolving low-frequency hyperactivity on fetal cortical EEG recordings, followed by sustained changes consistent with maturation of fetal sleep architecture. We postulate that these effects may contribute to improved neonatal outcomes. PMID:21646408

  6. EEG data compression techniques.

    PubMed

    Antoniol, G; Tonella, P

    1997-02-01

    In this paper, electroencephalograph (EEG) and Holter EEG data compression techniques which allow perfect reconstruction of the recorded waveform from the compressed one are presented and discussed. Data compression permits one to achieve significant reduction in the space required to store signals and in transmission time. The Huffman coding technique in conjunction with derivative computation reaches high compression ratios (on average 49% on Holter and 58% on EEG signals) with low computational complexity. By exploiting this result a simple and fast encoder/decoder scheme capable of real-time performance on a PC was implemented. This simple technique is compared with other predictive transformations, vector quantization, discrete cosine transform (DCT), and repetition count compression methods. Finally, it is shown that the adoption of a collapsed Huffman tree for the encoding/decoding operations allows one to choose the maximum codeword length without significantly affecting the compression ratio. Therefore, low cost commercial microcontrollers and storage devices can be effectively used to store long Holter EEG's in a compressed format. PMID:9214790

  7. Flexible electroencephalogram (EEG) headband

    NASA Technical Reports Server (NTRS)

    Raggio, L. J.

    1973-01-01

    Headband incorporates sensors which are embedded in sponges and are exposed only on surface that touches skin. Electrode sponge system is continually fed electrolyte through forced feed vacuum system. Headband may be used for EEG testing in hospitals, clinical laboratories, rest homes, and law enforcement agencies.

  8. EEG changes during forced alternate nostril breathing.

    PubMed

    Stancák, A; Kuna, M

    1994-10-01

    The effects of 10 min forced alternate nostril breathing (FANB) on EEG topography were studied in 18 trained subjects. One type of FANB consisted in left nostril inspiration and right nostril expiration and the other type in right nostril inspiration and left nostril expiration. Mean power in the beta bands and partially in the alpha band increased during FANB irrespective of the type of nostril breathing. In addition, hemisphere asymmetry in the beta 1 band decreased in the second half of FANB suggesting that FANB has a balancing effect on the functional activity of the left and right hemisphere. PMID:7876041

  9. Analysis of brainwave dominant after horizontal rotation (HR) intervention using EEG for Theta and Delta frequency bands

    Microsoft Academic Search

    R. S. S. A. Kadir; N. Ismail; H. A. Rahman; M. N. Taib; Z. H. Murat; S. Lias

    2009-01-01

    This paper presents analysis of brainwave dominant after horizontal rotation (HR) intervention using EEG. It was conducted by interviewed all samples. Then, EEG signals were captured from the samples before and after under-going three sessions of HR. Basically, brainwave has four frequency bands which are Alpha, Beta, Theta and Delta. However, this paper will only focus on theta and delta.

  10. Activation of the alpha2beta1 integrin-mediated malignant phenotype on type I collagen in pancreatic cancer cells by shifts in the concentrations of extracellular Mg2+ and Ca2+.

    PubMed

    Grzesiak, John J; Bouvet, Michael

    2008-05-15

    The authors have previously demonstrated that alpha(2)beta(1) integrin-mediated pancreatic cancer cell adhesion to Type I collagen is Mg(2+)-dependent, inhibited by Ca(2+), and that this integrin, purified from cell lysates using Type I-collagen-sepharose in Mg(2+), can be eluted with Ca(2+). In the present study, the authors examined the divalent cation-dependency of alpha(2)beta(1) integrin-mediated pancreatic cancer cell adhesion, migration and proliferation on Type I collagen, an extracellular matrix protein shown to be highly up-regulated, and to promote the malignant phenotype in vitro and in vivo. The results indicate that cells attach to Type I collagen maximally when Mg(2+) is greater than 1 mM, and that addition of increasing concentrations of Ca(2+) reduces this adhesion. These effects are reversible, in that previous cell attachment in Mg(2+) can be reversed by adding Ca(2+), and vice versa. They also demonstrate that pancreatic cancer cells migrate and proliferate on Type I collagen in Mg(2+) alone, but maximally when Mg(2+) is present at concentrations that promote maximal cell adhesion and Ca(2+) is present at concentrations less than Mg(2+). Cell adhesion and proliferation assays, as well as affinity chromatography on Type I collagen using anti-integrin function-blocking monoclonal antibodies indicate that the effects of these divalent cation shifts are mediated specifically by the alpha(2)beta(1) integrin. As pancreatic juice contains over 1,200-fold more Mg(2+) than Ca(2+) and solid tumors are characterized by increased magnesium load, these data indicate that such pathophysiological divalent cation shifts could be involved in the activation of the alpha(2)beta(1) integrin-mediated malignant phenotype on Type I collagen in the pancreatic cancer. PMID:18224679

  11. The Default Mode Network and EEG Regional Spectral Power: A Simultaneous fMRI-EEG Study

    PubMed Central

    Werner, Cornelius J.; Hitz, Konrad; Boers, Frank; Kawohl, Wolfram; Shah, N. Jon

    2014-01-01

    Electroencephalography (EEG) frequencies have been linked to specific functions as an “electrophysiological signature” of a function. A combination of oscillatory rhythms has also been described for specific functions, with or without predominance of one specific frequency-band. In a simultaneous fMRI-EEG study at 3 T we studied the relationship between the default mode network (DMN) and the power of EEG frequency bands. As a methodological approach, we applied Multivariate Exploratory Linear Optimized Decomposition into Independent Components (MELODIC) and dual regression analysis for fMRI resting state data. EEG power for the alpha, beta, delta and theta-bands were extracted from the structures forming the DMN in a region-of-interest approach by applying Low Resolution Electromagnetic Tomography (LORETA). A strong link between the spontaneous BOLD response of the left parahippocampal gyrus and the delta-band extracted from the anterior cingulate cortex was found. A positive correlation between the beta-1 frequency power extracted from the posterior cingulate cortex (PCC) and the spontaneous BOLD response of the right supplementary motor cortex was also established. The beta-2 frequency power extracted from the PCC and the precuneus showed a positive correlation with the BOLD response of the right frontal cortex. Our results support the notion of beta-band activity governing the “status quo” in cognitive and motor setup. The highly significant correlation found between the delta power within the DMN and the parahippocampal gyrus is in line with the association of delta frequencies with memory processes. We assumed “ongoing activity” during “resting state” in bringing events from the past to the mind, in which the parahippocampal gyrus is a relevant structure. Our data demonstrate that spontaneous BOLD fluctuations within the DMN are associated with different EEG-bands and strengthen the conclusion that this network is characterized by a specific electrophysiological signature created by combination of different brain rhythms subserving different putative functions. PMID:24505434

  12. Exon-intron structure of the human neuronal nicotinic acetylcholine receptor {alpha}4 subunit (CHRNA4)

    SciTech Connect

    Steinlein, O.; Weiland, S.; Stoodt, J.; Propping, P. [Univ. of Bonn (Germany)] [Univ. of Bonn (Germany)

    1996-03-01

    The human neuronal nicotinic acetylcholine receptor {alpha}4 subunit gene (CHRNA4) is located in the candidate region for three different phenotypes: benign familial neonatal convulsions, autosomal dominant nocturnal frontal lobe epilepsy, and low-voltage EEG. Recently, a missense mutation in transmembrane domain 2 of CHRNA4 was found to be associated with autosomal dominant nocturnal frontal lobe epilepsy in one extended pedigree. We have determined the genomic organization of CHRNA4, which consists of six exons distributed over approximately 17 kb of genomic DNA. The nucleotide sequence obtained from the genomic regions adjacent to the exon boundaries enabled us to develop a set of primer pairs for PCR amplification of the complete coding region. The sequence analysis provides the basis for a comprehensive mutation screening of CHRNA4 in the above-mentioned phenotypes and possibly in other types of idopathic epilepsies. 29 refs., 3 figs., 1 tab.

  13. How to write an EEG report

    PubMed Central

    Benbadis, Selim R.

    2013-01-01

    The EEG report is structured to include demographics of the patient studied and reason for the EEG; specifics of the EEG techniques used; a description of the patterns, frequencies, voltages, and progression of the EEG pattern that were recorded; and finally a clinical impression of the EEG significance. The interpretation should be concise, clear and to the point, avoid jargon and EEG specifics, and should be understandable by any health care practitioner. PMID:23267044

  14. [EEG in mathematical logical problem solving].

    PubMed

    Pavlygina, R A; Davydov, V I; Sakaharov, D S; Tutushkina, M V; Priamonosova, A A

    2010-01-01

    The model of mathematical logic tasks was developed at which decision there was a value coherence in delta-range raised. In low-frequency ranges (delta, theta, and alpha) a coherence of potentials of frontal cortex were increased. In high-frequency ranges (beta1, beta2, gamma) in frontal cortex coherence was decreased, and its increasing in central, parietal, temporal, and occipital areas with prevalence in the left hemisphere. Most changes of quantity of positive connections observed in value diagonal coherence. Analysis of spectral power EEG has shown, that at the decision of tasks there is a generalised raising on a cortex in delta-range. Theta-activity increased in a frontal cortex, and gamma band was raised in occipital areas. A spectral power in an alpha range mainly decreased. PMID:21260977

  15. Wavelet packet analysis of EEG signals from dyslexic children with writing disability.

    PubMed

    Fuad, N; Mansor, W; Lee, Khuan Y

    2013-01-01

    This paper describes Wavelet Packet Analysis of EEG signal of dyslexic children with writing disability. Two activities were carried out during EEG recordings; relax and and writing letters. EEG signals were collected using biosignal gMobilab system and analysed using Wavelet Packet Decomposition to extract alpha and beta brainwave rhythm. Statistical data such as log energy entropy and standard deviation were used to compare the characteristic of EEG signals from dyslexic and normal children. Result showed that the dyslexic children consumed higher energy at left parietal lobe during writing activity especially those who write incorrectly. The alpha band shows higher log energy entropy for dyslexic children compare to normal children at most channel during relax. PMID:24110331

  16. EEG biofeedback improves attentional bias in high trait anxiety individuals

    PubMed Central

    2013-01-01

    Background Emotion-related attentional bias is implicated in the aetiology and maintenance of anxiety disorders. Electroencephalogram (EEG) biofeedback can obviously improve the anxiety disorders and reduce stress level, and can also enhance attention performance in healthy subjects. The present study examined the effects and mechanisms of EEG biofeedback training on the attentional bias of high trait anxiety (HTA) individuals toward negative stimuli. Results Event-related potentials were recorded while HTA (n=24) and nonanxious (n=21) individuals performed the color-word emotional Stroop task. During the emotional Stroop task, HTA participants showed longer reaction times and P300 latencies induced by negative words, compared to nonanxious participants. The EEG biofeedback significantly decreased the trait anxiety inventory score and reaction time in naming the color of negative words in the HTA group. P300 latencies evoked by negative stimuli in the EEG biofeedback group were significantly reduced after the alpha training, while no significant changes were observed in the sham biofeedback group after the intervention. Conclusion The prolonged P300 latency is associated with attentional bias to negative stimuli in the HTA group. EEG biofeedback training demonstrated a significant improvement of negative emotional attentional bias in HTA individuals, which may be due to the normalization of P300 latency. PMID:24099141

  17. Studying the default mode and its mindfulness-induced changes using EEG functional connectivity.

    PubMed

    Berkovich-Ohana, Aviva; Glicksohn, Joseph; Goldstein, Abraham

    2014-10-01

    The default mode network (DMN) has been largely studied by imaging, but not yet by neurodynamics, using electroencephalography (EEG) functional connectivity (FC). mindfulness meditation (MM), a receptive, non-elaborative training is theorized to lower DMN activity. We explored: (i) the usefulness of EEG-FC for investigating the DMN and (ii) the MM-induced EEG-FC effects. To this end, three MM groups were compared with controls, employing EEG-FC (-MPC, mean phase coherence). Our results show that: (i) DMN activity was identified as reduced overall inter-hemispheric gamma MPC during the transition from resting state to a time production task and (ii) MM-induced a state increase in alpha MPC as well as a trait decrease in EEG-FC. The MM-induced EEG-FC decrease was irrespective of expertise or band. Specifically, there was a relative reduction in right theta MPC, and left alpha and gamma MPC. The left gamma MPC was negatively correlated with MM expertise, possibly related to lower internal verbalization. The trait lower gamma MPC supports the notion of MM-induced reduction in DMN activity, related with self-reference and mind-wandering. This report emphasizes the possibility of studying the DMN using EEG-FC as well as the importance of studying meditation in relation to it. PMID:24194576

  18. The spatiospectral characterization of brain networks: fusing concurrent EEG spectra and fMRI maps

    PubMed Central

    Bridwell, David A.; Wu, Lei; Eichele, Tom; Calhoun, Vince D.

    2013-01-01

    Different imaging modalities capture different aspects of brain activity. Functional Magnetic Resonance Imaging (fMRI) reveals intrinsic networks whose BOLD signals have periods from 100s (0.01 Hz) to about 10s (0.1 Hz). Electroencephalographic (EEG) recordings, in contrast, commonly reflect cortical electrical fluctuations with periods up to 20 ms (50 Hz) or above. We examined the correspondence between intrinsic fMRI and EEG network activity at rest in order to characterize brain networks both spatially (with fMRI) and spectrally (with EEG). Brain networks were separately identified within the concurrently recorded fMRI and EEG at the aggregate group level with group independent component analysis and the association between spatial fMRI and frequency by spatial EEG sources was examined by deconvolving their component time courses. The two modalities are considered linked if the estimated impulse response function (IRF) is significantly non-zero at biologically plausible delays. We found that negative associations were primarily present within two of five alpha components, which highlights the importance of considering multiple alpha sources in EEG-fMRI. Positive associations were primarily present within the lower (e.g. delta and theta) and higher (e.g. upper beta and lower gamma) spectral regions, sometimes within the same fMRI components. Collectively, the results demonstrate a promising approach to characterize brain networks spatially and spectrally, and reveal that positive and negative associations appear within partially distinct regions of the EEG spectrum. PMID:23266744

  19. Altered resting-state EEG source functional connectivity in schizophrenia: the effect of illness duration

    PubMed Central

    Di Lorenzo, Giorgio; Daverio, Andrea; Ferrentino, Fabiola; Santarnecchi, Emiliano; Ciabattini, Fabio; Monaco, Leonardo; Lisi, Giulia; Barone, Ylenia; Di Lorenzo, Cherubino; Niolu, Cinzia; Seri, Stefano; Siracusano, Alberto

    2015-01-01

    Despite the increasing body of evidence supporting the hypothesis of schizophrenia as a disconnection syndrome, studies of resting-state EEG Source Functional Connectivity (EEG-SFC) in people affected by schizophrenia are sparse. The aim of the present study was to investigate resting-state EEG-SFC in 77 stable, medicated patients with schizophrenia (SCZ) compared to 78 healthy volunteers (HV). In order to study the effect of illness duration, SCZ were divided in those with a short duration of disease (SDD; n = 25) and those with a long duration of disease (LDD; n = 52). Resting-state EEG recordings in eyes closed condition were analyzed and lagged phase synchronization (LPS) indices were calculated for each ROI pair in the source-space EEG data. In delta and theta bands, SCZ had greater EEG-SFC than HV; a higher theta band connectivity in frontal regions was observed in LDD compared with SDD. In the alpha band, SCZ showed lower frontal EEG-SFC compared with HV whereas no differences were found between LDD and SDD. In the beta1 band, SCZ had greater EEG-SFC compared with HVs and in the beta2 band, LDD presented lower frontal and parieto-temporal EEG-SFC compared with HV. In the gamma band, SDD had greater connectivity values compared with LDD and HV. This study suggests that resting state brain network connectivity is abnormally organized in schizophrenia, with different patterns for the different EEG frequency components and that EEG can be a powerful tool to further elucidate the complexity of such disordered connectivity. PMID:25999835

  20. Y-position cysteine substitution in type I collagen (alpha1(I) R888C/p.R1066C) is associated with osteogenesis imperfecta/Ehlers-Danlos syndrome phenotype.

    PubMed

    Cabral, Wayne A; Makareeva, Elena; Letocha, Anne D; Scribanu, Nina; Fertala, Andrzej; Steplewski, Andrzej; Keene, Douglas R; Persikov, Anton V; Leikin, Sergey; Marini, Joan C

    2007-04-01

    The most common mutations in type I collagen causing types II-IV osteogenesis imperfecta (OI) result in substitution for glycine in a Gly-Xaa-Yaa triplet by another amino acid. We delineated a Y-position substitution in a small pedigree with a combined OI/Ehlers-Danlos Syndrome (EDS) phenotype, characterized by moderately decreased DEXA z-score (-1.3 to -2.6), long bone fractures, and large-joint hyperextensibility. Affected individuals have an alpha1(I)R888C (p.R1066C) substitution in one COL1A1 allele. Polyacrylamide gel electrophoresis (PAGE) of [(3)H]-proline labeled steady-state collagen reveals slight overmodification of the alpha1(I) monomer band, much less than expected for a substitution of a neighboring glycine residue, and a faint alpha1(I) dimer. Dimers form in about 10% of proband type I collagen. Dimer formation is inefficient compared to a possible 25%, probably because the SH-side chains have less proximity in this Y-position than when substituting for a glycine. Theoretical stability calculations, differential scanning calorimetry (DSC) thermograms, and thermal denaturation curves showed only weak local destabilization from the Y-position substitution in one or two chains of a collagen helix, but greater destabilization is seen in collagen containing dimers. Y-position collagen dimers cause kinking of the helix, resulting in a register shift that is propagated the full length of the helix and causes resistance to procollagen processing by N-proteinase. Collagen containing the Y-position substitution is incorporated into matrix deposited in culture, including immaturely and maturely cross-linked fractions. In vivo, proband dermal fibrils have decreased density and increased diameter compared to controls, with occasional aggregate formation. This report on Y-position substitutions in type I collagen extends the range of phenotypes caused by nonglycine substitutions and shows that, similar to X- and Y-position substitutions in types II and III collagen, the phenotypes resulting from nonglycine substitutions in type I collagen are distinct from those caused by glycine substitutions. PMID:17206620

  1. Dry EEG Electrodes

    PubMed Central

    Lopez-Gordo, M. A.; Sanchez-Morillo, D.; Valle, F. Pelayo

    2014-01-01

    Electroencephalography (EEG) emerged in the second decade of the 20th century as a technique for recording the neurophysiological response. Since then, there has been little variation in the physical principles that sustain the signal acquisition probes, otherwise called electrodes. Currently, new advances in technology have brought new unexpected fields of applications apart from the clinical, for which new aspects such as usability and gel-free operation are first order priorities. Thanks to new advances in materials and integrated electronic systems technologies, a new generation of dry electrodes has been developed to fulfill the need. In this manuscript, we review current approaches to develop dry EEG electrodes for clinical and other applications, including information about measurement methods and evaluation reports. We conclude that, although a broad and non-homogeneous diversity of approaches has been evaluated without a consensus in procedures and methodology, their performances are not far from those obtained with wet electrodes, which are considered the gold standard, thus enabling the former to be a useful tool in a variety of novel applications. PMID:25046013

  2. Development of a novel EEG rating scale for head injury using dichotomous variables.

    PubMed

    Rae-Grant, A D; Barbour, P J; Reed, J

    1991-11-01

    We developed a new EEG rating scale for electrographic assessment of head injured patients. Phenomena present in posttraumatic EEG were scored as dichotomous variables (present or absent). These phenomena included background activity (alpha, beta, theta, delta), sleep spindles, focal abnormalities, reactivity and variability, epileptiform activity, and specific comatose patterns. Each variable was weighted according to its perceived prognostic value: i.e., normal alpha 10, flat EEG -10, spindles 4, etc. Combinations of possible scores ranged from +23 to -10. Fifty-seven EEGs from different head injured patients were independently and retrospectively analyzed by two investigators. There was a high correlation for intra- (r = 0.95) and inter- (r = 0.85) observer rating using the dichotomous test. When patients with scores over 15 (i.e., with reactive alpha) and patients with scores of -10 (i.e., ECI records) were excluded, the intra-rater and inter-rater correlations were still high (0.81 and 0.76, respectively). There was a high correlation between Glasgow outcome score at discharge and the dichotomous EEG score. This EEG scale scores most major categories of EEG activity, utilizes a multipoint scale for correlation purposes, and allows data to be analyzed in sub-categories (i.e., spindles in coma). The separate weighting score allows for refinement of the scale after data collection (i.e., to fit prospective outcome). We feel that this scale is reproducible and valid, and may be applicable to other patient groups with severely altered EEGs. PMID:1718707

  3. 21 CFR 882.1420 - Electroencephalogram (EEG) signal spectrum analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Electroencephalogram (EEG) signal spectrum analyzer. 882.1420 Section...Electroencephalogram (EEG) signal spectrum analyzer. (a) Identification...electroencephalogram (EEG) signal spectrum analyzer is a device used to...

  4. 21 CFR 882.1420 - Electroencephalogram (EEG) signal spectrum analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Electroencephalogram (EEG) signal spectrum analyzer. 882.1420 Section...Electroencephalogram (EEG) signal spectrum analyzer. (a) Identification...electroencephalogram (EEG) signal spectrum analyzer is a device used to...

  5. 21 CFR 882.1420 - Electroencephalogram (EEG) signal spectrum analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Electroencephalogram (EEG) signal spectrum analyzer. 882.1420 Section...Electroencephalogram (EEG) signal spectrum analyzer. (a) Identification...electroencephalogram (EEG) signal spectrum analyzer is a device used to...

  6. 21 CFR 882.1420 - Electroencephalogram (EEG) signal spectrum analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Electroencephalogram (EEG) signal spectrum analyzer. 882.1420 Section...Electroencephalogram (EEG) signal spectrum analyzer. (a) Identification...electroencephalogram (EEG) signal spectrum analyzer is a device used to...

  7. 21 CFR 882.1420 - Electroencephalogram (EEG) signal spectrum analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Electroencephalogram (EEG) signal spectrum analyzer. 882.1420 Section...Electroencephalogram (EEG) signal spectrum analyzer. (a) Identification...electroencephalogram (EEG) signal spectrum analyzer is a device used to...

  8. Electroclinical phenotypes in a pedigreed baboon colony

    PubMed Central

    Szabó, C. Ákos; Knape, Koyle D.; Leland, M. Michelle; Williams, Jeff T.

    2013-01-01

    Summary This is the first large-scale epidemiological study evaluating the prevalence of interictal epileptic discharges (IEDs) and photosensitivity (PS) recorded by scalp EEG in a natural nonhuman-primate model of photosensitive, generalized epilepsy. Scalp EEG was used to characterize electroclinical phenotypes in a large baboon pedigree housed at the Southwest National Primate Research Center at the Texas Biomedical Research Institute (Texas Biomed) based upon IEDs and photosensitivity. Scalp EEG studies including intermittent light stimulation (ILS) were performed in 671 baboons. Clinical histories were available for 531 (79%) of the animals. The EEG studies lasted 53 (±11) min, during which the baboons were lightly sedated with intramuscular ketamine doses of 5.6 (±0.8) mg. The animals were further classified according to electroclinical phenotypes recorded by scalp EEG: presence or absence of IEDs, seizures and photoparoxysmal or photoconvulsive responses. Effects of age, gender, and species on EEG phenotypes were compared using (Chi-square, two-sided, ? < 0.05). Sensitivity and specificity of IEDs and photosensitivity to detect a history of seizures was calculated. Generalized IEDs and photosensitivity were identified in 324 (49%) and 156 (23%) pedigreed baboons, respectively. Only photosensitivity was associated with gender, significantly increased in males. Otherwise, while IEDs were marginally more prevalent among males, there were no other significant associations of IEDs or photosensitivity with age or subspecies. Photosensitivity was significantly associated with IEDs, with demonstrating a possible association with gender and subspecies. Of 531 baboons with histories of clinical events, 91 (17%) had witnessed seizures and 269 (51%) were asymptomatic. IEDs demonstrated sensitivity and specificity of 62% and 57%, and photosensitivity of 40% and 83%, for prediction of seizures, respectively. While these EEG findings mirror the high prevalence of seizures in the colony, the sensitivity and specificity of scalp EEG may have been affected by ketamine’s ability to lower the threshold for IEDs and seizures, particularly in animals predisposed to epilepsy. Photosensitivity provides a specific biological marker for epilepsy in future epidemiological, genetic, behavioral and histopathological studies. PMID:23499213

  9. Modulation of the COMT Val158Met polymorphism on resting-state EEG power

    PubMed Central

    Solís-Ortiz, Silvia; Pérez-Luque, Elva; Gutiérrez-Muñoz, Mayra

    2015-01-01

    The catechol-O-methyltransferase (COMT) Val158Met polymorphism impacts cortical dopamine (DA) levels and may influence cortical electrical activity in the human brain. This study investigated whether COMT genotype influences resting-state electroencephalogram (EEG) power in the frontal, parietal and midline regions in healthy volunteers. EEG recordings were conducted in the resting-state in 13 postmenopausal healthy woman carriers of the Val/Val genotype and 11 with the Met/Met genotype. The resting EEG spectral absolute power in the frontal (F3, F4, F7, F8, FC3 and FC4), parietal (CP3, CP4, P3 and P4) and midline (Fz, FCz, Cz, CPz, Pz and Oz) was analyzed during the eyes-open and eyes-closed conditions. The frequency bands considered were the delta, theta, alpha1, alpha2, beta1 and beta2. EEG data of the Val/Val and Met/Met genotypes, brain regions and conditions were analyzed using a general linear model analysis. In the individuals with the Met/Met genotype, delta activity was increased in the eyes-closed condition, theta activity was increased in the eyes-closed and in the eyes-open conditions, and alpha1 band, alpha2 band and beta1band activity was increased in the eyes-closed condition. A significant interaction between COMT genotypes and spectral bands was observed. Met homozygote individuals exhibited more delta, theta and beta1 activity than individuals with the Val/Val genotype. No significant interaction between COMT genotypes and the resting-state EEG regional power and conditions were observed for the three brain regions studied. Our findings indicate that the COMT Val158Met polymorphism does not directly impact resting-state EEG regional power, but instead suggest that COMT genotype can modulate resting-state EEG spectral power in postmenopausal healthy women. PMID:25883560

  10. An EEG Finger-Print of fMRI deep regional activation.

    PubMed

    Meir-Hasson, Yehudit; Kinreich, Sivan; Podlipsky, Ilana; Hendler, Talma; Intrator, Nathan

    2014-11-15

    This work introduces a general framework for producing an EEG Finger-Print (EFP) which can be used to predict specific brain activity as measured by fMRI at a given deep region. This new approach allows for improved EEG spatial resolution based on simultaneous fMRI activity measurements. Advanced signal processing and machine learning methods were applied on EEG data acquired simultaneously with fMRI during relaxation training guided by on-line continuous feedback on changing alpha/theta EEG measure. We focused on demonstrating improved EEG prediction of activation in sub-cortical regions such as the amygdala. Our analysis shows that a ridge regression model that is based on time/frequency representation of EEG data from a single electrode, can predict the amygdala related activity significantly better than a traditional theta/alpha activity sampled from the best electrode and about 1/3 of the times, significantly better than a linear combination of frequencies with a pre-defined delay. The far-reaching goal of our approach is to be able to reduce the need for fMRI scanning for probing specific sub-cortical regions such as the amygdala as the basis for brain-training procedures. On the other hand, activity in those regions can be characterized with higher temporal resolution than is obtained by fMRI alone thus revealing additional information about their processing mode. PMID:24246494

  11. Envelope responses in single-trial EEG indicate attended speaker in a ‘cocktail party’

    NASA Astrophysics Data System (ADS)

    Horton, Cort; Srinivasan, Ramesh; D'Zmura, Michael

    2014-08-01

    Objective. Recent studies have shown that auditory cortex better encodes the envelope of attended speech than that of unattended speech during multi-speaker (‘cocktail party’) situations. We investigated whether these differences were sufficiently robust within single-trial electroencephalographic (EEG) data to accurately determine where subjects attended. Additionally, we compared this measure to other established EEG markers of attention. Approach. High-resolution EEG was recorded while subjects engaged in a two-speaker ‘cocktail party’ task. Cortical responses to speech envelopes were extracted by cross-correlating the envelopes with each EEG channel. We also measured steady-state responses (elicited via high-frequency amplitude modulation of the speech) and alpha-band power, both of which have been sensitive to attention in previous studies. Using linear classifiers, we then examined how well each of these features could be used to predict the subjects’ side of attention at various epoch lengths. Main results. We found that the attended speaker could be determined reliably from the envelope responses calculated from short periods of EEG, with accuracy improving as a function of sample length. Furthermore, envelope responses were far better indicators of attention than changes in either alpha power or steady-state responses. Significance. These results suggest that envelope-related signals recorded in EEG data can be used to form robust auditory BCI’s that do not require artificial manipulation (e.g., amplitude modulation) of stimuli to function.

  12. EEG Findings and Sleep Deprivation

    Microsoft Academic Search

    A. Tartara; A. Moglia; R. Manni; C. Corbellini

    1980-01-01

    EEG findings after sleep deprivation in 452 cases are reported. Effectiveness and specificity of this activating method in the field of epilepsy both in adult and in younger people are emphasized.Copyright © 1980 S. Karger AG, Basel

  13. Multimodal imaging: an evaluation of univariate and multivariate methods for simultaneous EEG/fMRI.

    PubMed

    De Martino, Federico; Valente, Giancarlo; de Borst, Aline W; Esposito, Fabrizio; Roebroeck, Alard; Goebel, Rainer; Formisano, Elia

    2010-10-01

    The combination of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has been proposed as a tool to study brain dynamics with both high temporal and high spatial resolution. Multimodal imaging techniques rely on the assumption of a common neuronal source for the different recorded signals. In order to maximally exploit the combination of these techniques, one needs to understand the coupling (i.e., the relation) between electroencephalographic (EEG) and fMRI blood oxygen level-dependent (BOLD) signals. Recently, simultaneous EEG-fMRI measurements have been used to investigate the relation between the two signals. Previous attempts at the analysis of simultaneous EEG-fMRI data reported significant correlations between regional BOLD activations and modulation of both event-related potential (ERP) and oscillatory EEG power, mostly in the alpha but also in other frequency bands. Beyond the correlation of the two measured brain signals, the relevant issue we address here is the ability of predicting the signal in one modality using information from the other modality. Using multivariate machine learning-based regression, we show how it is possible to predict EEG power oscillations from simultaneously acquired fMRI data during an eyes-open/eyes-closed task using either the original channels or the underlying cortically distributed sources as the relevant EEG signal for the analysis of multimodal data. PMID:20097029

  14. Effects of early intervention on EEG power and coherence in previously institutionalized children in Romania.

    PubMed

    Marshall, Peter J; Reeb, Bethany C; Fox, Nathan A; Nelson, Charles A; Zeanah, Charles H

    2008-01-01

    Two groups of Romanian children were compared on spectral power and coherence in the electroencephalogram (EEG) in early childhood. One group consisted of previously institutionalized children who had been randomly assigned to a foster care intervention at a mean age of 23 months. The second group had been randomized to remain in institutional care. Because of a policy of noninterference, a number of these children also experienced placement into alternative family care environments. There were minimal group differences between the foster care and institutionalized groups in EEG power and coherence across all measured frequency bands at 42 months of age. However, age at foster care placement within the foster care group was correlated with certain measures of EEG power and coherence. Earlier age at foster care placement was associated with increased alpha power and decreased short-distance EEG coherence. Further analyses separating age at placement from duration of intervention suggest that this effect may be more robust for EEG coherence than EEG band power. Supplementary analyses examined whether the EEG measures mediated changes in intellectual abilities within the foster care children, but no clear evidence of mediation was observed. PMID:18606035

  15. A 6.4MB duplication of the alpha-synuclein locus causing fronto-temporal dementia and parkinsonism - phenotype-genotype correlations

    PubMed Central

    Kara, Eleanna; Kiely, Aoife P; Proukakis, Christos; Giffin, Nicola; Love, Seth; Hehir, Jason; Rantell, Khadija; Pandraud, Amelie; Hernandez, Dena G; Nacheva, Elizabeth; Pittman, Alan M; Nalls, Mike A; Singleton, Andrew B; Revesz, Tamas; Bhatia, Kailash P; Quinn, Niall; Hardy, John; Holton, Janice L; Houlden, Henry

    2015-01-01

    Importance SNCA locus duplications are associated with variable clinical features and reduced penetrance but the reasons underlying this variability are unknown. Objective 1) To report a novel family carrying a heterozygous 6.4Mb duplication of the SNCA locus with an atypical clinical presentation strongly reminiscent of frontotemporal dementia (FTD) and late-onset pallidopyramidal syndromes. 2) To study phenotype-genotype correlations in SNCA locus duplications. Design, Setting, Participants and Data sources We report the clinical and neuropathologic features of a family carrying a 6.4Mb duplication of the SNCA locus. To identify candidate disease modifiers, we undertake a genetic analysis in the family and conduct statistical analysis on previously published cases carrying SNCA locus duplication using regression modelling with robust standard errors to account for clustering at the family level. Main outcome measures To assess whether length of the SNCA locus duplication influences disease penetrance and severity, and whether extra-duplication factors have a disease-modifying role. Results We identified a large 6.4Mb duplication of the SNCA locus in this family. Neuropathological analysis showed extensive ?-synuclein pathology with minimal phospho-tau pathology. Genetic analysis showed an increased burden of PD-related risk factors and the disease-predisposing H1/H1 MAPT haplotype. Statistical analysis of previously published cases suggested that there is a trend towards increasing disease severity and disease penetrance with increasing duplication size. The corresponding odds ratios (95% CI) from the univariate analyses were 1.17 (0.81 to 1.68) and 1.34 (0.78 to 2.31) respectively. Gender was significantly associated with both disease risk and severity; males compared to females had increased disease risk and severity and the corresponding odds ratios (95% CI) from the univariate analyses were 8.36 (1.97 to 35.42) and 5.55 (1.39 to 22.22) respectively. Conclusions and relevance These findings further expand the phenotypic spectrum of SNCA locus duplications. Increased dosage of genes located within the duplicated region probably cannot increase disease risk and disease severity without the contribution of additional risk factors. Identification of disease modifiers accounting for the substantial phenotypic heterogeneity of patients with SNCA locus duplications could provide insight into molecular events involved in ?-synuclein aggregation. PMID:25003242

  16. Bristle-sensors—low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications

    NASA Astrophysics Data System (ADS)

    Grozea, Cristian; Voinescu, Catalin D.; Fazli, Siamac

    2011-04-01

    In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use.

  17. Optimizing microsurgical skills with EEG neurofeedback

    PubMed Central

    Ros, Tomas; Moseley, Merrick J; Bloom, Philip A; Benjamin, Larry; Parkinson, Lesley A; Gruzelier, John H

    2009-01-01

    Background By enabling individuals to self-regulate their brainwave activity in the field of optimal performance in healthy individuals, neurofeedback has been found to improve cognitive and artistic performance. Here we assessed whether two distinct EEG neurofeedback protocols could develop surgical skill, given the important role this skill plays in medicine. Results National Health Service trainee ophthalmic microsurgeons (N = 20) were randomly assigned to either Sensory Motor Rhythm-Theta (SMR) or Alpha-Theta (AT) groups, a randomized subset of which were also part of a wait-list 'no-treatment' control group (N = 8). Neurofeedback groups received eight 30-minute sessions of EEG training. Pre-post assessment included a skills lab surgical procedure with timed measures and expert ratings from video-recordings by consultant surgeons, together with state/trait anxiety self-reports. SMR training demonstrated advantages absent in the control group, with improvements in surgical skill according to 1) the expert ratings: overall technique (d = 0.6, p < 0.03) and suture task (d = 0.9, p < 0.02) (judges' intraclass correlation coefficient = 0.85); and 2) with overall time on task (d = 0.5, p = 0.02), while everyday anxiety (trait) decreased (d = 0.5, p < 0.02). Importantly the decrease in surgical task time was strongly associated with SMR EEG training changes (p < 0.01), especially with continued reduction of theta (4–7 Hz) power. AT training produced marginal improvements in technique and overall performance time, which were accompanied by a standard error indicative of large individual differences. Notwithstanding, successful within session elevation of the theta-alpha ratio correlated positively with improvements in overall technique (r = 0.64, p = 0.047). Conclusion SMR-Theta neurofeedback training provided significant improvement in surgical technique whilst considerably reducing time on task by 26%. There was also evidence that AT training marginally reduced total surgery time, despite suboptimal training efficacies. Overall, the data set provides encouraging evidence of optimised learning of a complex medical specialty via neurofeedback training. PMID:19630948

  18. Gender differences in association between serotonin transporter gene polymorphism and resting-state EEG activity.

    PubMed

    Volf, N V; Belousova, L V; Knyazev, G G; Kulikov, A V

    2015-01-22

    Human brain oscillations represent important features of information processing and are highly heritable. Gender has been observed to affect association between the 5-HTTLPR (serotonin-transporter-linked polymorphic region) polymorphism and various endophenotypes. This study aimed to investigate the effects of 5-HTTLPR on the spontaneous electroencephalography (EEG) activity in healthy male and female subjects. DNA samples extracted from buccal swabs and resting EEG recorded at 60 standard leads were collected from 210 (101 men and 109 women) volunteers. Spectral EEG power estimates and cortical sources of EEG activity were investigated. It was shown that effects of 5-HTTLPR polymorphism on electrical activity of the brain vary as a function of gender. Women with the S/L genotype had greater global EEG power compared to men with the same genotype. In men, current source density was markedly different among genotype groups in only alpha 2 and alpha 3 frequency ranges: S/S allele carriers had higher current source density estimates in the left inferior parietal lobule in comparison with the L/L group. In women, genotype difference in global power asymmetry was found in the central-temporal region. Contrasting L/L and S/L genotype carriers also yielded significant effects in the right hemisphere inferior parietal lobule and the right postcentral gyrus with L/L genotype carriers showing lower current source density estimates than S/L genotype carriers in all but gamma bands. So, in women, the effects of 5-HTTLPR polymorphism were associated with modulation of the EEG activity in a wide range of EEG frequencies. The significance of the results lies in the demonstration of gene by sex interaction with resting EEG that has implications for understanding sex-related differences in affective states, emotion and cognition. PMID:25450956

  19. Multisensory integration of dynamic emotional faces and voices: method for simultaneous EEG-fMRI measurements

    PubMed Central

    Schelenz, Patrick D.; Klasen, Martin; Reese, Barbara; Regenbogen, Christina; Wolf, Dhana; Kato, Yutaka; Mathiak, Klaus

    2013-01-01

    Combined EEG-fMRI analysis correlates time courses from single electrodes or independent EEG components with the hemodynamic response. Implementing information from only one electrode, however, may miss relevant information from complex electrophysiological networks. Component based analysis, in turn, depends on a priori knowledge of the signal topography. Complex designs such as studies on multisensory integration of emotions investigate subtle differences in distributed networks based on only a few trials per condition. Thus, they require a sensitive and comprehensive approach which does not rely on a-priori knowledge about the underlying neural processes. In this pilot study, feasibility and sensitivity of source localization-driven analysis for EEG-fMRI was tested using a multisensory integration paradigm. Dynamic audiovisual stimuli consisting of emotional talking faces and pseudowords with emotional prosody were rated in a delayed response task. The trials comprised affectively congruent and incongruent displays. In addition to event-locked EEG and fMRI analyses, induced oscillatory EEG responses at estimated cortical sources and in specific temporo-spectral windows were correlated with the corresponding BOLD responses. EEG analysis showed high data quality with less than 10% trial rejection. In an early time window, alpha oscillations were suppressed in bilateral occipital cortices and fMRI analysis confirmed high data quality with reliable activation in auditory, visual and frontal areas to the presentation of multisensory stimuli. In line with previous studies, we obtained reliable correlation patterns for event locked occipital alpha suppression and BOLD signal time course. Our results suggest a valid methodological approach to investigate complex stimuli using the present source localization driven method for EEG-fMRI. This novel procedure may help to investigate combined EEG-fMRI data from novel complex paradigms with high spatial and temporal resolution. PMID:24294195

  20. Autonomic and EEG Patterns during Eyes-Closed Rest and Transcendental Meditation (TM) Practice: The Basis for a Neural Model of TM Practice

    Microsoft Academic Search

    Frederick Travis; R. Keith Wallace

    1999-01-01

    In this single-blind within-subject study, autonomic and EEG variables were compared during 10-min, order-balanced eyes-closed rest and Transcendental Meditation (TM) sessions. TM sessions were distinguished by (1) lower breath rates, (2) lower skin conductance levels, (3) higher respiratory sinus arrhythmia levels, and (4) higher alpha anterior–posterior and frontal EEG coherence. Alpha power was not significantly different between conditions. These results

  1. Functional brain signal processing : EEG and fMRI Electroencephalogram (EEG): Cortical sources of the scalp EEG signals; Linear

    E-print Network

    Bandyopadhyay, Antar

    Functional brain signal processing : EEG and fMRI Electroencephalogram (EEG): Cortical sources the course. 2. Electroencephalogram processing using neural networks, C. Robert, J.-F. Gaudy and A. M. Limoge

  2. Concordance between distributed EEG source localization and simultaneous EEG-fMRI studies of epileptic spikes

    E-print Network

    Daunizeau, Jean

    according to its concordance with EEG data. Nine patients with focal epilepsy who underwent EEG complementary strategies to assess and classify EEG-fMRI concordance. We showed that for most patients, part epileptic spikes are generated, we assessed the level of concordance between EEG source localization using

  3. Application of independent component analysis for the data mining of simultaneous Eeg-fMRI: preliminary experience on sleep onset.

    PubMed

    Lee, Jong-Hwan; Oh, Sungsuk; Jolesz, Ferenc A; Park, Hyunwook; Yoo, Seung-Schik

    2009-01-01

    The simultaneous acquisition of electroencephalogram (EEG) and functional MRI (fMRI) signals is potentially advantageous because of the superior resolution that is achieved in both the temporal and spatial domains, respectively. However, ballistocardiographic artifacts along with ocular artifacts are a major obstacle for the detection of the EEG signatures of interest. Since the sources corresponding to these artifacts are independent from those producing the EEG signatures, we applied the Infomax-based independent component analysis (ICA) technique to separate the EEG signatures from the artifacts. The isolated EEG signatures were further utilized to model the canonical hemodynamic response functions (HRFs). Subsequently, the brain areas from which these EEG signatures originated were identified as locales of activation patterns from the analysis of fMRI data. Upon the identification and subsequent evaluation of brain areas generating interictal epileptic discharge (IED) spikes from an epileptic subject, the presented method was successfully applied to detect the theta and alpha rhythms that are sleep onset-related EEG signatures along with the subsequent neural circuitries from a sleep-deprived volunteer. These results suggest that the ICA technique may be useful for the preprocessing of simultaneous EEG-fMRI acquisitions, especially when a reference paradigm is unavailable. PMID:19922343

  4. Plastic modulation of PTSD resting-state networks by EEG neurofeedback

    PubMed Central

    Kluetsch, Rosemarie C.; Ros, Tomas; Théberge, Jean; Frewen, Paul A.; Calhoun, Vince D.; Schmahl, Christian; Jetly, Rakesh; Lanius, Ruth A.

    2015-01-01

    Objective Electroencephalographic (EEG) neurofeedback training has been shown to produce plastic modulations in salience network and default mode network functional connectivity in healthy individuals. In this study, we investigated whether a single session of neurofeedback training aimed at the voluntary reduction of alpha rhythm (8–12 Hz) amplitude would be related to differences in EEG network oscillations, functional MRI (fMRI) connectivity, and subjective measures of state anxiety and arousal in a group of individuals with PTSD. Method 21 individuals with PTSD related to childhood abuse underwent 30 minutes of EEG neurofeedback training preceded and followed by a resting-state fMRI scan. Results Alpha desynchronizing neurofeedback was associated with decreased alpha amplitude during training, followed by a significant increase (‘rebound’) in resting-state alpha synchronization. This rebound was linked to increased calmness, greater salience network connectivity with the right insula, and enhanced default mode network connectivity with bilateral posterior cingulate, right middle frontal gyrus, and left medial prefrontal cortex. Conclusion Our study represents a first step in elucidating the potential neurobehavioral mechanisms mediating the effects of neurofeedback treatment on regulatory systems in PTSD. Moreover, it documents for the first time a spontaneous EEG ‘rebound’ after neurofeedback, pointing to homeostatic/compensatory mechanisms operating in the brain. PMID:24266644

  5. Resting State EEG Power and Coherence Abnormalities in Bipolar Disorder and Schizophrenia

    PubMed Central

    Kam, Julia W. Y.; Bolbecker, Amanda R.; O’Donnell, Brian F.; Hetrick, William P.; Brenner, Colleen A.

    2014-01-01

    Resting state electroencephalogram (EEG) abnormalities in schizophrenia and bipolar disorder patients suggest alterations in neural oscillatory activity. However, few studies directly compare these anomalies between patient groups, and none have examined EEG coherence. Therefore, this study investigated whether these electrophysiological characteristics differentiate clinical populations from one another, and from non-psychiatric controls. To address this question, resting EEG power and coherence were assessed in 76 bipolar patients (BP), 132 schizophrenia patients (SZ), and 136 non-psychiatric controls (NC). We conducted separate repeated-measures ANOVAs to examine group differences within seven frequency bands across several brain regions. BP showed significantly greater power relative to SZ at higher frequencies including Beta and Gamma across all regions. In terms of intra-hemispheric coherence, while SZ generally exhibited higher coherence at Delta compared to NC and BP, both SZ and BP showed higher coherence at Alpha1 and Alpha2. In contrast, BP and HC showed higher coherence within hemispheres compared to SZ at Beta 1. In terms of inter-hemispheric coherence, SZ displayed higher coherence compared to NC at temporal sites at both Alpha1 and Alpha2. Taken together, BP exhibited increased high frequency power with few disruptions in neural synchronization. In contrast, SZ generally exhibited enhanced synchronization within and across hemispheres. These findings suggest that resting EEG can be a sensitive measure for differentiating between clinical disorders. PMID:24090715

  6. Integrating wireless EEGs into medical sensor networks

    Microsoft Academic Search

    Behçet Sarikaya; M. Abdul Alim; Siamak Rezaei

    2006-01-01

    Wireless Electroencephalograms (EEG) are currently being used to wirelessly transmit the data from brain sensors to a computer and they carry huge potential for many future medical applications. This paper presents the design of a hybrid medical sensor network with Tmote Sky motes as wireless EEG sensor nodes at the lowest level collecting EEG signals and sending them to Stargate

  7. EEG oscillatory states as neuro-phenomenology of consciousness as revealed from patients in vegetative and minimally conscious states.

    PubMed

    Fingelkurts, Alexander A; Fingelkurts, Andrew A; Bagnato, Sergio; Boccagni, Cristina; Galardi, Giuseppe

    2012-03-01

    The value of resting electroencephalogram (EEG) in revealing neural constitutes of consciousness (NCC) was examined. We quantified the dynamic repertoire, duration and oscillatory type of EEG microstates in eyes-closed rest in relation to the degree of expression of clinical self-consciousness. For NCC a model was suggested that contrasted normal, severely disturbed state of consciousness and state without consciousness. Patients with disorders of consciousness were used. Results suggested that the repertoire, duration and oscillatory type of EEG microstates in resting condition quantitatively related to the level of consciousness expression in brain-damaged patients and healthy-conscious subjects. Specifically, results demonstrated that (a) decreased number of EEG microstate types was associated with altered states of consciousness, (b) unawareness was associated with the lack of diversity in EEG alpha-rhythmic microstates, and (c) the probability for the occurrence and duration of delta-, theta- and slow-alpha-rhythmic microstates were associated with unawareness, whereas the probability for the occurrence and duration of fast-alpha-rhythmic microstates were associated with consciousness. In conclusion, resting EEG has a potential value in revealing NCC. This work may have implications for clinical care and medical-legal decisions in patients with disorders of consciousness. PMID:22054641

  8. Phenotype-genotype characterization of alpha-thalassemia mental retardation syndrome due to isolated monosomy of 16p13.3.

    PubMed

    Gibson, William T; Harvard, Chansonette; Qiao, Ying; Somerville, Martin J; Lewis, M E Suzanne; Rajcan-Separovic, Evica

    2008-01-15

    An 8-year-old Caucasian girl presented with mild dysmorphic features and intellectual disability (ID) affecting multiple spheres. Dysmorphisms included a high forehead with up-slanting palpebral fissures, prominent nasal root and bridge, flattened maxilla, high-arched palate, and anterior frenulum. Structural brain anomalies included reduced periventricular white matter volume and thin corpus callosum. The presence of HbH bodies and her clinical presentation raised suspicion for autosomal alpha-thalassemia mental retardation syndrome (ATR-16). Whole-genome array analysis at 1 Mb resolution was performed, which revealed a sub-microscopic loss of 16p involving clones RP11-344L6 at 0.1 Mb, RP1-121I4 at 0.2 Mb and RP11-334D3 at 1 Mb. FISH confirmed deletion (del) of the terminal clone (RP1-121I4) on 16pter, which was de novo in origin. The more proximal clone RP11-334D3 (at 1 Mb) showed diminished FISH signal intensity on one of the homologues, suggesting that one breakpoint occurred within this clone. Quantitative PCR (qPCR) confirmed a de novo deletion encompassing SOX8 (at 0.97 Mb). ATR-16 is characterized by ID with mild, nonspecific dysmorphic features, and is associated with terminal del16p (MIM No. 141750). Cases of isolated monosomy for 16p are rarely described; such descriptions help to delineate the syndrome in the absence of confounding karyotypic anomalies. We describe detailed molecular cytogenetic and clinical findings relating to a subject with ATR-16. PMID:18076105

  9. Continuous and routine EEG in intensive care

    PubMed Central

    van der Goes, David N.; Nuwer, Marc R.; Nelson, Lonnie; Eccher, Matthew A.

    2013-01-01

    Objectives: To evaluate the effect of intensive care unit continuous EEG (cEEG) monitoring on inpatient mortality, hospital charges, and length of stay. Methods: A retrospective cross-sectional study was conducted using the Nationwide Inpatient Sample, a dataset representing 20% of inpatient discharges in nonfederal US hospitals. Adult discharge records reporting mechanical ventilation and EEG (routine EEG or cEEG) were included. cEEG was compared with routine EEG alone in association with the primary outcome of in-hospital mortality and secondary outcomes of total hospital charges and length of stay. Demographics, hospital characteristics, and medical comorbidity were used for multivariate adjustments of the primary and secondary outcomes. Results: A total of 40,945 patient discharges in the weighted sample met inclusion criteria, of which 5,949 had reported cEEG. Mechanically ventilated patients receiving cEEG were younger than routine EEG patients (56 vs 61 years; p < 0.001). There was no difference in the 2 groups in income or medical comorbidities. cEEG was significantly associated with lower in-hospital mortality in both univariate (odds ratio = 0.54, 95% confidence interval 0.45–0.64; p < 0.001) and multivariate (odds ratio = 0.63, 95% confidence interval 0.51–0.76; p < 0.001) analyses. There was no significant difference in costs or length of stay for patients who received cEEG relative to those receiving only routine EEG. Sensitivity analysis showed that adjusting for diagnosis-related groups (DRGs) for any neurologic diagnoses, DRGs for neurologic procedures, and specific DRGs for epilepsy/convulsions did not substantially alter the association of cEEG with reduced inpatient mortality. Conclusions: cEEG is favorably associated with inpatient survival in mechanically ventilated patients, without adding significant charges to the hospital stay. PMID:24186910

  10. Can arousing feedback rectify lapses in driving? Prediction from EEG power spectra

    NASA Astrophysics Data System (ADS)

    Lin, Chin-Teng; Huang, Kuan-Chih; Chuang, Chun-Hsiang; Ko, Li-Wei; Jung, Tzyy-Ping

    2013-10-01

    Objective. This study explores the neurophysiological changes, measured using an electroencephalogram (EEG), in response to an arousing warning signal delivered to drowsy drivers, and predicts the efficacy of the feedback based on changes in the EEG. Approach. Eleven healthy subjects participated in sustained-attention driving experiments. The driving task required participants to maintain their cruising position and compensate for randomly induced lane deviations using the steering wheel, while their EEG and driving performance were continuously monitored. The arousing warning signal was delivered to participants who experienced momentary behavioral lapses, failing to respond rapidly to lane-departure events (specifically the reaction time exceeded three times the alert reaction time). Main results. The results of our previous studies revealed that arousing feedback immediately reversed deteriorating driving performance, which was accompanied by concurrent EEG theta- and alpha-power suppression in the bilateral occipital areas. This study further proposes a feedback efficacy assessment system to accurately estimate the efficacy of arousing warning signals delivered to drowsy participants by monitoring the changes in their EEG power spectra immediately thereafter. The classification accuracy was up 77.8% for determining the need for triggering additional warning signals. Significance. The findings of this study, in conjunction with previous studies on EEG correlates of behavioral lapses, might lead to a practical closed-loop system to predict, monitor and rectify behavioral lapses of human operators in attention-critical settings.

  11. [Computer analysis of the EEG as an aid in terminating diet therapy in phenylketonuria].

    PubMed

    Donker, D N; Reits, D; Storm van Leeuwen, W; Van Sprang, F J; Wadman, S K

    1978-01-01

    In 6 patients with PKU, being on a low phenylalanine diet, the effect of reintroduction of phenylalanine on the E.E.G. was studied. The children, therefore, received daily loads of 100 or 150 mg phenylalanine/Kg bodyweight, equally divided over the meals. Computerized spectral analysis of the E.E.G's was performed during and after the loading tests. This made quantification possible of the following E.E.G. changes: 1) the increase of activities in the theta frequency band (4-8 Hz); 2) the frequency change of the alpha rhythm; 3) the change of the degree of synchrony between identical frequencies occurring in different derivations. A linear relation was found between these quantified E.E.G. parameters and the phenylalanine blood-level. After stopping the loading test E.E.G. abnormalities reversed suggesting that they could be considered as a measure for the degree of intoxication caused by the phenylalanine and/or its metabolites. It is suggested that the E.E.G. data may be useful parameters for alleviation or termination of the diet. PMID:663350

  12. Use of EEG to track visual attention in two dimensions

    NASA Astrophysics Data System (ADS)

    Coleman, Robert Alan

    This thesis investigates the use of EEG to track the spatial locus of covert, visual attention. Three experiments are described that were to detect the position of visual attention as it was deployed towards targets as they appeared. The first experiment uses flickering fields placed in the periphery of the visual field to induce SSVEPs, to be used to track the position of attention which varies horizontally between them. The flickers failed to produce significant SSVEP activity. However attention locus could still able to be tracked by endogenous lateralizations of 12Hz and 18Hz activity. A second experiment was then designed to track attention locus as it varied either horizontally or vertically using only endogenous EEG activity in the alpha (10Hz), low-beta (18Hz), high-beta (24Hz) and gamma (36Hz) bands. Tracking proved successful in all but a small number of subjects. Horizontally varying attention was associated with lateralizations of the alpha band and low-beta band, while vertically varying attention was associated with varying alpha band and low-beta band activity in the occipito-parietal junction over the central sulcus. A third experiment was then performed to track attention locus as it varied in two dimensions. Using a combination of the features found to be informative in the second experiment, tracking proved successful in up to nine bins of two-dimensional visual space. Tracking in either the horizontal or vertical dimension was also successful when attention varied in two dimensions. The success of this method shows that EEG can be used to passively detect the spatial position of attention, at varying degrees of position, as a person attends to objects they see.

  13. Masern-Schutzimpfung und EEG

    Microsoft Academic Search

    Klaus Müller; Gisela Eckoldt

    1966-01-01

    Bei 102 Kindern wurden vor sowie 8 Tage nach der Masernimpfung mit abgeschwächter Lebendvaccine EEG-Ableitungen vorgenommen. Dreimal traten leichte Veränderungen auf, die nach spätestens 3 Wochen wieder verschwanden. Sieben bereits vor der Impfung pathologische Kurven blieben unbeeinflußt. Diese und gleichartige Befunde anderer Autoren weisen vom elektrencephalographischen Standpunkt auf ein geringes Risiko bezüglich cerebraler Komplikationen bei Masernschutzimpfungen hin; insbesondere stellen präformierte

  14. Hypercapnia is a Key Correlate of EEG Activation and Daytime Sleepiness in Hypercapnic Sleep Disordered Breathing Patients

    PubMed Central

    Wang, David; Piper, Amanda J.; Yee, Brendon J.; Wong, Keith K.; Kim, Jong-Won; D'Rozario, Angela; Rowsell, Luke; Dijk, Derk-Jan; Grunstein, Ronald R.

    2014-01-01

    Background: The key determinants of daytime drowsiness in sleep disordered breathing (SDB) are unclear. Hypercapnia has not been examined as a potential contributor due to the lack of reliable measurement during sleep. To overcome this limitation, we studied predominantly hypercapnic SDB patients to investigate the role of hypercapnia on EEG activation and daytime sleepiness. Methods: We measured overnight polysomnography (PSG), arterial blood gases, and Epworth Sleepiness Scale in 55 severe SDB patients with obesity hypoventilation syndrome or overlap syndrome (COPD+ obstructive sleep apnea) before and ?3 months after positive airway pressure (PAP) treatment. Quantitative EEG analyses were performed, and the Delta/ Alpha ratio was used as an indicator of EEG activation. Results: After the PAP treatment, these patients showed a significant decrease in their waking pCO2, daytime sleepiness, as well as all key breathing/oxygenation parameters during sleep. Overnight Delta/Alpha ratio of EEG was significantly reduced. There is a significant cross-correlation between a reduced wake pCO2, a faster (more activated) sleep EEG (reduced Delta/Alpha ratio) and reduced daytime sleepiness (all p < 0.05) with PAP treatment. Multiple regression analyses showed the degree of change in hypercapnia to be the only significant predictor for both ESS and Delta/ Alpha ratio. Conclusions: Hypercapnia is a key correlate of EEG activation and daytime sleepiness in hypercapnic SDB patients. The relationship between hypercapnia and sleepiness may be mediated by reduced neuro-electrical brain activity. Commentary: A commentary on this article appears in this issue on page 523. Citation: Wang D, Piper AJ, Yee BJ, Wong KK, Kim JW, D'Rozario A, Rowsell L, Dijk DJ, Grunstein RR. Hypercapnia is a key correlate of EEG activation and daytime sleepiness in hypercapnic sleep disordered breathing patients. J Clin Sleep Med 2014;10(5):517-522. PMID:24910553

  15. Effects of Manual Lymph Drainage of the Neck on EEG in Subjects with Psychological Stress

    PubMed Central

    Shim, Jung-Myo; Kim, Sung-Joong

    2014-01-01

    [Purpose] The present study investigated the effect of manual lymph drainage (MLD) of the neck on electroencephalography (EEG) in subjects with psychological stress. [Methods] Twenty-six subjects were randomly allocated to receive one 15-min session of either MLD or resting on a bed (control). [Results] Analysis of EEG in the MLD group showed a significant increase in relaxation, manifested as an increase in average absolute and relative delta and alpha activity. [Conclusion] It is suggested that MLD provides acute neural effects that increase relaxation in subjects with psychological stress. PMID:24567691

  16. Effets des radiofréquences sur le système nerveux central chez l?homme : EEG, sommeil, cognition, vascularisation

    NASA Astrophysics Data System (ADS)

    Ghosn, Rania; Villégier, Anne-Sophie; Selmaoui, Brahim; Thuróczy, Georges; de Sèze, René

    2013-05-01

    Most of clinical studies on radiofrequency electromagnetic fields (RF) were directed at mobile phone-related exposures, usually at the level of the head, at their effect on some physiological functions including sleep, brain electrical activity (EEG), cognitive processes, brain vascularisation, and more generally on the cardiovascular and endocrine systems. They were frequently carried out on healthy adults. Effects on the amplitude of EEG alpha waves, mainly during sleep, look reproducible. It would however be important to define more precisely whether and how the absence of electromagnetic disturbance between RF exposure and the recording systems is checked. No consensus arises about cognitive effects. Some effects on cerebral vascularisation need complementary work.

  17. EEG-microstate dependent emergence of perceptual awareness

    PubMed Central

    Britz, Juliane; Díaz Hernàndez, Laura; Ro, Tony; Michel, Christoph M.

    2014-01-01

    We investigated whether the differences in perceptual awareness for stimuli at the threshold of awareness can arise from different global brain states before stimulus onset indexed by the EEG microstate. We used a metacontrast backward masking paradigm in which subjects had to discriminate between two weak stimuli and obtained measures of accuracy and awareness while their EEG was recorded from 256 channels. Comparing targets that were correctly identified with and without awareness allowed us to contrast differences in awareness while keeping performance constant for identical physical stimuli. Two distinct pre-stimulus scalp potential fields (microstate maps) dissociated correct identification with and without awareness, and their estimated intracranial generators were stronger in primary visual cortex before correct identification without awareness. This difference in activity cannot be explained by differences in alpha power or phase which were less reliably linked with differential pre-stimulus activation of primary visual cortex. Our results shed a new light on the function of pre-stimulus activity in early visual cortex in visual awareness and emphasize the importance of trial-by-trials analysis of the spatial configuration of the scalp potential field identified with multichannel EEG. PMID:24860450

  18. Effects of neural synchrony on surface EEG.

    PubMed

    Musall, Simon; von Pföstl, Veronika; Rauch, Alexander; Logothetis, Nikos K; Whittingstall, Kevin

    2014-04-01

    It has long been assumed that the surface electroencephalography (EEG) signal depends on both the amplitude and spatial synchronization of underlying neural activity, though isolating their respective contribution remains elusive. To address this, we made simultaneous surface EEG measurements along with intracortical recordings of local field potentials (LFPs) in the primary visual cortex of behaving nonhuman primates. We found that trial-by-trial fluctuations in EEG power could be explained by a linear combination of LFP power and interelectrode temporal synchrony. This effect was observed in both stimulus and stimulus-free conditions and was particularly strong in the gamma range (30-100 Hz). Subsequently, we used pharmacological manipulations to show that neural synchrony can produce a positively modulated EEG signal even when the LFP signal is negatively modulated. Taken together, our results demonstrate that neural synchrony can modulate EEG signals independently of amplitude changes in neural activity. This finding has strong implications for the interpretation of EEG in basic and clinical research, and helps reconcile EEG response discrepancies observed in different modalities (e.g., EEG vs. functional magnetic resonance imaging) and different spatial scales (e.g., EEG vs. intracranial EEG). PMID:23236202

  19. Effects of nootropics on the EEG in conscious rats and their modification by glutamatergic inhibitors.

    PubMed

    Vorobyov, Vasily; Kaptsov, Vladimir; Kovalev, Georgy; Sengpiel, Frank

    2011-05-30

    To study the effects of acute and repeated injections of nootropics and to learn how glutamate receptors might be involved in their mediation, the frequency spectra of cortical and hippocampal electroencephalogram (EEG) were analyzed in non-narcotized rats subcutaneously injected repeatedly with Piracetam (400mg/kg) or its analogue, Noopept (0.2mg/kg), after intracerebroventricular infusions of saline (5 ?l) or the antagonists of NMDA and quisqualate/AMPA receptors: CPP (0.1 nmol) and GDEE (1 ?mol), respectively. Piracetam increased alpha/beta1 EEG activity in the left frontal cortex, and alpha activity in both the right cortex and hippocampus, with a 10-min latency and 40-min duration. Noopept increased alpha/beta1 activity, with 30-min latency and 40-min duration in all brain areas. CPP pretreatment eliminated Piracetam EEG effects; reduced Noopept effects in the cortex and completely suppressed them in the hippocampus. After four injections of Piracetam, EEG effects were very small in the cortex, and completely lacking in the hippocampus, while GDEE pretreatment partially recovered them. The effect of Noopept in the alpha/beta1 ranges was replaced by increased beta2 activity after the eighth injection, while no effects were observed after the ninth one. GDEE pretreatment restored the effect of Noopept in the beta2 frequency range. These results demonstrate similarities in EEG effects and their mediatory mechanisms for Piracetam and its much more effective analogue, Noopept. Activation of NMDA receptors is involved in the effects of a single injection of the nootropics, whereas activation of quisqualate/AMPA receptors is associated with the decrease in their efficacy after repeated use. PMID:21414388

  20. Sleep misperception, EEG characteristics and autonomic nervous system activity in primary insomnia: a retrospective study on polysomnographic data.

    PubMed

    Maes, J; Verbraecken, J; Willemen, M; De Volder, I; van Gastel, A; Michiels, N; Verbeek, I; Vandekerckhove, M; Wuyts, J; Haex, B; Willemen, T; Exadaktylos, V; Bulckaert, A; Cluydts, R

    2014-03-01

    Misperception of Sleep Onset Latency, often found in Primary Insomnia, has been cited to be influenced by hyperarousal, reflected in EEG- and ECG-related indices. The aim of this retrospective study was to examine the association between Central Nervous System (i.e. EEG) and Autonomic Nervous System activity in the Sleep Onset Period and the first NREM sleep cycle in Primary Insomnia (n=17) and healthy controls (n=11). Furthermore, the study examined the influence of elevated EEG and Autonomic Nervous System activity on Stage2 sleep-protective mechanisms (K-complexes and sleep spindles). Confirming previous findings, the Primary Insomnia-group overestimated Sleep Onset Latency and this overestimation was correlated with elevated EEG activity. A higher amount of beta EEG activity during the Sleep Onset Period was correlated with the appearance of K-complexes immediately followed by a sleep spindle in the Primary Insomnia-group. This can be interpreted as an extra attempt to protect sleep continuity or as a failure of the sleep-protective role of the K-complex by fast EEG frequencies following within one second. The strong association found between K-alpha (K-complex within one second followed by 8-12 Hz EEG activity) in Stage2 sleep and a lower parasympathetic Autonomic Nervous System dominance (less high frequency HR) in Slow-wave sleep, further assumes a state of hyperarousal continuing through sleep in Primary Insomnia. PMID:24177246

  1. Phenotyping Bleeding

    PubMed Central

    James, Paula; Coller, Barry S.

    2013-01-01

    Purpose of review Although recorded evidence of phenotyping bleeding disorders extends back two millennia, standardization of phenotyping has only begun in the past half century. This was spurred by the need for greater precision in diagnosing disorders in order to select proper laboratory tests and treatment, and the realization that the bleeding history provides prognostic information about the future risk of bleeding with surgery or invasive procedures. Recent findings New bleeding assessment tools (BATs) have been developed to: 1. evaluate the relative bleeding risks associated with new anticoagulants and antiplatelet agents, 2. assess the efficacy of new thrombopoiesis stimulating agents in preventing hemorrhage in patients with immune thrombocytopenia, and 3. assess complex gene-gene and gene-environment interactions. New web-based systems allow many researchers to collaborate by sharing the same electronic phenotyping infrastructure. Major issues of validation remain, but at present, the data indicate that the new BATs have relatively high negative predictive value for excluding a significant bleeding disorder, but disappointingly low positive predictive values. Summary New instruments to phenotype bleeding have been developed to address a number of different important clinical and research goals. The improved standardization and opportunities for collaborative studies hold promise for maximizing diagnostic, prognostic, and scientific information. PMID:22759628

  2. Automated Epilepsy Diagnosis Using Interictal Scalp EEG

    E-print Network

    Bao, Forrest Sheng; Hu, Jing; Lie, Donald Y -C; Zhang, Yuanlin; Oommen, K J

    2009-01-01

    Approximately over 50 million people worldwide suffer from epilepsy. Traditional diagnosis of epilepsy relies on tedious visual screening by highly trained clinicians from lengthy EEG recording that contains the presence of seizure (ictal) activities. Nowadays, there are many automatic systems that can recognize seizure-related EEG signals to help the diagnosis. However, it is very costly and inconvenient to obtain long-term EEG data with seizure activities, especially in areas short of medical resources. We demonstrate in this paper that we can use the interictal scalp EEG data, which is much easier to collect than the ictal data, to automatically diagnose whether a person is epileptic. In our automated EEG recognition system, we extract three classes of features from the EEG data and build Probabilistic Neural Networks (PNNs) fed with these features. We optimize the feature extraction parameters and combine these PNNs through a voting mechanism. As a result, our system achieves an impressive 94.07% accuracy...

  3. The neurobiology of the EEG biomarker as a predictor of treatment response in depression.

    PubMed

    Baskaran, Anusha; Milev, Roumen; McIntyre, Roger S

    2012-09-01

    The management of depression remains a constant challenge in clinical practice. This is largely due to the fact that initial treatments frequently do not lead to remission and recovery. The current treatment approach involves lengthy trial-and-error periods. It would be beneficial to have early reliable predictors to determine whether patients will respond to treatment or not. Electroencephalography (EEG) derived biomarkers namely change in the activity of EEG frequency bands, hemispheric alpha asymmetry, theta cordance, the antidepressant treatment response index (ATR) and evoked potentials have all been shown to predict response to a variety of antidepressant medications. However, the neurobiology in support of this association has been largely unexplored. In this review, we discuss biological mechanisms for each EEG derived biomarker predictive of treatment response. Validating such biomarkers will not only greatly aid clinicians in selecting antidepressant treatment for individual patients but will also provide a critical step in drug discovery. PMID:22569197

  4. Eye contact reveals a relationship between Neuroticism and anterior EEG asymmetry.

    PubMed

    Uusberg, Helen; Allik, Jüri; Hietanen, Jari K

    2015-07-01

    Although anterior functional brain asymmetry has been linked to individual differences in affect and motivation, its relations with the Five Factor Model personality traits remain unclear. We investigated anterior EEG alpha-activity asymmetry in response to variable degrees of social contact induced by different gaze directions of a "live" model. Neuroticism was negatively related to the anterior EEG asymmetry scores in response to direct gaze, indicating that higher levels of Neuroticism were associated with avoidance-related, relative right-sided functional brain asymmetry. Neuroticism was also related to behavioral direct gaze avoidance and subjective averted gaze preference. These relationships arose primarily from the Withdrawal aspect factor, suggesting that two subdomains of Neuroticism may be differentially related to approach-avoidance tendencies. These findings demonstrate that experimental manipulations of social contact can reveal personality related differences in anterior EEG asymmetry responsiveness, offering a motivationally salient alternative to resting state measures. PMID:25980386

  5. Independent EEG sources are dipolar.

    PubMed

    Delorme, Arnaud; Palmer, Jason; Onton, Julie; Oostenveld, Robert; Makeig, Scott

    2012-01-01

    Independent component analysis (ICA) and blind source separation (BSS) methods are increasingly used to separate individual brain and non-brain source signals mixed by volume conduction in electroencephalographic (EEG) and other electrophysiological recordings. We compared results of decomposing thirteen 71-channel human scalp EEG datasets by 22 ICA and BSS algorithms, assessing the pairwise mutual information (PMI) in scalp channel pairs, the remaining PMI in component pairs, the overall mutual information reduction (MIR) effected by each decomposition, and decomposition 'dipolarity' defined as the number of component scalp maps matching the projection of a single equivalent dipole with less than a given residual variance. The least well-performing algorithm was principal component analysis (PCA); best performing were AMICA and other likelihood/mutual information based ICA methods. Though these and other commonly-used decomposition methods returned many similar components, across 18 ICA/BSS algorithms mean dipolarity varied linearly with both MIR and with PMI remaining between the resulting component time courses, a result compatible with an interpretation of many maximally independent EEG components as being volume-conducted projections of partially-synchronous local cortical field activity within single compact cortical domains. To encourage further method comparisons, the data and software used to prepare the results have been made available (http://sccn.ucsd.edu/wiki/BSSComparison). PMID:22355308

  6. Independent EEG Sources Are Dipolar

    PubMed Central

    Delorme, Arnaud; Palmer, Jason; Onton, Julie; Oostenveld, Robert; Makeig, Scott

    2012-01-01

    Independent component analysis (ICA) and blind source separation (BSS) methods are increasingly used to separate individual brain and non-brain source signals mixed by volume conduction in electroencephalographic (EEG) and other electrophysiological recordings. We compared results of decomposing thirteen 71-channel human scalp EEG datasets by 22 ICA and BSS algorithms, assessing the pairwise mutual information (PMI) in scalp channel pairs, the remaining PMI in component pairs, the overall mutual information reduction (MIR) effected by each decomposition, and decomposition ‘dipolarity’ defined as the number of component scalp maps matching the projection of a single equivalent dipole with less than a given residual variance. The least well-performing algorithm was principal component analysis (PCA); best performing were AMICA and other likelihood/mutual information based ICA methods. Though these and other commonly-used decomposition methods returned many similar components, across 18 ICA/BSS algorithms mean dipolarity varied linearly with both MIR and with PMI remaining between the resulting component time courses, a result compatible with an interpretation of many maximally independent EEG components as being volume-conducted projections of partially-synchronous local cortical field activity within single compact cortical domains. To encourage further method comparisons, the data and software used to prepare the results have been made available (http://sccn.ucsd.edu/wiki/BSSComparison). PMID:22355308

  7. EEG dynamics in patients with Alzheimer's disease.

    PubMed

    Jeong, Jaeseung

    2004-07-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by cognitive and intellectual deficits and behavior disturbance. The electroencephalogram (EEG) has been used as a tool for diagnosing AD for several decades. The hallmark of EEG abnormalities in AD patients is a shift of the power spectrum to lower frequencies and a decrease in coherence of fast rhythms. These abnormalities are thought to be associated with functional disconnections among cortical areas resulting from death of cortical neurons, axonal pathology, cholinergic deficits, etc. This article reviews main findings of EEG abnormalities in AD patients obtained from conventional spectral analysis and nonlinear dynamical methods. In particular, nonlinear alterations in the EEG of AD patients, i.e. a decreased complexity of EEG patterns and reduced information transmission among cortical areas, and their clinical implications are discussed. For future studies, improvement of the accuracy of differential diagnosis and early detection of AD based on multimodal approaches, longitudinal studies on nonlinear dynamics of the EEG, drug effects on the EEG dynamics, and linear and nonlinear functional connectivity among cortical regions in AD are proposed to be investigated. EEG abnormalities of AD patients are characterized by slowed mean frequency, less complex activity, and reduced coherences among cortical regions. These abnormalities suggest that the EEG has utility as a valuable tool for differential and early diagnosis of AD. PMID:15203050

  8. EEG evolution in Sturge-Weber syndrome.

    PubMed

    Kossoff, Eric H; Bachur, Catherine D; Quain, Angela M; Ewen, Joshua B; Comi, Anne M

    2014-05-01

    The EEG in Sturge-Weber syndrome (SWS) was theorized over 50 years ago as changing over time from normality to focal asymmetry to lastly epileptiform. We sought to validate these findings in a larger cohort today. Children with confirmed SWS and routine EEG at our center were evaluated retrospectively. An EEG score (0-3) was created and linked to patient current age, overall neurologic function, and seizure frequency. Eighty-one EEGs from 44 patients with SWS (mean age 2.0 years (range: 0.2-37.9 years)) were evaluated and assigned an EEG score. The mean age for patients with an EEG score of 0-1 (normal or focal slowing) was 3.2 years (SEM 0.6), whereas those with an EEG score of 2-3 (focal sharp waves or frequent spike-wave bursts) was 8.7 years (SEM 1.7) (p=0.006). There was no correlation between the EEG score and either the SWS overall neuroscore or seizure subscore (measuring frequency). The EEG in patients with SWS does appear to evolve over time, becoming more abnormal with more frequent epileptiform activity, as suspected in smaller studies decades ago. This progressive change, however, did not correlate with the child's neurologic function or seizure frequency. PMID:24560844

  9. EEG Evolution in Sturge-Weber Syndrome

    PubMed Central

    Kossoff, Eric H.; Bachur, Cathy; Quain, Angela M.; Ewen, Joshua B.; Comi, Anne M.

    2014-01-01

    SUMMARY The EEG in Sturge-Weber syndrome (SWS) was theorized over 50 years ago as changing over time from normality to focal asymmetry to lastly epileptiform. We sought to validate these findings in a larger cohort today. Children with confirmed SWS and routine EEG at our center were evaluated retrospectively. An EEG score (0–3) was created and linked to patient current age, overall neurologic function, and seizure frequency. Eighty-one EEGs from 44 patients with SWS (mean age 2.0 years (range: 0.2 – 37.9 years) were evaluated and assigned an EEG score. The mean age for patients with an EEG score of 0–1 (normal or focal slowing) was 3.2 years (SEM 0.6), whereas those with an EEG score of 2–3 (focal sharp waves or frequent spike-wave bursts) was 8.7 years (SEM 1.7) (p=0.006). There was no correlation between the EEG score and either the SWS overall neuroscore or seizure subscore (measuring frequency). The EEG in patients with SWS does appear to evolve over time, becoming more abnormal with more frequent epileptiform activity, as suspected in smaller studies decades ago. This progressive change, however, did not correlate with the child’s neurologic function or seizure frequency. PMID:24560844

  10. Time course of reaction time and EEG while performing a vigilance task during total sleep deprivation.

    PubMed

    Corsi-Cabrera, M; Arce, C; Ramos, J; Lorenzo, I; Guevara, M A

    1996-09-01

    Nine young adult male (23-30 years old) paid volunteers were subjected to total sleep deprivation (TSD), after two consecutive nights in the laboratory, for 40 hours (from 0800 hours on the first day to 2400 hours on the following day). Oral temperature (OT), reaction time (RT) in a visual vigilance task, and electroencephalogram (EEG; C3, C4, T3, and T4) while performing the task were recorded every 2 hours during TSD and after recovery sleep. One second of EEG, before target and non-target stimuli for every subject and condition was visually inspected, and artifact-free epochs were Fourier transformed. Absolute power (AP) was calculated for 4-20 Hz (full band) and for theta, alpha 1, alpha 2, and beta 1. Analyses of variance (ANOVAs), with TSD and time-of-day as factors, showed the following significant results. TSD induced an increase in RT and AP of the full band at C3 and C4, of all bands at C3, of theta at T3, and of beta 1 at T4 (p < 0.009 for all comparisons). No time-of-day effects nor interactions were found. OT was not affected by TSD. All variables returned to baseline values after recovery sleep. RT and EEG power showed a linear increase with accumulating hours of wakefulness. The increment in RT also correlated with the increase in EEG power. The results demonstrate that the increment in RT is associated with the increase in AP, particularly in the left central cortex; that the EEG may be used to identify sleepiness; and that EEG during task performance is more sensitive to TSD than during relaxed wakefulness. PMID:8899935

  11. EEG network connectivity changes in mild cognitive impairment - Preliminary results.

    PubMed

    Tóth, Brigitta; File, Bálint; Boha, Roland; Kardos, Zsófia; Hidasi, Zoltán; Gaál, Zsófia Anna; Csibri, Eva; Salacz, Pál; Stam, Cornelis Jan; Molnár, Márk

    2014-02-01

    Resting state EEGs were compared between patients with amnestic subtype of mild cognitive impairment (aMCI) and matched elderly controls at two times over a one year period. The study aimed at investigating the role of functional connectivity between and within different brain regions in relation to the progression of cognitive deficit in MCI. The EEG was recorded in two sessions during eyes closed and eyes open resting conditions. Functional brain connectivity was investigated based on the measurement of phase synchronization in different frequency bands. Delta and theta synchronization characteristics indicated decreased level of local and large-scale connectivity in the patients within the frontal, between the frontal and temporal, and frontal and parietal brain areas which was more pronounced 1year later. As a consequence of opening the eyes connectivity in the alpha1 band within the parietal lobe decreased compared to the eyes closed condition but only in the control group. The lack of alpha1 band reactivity following eye opening could reliably differentiate patients from controls. Our preliminary results support the notion that the functional disconnection between distant brain areas is a characteristic feature of MCI, and may prove to be predictive in terms of the progression of this condition. PMID:24508504

  12. EEG-Based Emotion Recognition Using Frequency Domain Features and

    E-print Network

    Lu, Bao-Liang

    on electroencephalogram (EEG) signals. Experiments using movie elicitation are designed for acquiring subject's EEG recognition, electroencephalogram. 1 Introduction Emotion plays an important role in human-human interaction

  13. 21 CFR 882.1855 - Electroencephalogram (EEG) telemetry system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Electroencephalogram (EEG) telemetry system. (a) Identification. ...electroencephalogram (EEG) telemetry system consists of transmitters, receivers, and other components...radio or telephone transmission systems. (b) Classification....

  14. 21 CFR 882.1855 - Electroencephalogram (EEG) telemetry system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Electroencephalogram (EEG) telemetry system. (a) Identification. ...electroencephalogram (EEG) telemetry system consists of transmitters, receivers, and other components...radio or telephone transmission systems. (b) Classification....

  15. Characterizing Alzheimer’s Disease Severity via Resting-Awake EEG Amplitude Modulation Analysis

    PubMed Central

    Fraga, Francisco J.; Falk, Tiago H.; Kanda, Paulo A. M.; Anghinah, Renato

    2013-01-01

    Changes in electroencephalography (EEG) amplitude modulations have recently been linked with early-stage Alzheimer’s disease (AD). Existing tools available to perform such analysis (e.g., detrended fluctuation analysis), however, provide limited gains in discriminability power over traditional spectral based EEG analysis. In this paper, we explore the use of an innovative EEG amplitude modulation analysis technique based on spectro-temporal signal processing. More specifically, full-band EEG signals are first decomposed into the five well-known frequency bands and the envelopes are then extracted via a Hilbert transform. Each of the five envelopes are further decomposed into four so-called modulation bands, which were chosen to coincide with the delta, theta, alpha and beta frequency bands. Experiments on a resting-awake EEG dataset collected from 76 participants (27 healthy controls, 27 diagnosed with mild-AD, and 22 with moderate-AD) showed significant differences in amplitude modulations between the three groups. Most notably, i) delta modulation of the beta frequency band disappeared with an increase in disease severity (from mild to moderate AD), ii) delta modulation of the theta band appeared with an increase in severity, and iii) delta modulation of the beta frequency band showed to be a reliable discriminant feature between healthy controls and mild-AD patients. Taken together, it is hoped that the developed tool can be used to assist clinicians not only with early detection of Alzheimer’s disease, but also to monitor its progression. PMID:24015222

  16. Atypical EEG Power Correlates With Indiscriminately Friendly Behavior in Internationally Adopted Children

    PubMed Central

    Tarullo, Amanda R.; Garvin, Melissa C.; Gunnar, Megan R.

    2012-01-01

    While effects of institutional care on behavioral development have been studied extensively, effects on neural systems underlying these socioemotional and attention deficits are only beginning to be examined. The current study assessed electroencephalogram (EEG) power in 18-month-old internationally adopted, post-institutionalized children (n = 37) and comparison groups of non-adopted children (n = 47) and children internationally adopted from foster care (n = 39). For their age, post-institutionalized children had an atypical EEG power distribution, with relative power concentrated in lower frequency bands compared to non-adopted children. Both internationally adopted groups had lower absolute alpha power than non-adopted children. EEG power was not related to growth at adoption or to global cognitive ability. Atypical EEG power distribution at 18 months predicted indiscriminate friendliness and poorer inhibitory control at 36 months. Both post-institutionalized and foster care children were more likely than non-adopted children to exhibit indiscriminate friendliness. Results are consistent with a cortical hypoactivation model of the effects of early deprivation on neural development and provide initial evidence associating this atypical EEG pattern with indiscriminate friendliness. Outcomes observed in the foster care children raise questions about the specificity of institutional rearing as a risk factor and emphasize the need for broader consideration of the effects of early deprivation and disruptions in care. PMID:21171750

  17. Atypical EEG power correlates with indiscriminately friendly behavior in internationally adopted children.

    PubMed

    Tarullo, Amanda R; Garvin, Melissa C; Gunnar, Megan R

    2011-03-01

    While effects of institutional care on behavioral development have been studied extensively, effects on neural systems underlying these socioemotional and attention deficits are only beginning to be examined. The current study assessed electroencephalogram (EEG) power in 18-month-old internationally adopted, postinstitutionalized children (n = 37) and comparison groups of nonadopted children (n = 47) and children internationally adopted from foster care (n = 39). For their age, postinstitutionalized children had an atypical EEG power distribution, with relative power concentrated in lower frequency bands compared with nonadopted children. Both internationally adopted groups had lower absolute alpha power than nonadopted children. EEG power was not related to growth at adoption or to global cognitive ability. Atypical EEG power distribution at 18 months predicted indiscriminate friendliness and poorer inhibitory control at 36 months. Both postinstitutionalized and foster care children were more likely than nonadopted children to exhibit indiscriminate friendliness. Results are consistent with a cortical hypoactivation model of the effects of early deprivation on neural development and provide initial evidence associating this atypical EEG pattern with indiscriminate friendliness. Outcomes observed in the foster care children raise questions about the specificity of institutional rearing as a risk factor and emphasize the need for broader consideration of the effects of early deprivation and disruptions in care. PMID:21171750

  18. Quantitative EEG is an objective, sensitive, and reliable indicator of transient anesthetic effects during Wada tests.

    PubMed

    Tu, Bin; Assassi, Nadege J; Bazil, Carl W; Hamberger, Marla J; Hirsch, Lawrence J

    2015-04-01

    The intracarotid amobarbital or Wada procedure is a component of the presurgical evaluation for refractory epilepsy, during which monitoring the onset and offset of transient anesthetic effects is critical. In this study, the authors characterized changes of 8 quantitative measures during 26 Wada tests, which included alpha, beta, theta, and delta powers, alpha/delta power ratio, beta/delta power ratio, median amplitude-integrated EEG, and 90% spectral edge frequency (SEF90), and correlated them with contralateral hemiplegia. The authors found that on the side of injection, delta and theta powers, alpha/delta power ratio, beta/delta power ratio, and SEF90 peaked within 1 minute after injection of 70 to 150 mg amobarbital or 4 to 7 mg methohexital. When contralateral arm strength returned to 3/5, delta power and amplitude-integrated EEG decayed on average 24% and 19%, respectively, for amobarbital, similar to that of methohexital (27% and 18%). Because delta power resolution most closely mirrored that of the hemiplegia and amplitude-integrated EEG had the highest signal/noise ratio, these quantitative values appear to be the best measures for decay of anesthetic effects. Increase in alpha power persisted longest, and therefore may be the best measure of late residual anesthetic effects. PMID:25580802

  19. Age-dependent electroencephalogram (EEG) patterns during sevoflurane general anesthesia in infants.

    PubMed

    Cornelissen, Laura; Kim, Seong-Eun; Purdon, Patrick L; Brown, Emery N; Berde, Charles B

    2015-01-01

    Electroencephalogram (EEG) approaches may provide important information about developmental changes in brain-state dynamics during general anesthesia. We used multi-electrode EEG, analyzed with multitaper spectral methods and video recording of body movement to characterize the spatio-temporal dynamics of brain activity in 36 infants 0-6 months old when awake, and during maintenance of and emergence from sevoflurane general anesthesia. During maintenance: (1) slow-delta oscillations were present in all ages; (2) theta and alpha oscillations emerged around 4 months; (3) unlike adults, all infants lacked frontal alpha predominance and coherence. Alpha power was greatest during maintenance, compared to awake and emergence in infants at 4-6 months. During emergence, theta and alpha power decreased with decreasing sevoflurane concentration in infants at 4-6 months. These EEG dynamic differences are likely due to developmental factors including regional differences in synaptogenesis, glucose metabolism, and myelination across the cortex. We demonstrate the need to apply age-adjusted analytic approaches to develop neurophysiologic-based strategies for pediatric anesthetic state monitoring. PMID:26102526

  20. Biofeedback as a placebo: Anxiety reduction facilitated by training in either suppression or enhancement of alpha brainwaves

    Microsoft Academic Search

    William B. Plotkin; Kathleen M. Rice

    1981-01-01

    Assessed the differential effects (on experiential reports of anxiety) of actual performance and perceived success at an EEG biofeedback task. 10 college students who were high in trait anxiety (MMPI, State-Trait Anxiety Inventory) underwent training in either the suppression of enhancement of EEG alpha activity with the expectation that success at their biofeedback task would result in reductions of chronic

  1. EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation

    PubMed Central

    Roggeveen, Suzanne; van Os, Jim; Viechtbauer, Wolfgang; Lousberg, Richel

    2015-01-01

    The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings. PMID:26053854

  2. Measurement of neural signals from inexpensive, wireless and dry EEG systems.

    PubMed

    Grummett, T S; Leibbrandt, R E; Lewis, T W; DeLosAngeles, D; Powers, D M W; Willoughby, J O; Pope, K J; Fitzgibbon, S P

    2015-07-01

    Electroencephalography (EEG) is challenged by high cost, immobility of equipment and the use of inconvenient conductive gels. We compared EEG recordings obtained from three systems that are inexpensive, wireless, and/or dry (no gel), against recordings made with a traditional, research-grade EEG system, in order to investigate the ability of these 'non-traditional' systems to produce recordings of comparable quality to a research-grade system. The systems compared were: Emotiv EPOC (inexpensive and wireless), B-Alert (wireless), g.Sahara (dry) and g.HIamp (research-grade). We compared the ability of the systems to demonstrate five well-studied neural phenomena: (1) enhanced alpha activity with eyes closed versus open; (2) visual steady-state response (VSSR); (3) mismatch negativity; (4) P300; and (5) event-related desynchronization/synchronization. All systems measured significant alpha augmentation with eye closure, and were able to measure VSSRs (although these were smaller with g.Sahara). The B-Alert and g.Sahara were able to measure the three time-locked phenomena equivalently to the g.HIamp. The Emotiv EPOC did not have suitably located electrodes for two of the tasks and synchronization considerations meant that data from the time-locked tasks were not assessed. The results show that inexpensive, wireless, or dry systems may be suitable for experimental studies using EEG, depending on the research paradigm, and within the constraints imposed by their limited electrode placement and number. PMID:26020164

  3. Non-linear dynamic complexity of the human EEG during meditation.

    PubMed

    Aftanas, L I; Golocheikine, S A

    2002-09-20

    We used non-linear analysis to investigate the dynamical properties underlying the EEG in the model of Sahaja Yoga meditation. Non-linear dimensional complexity (DCx) estimates, indicating complexity of neuronal computations, were analyzed in 20 experienced meditators during rest and meditation using 62-channel EEG. When compared to rest, the meditation was accompanied by a focused decrease of DCx estimates over midline frontal and central regions. By contrast, additionally computed linear measures exhibited the opposite direction of changes: power in the theta-1 (4-6 Hz), theta-2 (6-8 Hz) and alpha-1 (8-10 Hz) frequency bands was increased over these regions. The DCx estimates negatively correlated with theta-2 and alpha-1 and positively with beta-3 (22-30 Hz) band power. It is suggested that meditative experience, characterized by less complex dynamics of the EEG, involves 'switching off' irrelevant networks for the maintenance of focused internalized attention and inhibition of inappropriate information. Overall, the results point to the idea that dynamically changing inner experience during meditation is better indexed by a combination of non-linear and linear EEG variables. PMID:12231432

  4. EEG Sleep Activities React Topographically Different to GABAergic Sleep Modulation by Flunitrazepam: Relationship to Regional Distribution of Benzodiazepine Receptor Subtypes?

    Microsoft Academic Search

    Wolfgang Scheuler

    1991-01-01

    Spectral analysis was performed to study the response of various EEG sleep activities to a modification of GABAergic sleep regulation by flunitrazepam. We observed sleep stage- and sleep cycle-dependent differences in the topographic distribution of the reactions. An increase in power density was found in the frontal regions for the alpha 2 and sigma 1 frequency band whereas a decrease

  5. EEG switching: three views from dynamical systems

    E-print Network

    Lourenço, Carlos

    population capable of a high degree of multitasking. For instance, in a study of the mouse sleepEEG switching: three views from dynamical systems Carlos Louren¸co 1 Faculty of Sciences substrate may sup- port different dynamical regimes and hence give rise to different EEG signals. However

  6. EEG switching: three views from dynamical systems

    E-print Network

    Lourenço, Carlos

    of multitasking. For instance, in a study of the mouse sleep­wake behavior [4], the Authors tend to emphasizeEEG switching: three views from dynamical systems Carlos Louren�co 1 Faculty of Sciences substrate may sup­ port di#erent dynamical regimes and hence give rise to di#erent EEG signals. However

  7. Characterization of EEG--a comparative study.

    PubMed

    Kannathal, N; Acharya, U Rajendra; Lim, C M; Sadasivan, P K

    2005-10-01

    The Electroencephalogram (EEG) is a representative signal containing information about the condition of the brain. The shape of the wave may contain useful information about the state of the brain. However, the human observer cannot directly monitor these subtle details. Besides, since bio-signals are highly subjective, the symptoms may appear at random in the time scale. Therefore, the EEG signal parameters, extracted and analyzed using computers, are highly useful in diagnostics. Chaotic measures like correlation dimension (CD), largest Lyapunov exponent (LLE), Hurst exponent (H) and entropy are used to characterize the signal. Results indicate that these nonlinear measures are good discriminators of normal and epileptic EEG signals. These measures distinguish epileptic EEG and alcoholic from normal EEG with an accuracy of more than 90%. The dynamical behavior is less random for alcoholic and epileptic compared to normal. This indicates less of information processing in the brain due to the hyper-synchronization of the EEG. Hence, the application of nonlinear time series analysis to EEG signals offers insight into the dynamical nature and variability of the brain signals. As a pre-analysis step, the EEG data is tested for nonlinearity using surrogate data analysis and the results exhibited a significant difference in the correlation dimension measure of the actual data and the surrogate data. PMID:16099533

  8. EEG seizure prediction: Measures and challenges

    Microsoft Academic Search

    A. Aarabi; R. Fazel-Rezai; Y. Aghakhani

    2009-01-01

    Different types of analyses of scalp and intracranial electroencephalography (EEG) recordings using linear and nonlinear time series analysis method have been done. They showed strong evidence of detectable changes in the EEG dynamics from minutes up to several hours in advance of seizure onset. The predictive performance of univariate and bivariate measures, comprising both linear and non-linear approaches have been

  9. Development of Brainwave Balancing Index Using EEG

    Microsoft Academic Search

    Zunairah Hj. Murat; Mohd Nasir Taib; Sahrim Lias; Ros Shilawani S. Abdul Kadir; Norizam Sulaiman; Zodie Mohd Hanafiah

    2011-01-01

    In this research, Wireless EEG equipment via Bluetooth technology named g-Mobilab was used to measure the brainwave signals in the right and left frontal area of the brain. The recorded EEG signals were channelled into an automatic artifact removal analysis whereby signals above values of 100 micro-volts were removed by means of a program using Matlab. Consequently, Power Spectral Density

  10. EEG Analysis for Brainwave Balancing Index (BBI)

    Microsoft Academic Search

    Z. H. Murat; M. N. Taib; S. Lias; R. S. S. A. Kadir; N. Sulaiman; M. Mustafa

    2010-01-01

    The purpose of this research is to establish the fundamental brainwave balancing index (BBI) using EEG signals. Brainwave signals from EEG were measured and analyzed using intelligent signal processing techniques and specific algorithm. Consequently, the signals were statistically correlated with established psychoanalysis techniques to produce BBI system. The result shows that the PSD analysis provides reliable BBI with 80% conformity.

  11. EEG entropy measures in anesthesia

    PubMed Central

    Liang, Zhenhu; Wang, Yinghua; Sun, Xue; Li, Duan; Voss, Logan J.; Sleigh, Jamie W.; Hagihira, Satoshi; Li, Xiaoli

    2015-01-01

    Highlights: ? Twelve entropy indices were systematically compared in monitoring depth of anesthesia and detecting burst suppression.? Renyi permutation entropy performed best in tracking EEG changes associated with different anesthesia states.? Approximate Entropy and Sample Entropy performed best in detecting burst suppression. Objective: Entropy algorithms have been widely used in analyzing EEG signals during anesthesia. However, a systematic comparison of these entropy algorithms in assessing anesthesia drugs' effect is lacking. In this study, we compare the capability of 12 entropy indices for monitoring depth of anesthesia (DoA) and detecting the burst suppression pattern (BSP), in anesthesia induced by GABAergic agents. Methods: Twelve indices were investigated, namely Response Entropy (RE) and State entropy (SE), three wavelet entropy (WE) measures [Shannon WE (SWE), Tsallis WE (TWE), and Renyi WE (RWE)], Hilbert-Huang spectral entropy (HHSE), approximate entropy (ApEn), sample entropy (SampEn), Fuzzy entropy, and three permutation entropy (PE) measures [Shannon PE (SPE), Tsallis PE (TPE) and Renyi PE (RPE)]. Two EEG data sets from sevoflurane-induced and isoflurane-induced anesthesia respectively were selected to assess the capability of each entropy index in DoA monitoring and BSP detection. To validate the effectiveness of these entropy algorithms, pharmacokinetic/pharmacodynamic (PK/PD) modeling and prediction probability (Pk) analysis were applied. The multifractal detrended fluctuation analysis (MDFA) as a non-entropy measure was compared. Results: All the entropy and MDFA indices could track the changes in EEG pattern during different anesthesia states. Three PE measures outperformed the other entropy indices, with less baseline variability, higher coefficient of determination (R2) and prediction probability, and RPE performed best; ApEn and SampEn discriminated BSP best. Additionally, these entropy measures showed an advantage in computation efficiency compared with MDFA. Conclusion: Each entropy index has its advantages and disadvantages in estimating DoA. Overall, it is suggested that the RPE index was a superior measure. Investigating the advantages and disadvantages of these entropy indices could help improve current clinical indices for monitoring DoA. PMID:25741277

  12. Event-related EEG time-frequency PCA and the orienting reflex to auditory stimuli.

    PubMed

    Barry, Robert J; De Blasio, Frances M; Bernat, Edward M; Steiner, Genevieve Z

    2015-04-01

    We recently reported an auditory habituation series with counterbalanced indifferent and significant (counting) instructions. Time-frequency (t-f) analysis of electrooculogram-corrected EEG was used to explore event-related synchronization (ERS)/desynchronization (ERD) in four EEG bands using arbitrarily selected time epochs and traditional frequency ranges. ERS in delta, theta, and alpha, and subsequent ERD in theta, alpha, and beta, showed substantial decrement over trials, yet effects of stimulus significance (count vs. no-task) were minimal. Here, we used principal components analysis (PCA) of the t-f data to investigate the natural frequency and time combinations involved in such stimulus processing. We identified four ERS and four ERD t-f components: six showed decrement over trials, four showed count > no-task effects, and six showed Significance?×?Trial interactions. This increased sensitivity argues for the wider use of our data-driven t-f PCA approach. PMID:25353309

  13. Alpha attenuation soon after closing the eyes as an objective indicator of sleepiness.

    PubMed

    Putilov, Arcady A; Donskaya, Olga G

    2014-12-01

    Attenuation of alpha rhythm in occipital derivation serves as a reliable electroencephalographic (EEG) marker of sleep onset. If such attenuation not only coincides with but also anticipates sleep onset, objective evaluation of sleepiness of permanently waking individuals might be facilitated by probing alpha attenuation immediately after closing eyes. We tested whether alpha-based EEG indexes reflect self-scored sleepiness and objectively measured waking ability. A total of 15 young adults self-scored their sleepiness before and after recording of their resting EEG with a 2-h interval in the course of 43-61-h wakefulness. For each EEG record, power spectra were calculated on 2-min intervals of the eyes open section and on five following 1-min intervals of the eyes closed section. Aking ability was assessed as latency to sleep onset marked by zero-crossing decline of such EEG indexes as alpha-theta power difference in occipital derivation and scores on the second principal component of the EEG spectrum in frontal and occipital derivations. Alpha attenuation during the first minute with eyes closed was found to be significantly related to the levels of subjective sleepiness and waking ability. The relationship between alpha attenuation and subjective sleepiness was confirmed by analysing 1-min eyes closed EEG recordings obtained with a 3-h interval in the course of 24-h sustained wakefulness of 130 adolescents and adults. We concluded that such 1-min eyes closed EEG recordings might be used for simple and quick measurements of sleepiness and waking ability in experimental and field studies of permanently waking individuals. PMID:25224885

  14. Functional Connectivity Changes in Resting-State EEG as Potential Biomarker for Amyotrophic Lateral Sclerosis

    PubMed Central

    Iyer, Parameswaran Mahadeva; Egan, Catriona; Pinto-Grau, Marta; Burke, Tom; Elamin, Marwa; Nasseroleslami, Bahman; Pender, Niall; Lalor, Edmund C.; Hardiman, Orla

    2015-01-01

    Background Amyotrophic Lateral Sclerosis (ALS) is heterogeneous and overlaps with frontotemporal dementia. Spectral EEG can predict damage in structural and functional networks in frontotemporal dementia but has never been applied to ALS. Methods 18 incident ALS patients with normal cognition and 17 age matched controls underwent 128 channel EEG and neuropsychology assessment. The EEG data was analyzed using FieldTrip software in MATLAB to calculate simple connectivity measures and scalp network measures. sLORETA was used in nodal analysis for source localization and same methods were applied as above to calculate nodal network measures. Graph theory measures were used to assess network integrity. Results Cross spectral density in alpha band was higher in patients. In ALS patients, increased degree values of the network nodes was noted in the central and frontal regions in the theta band across seven of the different connectivity maps (p<0.0005). Among patients, clustering coefficient in alpha and gamma bands was increased in all regions of the scalp and connectivity were significantly increased (p=0.02). Nodal network showed increased assortativity in alpha band in the patients group. The Clustering Coefficient in Partial Directed Connectivity (PDC) showed significantly higher values for patients in alpha, beta, gamma, theta and delta frequencies (p=0.05). Discussion There is increased connectivity in the fronto-central regions of the scalp and areas corresponding to Salience and Default Mode network in ALS, suggesting a pathologic disruption of neuronal networking in early disease states. Spectral EEG has potential utility as a biomarker in ALS. PMID:26091258

  15. EEG frontal asymmetry related to pleasantness of music perception in healthy children and cochlear implanted users.

    PubMed

    Vecchiato, G; Maglione, A G; Scorpecci, A; Malerba, P; Marsella, P; Di Francesco, G; Vitiello, S; Colosimo, A; Babiloni, Fabio

    2012-01-01

    Interestingly, the international debate about the quality of music fruition for cochlear implanted users does not take into account the hypothesis that bilateral users could perceive music in a more pleasant way with respect to monolateral users. In this scenario, the aim of the present study was to investigate if cerebral signs of pleasantness during music perception in healthy child are similar to those observed in monolateral and in bilateral cochlear implanted users. In fact, previous observations in literature on healthy subjects have indicated that variations of the frontal EEG alpha activity are correlated with the perceived pleasantness of the sensory stimulation received (approach-withdrawal theory). In particular, here we described differences between cortical activities estimated in the alpha frequency band for a healthy child and in patients having a monolateral or a bilateral cochlear implant during the fruition of a musical cartoon. The results of the present analysis showed that the alpha EEG asymmetry patterns observed in a healthy child and that of a bilateral cochlear implanted patient are congruent with the approach-withdrawal theory. Conversely, the scalp topographic distribution of EEG power spectra in the alpha band resulting from the monolateral cochlear user presents a different EEG pattern from the normal and bilateral implanted patients. Such differences could be explained at the light of the approach-withdrawal theory. In fact, the present findings support the hypothesis that a monolateral cochlear implanted user could perceive the music in a less pleasant way when compared to a healthy subject or to a bilateral cochlear user. PMID:23366987

  16. Resting state EEG oscillatory power differences in ADHD college students and their peers

    PubMed Central

    2012-01-01

    Background Among the most robust neural abnormalities differentiating individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) from typically developing controls are elevated levels of slow oscillatory activity (e.g., theta) and reduced fast oscillatory activity (e.g., alpha and beta) during resting-state electroencephalography (EEG). However, studies of resting state EEG in adults with ADHD are scarce and yield inconsistent findings. Methods EEG profiles, recorded during a resting-state with eyes-open and eyes-closed conditions, were compared for college students with ADHD (n?=?18) and a nonclinical comparison group (n?=?17). Results The ADHD group showed decreased power for fast frequencies, especially alpha. This group also showed increased power in the slow frequency bands, however, these effects were strongest using relative power computations. Furthermore, the theta/beta ratio measure was reliably higher for the ADHD group. All effects were more pronounced for the eyes-closed compared to the eyes-open condition. Measures of intra-individual variability suggested that brains of the ADHD group were less variable than those of controls. Conclusions The findings of this pilot study reveal that college students with ADHD show a distinct neural pattern during resting state, suggesting that oscillatory power, especially alpha, is a useful index for reflecting differences in neural communication of ADHD in early adulthood. PMID:23249444

  17. Regularized tensor discriminant analysis for single trial EEG classification in BCI Jie Li, Liqing Zhang *

    E-print Network

    Zhang, Liqing

    ) Channel selection Electroencephalogram (EEG) Regularized tensor discriminant analysis (RTDA) Single trial trial electroencephalogram (EEG) classifica- tion in brain computer interfacing (BCI). Firstly, EEG

  18. Bimodal BCI using simultaneously NIRS and EEG.

    PubMed

    Tomita, Yohei; Vialatte, François-Benoît; Dreyfus, Gérard; Mitsukura, Yasue; Bakardjian, Hovagim; Cichocki, Andrzej

    2014-04-01

    Although noninvasive brain-computer interfaces (BCI) based on electroencephalographic (EEG) signals have been studied increasingly over the recent decades, their performance is still limited in two important aspects. First, the difficulty of performing a reliable detection of BCI commands increases when EEG epoch length decreases, which makes high information transfer rates difficult to achieve. Second, the BCI system often misclassifies the EEG signals as commands, although the subject is not performing any task. In order to circumvent these limitations, the hemodynamic fluctuations in the brain during stimulation with steady-state visual evoked potentials (SSVEP) were measured using near-infrared spectroscopy (NIRS) simultaneously with EEG. BCI commands were estimated based on responses to a flickering checkerboard (ON-period). Furthermore, an "idle" command was generated from the signal recorded by the NIRS system when the checkerboard was not flickering (OFF-period). The joint use of EEG and NIRS was shown to improve the SSVEP classification. For 13 subjects, the relative improvement in error rates obtained by using the NIRS signal, for nine classes including the "idle" mode, ranged from 85% to 53 %, when the epoch length increase from 3 to 12 s. These results were obtained from only one EEG and one NIRS channel. The proposed bimodal NIRS-EEG approach, including detection of the idle mode, may make current BCI systems faster and more reliable. PMID:24658251

  19. Optimal set of EEG features for emotional state classification and trajectory visualization in Parkinson's disease.

    PubMed

    Yuvaraj, R; Murugappan, M; Ibrahim, Norlinah Mohamed; Sundaraj, Kenneth; Omar, Mohd Iqbal; Mohamad, Khairiyah; Palaniappan, R

    2014-12-01

    In addition to classic motor signs and symptoms, individuals with Parkinson's disease (PD) are characterized by emotional deficits. Ongoing brain activity can be recorded by electroencephalograph (EEG) to discover the links between emotional states and brain activity. This study utilized machine-learning algorithms to categorize emotional states in PD patients compared with healthy controls (HC) using EEG. Twenty non-demented PD patients and 20 healthy age-, gender-, and education level-matched controls viewed happiness, sadness, fear, anger, surprise, and disgust emotional stimuli while fourteen-channel EEG was being recorded. Multimodal stimulus (combination of audio and visual) was used to evoke the emotions. To classify the EEG-based emotional states and visualize the changes of emotional states over time, this paper compares four kinds of EEG features for emotional state classification and proposes an approach to track the trajectory of emotion changes with manifold learning. From the experimental results using our EEG data set, we found that (a) bispectrum feature is superior to other three kinds of features, namely power spectrum, wavelet packet and nonlinear dynamical analysis; (b) higher frequency bands (alpha, beta and gamma) play a more important role in emotion activities than lower frequency bands (delta and theta) in both groups and; (c) the trajectory of emotion changes can be visualized by reducing subject-independent features with manifold learning. This provides a promising way of implementing visualization of patient's emotional state in real time and leads to a practical system for noninvasive assessment of the emotional impairments associated with neurological disorders. PMID:25109433

  20. Separation of circadian and wake duration-dependent modulation of EEG activation during wakefulness

    NASA Technical Reports Server (NTRS)

    Cajochen, C.; Wyatt, J. K.; Czeisler, C. A.; Dijk, D. J.

    2002-01-01

    The separate contribution of circadian rhythmicity and elapsed time awake on electroencephalographic (EEG) activity during wakefulness was assessed. Seven men lived in an environmental scheduling facility for 4 weeks and completed fourteen 42.85-h 'days', each consisting of an extended (28.57-h) wake episode and a 14.28-h sleep opportunity. The circadian rhythm of plasma melatonin desynchronized from the 42.85-h day. This allowed quantification of the separate contribution of circadian phase and elapsed time awake to variation in EEG power spectra (1-32 Hz). EEG activity during standardized behavioral conditions was markedly affected by both circadian phase and elapsed time awake in an EEG frequency- and derivation-specific manner. The nadir of the circadian rhythm in alpha (8-12 Hz) activity in both fronto-central and occipito-parietal derivations occurred during the biological night, close to the crest of the melatonin rhythm. The nadir of the circadian rhythm of theta (4.5-8 Hz) and beta (20-32 Hz) activity in the fronto-central derivation was located close to the onset of melatonin secretion, i.e. during the wake maintenance zone. As time awake progressed, delta frequency (1-4.5 Hz) and beta (20-32 Hz) activity rose monotonically in frontal derivations. The interaction between the circadian and wake-dependent increase in frontal delta was such that the intrusion of delta was minimal when sustained wakefulness coincided with the biological day, but pronounced during the biological night. Our data imply that the circadian pacemaker facilitates frontal EEG activation during the wake maintenance zone, by generating an arousal signal that prevents the intrusion of low-frequency EEG components, the propensity for which increases progressively during wakefulness.

  1. Alterations in EEG activity and sleep after influenza viral infection in GHRH receptor-deficient mice.

    PubMed

    Alt, Jeremy A; Obal, Ferenc; Traynor, T R; Gardi, Janos; Majde, Jeannine A; Krueger, James M

    2003-08-01

    Viral infections induce excess non-rapid eye movement sleep (NREMS) in mice. Growth hormone-releasing hormone receptor (GHRH receptor) was previously identified as a candidate gene responsible for NREMS responses to influenza challenge in mice. The dwarf lit/lit mouse with a nonfunctional GHRH receptor was used to assess the role of the GHRH receptor in viral-induced NREMS. After influenza A virus infection the duration and intensity [electroencephalogram (EEG) delta power] of NREMS increased in heterozygous mice with the normal phenotype, whereas NREMS and EEG delta power decreased in homozygous lit/lit mice. Lit/lit mice developed a pathological state with EEG slow waves and enhanced muscle tone. Other influenza-induced responses (decreases in rapid eye movement sleep, changes in the EEG high-frequency bands during the various stages of vigilance, hypothermia, and decreased motor activity) did not differ between the heterozygous and lit/lit mice. GH replacement failed to normalize the NREMS responses in the lit/lit mice after influenza inoculation. Decreases in NREMS paralleled hypothermia in the lit/lit mice. Lung virus levels were similar in the two mouse strains. Lit/lit mice had a higher death rate after influenza challenge than the heterozygotes. In conclusion, GHRH signaling is involved in the NREMS response to influenza infection. PMID:12598490

  2. [Continuous EEG monitoring for aneurysmal subarachnoid hemorrhage].

    PubMed

    Pugin, D; Vulliemoz, S; Bijlenga, P; Gasche, Y

    2014-12-10

    Subarachnoid hemorrhage (SAH) still carries a high morbidity and mortality, despite improvement in surgical and medical management. Seizures and delayed cerebral ischemia (DCI) secondary to vasospasm or cortical spreading depression are frequent after SAH. Continuous EEG allows early detection of non-convulsive seizures or delayed cerebral ischemia and may become a promissing tool in the monitoring of SAH patients. However, its use in clinical practice is still limited because many resources are required for recording and analyzing continuous EEG. Moreover, we require more data to confirm the relationship between aggressive treatment of non-convulsive seizure or delayed cerebral ischemia triggered by continuous EEG and outcome. PMID:25632630

  3. Enabling computer decisions based on EEG input

    NASA Technical Reports Server (NTRS)

    Culpepper, Benjamin J.; Keller, Robert M.

    2003-01-01

    Multilayer neural networks were successfully trained to classify segments of 12-channel electroencephalogram (EEG) data into one of five classes corresponding to five cognitive tasks performed by a subject. Independent component analysis (ICA) was used to segregate obvious artifact EEG components from other sources, and a frequency-band representation was used to represent the sources computed by ICA. Examples of results include an 85% accuracy rate on differentiation between two tasks, using a segment of EEG only 0.05 s long and a 95% accuracy rate using a 0.5-s-long segment.

  4. DESIGN AND IMPLEMENTATION OF WIRELESS MULTICHANNEL EEG RECORDING SYSTEM AND STUDY OF EEG CLUSTERING METHOD

    Microsoft Academic Search

    ROBERT LIN; REN-GUEY LEE; CHWAN-LU TSENG; YAN-FA WU; JOE-AIR JIANG

    2006-01-01

    A multi-channel wireless EEG (electroencephalogram) acquisition and recording system is developed in this work. The system includes an EEG sensing and transmission unit and a digital processing circuit. The former is composed of pre-amplifiers, filters, and gain amplifiers. The kernel of the later digital processing circuit is a micro-controller unit (MCU, TI-MSP430), which is utilized to convert the EEG signals

  5. Differences in the perceived music pleasantness between monolateral cochlear implanted and normal hearing children assessed by EEG.

    PubMed

    Vecchiato, G; Maglione, A G; Scorpecci, A; Malerba, P; Graziani, I; Cherubino, P; Astolfi, L; Marsella, P; Colosimo, A; Babiloni, Fabio

    2013-01-01

    The perception of the music in cochlear implanted (CI) patients is an important aspect of their quality of life. In fact, the pleasantness of the music perception by such CI patients can be analyzed through a particular analysis of EEG rhythms. Studies on healthy subjects show that exists a particular frontal asymmetry of the EEG alpha rhythm which can be correlated with pleasantness of the perceived stimuli (approach-withdrawal theory). In particular, here we describe differences between EEG activities estimated in the alpha frequency band for a monolateral CI group of children and a normal hearing one during the fruition of a musical cartoon. The results of the present analysis showed that the alpha EEG asymmetry patterns related to the normal hearing group refers to a higher pleasantness perception when compared to the cerebral activity of the monolateral CI patients. In fact, the present results support the statement that a monolateral CI group could perceive the music in a less pleasant way when compared to normal hearing children. PMID:24110962

  6. Making the case for mobile cognition: EEG and sports performance.

    PubMed

    Park, Joanne L; Fairweather, Malcolm M; Donaldson, David I

    2015-05-01

    In the high stakes world of International sport even the smallest change in performance can make the difference between success and failure, leading sports professionals to become increasingly interested in the potential benefits of neuroimaging. Here we describe evidence from EEG studies that either identify neural signals associated with expertise in sport, or employ neurofeedback to improve performance. Evidence for the validity of neurofeedback as a technique for enhancing sports performance remains limited. By contrast, progress in characterizing the neural correlates of sporting behavior is clear: frequency domain studies link expert performance to changes in alpha rhythms, whilst time-domain studies link expertise in response evaluation and motor output with modulations of P300 effects and readiness potentials. Despite early promise, however, findings have had relatively little impact for sports professionals, at least in part because there has been a mismatch between lab tasks and real sporting activity. After selectively reviewing existing findings and outlining limitations, we highlight developments in mobile EEG technology that offer new opportunities for sports neuroscience. PMID:25735956

  7. Energetical bases of extraversion: effort, arousal, EEG, and performance.

    PubMed

    Beauducel, André; Brocke, Burkhard; Leue, Anja

    2006-11-01

    This study investigates an extension of H.J. Eysenck's [Eysenck, H.J., 1967. The Biological Basis of Personality. Charles C. Thomas, Springfield, IL] arousal theory of extraversion, incorporating an effort system as a control system for different aspects of arousal. Extraverts were expected to have lower levels of reticocortical arousal than introverts, to invest more effort, and to have lower task performance in a monotonous vigilance task. In a 40-min vigilance task, participants had to react to the shorter of two 1 kHz tones presented binaurally at an event rate of 200 per 10 min. Spontaneous EEG, event-related potential, and performance data of 40 extremely introverted and 41 extremely extraverted students were available for statistical analysis. A tendency for lower arousal levels of extraverts (alpha 2 band), the expected higher effort investment (P300) and a lower performance (hits) of extraverts were found. PMID:16426692

  8. Short-Term EEG Spectral Pattern as a Single Event in EEG Phenomenology

    PubMed Central

    Fingelkurts, Al. A; Fingelkurts, An. A

    2010-01-01

    Spectral decomposition, to this day, still remains the main analytical paradigm for the analysis of EEG oscillations. However, conventional spectral analysis assesses the mean characteristics of the EEG power spectra averaged out over extended periods of time and/or broad frequency bands, thus resulting in a “static” picture which cannot reflect adequately the underlying neurodynamic. A relatively new promising area in the study of EEG is based on reducing the signal to elementary short-term spectra of various types in accordance with the number of types of EEG stationary segments instead of using averaged power spectrum for the whole EEG. It is suggested that the various perceptual and cognitive operations associated with a mental or behavioural condition constitute a single distinguishable neurophysiological state with a distinct and reliable spectral pattern. In this case, one type of short-term spectral pattern may be considered as a single event in EEG phenomenology. To support this assumption the following issues are considered in detail: (a) the relations between local EEG short-term spectral pattern of particular type and the actual state of the neurons in underlying network and a volume conduction; (b) relationship between morphology of EEG short-term spectral pattern and the state of the underlying neurodynamical system i.e. neuronal assembly; (c) relation of different spectral pattern components to a distinct physiological mechanism; (d) relation of different spectral pattern components to different functional significance; (e) developmental changes of spectral pattern components; (f) heredity of the variance in the individual spectral pattern and its components; (g) intra-individual stability of the sets of EEG short-term spectral patterns and their percent ratio; (h) discrete dynamics of EEG short-term spectral patterns. Functional relevance (consistency) of EEG short-term spectral patterns in accordance with the changes of brain functional state, cognitive task and with different neuropsychopathologies is demonstrated. PMID:21379390

  9. Nonconvulsive status epilepticus and Creutzfeldt–Jakob-like EEG changes in a case of lithium toxicity

    PubMed Central

    Madhusudhan, B.K.

    2014-01-01

    We report a case of a 63-year-old lady with bipolar affective disorder on lithium who was brought to our emergency center in a comatose state. Neurologically, the patient was comatose and had generalized hypotonia and hyporeflexia. Lithium toxicity was considered. Laboratory examinations revealed leukocytosis, normal blood sugar, blood level of lithium was 4.7 mEq/L and she had renal dysfunction. Cerebrospinal fluid examination and cranial computerized tomography were unremarkable. Blood lithium level was 4.7 mEq/L. Hemodialysis was initiated. However, in spite of dialysis and decreasing lithium levels, the patient remained unconscious. A possibility of nonconvulsive status epilepticus was considered; hence, EEG was advised. The EEG demonstrated bihemispheric slowing (4- to 5-Hz theta range) with bilateral periodic triphasic waves of 1- to 2-Hz frequency, similar to the EEG changes seen in Creutzfeldt–Jakob disease. She was started on lorazepam. Her sensorium improved gradually, which correlated with the decline in blood lithium levels. A normal background alpha rhythm on EEG was ensured prior to discharge. At discharge, clinically, she had recovered completely, with no apparent neurological deficit or cognitive impairment. This case highlights the importance of therapeutic drug-level monitoring of lithium, especially where toxicity is suspected, and the important role electroencephalography plays in diagnosing NCSE and its management. PMID:25667908

  10. Alpha brainwave training and perception of time passing: Preliminary findings

    Microsoft Academic Search

    Margaret S. Wacker

    1996-01-01

    The ability to generate alpha brainwaves has been associated with the self-regulation of stress. It has been suggested that generation of these brainwaves, above what is to be expected in a normal 24-hour EEG, contributes to an expanded state of consciousness. This study attempted to test Newman's theory that expansion of consciousness could be observed in perception of time passing.

  11. Radiofrequency signal affects alpha band in resting electroencephalogram.

    PubMed

    Ghosn, Rania; Yahia-Cherif, Lydia; Hugueville, Laurent; Ducorps, Antoine; Lemaréchal, Jean-Didier; Thuróczy, György; de Seze, René; Selmaoui, Brahim

    2015-04-01

    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. PMID:25695646

  12. Impact of regular meditation practice on EEG activity at rest and during evoked negative emotions.

    PubMed

    Aftanas, Ljubomir; Golosheykin, Semen

    2005-06-01

    The main objective of the present investigation was to examine how long-term meditation practice is manifested in EEG activity under conditions of non-emotional arousal (eyes-closed and eyes-open periods, viewing emotionally neutral movie clip) and while experiencing experimentally induced negative emotions (viewing aversive movie clip). The 62-channel EEG was recorded in age-matched control individuals (n=25) and Sahaja Yoga meditators (SYM, n=25). Findings from the non-emotional continuum show that at the lowest level of arousal (eyes closed) SYM manifested larger power values in theta-1 (4-6 Hz), theta-2 (6-8 Hz) and alpha-1 (8-10 Hz) frequency bands. Although increasing arousal desynchronized activity in these bands in both groups, the theta-2 and alpha-1 power in the eyes-open period and alpha-1 power while viewing the neutral clip remained still higher in the SYM. During eyes-closed and eyes-open periods the controls were marked by larger right than left hemisphere power, indexing relatively more active left hemisphere parieto-temporal cortex whereas meditators manifested no hemisphere asymmetry. When contrasted with the neutral, the aversive movie clip yielded significant alpha desynchronization in both groups, reflecting arousing nature of emotional induction. In the control group along with alpha desynchronization affective movie clip synchronized gamma power over anterior cortical sites. This was not seen in the SYM. Overall, the presented report emphasizes that the revealed changes in the electrical brain activity associated with regular meditation practice are dynamical by nature and depend on arousal level. The EEG power findings also provide the first empirical proof of a theoretical assumption that meditators have better capabilities to moderate intensity of emotional arousal. PMID:16019582

  13. Ordinal patterns in epileptic brains: Analysis of intracranial EEG and simultaneous EEG-fMRI

    NASA Astrophysics Data System (ADS)

    Rummel, C.; Abela, E.; Hauf, M.; Wiest, R.; Schindler, K.

    2013-06-01

    Epileptic seizures are associated with high behavioral stereotypy of the patients. In the EEG of epilepsy patients characteristic signal patterns can be found during and between seizures. Here we use ordinal patterns to analyze EEGs of epilepsy patients and quantify the degree of signal determinism. Besides relative signal redundancy and the fraction of forbidden patterns we introduce the fraction of under-represented patterns as a new measure. Using the logistic map, parameter scans are performed to explore the sensitivity of the measures to signal determinism. Thereafter, application is made to two types of EEGs recorded in two epilepsy patients. Intracranial EEG shows pronounced determinism peaks during seizures. Finally, we demonstrate that ordinal patterns may be useful for improving analysis of non-invasive simultaneous EEG-fMRI.

  14. Effect of spatial ability and sex on inter- and intrahemispheric correlation of EEG activity.

    PubMed

    Corsi-Cabrera, M; Arce, C; Ramos, J; Guevara, M A

    1997-01-01

    Inter- and intrahemispheric correlation of the EEG activity at rest was computed in two groups of men and women, between 17 and 21 years old, with extreme degrees of spatial ability (SA) evaluated by the Spatial Relations Subtest of the Differential Aptitudes Test (DAT). Interhemispheric (INTERr) and intrahemispheric (INTRAr) EEG correlations were computed by means of Pearson product-moment coefficients for 5 EEG bands after digitally filtering with an FFT. Women showed significantly higher INTERr of alpha 1 between left and right centrals, lower INTRAr between right frontal and right central regions and lower INTRAr within the left than in the right hemisphere. High SA subjects showed lower INTERr between left and right frontal derivations and higher INTRAr between frontal and parietal and between central and parietal regions of both hemispheres. Sex interacted with SA in INTRAr of alpha between right frontal and right temporal regions with high SA women showing lower INTRAr than low SA women and than men. The present results indicate a different inter- and intrahemispheric functional organization in men and women and in subjects with high and low spatial ability. PMID:9060849

  15. dahee@sclab.yonsei.ac.kr, sbcho@cs.yonsei.ac.kr A Shared Vehicle Control System using Partial Filters of EEG Signals

    E-print Network

    Cho, Sung-Bae

    matrix), (Sparse matrix), (Common Average Reference: CAR) . t- CAR . 1. EEG . . , . , . 3 , t- CAR . 2. EEG . EEG , [1]. 1. EEG F. Galan (2004) [2] Robots & wheelchairs EEG 64 L. Tonin (2010) [3] Robot EEG 16 M. Lee (2012) [4

  16. Alpha Thalassemia

    MedlinePLUS

    ... the anemia. Normal alpha globin genes found on chromosome 16 People who do not produce enough alpha ... by four genes, two on each strand of chromosome 16. Individuals who have one or two abnormal ...

  17. Responders to vagus nerve stimulation (VNS) in refractory epilepsy have reduced interictal cortical synchronicity on scalp EEG.

    PubMed

    Bodin, Clémentine; Aubert, Sandrine; Daquin, Géraldine; Carron, Romain; Scavarda, Didier; McGonigal, Aileen; Bartolomei, Fabrice

    2015-07-01

    EEG desynchronization has been proposed to be an important mechanism for antiepileptic effect of vagus nerve stimulation (VNS) but has never been clearly documented in human. The aim of this study was to evaluate impact of VNS on the synchronicity of interictal EEG rhythms. We estimated synchronization between scalp EEG signals using phase lag index (PLI) in 19 patients with chronic VNS therapy. We estimated changes in synchronization between ON and OFF phases and between responder (R) and non-responder (NR) patients. We found that R have a lower global level of synchronization (EEG broadband) than NR (p<0.0001) In addition, ON periods were characterized by lower values in comparison with OFF periods (p<0.001). R had significantly lower global synchronization levels in delta and alpha frequency bands (p<0.0001). Patients responding to VNS have thus a lower level of broadband EEG synchronization than non-responders. Estimating changes of synchronization level is thus a promising tool for predicting response to VNS. PMID:25986196

  18. Basal forebrain administration of the somatostatin-analog octreotide does not affect cortical EEG in urethane anaesthetized rats.

    PubMed

    Tóth, Attila; Henter, T; Détári, L

    2012-12-01

    Basal forebrain (BF) plays an important role in the regulation of cortical activation. Somatostatin (SOM) is present both in local neurons as well as in fibers in the BF. In previous studies, SOM axons were found to innervate corticopetal cholinergic cells and SOM was found to presynaptically modulate GABA and glutamate release onto cholinergic neurons in the BF. However, no systematic analysis is available about the EEG effects of SOM or its analog, octreotide (OCTR) injected directly into the BF. In the present experiments, EEG changes were examined following an OCTR injection (0.5 microliter, 500 nmol) into the BF areas containing several choline acetyl transferase-immunoreactive neurons of urethane-anaesthetized rats. Fronto-occipital EEG was recorded on both sides and relative EEG power was calculated in the delta (0-3 Hz), theta (3-9 Hz), alpha (9-16 Hz) and beta (16-48 Hz) frequency bands. OCTR injected to the BF failed to induce significant EEG changes and did not affect tail pinch-evoked cortical activation. Lack of effect may be attributed to the urethane anaesthesia as well as to the possible complex interactions between SOM and BF cholinergic and GABAergic neurons. PMID:23238548

  19. Change in the characteristics of EEG color noise in Alzheimer's disease.

    PubMed

    Vysata, Oldrich; Procházka, Ales; Mares, Jan; Rusina, Robert; Pazdera, Ladislav; Valis, Martin; Kukal, Jaromír

    2014-07-01

    Neurophysiological experiments support the hypothesis of the presence of critical dynamics of brain activity. This is also manifested by power law of electroencephalography (EEG) power spectra, which can be described by the relation 1/f(alpha). This dependence is a result of internal interactions between parts of the brain and is probably required for optimal processing of information. In Alzheimer's disease, changes in the functional organization of the brain occur, which may be manifested by changes in the alpha coefficient. We compared the average values of alpha for 19 electrodes in the resting EEG record in 110 patients with moderate to severe Alzheimer's disease (Mini-Mental State Examination [MMSE] score = 10-19) with 110 healthy controls. Statistically, the most significant differences are present in the prefrontal areas. In addition to the prefrontal and frontal areas, the largest separation value in the evaluation of receiver operating characteristic (ROC) curves was recorded in the temporal area. The coefficient alpha has few false-positive results in the optimal operating point of the ROC curve, and is thereby highly specific for Alzheimer's disease. PMID:24131619

  20. The AASM Recommended and Acceptable EEG Montages are Comparable for the Staging of Sleep and Scoring of EEG Arousals

    PubMed Central

    Duce, Brett; Rego, Conchita; Milosavljevic, Jasmina; Hukins, Craig

    2014-01-01

    Study Objective: To examine the measurement differences in sleep and EEG arousal statistics between the American Academy of Sleep Medicine (AASM) recommended EEG montage (F4-M1, C4-M1, O2-M1) and acceptable EEG montage (Fz-Cz, C4-M1, Oz-Cz). Design: Prospective, blinded, randomized comparison. Setting: Australian clinical sleep laboratory in a tertiary hospital. Patients or Participants: 50 consecutive patients undertaking polysomnography (PSG) for the clinical suspicion of sleep disordered breathing. Interventions: N/A Measurements and Results: Patient EEGs were recorded using both the AASM recommended and acceptable EEG montages during the PSG. Two scorers were used to examine the difference in PSG statistics using the two EEG montages. The scorers analyzed the 50 studies using the two EEG montages. Ten of the studies were scored twice for each montage by each scorer to calculate intra-scorer and inter-scorer agreement. No statistically significant differences were observed between the PSG statistics of the recommended and acceptable EEG montages. The recommended EEG montage had greater inter-scorer agreement but no difference in intra-scorer agreement. Conclusions: This study demonstrates that the two EEG montages endorsed by the AASM Manual produce similar sleep and EEG arousal statistics. Citation: Duce B, Rego C, Milosavljevic J, Hukins C. The AASM recommended and acceptable EEG montages are comparable for the staging of sleep and scoring of EEG arousals. J Clin Sleep Med 2014;10(7):803-809. PMID:25024660

  1. Real-time EEG feedback during simultaneous EEG-fMRI identifies the cortical signature of motor imagery.

    PubMed

    Zich, Catharina; Debener, Stefan; Kranczioch, Cornelia; Bleichner, Martin G; Gutberlet, Ingmar; De Vos, Maarten

    2015-07-01

    Motor imagery (MI) combined with real-time electroencephalogram (EEG) feedback is a popular approach for steering brain-computer interfaces (BCI). MI BCI has been considered promising as add-on therapy to support motor recovery after stroke. Yet whether EEG neurofeedback indeed targets specific sensorimotor activation patterns cannot be unambiguously inferred from EEG alone. We combined MI EEG neurofeedback with concurrent and continuous functional magnetic resonance imaging (fMRI) to characterize the relationship between MI EEG neurofeedback and activation in cortical sensorimotor areas. EEG signals were corrected online from interfering MRI gradient and ballistocardiogram artifacts, enabling the delivery of real-time EEG feedback. Significantly enhanced task-specific brain activity during feedback compared to no feedback blocks was present in EEG and fMRI. Moreover, the contralateral MI related decrease in EEG sensorimotor rhythm amplitude correlated inversely with fMRI activation in the contralateral sensorimotor areas, whereas a lateralized fMRI pattern did not necessarily go along with a lateralized EEG pattern. Together, the findings indicate a complex relationship between MI EEG signals and sensorimotor cortical activity, whereby both are similarly modulated by EEG neurofeedback. This finding supports the potential of MI EEG neurofeedback for motor rehabilitation and helps to better understand individual differences in MI BCI performance. PMID:25887263

  2. Alpha Particle

    Microsoft Academic Search

    P. Murdin

    2000-01-01

    Term that is sometimes used to describe a helium nucleus, a positively charged particle that consists of two protons and two neutrons, bound together. Alpha particles, which were discovered by Ernest Rutherford (1871-1937) in 1898, are emitted by atomic nuclei that are undergoing alpha radioactivity. During this process, an unstable heavy nucleus spontaneously emits an alpha particle and transmut...

  3. Monte Carlo Simulation Studies of EEG and MEG Localization Accuracy

    E-print Network

    Sereno, Martin

    The electromagnetic inverse problem for the human brain is to determine the neural source distribution that gives rise to external electromagnetic potentials and fields, measured by electroencephalography (EEG: Both electroencephalography (EEG) and magnetoencephalography (MEG) are currently used to localize brain

  4. A First Step towards Eye State Prediction Using EEG

    E-print Network

    Suendermann, David

    and technological community, we decided not to use a medical EEG but the Emotiv EPOC headset1 . Compared to a medical EEG, the EPOC headset is much more affordable, and it can be set up quickly and without the help

  5. Framework for Evaluating EEG Signal Quality of Dry Electrode Recordings

    E-print Network

    Serdijn, Wouter A.

    would facilitate this process and help EEG system developers to test their designs. This paper describes/AgCl cup electro- des connected to separate blocks of the biosignal amplifier g.USBamp [5]. The EEG

  6. Temporal dynamics of sensorimotor integration in speech perception and production: independent component analysis of EEG data

    PubMed Central

    Jenson, David; Bowers, Andrew L.; Harkrider, Ashley W.; Thornton, David; Cuellar, Megan; Saltuklaroglu, Tim

    2014-01-01

    Activity in anterior sensorimotor regions is found in speech production and some perception tasks. Yet, how sensorimotor integration supports these functions is unclear due to a lack of data examining the timing of activity from these regions. Beta (~20 Hz) and alpha (~10 Hz) spectral power within the EEG ? rhythm are considered indices of motor and somatosensory activity, respectively. In the current study, perception conditions required discrimination (same/different) of syllables pairs (/ba/ and /da/) in quiet and noisy conditions. Production conditions required covert and overt syllable productions and overt word production. Independent component analysis was performed on EEG data obtained during these conditions to (1) identify clusters of ? components common to all conditions and (2) examine real-time event-related spectral perturbations (ERSP) within alpha and beta bands. 17 and 15 out of 20 participants produced left and right ?-components, respectively, localized to precentral gyri. Discrimination conditions were characterized by significant (pFDR < 0.05) early alpha event-related synchronization (ERS) prior to and during stimulus presentation and later alpha event-related desynchronization (ERD) following stimulus offset. Beta ERD began early and gained strength across time. Differences were found between quiet and noisy discrimination conditions. Both overt syllable and word productions yielded similar alpha/beta ERD that began prior to production and was strongest during muscle activity. Findings during covert production were weaker than during overt production. One explanation for these findings is that ?-beta ERD indexes early predictive coding (e.g., internal modeling) and/or overt and covert attentional/motor processes. ?-alpha ERS may index inhibitory input to the premotor cortex from sensory regions prior to and during discrimination, while ?-alpha ERD may index sensory feedback during speech rehearsal and production. PMID:25071633

  7. Temporal dynamics of sensorimotor integration in speech perception and production: independent component analysis of EEG data.

    PubMed

    Jenson, David; Bowers, Andrew L; Harkrider, Ashley W; Thornton, David; Cuellar, Megan; Saltuklaroglu, Tim

    2014-01-01

    Activity in anterior sensorimotor regions is found in speech production and some perception tasks. Yet, how sensorimotor integration supports these functions is unclear due to a lack of data examining the timing of activity from these regions. Beta (~20 Hz) and alpha (~10 Hz) spectral power within the EEG ? rhythm are considered indices of motor and somatosensory activity, respectively. In the current study, perception conditions required discrimination (same/different) of syllables pairs (/ba/ and /da/) in quiet and noisy conditions. Production conditions required covert and overt syllable productions and overt word production. Independent component analysis was performed on EEG data obtained during these conditions to (1) identify clusters of ? components common to all conditions and (2) examine real-time event-related spectral perturbations (ERSP) within alpha and beta bands. 17 and 15 out of 20 participants produced left and right ?-components, respectively, localized to precentral gyri. Discrimination conditions were characterized by significant (pFDR < 0.05) early alpha event-related synchronization (ERS) prior to and during stimulus presentation and later alpha event-related desynchronization (ERD) following stimulus offset. Beta ERD began early and gained strength across time. Differences were found between quiet and noisy discrimination conditions. Both overt syllable and word productions yielded similar alpha/beta ERD that began prior to production and was strongest during muscle activity. Findings during covert production were weaker than during overt production. One explanation for these findings is that ?-beta ERD indexes early predictive coding (e.g., internal modeling) and/or overt and covert attentional/motor processes. ?-alpha ERS may index inhibitory input to the premotor cortex from sensory regions prior to and during discrimination, while ?-alpha ERD may index sensory feedback during speech rehearsal and production. PMID:25071633

  8. Sex differences between the combined and inattentive types of attention-deficit/hyperactivity disorder: an EEG perspective.

    PubMed

    Dupuy, Franca E; Barry, Robert J; Clarke, Adam R; McCarthy, Rory; Selikowitz, Mark

    2013-09-01

    This study investigated sex differences between the EEGs of Combined and Inattentive types of attention-deficit/hyperactivity disorder (AD/HD) within boys and girls aged 8-12 years. Subject groups included 80 AD/HD Combined type (40 boys and 40 girls), 80 AD/HD Inattentive type (40 boys and 40 girls) and 80 controls (40 boys and 40 girls). An eyes-closed resting EEG was recorded and Fourier transformed to provide estimates for absolute and relative power in the delta, theta, alpha and beta frequency bands, as well as total power and the theta/beta ratio. The boy AD/HD groups, compared with boy controls, had greater absolute and relative theta, greater theta/beta ratio, reduced absolute and relative alpha, and reduced absolute and relative beta. The girl AD/HD groups, compared with girl controls, had greater absolute delta, greater absolute and relative theta, greater theta/beta ratio, greater total power, and reduced relative delta and relative beta. Between AD/HD types, Combined type boys had globally greater absolute and relative theta, greater theta/beta ratio, and less relative alpha than Inattentive type boys. While topographical differences emerged, there were no significant global differences between AD/HD types in girls. That is, EEG differences between AD/HD types are dissimilar in boys and girls. Different EEG maturational patterns between boys and girls also obscure AD/HD-related EEG abnormalities. These results have important implications for our understanding of AD/HD in girls. Ignoring such sex differences may have compromised the value of previous AD/HD investigations, and these sex differences should be recognised in future research. PMID:23603052

  9. Waking EEG spectral power and coherence differences between high and low hypnotizable subjects.

    PubMed

    Kirenskaya, Anna V; Novototsky-Vlasov, Vladimir Y; Zvonikov, Vyacheslav M

    2011-01-01

    EEG spectral power and coherence were analyzed under waking baseline condition in 19 high (HH) and 12 low (LH) hypnotizable subjects. In HH subjects, the theta1 and theta2 spectral power was higher than in LH. The major new finding of this study is that coherence between distributed brain regions was sharply elevated in HH subjects within the theta and alpha frequency bands. In contrast, spectral power and coherence of beta2 and gamma1 bands were higher in LH subjects as compared to HH subjects. However, the long distance coherence between frontal and posterior areas within beta-gamma frequency ranges was higher in HH subjects. It might be supposed that HH subjects are engaged in imaginal mental activity whereas LH ones are mainly engaged in linguistic activity. The neurophysiological basis of the obtained EEG differences is discussed. PMID:21867379

  10. Toward correlating functional MRI and EEG sources

    NASA Astrophysics Data System (ADS)

    Singh, Manbir; Khosla, Deepak

    1996-04-01

    Though excellent spatial resolution (on the order of 1 mm) is obtainable in functional MRI (fMRI), its temporal resolution is limited to about 1 second by hemodynamics. On the other hand, magnetoencephalography (MEG) and electroencephalography (EEG) provide millisecond temporal resolution but a relatively crude (on the order of 1 cm) spatial resolution to localized sources. Thus, techniques that could combine the high temporal resolution of MEG or EEG with the high spatial resolution of fMRI would be of great significance in imaging the spatiotemporal distribution of neuronal activation. With the ultimate objective of combining fMRI and EEG activation studies, we have conducted experiments to determine how pixels activated in fMRI correlate with underlying EEG sources in a given subject during visual stimulation. Results of a three-subject study suggest good correlation between the center-of-gravity of activated pixels seen in fMRI and the center-of-gravity of regions localized through EEG measurements.

  11. EEG-Based Emotion Recognition in Music Listening

    Microsoft Academic Search

    Yuan-Pin Lin; Chi-Hong Wang; Tzyy-Ping Jung; Tien-Lin Wu; Shyh-Kang Jeng; Jeng-Ren Duann; Jyh-Horng Chen

    2010-01-01

    Ongoing brain activity can be recorded as electroen-cephalograph (EEG) to discover the links between emotional states and brain activity. This study applied machine-learning algorithms to categorize EEG dynamics according to subject self-reported emotional states during music listening. A framework was proposed to optimize EEG-based emotion recognition by systematically 1) seeking emotion-specific EEG features and 2) exploring the efficacy of the

  12. Exploring miniaturized EEG electrodes for brain-computer interfaces. An EEG you do not see?

    PubMed

    Bleichner, Martin G; Lundbeck, Micha; Selisky, Matthias; Minow, Falk; Jäger, Manuela; Emkes, Reiner; Debener, Stefan; De Vos, Maarten

    2015-04-01

    Electroencephalography (EEG) allows the study of the brain-behavior relationship in humans. Most of what we have learned with EEG was through observing the brain-behavior relationship under well-controlled laboratory conditions. However, by reducing "normal" behavior to a minimum the ecological validity of the results can be limited. Recent developments toward mobile EEG solutions allow to study the brain-behavior relationship outside the laboratory in more natural situations. Besides mobility and robustness with respect to motion, mobile EEG systems should also interfere as little as possible with the participant's behavior. For example, natural interaction with other people could be hindered when it is obvious that a participant wears an EEG cap. This study evaluates the signal quality obtained with an unobtrusive solution for EEG monitoring through the integration of miniaturized EEG ton-electrodes into both a discreet baseball cap and an individualized ear piece. We show that such mini electrodes located at scalp and ear locations can reliably record event related potentials in a P300 brain-computer-interface application. PMID:25847919

  13. The genetic basis of the normal human electroencephalogram (EEG)

    Microsoft Academic Search

    FRIEDRICII VOGEL

    1970-01-01

    The genetic basis of the normal human electroencephalogram (EEG) was analyzed. Twin investigations showed complete concordance for most EEG characteristics in monozygotic twins of all age groups. Differences in high age include focal abnormalities and dysrhythmic groups. These differences failed to show a relation to mental performance. For a number of special EEG variants, population frequencies were determined, and the

  14. Neonatal EEG Sleep Stages Modelling by Temporal Profiles

    Microsoft Academic Search

    Vladimir Krajca; Svojmil Petránek; Jitka Mohylová; Karel Paul; Václav Gerla; Lenka Lhotská

    2007-01-01

    The paper deals with the application of the EEG temporal profiles for the neonatal sleep stages modelling. The temporal profiles\\u000a created by adaptive segmentation and cluster analysis reflect the time structure of the EEG during different periods of sleep.\\u000a They can be used for neonatal EEG quantification and for the detection of sleep stage changes.

  15. Ontogeny of EEG-sleep from neonatal through infancy periods

    Microsoft Academic Search

    Mark S. Scher

    2008-01-01

    Serial neonatal and infant electroencephalographic (EEG)–polysomnographic studies document the ontogeny of cerebral and noncerebral physiologic behaviors based on visual inspection or computer analyses. EEG patterns and their relationship to other physiologic signals serve as templates for normal brain organization and maturation, subserving multiple interconnected neuronal networks. Interpretation of serial EEG-sleep patterns also helps track the continuity of brain functions from

  16. Multivariate Temporal Dictionary Learning for EEG Q. Barthelemya,b

    E-print Network

    Boyer, Edmond

    spatial resolution, EEG is still widely used in medi- cal contexts (e.g. sleep analysis, anesthesiaMultivariate Temporal Dictionary Learning for EEG Q. Barth´elemya,b , C. Gouy-Paillera , Y. Isaaca This article addresses the issue of representing electroencephalographic (EEG) signals in an efficient way

  17. Individualising EEG frequency bands for sleep deprivation studies

    Microsoft Academic Search

    Andreas Henelius; Jussi Korpela; Minna Huotilainen

    2011-01-01

    A method for determining individualised frequency bands from electroencephalographic (EEG) power spectral density (PSD) plots is presented. EEG was collected during the performance of a computerised multitask test from 21 healthy male subjects, of which an experimental group of 14 subjects underwent sleep deprivation and 7 subjects formed the control group. EEG PSD plots were compared between the groups and

  18. Interrater reliability of EEG-video monitoring

    PubMed Central

    Benbadis, S R.; LaFrance, W C.; Papandonatos, G D.; Korabathina, K; Lin, K; Kraemer, H C.

    2009-01-01

    Objective: The diagnosis of psychogenic nonepileptic seizures (PNES) can be challenging. In the absence of a gold standard to verify the reliability of the diagnosis by EEG-video, we sought to assess the interrater reliability of the diagnosis using EEG-video recordings. Methods: Patient samples consisted of 22 unselected consecutive patients who underwent EEG-video monitoring and had at least an episode recorded. Other test results and histories were not provided because the goal was to assess the reliability of the EEG-video. Data were sent to 22 reviewers, who were board-certified neurologists and practicing epileptologists at epilepsy centers. Choices were 1) PNES, 2) epilepsy, and 3) nonepileptic but not psychogenic (“physiologic”) events. Interrater agreement was measured using a ? coefficient for each diagnostic category. We used generalized ? coefficients, which measure the overall level of between-method agreement beyond that which can be ascribed to chance. We also report category-specific ? values. Results: For the diagnosis of PNES, there was moderate agreement (? = 0.57, 95% confidence interval [CI] 0.39–0.76). For the diagnosis of epilepsy, there was substantial agreement (? = 0.69, 95% CI 0.51–0.86). For physiologic nonepileptic episodes, the agreement was low (? = 0.09, 95% CI 0.02–0.27). The overall ? statistic across all 3 diagnostic categories was moderate at 0.56 (95% CI 0.41–0.73). Conclusions: Interrater reliability for the diagnosis of psychogenic nonepileptic seizures by EEG-video monitoring was only moderate. Although this may be related to limitations of the study (diagnosis based on EEG-video alone, artificial nature of the forced choice paradigm, single episode), it highlights the difficulties and subjective components inherent to this diagnosis. GLOSSARY ABCN = American Board of Clinical Neurophysiology; ABPN = American Board of Psychiatry and Neurology; CI = confidence interval; IRR = interrater reliability; PNES = psychogenic nonepileptic seizures. PMID:19752450

  19. Transcranial direct current stimulation and power spectral parameters: a tDCS/EEG co-registration study

    PubMed Central

    Mangia, Anna L.; Pirini, Marco; Cappello, Angelo

    2014-01-01

    Transcranial direct current stimulation (tDCS) delivers low electric currents to the brain through the scalp. Constant electric currents induce shifts in neuronal membrane excitability, resulting in secondary changes in cortical activity. Concomitant electroencephalography (EEG) monitoring during tDCS can provide valuable information on the tDCS mechanisms of action. This study examined the effects of anodal tDCS on spontaneous cortical activity in a resting brain to disclose possible modulation of spontaneous oscillatory brain activity. EEG activity was measured in ten healthy subjects during and after a session of anodal stimulation of the postero-parietal cortex to detect the tDCS-induced alterations. Changes in the theta, alpha, beta, and gamma power bands were investigated. Three main findings emerged: (1) an increase in theta band activity during the first minutes of stimulation; (2) an increase in alpha and beta power during and after stimulation; (3) a widespread activation in several brain regions. PMID:25147519

  20. Comparative Analysis of Temporal Dynamics of EEG and Phase Synchronization of EEG to Localize Epileptic Sites from High Density

    E-print Network

    Freeman, Walter J.

    Comparative Analysis of Temporal Dynamics of EEG and Phase Synchronization of EEG to Localize the epilepsy areas in patients. This was done by examining the long-range temporal correlations (LRTC) of EEGs. The SI between a pair of channel was inferred from a statistical tendency to maintain a nearly constant

  1. Fractal Dimension in Epileptic EEG Signal Analysis

    NASA Astrophysics Data System (ADS)

    Uthayakumar, R.

    Fractal Analysis is the well developed theory in the data analysis of non-linear time series. Especially Fractal Dimension is a powerful mathematical tool for modeling many physical and biological time signals with high complexity and irregularity. Fractal dimension is a suitable tool for analyzing the nonlinear behaviour and state of the many chaotic systems. Particularly in analysis of chaotic time series such as electroencephalograms (EEG), this feature has been used to identify and distinguish specific states of physiological function.Epilepsy is the main fatal neurological disorder in our brain, which is analyzed by the biomedical signal called Electroencephalogram (EEG). The detection of Epileptic seizures in the EEG Signals is an important tool in the diagnosis of epilepsy. So we made an attempt to analyze the EEG in depth for knowing the mystery of human consciousness. EEG has more fluctuations recorded from the human brain due to the spontaneous electrical activity. Hence EEG Signals are represented as Fractal Time Series.The algorithms of fractal dimension methods have weak ability to the estimation of complexity in the irregular graphs. Divider method is widely used to obtain the fractal dimension of curves embedded into a 2-dimensional space. The major problem is choosing initial and final step length of dividers. We propose a new algorithm based on the size measure relationship (SMR) method, quantifying the dimensional behaviour of irregular rectifiable graphs with minimum time complexity. The evidence for the suitability (equality with the nature of dimension) of the algorithm is illustrated graphically.We would like to demonstrate the criterion for the selection of dividers (minimum and maximum value) in the calculation of fractal dimension of the irregular curves with minimum time complexity. For that we design a new method of computing fractal dimension (FD) of biomedical waveforms. Compared to Higuchi's algorithm, advantages of this method include greater speed and the criterion to choose the maximum and minimum values for time intervals. Comparisons with the other waveform fractal dimension algorithms are also demonstrated. In order to discriminate the Healthy and the Epileptic EEGs, an improved method of Multifractal Measure such as Generalized Fractal Dimensions (GFD) is also proposed. Finally we conclude that there are significant differences between the Healthy and Epileptic Signals in the designed method than the GFD through graphical and statistical tools. The improved multifractal measure is very efficient technique to analyze the EEG Signals and to compute the state of illness of the Epileptic patients.

  2. The processing and transmission of EEG data

    NASA Technical Reports Server (NTRS)

    Schulze, A. E.

    1974-01-01

    Interest in sleep research was stimulated by the discovery of a number of physiological changes that occur during sleep and by the observed effects of sleep on physical and mental performance and status. The use of the relatively new methods of EEG measurement, transmission, and automatic scoring makes sleep analysis and categorization feasible. Sleep research involving the use of the EEG as a fundamental input has the potential of answering many unanswered questions involving physical and mental behavior, drug effects, circadian rhythm, and anesthesia.

  3. Correlation between amygdala BOLD activity and frontal EEG asymmetry during real-time fMRI neurofeedback training in patients with depression

    E-print Network

    Zotev, Vadim; Misaki, Masaya; Phillips, Raquel; Young, Kymberly D; Feldner, Matthew T; Bodurka, Jerzy

    2014-01-01

    Background: Real-time fMRI neurofeedback (rtfMRI-nf) is a promising approach for studies and treatment of major depressive disorder (MDD). EEG performed simultaneously with rtfMRI-nf procedure allows independent evaluation of rtfMRI-nf effects. Frontal EEG asymmetry in the alpha band is a widely used measure of emotion and motivation that shows profound changes in depression. However, it has never been related to simultaneously acquired fMRI data. Methods: We performed the first study combining rtfMRI-nf with simultaneous (passive) EEG recordings. MDD patients in the experimental group (n=13) learned to upregulate BOLD activity of the left amygdala using rtfMRI-nf during a positive emotion induction task. MDD patients in the control group (n=11) were provided with sham rtfMRI-nf. Correlations between frontal EEG asymmetry in the upper-alpha band and BOLD activity across the brain were examined. Results: Participants in the experimental group showed positive average changes in frontal EEG asymmetry during the ...

  4. Preliminary Study: The Comparison between Hands-Free and Handheld 3G Mobile Phone on Alpha Brainwave

    Microsoft Academic Search

    Ros Shilawani S. Abdul Kadir; Noor Atisha Aliyasak; Zunairah Hj Murat; Rozita Jailani

    2012-01-01

    This paper presents a preliminary study on the comparison between hands-free and handheld 3G mobile phone on alpha brainwave signal for thirty samples. The resting alpha brainwave activities were recorded using EEG for three stages which are before, during and after calls. The data analysis involved correlation between left and right brainwaves signals using SPSS (Statistical Package for the Social

  5. Roles of Adrenergic ?1 and Dopamine D1 and D2 Receptors in the Mediation of the Desynchronization Effects of Modafinil in a Mouse EEG Synchronization Model

    PubMed Central

    Chen, Chang-Rui; Yang, Su-Rong; Liu, Yuan-Yuan; Qu, Wei-Min; Urade, Yoshihiro; Huang, Zhi-Li

    2013-01-01

    Background Synchronized electroencephalogram (EEG) activity is observed in pathological stages of cognitive impairment and epilepsy. Modafinil, known to increase the release of catecholamines, is a potent wake-promoting agent, and has shown some abilities to desynchronize EEG,but its receptor mechanisms by which modafinil induces desynchoronization remain to be elucidated. Here we used a pharmacological EEG synchronization model to investigate the involvement of adrenergic ?1 receptors (R, ?1R) and dopamine (DA) D1 and D2 receptors (D1Rs and D2Rs) on modafinil-induced desynchronization in mice. Methodology/Principal Findings Mice were treated with cholinergic receptor antagonist scopolamine and monoamine depletor reserpine to produce experimental EEG synchronization characterized by continuous large-amplitude synchronized activity, with prominent increased delta and decreased theta, alpha, and beta power density. The results showed that modafinil produced an EEG desynchronization in the model. This was characterized by a general decrease in amplitude of all the frequency bands between 0 and 20 Hz, a prominent reduction in delta power density, and an increase in theta power density. Adrenergic ?1R antagonist terazosin (1 mg/kg, i.p.) completely antagonized the EEG desynchronization effects of modafinil at 90 mg/kg. However, DA D1R and D2R blockers partially attenuated the effects of modafinil. The modafinil-induced decrease in the amplitudes of the delta, theta, alpha, and beta waves and in delta power density were completely abolished by pretreatment with a combination of the D1R antagonist SCH 23390 (30 µg/kg) and the D2R antagonist raclopride (2 mg/kg, i.p.). Conclusions/Significance These results suggest that modafinil-mediated desynchronization may be attributed to the activation of adrenergic ?1R, and dopaminergic D1R and D2R in a model of EEG synchronization. PMID:24116090

  6. Frequency analysis of EEG in rats during the preconvulsive period of O2 poisoning.

    PubMed

    Torbati, D; Simon, A J; Ranade, A

    1981-10-01

    The EEG of rats exposed to hyperbaric oxygenation (HBO) displays electrical discharges prior to the onset of generalized clinical convulsions (GCC). The characteristics of preconvulsive electrocorticogram (ECoG) in awake, unrestrained rats exposed to 3, 4, and 5 ATA O2 were determined. The ECoG was continuously monitored and analyzed by a hybrid analog-digital system until GCC developed. The time integral of rectified voltage of the individual delta (0.5-4 c/s), theta (4-8 c/s), alpha (8-13 c/s) beta 1 (13-20 c/s), and beta 2 (20-30 c/s) bands were plotted vs. time. An elevation in delta and a temporary reduction in alpha activity before the onset of the first electrical discharge (FED) was observed. There was a continuous reduction in beta 1 and beta 2 frequency bands during the entire pre-electrical discharge period. The activity of theta, and alpha frequency bands was significantly elevated only about 1 min before the onset of the FED, and of beta 1 and beta 2 during appearance of the FED. The possible relationship between the occurrence of preconvulsive EEG changes and pathological effects of hyperbaric oxygenation is discussed. PMID:7295246

  7. Bright light as a sleepiness prophylactic: a laboratory study of subjective ratings and EEG.

    PubMed

    Akerstedt, Torbjörn; Landström, Ulf; Byström, Marianne; Nordström, Bertil; Wibom, Roger

    2003-12-01

    Sleepiness is a major problem when driving a vehicle and contributes to 15 to 30% of all road accidents. One possible countermeasure may be exposure to light. This study was designed to test whether 30 min. of exposure to a bright light would reduce subjective sleepiness and EEG indicators of sleepiness, such as alpha and theta power density. 10 female and 10 male university students (recruited through advertisements) participated in a laboratory study, consisting of 30 min. of dim light followed by 30 min. of bright light (or red light in the control condition) exposures and then by 30 min. of dim light exposure. In the dim light exposure, the luminance was 20 cd/m2, and the illuminance was about 5 Lux. In the bright exposure, the luminance was 500 cd/m2 and the illuminance about 2000 Lux. In the red light exposure, the luminance was 10 cd/m2 and the illuminance about 30 Lux. The subject sat in a chair with a seating comfort corresponding to that of a driver's seat. Analysis showed that the subjects became subjectively sleepier during the pre-exposure condition, and alpha and theta power density increased in their EEGs. The intervention significantly reduced subjective sleepiness but did not have significant effects on alpha or theta power density. The results suggest that a short (30 min.) exposure to bright light may not be a useful prophylactic against sleepiness for the period following the exposure. PMID:14738346

  8. Simultaneous EEG-fMRI brain signatures of auditory cue utilization

    PubMed Central

    Scharinger, Mathias; Herrmann, Björn; Nierhaus, Till; Obleser, Jonas

    2014-01-01

    Optimal utilization of acoustic cues during auditory categorization is a vital skill, particularly when informative cues become occluded or degraded. Consequently, the acoustic environment requires flexible choosing and switching amongst available cues. The present study targets the brain functions underlying such changes in cue utilization. Participants performed a categorization task with immediate feedback on acoustic stimuli from two categories that varied in duration and spectral properties, while we simultaneously recorded Blood Oxygenation Level Dependent (BOLD) responses in fMRI and electroencephalograms (EEGs). In the first half of the experiment, categories could be best discriminated by spectral properties. Halfway through the experiment, spectral degradation rendered the stimulus duration the more informative cue. Behaviorally, degradation decreased the likelihood of utilizing spectral cues. Spectrally degrading the acoustic signal led to increased alpha power compared to nondegraded stimuli. The EEG-informed fMRI analyses revealed that alpha power correlated with BOLD changes in inferior parietal cortex and right posterior superior temporal gyrus (including planum temporale). In both areas, spectral degradation led to a weaker coupling of BOLD response to behavioral utilization of the spectral cue. These data provide converging evidence from behavioral modeling, electrophysiology, and hemodynamics that (a) increased alpha power mediates the inhibition of uninformative (here spectral) stimulus features, and that (b) the parietal attention network supports optimal cue utilization in auditory categorization. The results highlight the complex cortical processing of auditory categorization under realistic listening challenges. PMID:24926232

  9. [Testing method of human body's current threshold for perception based on EEG analysis].

    PubMed

    Wang, Xiaofei; Shi, Lijuan; Li, Dong; Zhao, Xu; Shao, Haiming

    2014-02-01

    Electric and electronic products are required to pass through the certification on electrical safety performance before entering into the market in order to reduce electrical shock and electrical fire so as to protect the safety of people and property. The leakage current is the most important factor in testing the electrical safety performance and the test theory is based on the perception current effect and threshold. The traditional method testing the current threshold for perception only depends on the sensing of the human body and is affected by psychological factors. Some authors filter the effect of subjective sensation by using physiological and psychological statistical algorithm in recent years and the reliability and consistency of the experiment data are improved. We established an experiment system of testing the human hody's current threshold for perception based on EEG feature analysis, and obtained 967 groups of data. We used wavelet packet analysis to detect a wave from EEG, and used FFT to do spectral analysis on alpha wave before and after the current flew through the human body. The study has shown that about 97.72% alpha wave energy changes significantly when electrical stimulation occurs. It is well proved that when the EEG feature identification is applied to test the human body current threshold for perception, and meanwhile alpha wave energy change and human body sensing are used together to confirm if the current flowing through the human body reaches the perception threshold, the measurement of the human body current threshold for perception could be carried out objectively and accurately. PMID:24804476

  10. Hemispheric Relationships in Composing: An EEG Study.

    ERIC Educational Resources Information Center

    Glassner, Benjamin M.

    The left hemisphere of the brain is analytic and "particularistic" in orientation--focusing on individual elements within a field and analyzing them sequentially. The right hemisphere of the brain is holistic or relational in processing, and is predisposed to see wholes simultaneously. One of the most prominant features of the EEG is the asymmetry…

  11. Sparse EEG Imaging Soe Therese Hansen

    E-print Network

    ) and was suggested by Kappen et al. in a not yet published article. The algo- rithm makes two key assumptions's performance, as described by Kappen et al., was conrmed initially. Reformulations of the VG problem reducing brug i EEG biofeedback. Den nye teknik kaldes variational Garrote (VG) og blev foreslået af Kappen et

  12. Automated Sleep Quality Measurement using EEG Signal

    E-print Network

    Wang, Ye

    Automated Sleep Quality Measurement using EEG Signal -First Step Towards a Domain Specific Music suffer from sleep problems. Music therapy, as a non-medication approach to mitigating sleep problems, has according to their sleep quality. The proposed sys- tem requires multidisciplinary efforts including

  13. Music Shifts Frontal EEG in Depressed Adolescents.

    ERIC Educational Resources Information Center

    Field, Tiffany; Martinez, Alex; Nawrocki, Thomas; Pickens, Jeffrey; Fox, Nathan A.; Schanberg, Saul

    1998-01-01

    Fourteen chronically depressed female adolescents listened to rock music for a 23-minute session. EEG was recorded and saliva samples were collected to determine the effects of the music on stress hormone cortisol levels. No differences were reported for mood state; however, cortisol levels decreased and relative right-frontal activation was…

  14. Hot water epilepsy: Phenotype and single photon emission computed tomography observations

    PubMed Central

    Patel, Mehul; Satishchandra, Parthasarathy; Aravinda, Hanumanthapura; Bharath, Rose D.; Sinha, Sanjib

    2014-01-01

    We studied the anatomical correlates of reflex hot water epilepsy (HWE) using multimodality investigations viz. magnetic resonance imaging (MRI), electroencephalography (EEG), and single photon emission computed tomography (SPECT). Five men (mean age: 27.0 ? 5.8 years) with HWE were subjected to MRI of brain, video-EEG studies, and SPECT scan. These were correlated with phenotypic presentations. Seizures could be precipitated in three patients with pouring of hot water over the head and semiology of seizures was suggestive of temporal lobe epilepsy. Ictal SPECT showed hyperperfusion in: left medial temporal — one, left lateral temporal — one, and right parietal — one. Interictal SPECT was normal in all five patients and did not help in localization. MRI and interictal EEG was normal in all the patients. The clinical and SPECT studies suggested temporal lobe as the seizure onset zone in some of the patients with HWE. PMID:25506178

  15. Hot water epilepsy: Phenotype and single photon emission computed tomography observations.

    PubMed

    Patel, Mehul; Satishchandra, Parthasarathy; Aravinda, Hanumanthapura; Bharath, Rose D; Sinha, Sanjib

    2014-10-01

    We studied the anatomical correlates of reflex hot water epilepsy (HWE) using multimodality investigations viz. magnetic resonance imaging (MRI), electroencephalography (EEG), and single photon emission computed tomography (SPECT). Five men (mean age: 27.0 ? 5.8 years) with HWE were subjected to MRI of brain, video-EEG studies, and SPECT scan. These were correlated with phenotypic presentations. Seizures could be precipitated in three patients with pouring of hot water over the head and semiology of seizures was suggestive of temporal lobe epilepsy. Ictal SPECT showed hyperperfusion in: left medial temporal - one, left lateral temporal - one, and right parietal - one. Interictal SPECT was normal in all five patients and did not help in localization. MRI and interictal EEG was normal in all the patients. The clinical and SPECT studies suggested temporal lobe as the seizure onset zone in some of the patients with HWE. PMID:25506178

  16. Determination of observer-rated alpha activity during sleep.

    PubMed

    Flanigan, M J; Morehouse, R L; Shapiro, C M

    1995-10-01

    Patients suffering from chronic fatigue syndrome (CFS) have been described as having alpha intrusion into sleep. In a separate study of the relationship between depression and CFS, we investigated the sleep of CFS patients. We could not detect any observable alpha anomaly in our group of CFS patients. It is possible that there is a subgroup of CFS patients in whom no alpha anomaly is present. However, the sleep electroencephalogram (EEG) montage used in our study was different to that employed by previous researchers. This paper investigates the influence of electrode derivations on the outcome of observable alpha ratings. We compared simultaneous recordings of sleep EEG using three commonly employed montages. Our results indicate that use of the mastoid reference (montage 1) results in the highest observer-related alpha. This may suggest that data regarding alpha intrusion should always be collected using montage 1. However, there is a possibility that the mastoid electrode is not electrically silent and is contaminating the data of the referenced channels. The implications of these findings are discussed in relation to the validity of alpha intrusion measurement of CFS and fibromyalgia. PMID:8560138

  17. Stress assessment based on EEG univariate features and functional connectivity measures.

    PubMed

    Alonso, J F; Romero, S; Ballester, M R; Antonijoan, R M; Mañanas, M A

    2015-07-01

    The biological response to stress originates in the brain but involves different biochemical and physiological effects. Many common clinical methods to assess stress are based on the presence of specific hormones and on features extracted from different signals, including electrocardiogram, blood pressure, skin temperature, or galvanic skin response. The aim of this paper was to assess stress using EEG-based variables obtained from univariate analysis and functional connectivity evaluation. Two different stressors, the Stroop test and sleep deprivation, were applied to 30 volunteers to find common EEG patterns related to stress effects. Results showed a decrease of the high alpha power (11 to 12?Hz), an increase in the high beta band (23 to 36?Hz, considered a busy brain indicator), and a decrease in the approximate entropy. Moreover, connectivity showed that the high beta coherence and the interhemispheric nonlinear couplings, measured by the cross mutual information function, increased significantly for both stressors, suggesting that useful stress indexes may be obtained from EEG-based features. PMID:26015439

  18. Dynamical complexity in a mean-field model of human EEG

    NASA Astrophysics Data System (ADS)

    Frascoli, Federico; Dafilis, Mathew P.; van Veen, Lennaert; Bojak, Ingo; Liley, David T. J.

    2008-12-01

    A recently proposed mean-field theory of mammalian cortex rhythmogenesis describes the salient features of electrical activity in the cerebral macrocolumn, with the use of inhibitory and excitatory neuronal populations (Liley et al 2002). This model is capable of producing a range of important human EEG (electroencephalogram) features such as the alpha rhythm, the 40 Hz activity thought to be associated with conscious awareness (Bojak & Liley 2007) and the changes in EEG spectral power associated with general anesthetic effect (Bojak & Liley 2005). From the point of view of nonlinear dynamics, the model entails a vast parameter space within which multistability, pseudoperiodic regimes, various routes to chaos, fat fractals and rich bifurcation scenarios occur for physiologically relevant parameter values (van Veen & Liley 2006). The origin and the character of this complex behaviour, and its relevance for EEG activity will be illustrated. The existence of short-lived unstable brain states will also be discussed in terms of the available theoretical and experimental results. A perspective on future analysis will conclude the presentation.

  19. Effect of Sahaja yoga practice on seizure control & EEG changes in patients of epilepsy.

    PubMed

    Panjwani, U; Selvamurthy, W; Singh, S H; Gupta, H L; Thakur, L; Rai, U C

    1996-03-01

    The effect of Sahaja yoga meditation on seizure control and electroencephalographic alterations was assessed in 32 patients of idiopathic epilepsy. The subjects were randomly divided into 3 groups. Group I (n = 10) practised Sahaja yoga for 6 months, Group II (n = 10) practised exercises mimicking Sahaja yoga for 6 months and Group III (n = 12) served as the epileptic control group. Group I subjects reported a 62 per cent decrease in seizure frequency at 3 months and a further decrease of 86 per cent at 6 months of intervention. Power spectral analysis of EEG showed a shift in frequency from 0-8 Hz towards 8-20 Hz. The ratios of EEG powers in delta (D), theta (T), alpha (A) and beta (B) bands i.e., A/D, A/D + T, A/T and A + B/D + T were increased. Per cent D power decreased and per cent A increased. No significant changes in any of the parameters were found in Groups II and III, indicating that Sahaja yoga practice brings about seizure reduction and EEG changes. Sahaja yoga could prove to be beneficial in the management of patients of epilepsy. PMID:9062044

  20. Longitudinal sleep EEG power spectral analysis studies in adolescents with minor head injury.

    PubMed

    Parsons, L C; Crosby, L J; Perlis, M; Britt, T; Jones, P

    1997-08-01

    Power spectral analysis (PSA) was used to evaluate the longitudinal overnight electroencephalographic (EEG) sleep recordings of eight subjects, between the ages of 15 and 19 years, who had sustained a minor head injury (MHI). Recordings occurred within 72 h, 6 weeks, and 12 weeks following MHI. A conditioning night preceded the first study night during which EEG electrodes were in place and subjects slept at least 7.5 h with a mean sleep efficiency of 91%. PSA was performed on four channels of EEG data recorded from fronto-temporal (F3-T3, F4-T4), and temporal (T3-T5, T4-T6) electrodes. The three waveforms associated with sleep, Delta, Theta, and Alpha-1 were all significantly elevated within 72 h post-MHI. Over time all wave forms decreased in mean log power. Theta in rapid eye movement (REM) sleep Cycle 1 decreased significantly within 6 weeks postinjury. The greatest number of significant changes, over the 12-week period were recorded during the non-REM (NREM) sleep. Changes included (1) significant decreases in mean log power of Theta and Alpha-1 in Cycle 1 from fronto-temporal leads; (2) significant decreases in Delta, Theta, and Alpha-1 in Cycle 2 from fronto-temporal leads, and (3) significant decreases in Delta and Theta for consistency during Cycle 2 from temporal leads. The intrusion of Theta into the first REM cycle within 6 weeks and its subsequent decrease within 6 weeks suggested the initiation of recovery toward baseline values. This was followed by decreased levels of Theta power during NREM Cycles 1 and 2, and Delta power in Cycle 2, both of which approached their lowest levels within 12 wks. The decrease in Alpha-1 power occurred last. Alpha-1 remained elevated through both Cycles 1 and 2 of the 6th week and then showed a precipitous decrease between the sixth and twelfth week. These findings suggested that following MHI, the brain has a specific sequence of recovery as illustrated by Delta, Theta, and Alpha-1 powers requiring different time frames to reach their lowest levels. PMID:9300565

  1. Causality within the Epileptic Network: An EEG-fMRI Study Validated by Intracranial EEG

    PubMed Central

    Vaudano, Anna Elisabetta; Avanzini, Pietro; Tassi, Laura; Ruggieri, Andrea; Cantalupo, Gaetano; Benuzzi, Francesca; Nichelli, Paolo; Lemieux, Louis; Meletti, Stefano

    2013-01-01

    Accurate localization of the Seizure Onset Zone (SOZ) is crucial in patients with drug-resistance focal epilepsy. EEG with fMRI recording (EEG-fMRI) has been proposed as a complementary non-invasive tool, which can give useful additional information in the pre-surgical work-up. However, fMRI maps related to interictal epileptiform activities (IED) often show multiple regions of signal change, or “networks,” rather than highly focal ones. Effective connectivity approaches like Dynamic Causal Modeling (DCM) applied to fMRI data potentially offers a framework to address which brain regions drives the generation of seizures and IED within an epileptic network. Here, we present a first attempt to validate DCM on EEG-fMRI data in one patient affected by frontal lobe epilepsy. Pre-surgical EEG-fMRI demonstrated two distinct clusters of blood oxygenation level dependent (BOLD) signal increases linked to IED, one located in the left frontal pole and the other in the ipsilateral dorso-lateral frontal cortex. DCM of the IED-related BOLD signal favored a model corresponding to the left dorso-lateral frontal cortex as driver of changes in the fronto-polar region. The validity of DCM was supported by: (a) the results of two different non-invasive analysis obtained on the same dataset: EEG source imaging (ESI), and “psycho-physiological interaction” analysis; (b) the failure of a first surgical intervention limited to the fronto-polar region; (c) the results of the intracranial EEG monitoring performed after the first surgical intervention confirming a SOZ located over the dorso-lateral frontal cortex. These results add evidence that EEG-fMRI together with advanced methods of BOLD signal analysis is a promising tool that can give relevant information within the epilepsy surgery diagnostic work-up. PMID:24294210

  2. miR-1236 down-regulates alpha-fetoprotein, thus causing PTEN accumulation, which inhibits the PI3K/Akt pathway and malignant phenotype in hepatoma cells

    PubMed Central

    Yang, Xi; Shuang, Zeyu; Liu, Min; Li, Shengping; Tang, Hua

    2015-01-01

    Alpha fetoprotein (AFP) is a clinical biomarker of hepatocellular carcinoma (HCC). Here, we found that miR-1236 is down-regulated, whereas AFP is highly expressed in HCC tissues and cells. We demonstrated that miR-1236 directly targets the 3?UTR of AFP and down-regulates its expression. Also, miR-1236 inhibited and AFP stimulated proliferation, migration, invasion and vasculogenic mimicry (VM) of HCC. In agreement, AFP over-expression counteracted the inhibitory effect of miR-1236. We demonstrated that AFP promoted the ubiquitination of PTEN, thus decreasing PTEN levels, while miR-1236 inhibited the PI3K/Akt pathway. PMID:25714026

  3. [EEG and fMRI reactions of a healthy brain at active and passive movements by a leading hand].

    PubMed

    Boldyreva, G N; Sharova, E V; Zhavoronkova, L A; Cheliapina, M V; Dubrovskaia, L P; Simonova, O A; Smirnov, A S; Troshina, E M; Kornienko, V N

    2014-01-01

    Bioelectrical (EEG) and hemodynamic (fMRI) responses of cerebral reactions to active and passive movements by the right hand were analyzed in 17 right-handed healthy persons. Individual and averaged fMRI and EEG data was analyzed. The main cortex fMRI responses (sensorimotor cortex of the contralateral, left hemisphere) were topographically similar during both active and passive movements. This fact allows us to recommend the usage of the passive movement paradigm for the mapping of the motor areas in patients with movement disorders. Including in reactive process of cerebellum and subcortical structures at passive movements was more variability than active ones. FMRI-reactions at passive movements were characterized more individual variability than during active ones at the expense of diversity of cerebellum and subcortical structures answers. The EEG analysis revealed that at both passive and active movements there is a coherence increase in the high-frequency alpha-ban in left central-frontal area of the left, activated hemisphere. The power-frequency changes of the EEG parameters during active and passive movements were primarily shown in a frequency increase and the desynchronization of the beta-band. Consistency with the topography of the fMRI response was not found. PMID:25710070

  4. Comprehensive common spatial patterns with temporal structure information of EEG data: minimizing nontask related EEG component.

    PubMed

    Wang, Haixian; Xu, Dong

    2012-09-01

    In the context of electroencephalogram (EEG)-based brain-computer interfaces (BCI), common spatial patterns (CSP) is widely used for spatially filtering multichannel EEG signals. CSP is a supervised learning technique depending on only labeled trials. Its generalization performance deteriorates due to overfitting occurred when the number of training trials is small. On the other hand, a large number of unlabeled trials are relatively easy to obtain. In this paper, we contribute a comprehensive learning scheme of CSP (cCSP) that learns on both labeled and unlabeled trials. cCSP regularizes the objective function of CSP by preserving the temporal relationship among samples of unlabeled trials in terms of linear representation. The intrinsically temporal structure is characterized by an l(1) graph. As a result, the temporal correlation information of unlabeled trials is incorporated into CSP, yielding enhanced generalization capacity. Interestingly, the regularizer of cCSP can be interpreted as minimizing a nontask related EEG component, which helps cCSP alleviate nonstationarities. Experiment results of single-trial EEG classification on publicly available EEG datasets confirm the effectiveness of the proposed method. PMID:22736634

  5. Memories of attachment hamper EEG cortical connectivity in dissociative patients.

    PubMed

    Farina, Benedetto; Speranza, Anna Maria; Dittoni, Serena; Gnoni, Valentina; Trentini, Cristina; Vergano, Carola Maggiora; Liotti, Giovanni; Brunetti, Riccardo; Testani, Elisa; Della Marca, Giacomo

    2014-08-01

    In this study, we evaluated cortical connectivity modifications by electroencephalography (EEG) lagged coherence analysis, in subjects with dissociative disorders and in controls, after retrieval of attachment memories. We asked thirteen patients with dissociative disorders and thirteen age- and sex-matched healthy controls to retrieve personal attachment-related autobiographical memories through adult attachment interviews (AAI). EEG was recorded in the closed eyes resting state before and after the AAI. EEG lagged coherence before and after AAI was compared in all subjects. In the control group, memories of attachment promoted a widespread increase in EEG connectivity, in particular in the high-frequency EEG bands. Compared to controls, dissociative patients did not show an increase in EEG connectivity after the AAI. Conclusions: These results shed light on the neurophysiology of the disintegrative effect of retrieval of traumatic attachment memories in dissociative patients. PMID:24121863

  6. Study on Bayes Discriminant Analysis of EEG Data

    PubMed Central

    Shi, Yuan; He, DanDan; Qin, Fang

    2014-01-01

    Objective: In this paper, we have done Bayes Discriminant analysis to EEG data of experiment objects which are recorded impersonally come up with a relatively accurate method used in feature extraction and classification decisions. Methods: In accordance with the strength of ? wave, the head electrodes are divided into four species. In use of part of 21 electrodes EEG data of 63 people, we have done Bayes Discriminant analysis to EEG data of six objects. Results In use of part of EEG data of 63 people, we have done Bayes Discriminant analysis, the electrode classification accuracy rates is 64.4%. Conclusions: Bayes Discriminant has higher prediction accuracy, EEG features (mainly ?wave) extract more accurate. Bayes Discriminant would be better applied to the feature extraction and classification decisions of EEG data. PMID:25852784

  7. RESEARCH OF SACCADE-RELATED EEG: COMPARISON OF ENSEMBLE AVERAGING METHOD AND INDEPENDENT

    E-print Network

    Cichocki, Andrzej

    Electroencephalogram (EEG) related to fast eye move- ment (saccade), has been the subject of application oriented are used to connect a user and a computer via an electroencephalogram (EEG). The EEG is related to emotion

  8. Canonical Decomposition of scalp EEG in epileptic seizure localisation Maarten De Vos 1,

    E-print Network

    the seizures. The electroencephalogram (EEG) is then recorded over several days as it is the direct measurement of seizure onset zone is recording of ictal scalp electroencephalogram (EEG) [10]. The EEG measures electric

  9. Exploring EEG signals in a Brain-Computer Interface

    NASA Astrophysics Data System (ADS)

    Zubrycki, Pawe?; Mulawka, Jan

    2014-11-01

    This article shows the basic methods of electroencephalography EEG signal exploration. It contains information about data acquisition and different methods in which brain-computer interfaces can be made. The main focus of the paper is to find a way to determine the best set of parameters to detect movement of a hand in EEG signal. In the introduction there is also short introduction to EEG as well as fundamentals of support vector machine.

  10. ALPHA OMEGA ALPHA National Honor Medical Society

    E-print Network

    12/7/2011 1 ALPHA OMEGA ALPHA National Honor Medical Society www.alphaomegaalpha.org AA and Leadership William Root The Alpha Omega Alpha honor medical society was initially organized in 1902/community service. AA and Medical Professionalism "Be Worthy to Serve the Suffering" #12;Alpha Omega Alpha Honor

  11. EEG Quality:The Image Acquisition Artefact

    Microsoft Academic Search

    Petra Ritter; Robert Becker; Frank Freyer; Arno Villringer

    \\u000a In this chapter, we focus on the artefacts that arise in the EEG during the fMRI acquisition process. Functional MRI using\\u000a echo planar imaging (EPI) sequences involves the application of rapidly varying magnetic field gradients for spatial encoding\\u000a of the MR signal and radiofrequency (RF) pulses for spin excitation (see the chapter “The Basics of Functional Magnetic Resonance\\u000a Imaging”). Early

  12. Detection of EEG electrodes in brain volumes.

    PubMed

    Graffigna, Juan P; Gómez, M Eugenia; Bustos, José J

    2010-01-01

    This paper presents a method to detect 128 EEG electrodes in image study and to merge with the Nuclear Magnetic Resonance volume for better diagnosis. First we propose three hypotheses to define a specific acquisition protocol in order to recognize the electrodes and to avoid distortions in the image. In the second instance we describe a method for segmenting the electrodes. Finally, registration is performed between volume of the electrodes and NMR. PMID:21095810

  13. Cross coherence independent component analysis in resting and action states EEG discrimination

    NASA Astrophysics Data System (ADS)

    Almurshedi, A.; Ismail, A. K.

    2014-11-01

    Cross Coherence time frequency transform and independent component analysis (ICA) method were used to analyse the electroencephalogram (EEG) signals in resting and action states during open and close eyes conditions. From the topographical scalp distributions of delta, theta, alpha, and beta power spectrum can clearly discriminate between the signal when the eyes were open or closed, but it was difficult to distinguish between resting and action states when the eyes were closed. In open eyes condition, the frontal area (Fp1, Fp2) was activated (higher power) in delta and theta bands whilst occipital (O1, O2) and partial (P3, P4, Pz) area of brain was activated alpha band in closed eyes condition. The cross coherence method of time frequency analysis is capable of discrimination between rest and action brain signals in closed eyes condition.

  14. Noisy galvanic vestibular stimulation modulates the amplitude of EEG synchrony patterns.

    PubMed

    Kim, Diana J; Yogendrakumar, Vignan; Chiang, Joyce; Ty, Edna; Wang, Z Jane; McKeown, Martin J

    2013-01-01

    Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson's disease; yet, the mechanism of action is unclear. Since Parkinson's and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4-7.5 Hz), low alpha (8-10 Hz), high alpha (10.5-12 Hz), beta (13-30 Hz) and gamma (31-50 Hz) bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents - at 10, 26, 42, 58, 74 and 90% of sensory threshold - to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20-25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously-described cognitive and motor effects of vestibular stimulation, and noisy galvanic vestibular stimulation may provide an additional non-invasive means for neuromodulation of functional brain networks. PMID:23874865

  15. Preliteracy signatures of poor-reading abilities in resting-state EEG.

    PubMed

    Schiavone, Giuseppina; Linkenkaer-Hansen, Klaus; Maurits, Natasha M; Plakas, Anna; Maassen, Ben A M; Mansvelder, Huibert D; van der Leij, Aryan; van Zuijen, Titia L

    2014-01-01

    The hereditary character of dyslexia suggests the presence of putative underlying neural anomalies already in preliterate age. Here, we investigated whether early neurophysiological correlates of future reading difficulties-a hallmark of dyslexia-could be identified in the resting-state EEG of preliterate children. The children in this study were recruited at birth and classified on the basis of parents' performance on reading tests to be at-risk of becoming poor readers (n = 48) or not (n = 14). Eyes-open rest EEG was measured at the age of 3 years, and the at-risk children were divided into fluent readers (n = 24) and non-fluent readers (n = 24) after reading assessment at their third grade of school. We found that fluent readers and non-fluent readers differed in normalized spectral amplitude. Non-fluent readers were characterized by lower amplitude in the delta-1 frequency band (0.5-2 Hz) and higher amplitude in the alpha-1 band (6-8 Hz) in multiple scalp regions compared to control and at-risk fluent readers. Interestingly, across groups these EEG biomarkers correlated with several behavioral test scores measured in the third grade. Specifically, the performance on reading fluency, phonological and orthographic tasks and rapid automatized naming task correlated positively with delta-1 and negatively with alpha-1. Together, our results suggest that combining family-risk status, neurophysiological testing and behavioral test scores in a longitudinal setting may help uncover physiological mechanisms implicated with neurodevelopmental disorders such as the predisposition to reading disabilities. PMID:25285075

  16. Noisy Galvanic Vestibular Stimulation Modulates the Amplitude of EEG Synchrony Patterns

    PubMed Central

    Kim, Diana J.; Yogendrakumar, Vignan; Chiang, Joyce; Ty, Edna; Wang, Z. Jane; McKeown, Martin J.

    2013-01-01

    Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson’s disease; yet, the mechanism of action is unclear. Since Parkinson’s and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4–7.5 Hz), low alpha (8–10 Hz), high alpha (10.5–12 Hz), beta (13–30 Hz) and gamma (31–50 Hz) bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents – at 10, 26, 42, 58, 74 and 90% of sensory threshold – to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20–25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously-described cognitive and motor effects of vestibular stimulation, and noisy galvanic vestibular stimulation may provide an additional non-invasive means for neuromodulation of functional brain networks. PMID:23874865

  17. Medial profrontal cortex and anterior cingulate cortex in the generation of alpha activity induced by transcendental meditation: a magnetoencephalographic study.

    PubMed

    Yamamoto, Shin; Kitamura, Yoshihiro; Yamada, Norihito; Nakashima, Yoshihiko; Kuroda, Shigetoshi

    2006-02-01

    Previous EEG studies have shown that transcendental meditation (TM) increases frontal and central alpha activity. The present study was aimed at identifying the source of this alpha activity using magnetoencephalography (MEG) and electroencephalography (EEG) simultaneously on eight TM practitioners before, during, and after TM. The magnetic field potentials corresponding to TM-induced alpha activities on EEG recordings were extracted, and we attempted to localize the dipole sources using the multiple signal classification (MUSIC) algorithm, equivalent current dipole source analysis, and the multiple spatio-temporal dipole model. Since the dipoles were mapped to both the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC), it is suggested that the mPFC and ACC play an important role in brain activity induced by TM. PMID:16508689

  18. Long-term EEG in children.

    PubMed

    Montavont, A; Kaminska, A; Soufflet, C; Taussig, D

    2015-03-01

    Long-term video-EEG corresponds to a recording ranging from 1 to 24 h or even longer. It is indicated in the following situations: diagnosis of epileptic syndromes or unclassified epilepsy, pre-surgical evaluation for drug-resistant epilepsy, follow-up of epilepsy or in cases of paroxysmal symptoms whose etiology remains uncertain. There are some specificities related to paediatric care: a dedicated pediatric unit; continuous monitoring covering at least a full 24-hour period, especially in the context of pre-surgical evaluation; the requirement of presence by the parents, technician or nurse; and stronger attachment of electrodes (cup electrodes), the number of which is adapted to the age of the child. The chosen duration of the monitoring also depends on the frequency of seizures or paroxysmal events. The polygraphy must be adapted to the type and topography of movements. It is essential to have at least an electrocardiography (ECG) channel, respiratory sensor and electromyography (EMG) on both deltoids. There is no age limit for performing long-term video-EEG even in newborns and infants; nevertheless because of scalp fragility, strict surveillance of the baby's skin condition is required. In the specific context of pre-surgical evaluation, long-term video-EEG must record all types of seizures observed in the child. This monitoring is essential in order to develop hypotheses regarding the seizure onset zone, based on electroclinical correlations, which should be adapted to the child's age and the psychomotor development. PMID:25687590

  19. Hypnosis and the EEG. A quantitative investigation.

    PubMed

    Teb?cis, A K; Provins, K A; Farnbach, R W; Pentony, P

    1975-07-01

    A quantitative investigation of the EEG during hypnosis was made by analyzing the analogue power frequency spectrum of one group of subjects in the awake and hypnotized conditions, and another group (random sample) in the awake condition. Individuals of the first group were thoroughly experienced in self-hypnosis and highly hypnotizable, whereas those of the second group had never been hypnotized and were low in waking suggestibility. There were no statistically significant differences in mean power of the whole EEG spectrum between the awake and hypnotized conditions of the experimental group, although a trend toward increased theta (4 to 8 Hz) density during hypnosis was apparent. This group, however, exhibited significantly more theta activity during both the hypnotized and the awake conditions than the random sample of controls in the awake condition, irrespective of whether the eyes were closed or open. We suggest that this increased theta density in the EEG is related to frequent experience of self-hypnosis, high hypnotizability, or both. PMID:1151356

  20. Spatial-temporal structures of human alpha rhythms: theory, microcurrent sources, multiscale measurements, and global binding of local networks.

    PubMed

    Nunez, P L; Wingeier, B M; Silberstein, R B

    2001-07-01

    A theoretical framework supporting experimental measures of dynamic properties of human EEG is proposed with emphasis on distinct alpha rhythms. Robust relationships between measured dynamics and cognitive or behavioral conditions are reviewed, and proposed physiological bases for EEG at cellular levels are considered. Classical EEG data are interpreted in the context of a conceptual framework that distinguishes between locally and globally dominated dynamic processes, as estimated with coherence or other measures of phase synchronization. Macroscopic (scalp) potentials generated by cortical current sources are described at three spatial scales, taking advantage of the columnar structure of neocortex. New EEG data demonstrate that both globally coherent and locally dominated behavior can occur within the alpha band, depending on narrow band frequency, spatial measurement scale, and brain state. Quasi-stable alpha phase structures consistent with global standing waves are observed. At the same time, alpha and theta phase locking between cortical regions during mental calculations is demonstrated, consistent with neural network formation. The brain-binding problem is considered in the context of EEG dynamic behavior that generally exhibits both of these local and global aspects. But specific experimental designs and data analysis methods may severely bias physiological interpretations in either local or global directions. PMID:11376500

  1. Using single-trial EEG to predict and analyze subsequent memory.

    PubMed

    Noh, Eunho; Herzmann, Grit; Curran, Tim; de Sa, Virginia R

    2014-01-01

    We show that it is possible to successfully predict subsequent memory performance based on single-trial EEG activity before and during item presentation in the study phase. Two-class classification was conducted to predict subsequently remembered vs. forgotten trials based on subjects' responses in the recognition phase. The overall accuracy across 18 subjects was 59.6% by combining pre- and during-stimulus information. The single-trial classification analysis provides a dimensionality reduction method to project the high-dimensional EEG data onto a discriminative space. These projections revealed novel findings in the pre- and during-stimulus periods related to levels of encoding. It was observed that the pre-stimulus information (specifically oscillatory activity between 25 and 35Hz) -300 to 0ms before stimulus presentation and during-stimulus alpha (7-12Hz) information between 1000 and 1400ms after stimulus onset distinguished between recollection and familiarity while the during-stimulus alpha information and temporal information between 400 and 800ms after stimulus onset mapped these two states to similar values. PMID:24064073

  2. [Dextrose and vigilance: the effect of dextrose on the spectro-analytic parameters of pharmaco-EEG].

    PubMed

    Gessner, B; Cnota, P J; Schaaf, B

    1992-09-01

    In a randomized single-blind cross-over-design the effect of 15 g dextrose was investigated against placebo with 48 healthy subjects at two different days each. The quantitative pharmaco-EEG was recorded occipitocentral at the left side (O1-Cz) under vigilance controlled conditions and then under resting conditions (three minutes each). Having measured its baseline it was repeated six times every 20 minutes starting 10 minutes after the application of the substance. After the administration of dextrose a stabilization of vigilance could be seen in the EEG by the following differences of statistical significance (p < = 0.05) between dextrose and placebo under resting recording conditions: In the first control (14.-16. minute post) there was a significant decrease of the relative power in the delta and in the theta range combined with an increase of alpha 2. In the second control (34.-36. minute post) there was a significant decrease of relative power in the theta range and significant increase in the alpha 1 range. In the third control (54.-56. minute post) and later on no effects of dextrose were left in the pharmaco-EEG. The significant differences in the first and second control have to be interpreted as follows: After the administration of dextrose the level of vigilance was increased compared to the placebo group. PMID:1425394

  3. [Peculiarities of EEG dynamics in cognitive activity demanding persistent attention in patients with schizophrenia and schizoaffective psychosis and their relatives].

    PubMed

    Uvarova, L G; Alfimova, M V

    2005-01-01

    The search for neurophysiologic correlates of attention and working memory dysfunction in families with schizophrenia, 55 patients with schizophrenia and schizoaffective psychosis, 91 unaffected first degree relatives and 48 mentally normal subjects without family history of mental disorders have been studied. Changes in power of 5 EEG frequency bands in 16 records during serial mental arithmetic tasks were analyzed. Abnormalities in EEG reactivity were found both in patients and their relatives. Both groups were characterized by diffuse elevation of delta-rhythm power, the signs of hypoactivation and inversion of reaction asymmetry for different rhythm bands in the frontal area. In relatives, more pronounced attention dysfunction corresponded to more expressed abnormalities in EEG reactivity. Moreover, patients demonstrated insufficient depression of alpha and fast waves activity in the posterior cortex areas relevant to arithmetic activity. The results obtained allow considering an impaired reaction of alpha and fast rhythms inhibition in the posterior cortex areas as characteristic of the disease, and diffuse elevation of delta-waves power and frontal lobe hypoactivation with the inversion of reaction asymmetry as familial features that might reflect an impact of the factors predisposing to psychosis. This predisposition emerged during the cognitive task involving sustained attention and working memory. PMID:16180499

  4. PROPERTIES AND PARAMETER SELECTION FOR PHASE SYNCHRONY PROCESSING OF EEG SIGNALS

    E-print Network

    Beex, A. A. "Louis"

    application in EEG (electroencephalogram) processing. A Phase Synchrony Processor is proposed and its. Introduction The electroencephalogram (EEG) is a weak (generally, less than 300 V) electrical signal obtained

  5. JOURNAL NAME, VOL. X, NO. X, MONTH YEAR 1 Compressive Sensing of Multi-Channel EEG

    E-print Network

    electroencephalogram (EEG), compressive sensing, cosparse signal recovery, low rank matrix recovery, alternating for signal processing [1]. The electroencephalogram (EEG) signal is one of the most frequently used

  6. Frequency-domain localization of alpha rhythm in humans via a maximum entropy approach

    NASA Astrophysics Data System (ADS)

    Patel, Pankaj; Khosla, Deepak; Al-Dayeh, Louai; Singh, Manbir

    1997-05-01

    Generators of spontaneous human brain activity such as alpha rhythm may be easier and more accurate to localize in frequency-domain than in time-domain since these generators are characterized by a specific frequency range. We carried out a frequency-domain analysis of synchronous alpha sources by generating equivalent potential maps using the Fourier transform of each channel of electro-encephalographic (EEG) recordings. SInce the alpha rhythm recorded by EEG scalp measurements is probably produced by several independent generators, a distributed source imaging approach was considered more appropriate than a model based on a single equivalent current dipole. We used an imaging approach based on a Bayesian maximum entropy technique. Reconstructed sources were superposed on corresponding anatomy form magnetic resonance imaging. Results from human studies suggest that reconstructed sources responsible for alpha rhythm are mainly located in the occipital and parieto- occipital lobes.

  7. Standardized Computer-based Organized Reporting of EEG: SCORE

    PubMed Central

    Beniczky, Sándor; Aurlien, Harald; Brøgger, Jan C; Fuglsang-Frederiksen, Anders; Martins-da-Silva, António; Trinka, Eugen; Visser, Gerhard; Rubboli, Guido; Hjalgrim, Helle; Stefan, Hermann; Rosén, Ingmar; Zarubova, Jana; Dobesberger, Judith; Alving, Jørgen; Andersen, Kjeld V; Fabricius, Martin; Atkins, Mary D; Neufeld, Miri; Plouin, Perrine; Marusic, Petr; Pressler, Ronit; Mameniskiene, Ruta; Hopfengärtner, Rüdiger; Emde Boas, Walter; Wolf, Peter

    2013-01-01

    The electroencephalography (EEG) signal has a high complexity, and the process of extracting clinically relevant features is achieved by visual analysis of the recordings. The interobserver agreement in EEG interpretation is only moderate. This is partly due to the method of reporting the findings in free-text format. The purpose of our endeavor was to create a computer-based system for EEG assessment and reporting, where the physicians would construct the reports by choosing from predefined elements for each relevant EEG feature, as well as the clinical phenomena (for video-EEG recordings). A working group of EEG experts took part in consensus workshops in Dianalund, Denmark, in 2010 and 2011. The faculty was approved by the Commission on European Affairs of the International League Against Epilepsy (ILAE). The working group produced a consensus proposal that went through a pan-European review process, organized by the European Chapter of the International Federation of Clinical Neurophysiology. The Standardised Computer-based Organised Reporting of EEG (SCORE) software was constructed based on the terms and features of the consensus statement and it was tested in the clinical practice. The main elements of SCORE are the following: personal data of the patient, referral data, recording conditions, modulators, background activity, drowsiness and sleep, interictal findings, “episodes” (clinical or subclinical events), physiologic patterns, patterns of uncertain significance, artifacts, polygraphic channels, and diagnostic significance. The following specific aspects of the neonatal EEGs are scored: alertness, temporal organization, and spatial organization. For each EEG finding, relevant features are scored using predefined terms. Definitions are provided for all EEG terms and features. SCORE can potentially improve the quality of EEG assessment and reporting; it will help incorporate the results of computer-assisted analysis into the report, it will make possible the build-up of a multinational database, and it will help in training young neurophysiologists. PMID:23506075

  8. Alpha Oscillations in Response to Affective and Cigarette-Related Stimuli in Smokers

    PubMed Central

    2013-01-01

    Introduction: The presence of cigarette-related cues has been associated with smoking relapse. These cues are believed to activate brain mechanisms underlying emotion, attention, and memory. Electroencephalography (EEG) alpha desynchronization (i.e., reduction in alpha power) has been suggested to index the engagement of these mechanisms. Analyzing EEG alpha desynchronization in response to affective and smoking cues might improve our understanding of how smokers process these cues, and the potential impact of this processing on relapse. Methods: Before the start of a medication-assisted cessation attempt, we recorded EEG from 179 smokers during the presentation of neutral, pleasant, unpleasant, and cigarette-related pictures. Wavelet analysis was used to extract EEG alpha oscillations (8–12 Hz) in response to these pictures. Alpha oscillations were analyzed as a function of picture valence and arousal dimensions. Results: Emotional and cigarette-related stimuli induced a higher level of alpha desynchronization (i.e., less power in the alpha frequency band) than neutral stimuli. In addition, the level of alpha desynchronization induced by cigarette-related stimuli was similar to that induced by highly arousing stimuli (i.e., erotica and mutilations). Conclusions: These results suggest that, for smokers, cigarette-related cues are motivationally significant stimuli that may engage emotional, attentional, and memory-related neural mechanisms at a level comparable to that seen in response to highly arousing stimuli. This finding suggests that activation of emotional, attentional, and memory-related brain mechanisms may be an important contributor to cue-induced smoking relapse. PMID:23060019

  9. Quantitative EEG and Current Source Density Analysis of Combined Antiepileptic Drugs and Dopaminergic Agents in Genetic Epilepsy: Two Case Studies.

    PubMed

    Emory, Hamlin; Wells, Christopher; Mizrahi, Neptune

    2015-07-01

    Two adolescent females with absence epilepsy were classified, one as attention deficit and the other as bipolar disorder. Physical and cognitive exams identified hypotension, bradycardia, and cognitive dysfunction. Their initial electroencephalograms (EEGs) were considered slightly slow, but within normal limits. Quantitative EEG (QEEG) data included relative theta excess and low alpha mean frequencies. A combined treatment of antiepileptic drugs with a catecholamine agonist/reuptake inhibitor was sequentially used. Both patients' physical and cognitive functions improved and they have remained seizure free. The clinical outcomes were correlated with statistically significant changes in QEEG measures toward normal Z-scores in both anterior and posterior regions. In addition, low resolution electromagnetic tomography (LORETA) Z-scored source correlation analyses of the initial and treated QEEG data showed normalized patterns, supporting a neuroanatomic resolution. This study presents preliminary evidence for a neurophysiologic approach to patients with absence epilepsy and comorbid disorders and may provide a method for further research. PMID:25326290

  10. On the analysis of EEG power, frequency and asymmetry in Parkinson’s disease during emotion processing

    PubMed Central

    2014-01-01

    Objective While Parkinson’s disease (PD) has traditionally been described as a movement disorder, there is growing evidence of disruption in emotion information processing associated with the disease. The aim of this study was to investigate whether there are specific electroencephalographic (EEG) characteristics that discriminate PD patients and normal controls during emotion information processing. Method EEG recordings from 14 scalp sites were collected from 20 PD patients and 30 age-matched normal controls. Multimodal (audio-visual) stimuli were presented to evoke specific targeted emotional states such as happiness, sadness, fear, anger, surprise and disgust. Absolute and relative power, frequency and asymmetry measures derived from spectrally analyzed EEGs were subjected to repeated ANOVA measures for group comparisons as well as to discriminate function analysis to examine their utility as classification indices. In addition, subjective ratings were obtained for the used emotional stimuli. Results Behaviorally, PD patients showed no impairments in emotion recognition as measured by subjective ratings. Compared with normal controls, PD patients evidenced smaller overall relative delta, theta, alpha and beta power, and at bilateral anterior regions smaller absolute theta, alpha, and beta power and higher mean total spectrum frequency across different emotional states. Inter-hemispheric theta, alpha, and beta power asymmetry index differences were noted, with controls exhibiting greater right than left hemisphere activation. Whereas intra-hemispheric alpha power asymmetry reduction was exhibited in patients bilaterally at all regions. Discriminant analysis correctly classified 95.0% of the patients and controls during emotional stimuli. Conclusion These distributed spectral powers in different frequency bands might provide meaningful information about emotional processing in PD patients. PMID:24716619

  11. [Structural and functional peculiarity of brain activity to performance and imaginary motor tasks in healthy persons (EEG and fMRI study)].

    PubMed

    Boldyreva, G N; Sharova, E V; Zhavoronkova, L A; Cheliapina, M V; Dubrovskaia, L P; Simonova, O A; Fadeeva, L M; Pronin, I N; Kornienko, V N

    2013-01-01

    Bioelectrical (EEG) and hemodynamic (fMRI-response) cerebral reactions to performance and imaginary motor tasks by right or left hand were analyzed in 15 right-handed healthy persons (21-39 years old). During actual movement the main fMRI-response was registered in the area of central gyrus of the hemisphere contralateral to the working hand. Areas of activation were also revealed in the supplemental motor area and the ipsilateral hemisphere of the cerebellum. EEG data showed coherence increase in high frequency alpha- and beta-bands in the activated hemisphere. In imaginary motor tasks the intensity and topography of fMRI-response became the more variable; response was decreased in the motor area and in cerebellum, they increased in the subcortical structures and in the parietal association zones. EEG changes were very variable in this situation also; it was observe an increase of EEG coherence in the right hemisphere for higher frequency of alpha and beta spectral bands. Changes of power spectrum parameters were similar to performance and imaginary motor tasks. Spectrum power and middle frequency of beta band were increased. Topographically these changes did not correspond to activated hemisphere and it was more in the left hemisphere. These changes were reflected nonspecific component of reaction. PMID:24450163

  12. Resting-state EEG study of comatose patients: a connectivity and frequency analysis to find differences between vegetative and minimally conscious states

    PubMed Central

    Lehembre, Rémy; Bruno, Marie-Aurélie; Vanhaudenhuyse, Audrey; Chatelle, Camille; Cologan, Victor; Leclercq, Yves; Soddu, Andrea; Macq, Benoît; Laureys, Steven; Noirhomme, Quentin

    2012-01-01

    Summary The aim of this study was to look for differences in the power spectra and in EEG connectivity measures between patients in the vegetative state (VS/UWS) and patients in the minimally conscious state (MCS). The EEG of 31 patients was recorded and analyzed. Power spectra were obtained using modern multitaper methods. Three connectivity measures (coherence, the imaginary part of coherency and the phase lag index) were computed. Of the 31 patients, 21 were diagnosed as MCS and 10 as VS/UWS using the Coma Recovery Scale-Revised (CRS-R). EEG power spectra revealed differences between the two conditions. The VS/UWS patients showed increased delta power but decreased alpha power compared with the MCS patients. Connectivity measures were correlated with the CRS-R diagnosis; patients in the VS/UWS had significantly lower connectivity than MCS patients in the theta and alpha bands. Standard EEG recorded in clinical conditions could be used as a tool to help the clinician in the diagnosis of disorders of consciousness. PMID:22687166

  13. A 200 W Eight-Channel EEG Acquisition ASIC for Ambulatory EEG Systems

    Microsoft Academic Search

    Refet Firat Yazicioglu; Patrick Merken; Robert Puers; Chris Van Hoof

    2008-01-01

    The growing interest toward the improvement of patients' quality of life and the use of medical signals in nonmedical applications such as entertainment, sports, and brain-computerinterfaces, requires the implementation of miniaturized and wireless biopotential acquisition systems with ultralow power dissipation. Therefore, this paper presents the implementation of a complete EEG acquisition ASIC tailored towards the needs of such applications, i.e.,

  14. An empirical EEG analysis in brain death diagnosis for adults

    PubMed Central

    Cao, Jianting; Cao, Yang; Zhang, Yue; Gu, Fanji; Zhu, Guoxian; Hong, Zhen; Wang, Bin; Cichocki, Andrzej

    2008-01-01

    Electroencephalogram (EEG) is often used in the confirmatory test for brain death diagnosis in clinical practice. Because EEG recording and monitoring is relatively safe for the patients in deep coma, it is believed to be valuable for either reducing the risk of brain death diagnosis (while comparing other tests such as the apnea) or preventing mistaken diagnosis. The objective of this paper is to study several statistical methods for quantitative EEG analysis in order to help bedside or ambulatory monitoring or diagnosis. We apply signal processing and quantitative statistical analysis for the EEG recordings of 32 adult patients. For EEG signal processing, independent component analysis (ICA) was applied to separate the independent source components, followed by Fourier and time-frequency analysis. For quantitative EEG analysis, we apply several statistical complexity measures to the EEG signals and evaluate the differences between two groups of patients: the subjects in deep coma, and the subjects who were categorized as brain death. We report statistically significant differences of quantitative statistics with real-life EEG recordings in such a clinical study, and we also present interpretation and discussions on the preliminary experimental results. PMID:19003489

  15. Juvenile myoclonic epilepsy: A clinical and sleep EEG study

    Microsoft Academic Search

    A. K. Dhanuka; B. K. Jain; Singh Daljit; D. Maheshwari

    2001-01-01

    Juvenile myoclonic epilepsy (JME) is characterized by myoclonic jerks on awakening, generalized tonic–clonic seizures (GTCS) and is associated with absence seizures in more than one third of cases. Fifteen patients with juvenile myoclonic epilepsy were studied with regard to their clinical profile, EEG data and sleep EEG findings. There was a delay in the diagnosis of JME (mean of 3.5

  16. Insecure attachment is associated with the ?-EEG anomaly during sleep

    Microsoft Academic Search

    Eileen P Sloan; Robert G Maunder; Jonathan J Hunter; Harvey Moldofsky

    2007-01-01

    BACKGROUND: The ?-EEG anomaly during sleep, originally associated with chronic pain, is noted in several psychiatric and medical conditions and is also present in some normal subjects. The exact significance of the ?-EEG anomaly is uncertain, but it has been suggested to be a nonspecific response to a variety of noxious stimuli. We propose that attachment insecurity, which is often

  17. Grouping of MEG gamma oscillations by EEG sleep spindles

    Microsoft Academic Search

    Amr Ayoub; Matthias Mölle; Hubert Preissl; Jan Born

    Studies have revealed an association between EEG sleep spindles and processing of memories during sleep. Here we investigated whether there is a temporal relation between sleep spindles and MEG oscillatory activity in the gamma frequency band (>30Hz) which is considered to reflect local cortical processing of memory representations. MEG and simultaneous EEG (at Cz) were obtained in subjects during sleep

  18. Bayes Consistent Classification of EEG Data by Approximate Marginalisation

    E-print Network

    Roberts, Stephen

    EEG segments and to classification of sleep spindles. 1.1 Introduction Once we opt for decision1 Bayes Consistent Classification of EEG Data by Approximate Marginalisation P. Sykacek, I. Rezek analysis within a Bayesian framework, we must do this throughout the entire process. The approach studied

  19. Dynamics of parameters of neurophysiological models from phenomenological EEG modeling

    Microsoft Academic Search

    E. Olbrich; Thomas Wennekers

    2007-01-01

    We investigate a recently proposed method for the analysis of oscillatory patterns in EEG data, with respect to its capacity of further quantifying processes on slower (< 1 Hz) time scales. The method is based on modeling the EEG time series by linear autoregressive (AR) models with time dependent parameters. Systems described by such linear models can be interpreted as

  20. Topographic Organization of Nonlinear Interdependence in Multichannel Human EEG

    E-print Network

    Breakspear, Michael

    in a small but statistically robust number of epochs. The occurrence of nonlinear interdependence in any in regional coherence. Recent advances in time series analysis now permit the examination of EEG data) EEG channels prior to and dur- ing epileptic seizures. It appears that in temporal lobe epilepsy

  1. An artificial intelligence approach to classify and analyse EEG traces

    Microsoft Academic Search

    C. Castellaro; G. Favaro; A. Castellaro; A. Casagrande; S. Castellaro; D. V. Puthenparampil; C. Fattorello Salimbeni

    2002-01-01

    We present a fully automatic system for the classification and analysis of adult electroencephalograms (EEGs). The system is based on an artificial neural network which classifies the single epochs of trace, and on an Expert System (ES) which studies the time and space correlation among the outputs of the neural network; compiling a final report. On the last 2000 EEGs

  2. Using EEG to Study Cognitive Development: Issues and Practices

    ERIC Educational Resources Information Center

    Bell, Martha Ann; Cuevas, Kimberly

    2012-01-01

    Developmental research is enhanced by use of multiple methodologies for examining psychological processes. The electroencephalogram (EEG) is an efficient and relatively inexpensive method for the study of developmental changes in brain-behavior relations. In this review, we highlight some of the challenges for using EEG in cognitive development…

  3. Application of quantitative EEG to aircraft assessment, management, and control

    Microsoft Academic Search

    M. B. Sterman

    1995-01-01

    Recent advances in the understanding and computer processing of human brain wave (EEG) activity have produced renewed interest in the possibility of a bioengineering control interface using this signal. Evidence concerning the neurophysiological substrates of EEG frequency modulation and topographic expression provide a basis for the differentiation of functional states during vehicle control performance. These and other studies have identified

  4. EEG brainwave pattern for smoking behaviour after Horizontal Rotation treatment

    Microsoft Academic Search

    Z. M. Hanafiah; K. F. M. Yunos; Z. H. Murat; M. N. Taib; S. Lias

    2009-01-01

    The main focus of this research is to analyze EEG signal of smokers after undergoing Horizontal Rotation (HR) treatment. 21 male smokers were sampled in this study. EEG data was captured before and after HR for 5 sessions. In addition, some demographic data were gathered from the samples to check their smoking habits. It was found that, HR significantly improves

  5. Predicting EEG complexity from sleep macro and microstructure

    Microsoft Academic Search

    I. Chouvarda; M. O. Mendez; V. Rosso; A. M. Bianchi; L. Parrino; A. Grassi; M. Terzano; N. Maglaveras; S. Cerutti

    2011-01-01

    This work investigates the relation between the complexity of electroencephalography (EEG) signal, as measured by fractal dimension (FD), and normal sleep structure in terms of its macrostructure and microstructure. Sleep features are defined, encoding sleep stage and cyclic alternating pattern (CAP) related information, both in short and long term. The relevance of each sleep feature to the EEG FD is

  6. EEG-Based Multivariate Statistical Analysis of Sleep Stages

    Microsoft Academic Search

    L. Molinari; G. Dumermuth; B. Lange

    1984-01-01

    All-night sleep of 5 healthy male subjects was scored on the basis of EEG (paper records), EMG and EOG into the stages of wakefulness, REM sleep and slow sleep stages 1–4 according to Rechtschaffen and Kales. Spectral analysis for 8 EEG channels was then performed and spectral parameters (total power and coherence for certain frequency bands) extracted. Stepwise linear discriminant

  7. EEG Markers for Attention Deficit Disorder: Pharmacological and Neurofeedback Applications.

    ERIC Educational Resources Information Center

    Sterman, M. Barry

    2000-01-01

    Examined contribution of EEG findings in the classification and treatment of attention deficit and related behavioral problems in children. Found that quantitative EEG methods disclosed patterns of abnormality in children with ADD, suggested improved guidelines for pharmacological treatment, and introduced neurofeedback, a behavioral treatment for…

  8. Classification of EEG abnormalities in partial epilepsy with simultaneous EEG-fMRI recordings.

    PubMed

    Pedreira, C; Vaudano, A E; Thornton, R C; Chaudhary, U J; Vulliemoz, S; Laufs, H; Rodionov, R; Carmichael, D W; Lhatoo, S D; Guye, M; Quian Quiroga, R; Lemieux, L

    2014-10-01

    Scalp EEG recordings and the classification of interictal epileptiform discharges (IED) in patients with epilepsy provide valuable information about the epileptogenic network, particularly by defining the boundaries of the "irritative zone" (IZ), and hence are helpful during pre-surgical evaluation of patients with severe refractory epilepsies. The current detection and classification of epileptiform signals essentially rely on expert observers. This is a very time-consuming procedure, which also leads to inter-observer variability. Here, we propose a novel approach to automatically classify epileptic activity and show how this method provides critical and reliable information related to the IZ localization beyond the one provided by previous approaches. We applied Wave_clus, an automatic spike sorting algorithm, for the classification of IED visually identified from pre-surgical simultaneous Electroencephalogram-functional Magnetic Resonance Imagining (EEG-fMRI) recordings in 8 patients affected by refractory partial epilepsy candidate for surgery. For each patient, two fMRI analyses were performed: one based on the visual classification and one based on the algorithmic sorting. This novel approach successfully identified a total of 29 IED classes (compared to 26 for visual identification). The general concordance between methods was good, providing a full match of EEG patterns in 2 cases, additional EEG information in 2 other cases and, in general, covering EEG patterns of the same areas as expert classification in 7 of the 8 cases. Most notably, evaluation of the method with EEG-fMRI data analysis showed hemodynamic maps related to the majority of IED classes representing improved performance than the visual IED classification-based analysis (72% versus 50%). Furthermore, the IED-related BOLD changes revealed by using the algorithm were localized within the presumed IZ for a larger number of IED classes (9) in a greater number of patients than the expert classification (7 and 5, respectively). In contrast, in only one case presented the new algorithm resulted in fewer classes and activation areas. We propose that the use of automated spike sorting algorithms to classify IED provides an efficient tool for mapping IED-related fMRI changes and increases the EEG-fMRI clinical value for the pre-surgical assessment of patients with severe epilepsy. PMID:24830841

  9. ALPHA OMEGA ALPHA National Honor Medical Society

    E-print Network

    12/6/2012 1 ALPHA OMEGA ALPHA National Honor Medical Society www.alphaomegaalpha.org AA and Leadership The Alpha Omega Alpha honor medical society was organized in 1902 to "recognize and perpetuate Omega Alpha Honor Medical Society Wisconsin beta Chapter All upcoming MCW seniors who are interested

  10. The Drosophila phenotype ontology

    PubMed Central

    2013-01-01

    Background Phenotype ontologies are queryable classifications of phenotypes. They provide a widely-used means for annotating phenotypes in a form that is human-readable, programatically accessible and that can be used to group annotations in biologically meaningful ways. Accurate manual annotation requires clear textual definitions for terms. Accurate grouping and fruitful programatic usage require high-quality formal definitions that can be used to automate classification. The Drosophila?phenotype ontology (DPO) has been used to annotate over 159,000 phenotypes in FlyBase to date, but until recently lacked textual or formal definitions. Results We have composed textual definitions for all DPO terms and formal definitions for 77% of them. Formal definitions reference terms from a range of widely-used ontologies including the Phenotype and Trait Ontology (PATO), the Gene Ontology (GO) and the Cell Ontology (CL). We also describe a generally applicable system, devised for the DPO, for recording and reasoning about the timing of death in populations. As a result of the new formalisations, 85% of classifications in the DPO are now inferred rather than asserted, with much of this classification leveraging the structure of the GO. This work has significantly improved the accuracy and completeness of classification and made further development of the DPO more sustainable. Conclusions The DPO provides a set of well-defined terms for annotating Drosophila?phenotypes and for grouping and querying the resulting annotation sets in biologically meaningful ways. Such queries have already resulted in successful function predictions from phenotype annotation. Moreover, such formalisations make extended queries possible, including cross-species queries via the external ontologies used in formal definitions. The DPO is openly available under an open source license in both OBO and OWL formats. There is good potential for it to be used more broadly by the Drosophila?community, which may ultimately result in its extension to cover a broader range of phenotypes. PMID:24138933

  11. Computer-Aided Diagnosis of Depression Using EEG Signals.

    PubMed

    Acharya, U Rajendra; Sudarshan, Vidya K; Adeli, Hojjat; Santhosh, Jayasree; Koh, Joel E W; Adeli, Amir

    2015-01-01

    The complex, nonlinear and non-stationary electroencephalogram (EEG) signals are very tedious to interpret visually and highly difficult to extract the significant features from them. The linear and nonlinear methods are effective in identifying the changes in EEG signals for the detection of depression. Linear methods do not exhibit the complex dynamical variations in the EEG signals. Hence, chaos theory and nonlinear dynamic methods are widely used in extracting the EEG signal features for computer-aided diagnosis (CAD) of depression. Hence, this article presents the recent efforts on CAD of depression using EEG signals with a focus on using nonlinear methods. Such a CAD system is simple to use and may be used by the clinicians as a tool to confirm their diagnosis. It should be of a particular value to enable the early detection of depression. © 2015 S. Karger AG, Basel. PMID:25997732

  12. Amplitude Integrated EEG: The Child Neurologist’s Perspective

    PubMed Central

    Glass, Hannah C.; Wusthoff, Courtney J.; Shellhaas, Renée A.

    2014-01-01

    Neurologists increasingly recognize that critically ill patients are at high risk for seizures - particularly non-convulsive seizures - and that neuromonitoring is a useful tool for diagnosing seizures and assessing brain function in these patients. Amplitude-integrated electroencephalography (aEEG) is a simplified bedside neurophysiology tool that has become widely used in neonates over the past decade. Despite widespread interest by both neurologists and neonatologists in continuous brain monitoring, aEEG has been largely ignored by neurologists, forcing neonatologists to “go it alone” when interpreting data from this bedside tool. Although aEEG cannot replace conventional EEG for background monitoring and detection of seizures, it remains a useful instrument that complements conventional EEG, is being widely adopted by neonatologists, and should be supported by neonatal neurologists. PMID:23690296

  13. Wireless recording systems: from noninvasive EEG-NIRS to invasive EEG devices.

    PubMed

    Sawan, Mohamad; Salam, Muhammad T; Le Lan, Jérôme; Kassab, Amal; Gelinas, Sébastien; Vannasing, Phetsamone; Lesage, Frédéric; Lassonde, Maryse; Nguyen, Dang K

    2013-04-01

    In this paper, we present the design and implementation of a wireless wearable electronic system dedicated to remote data recording for brain monitoring. The reported wireless recording system is used for a) simultaneous near-infrared spectrometry (NIRS) and scalp electro-encephalography (EEG) for noninvasive monitoring and b) intracerebral EEG (icEEG) for invasive monitoring. Bluetooth and dual radio links were introduced for these recordings. The Bluetooth-based device was embedded in a noninvasive multichannel EEG-NIRS system for easy portability and long-term monitoring. On the other hand, the 32-channel implantable recording device offers 24-bit resolution, tunable features, and a sampling frequency up to 2 kHz per channel. The analog front-end preamplifier presents low input-referred noise of 5 ? VRMS and a signal-to-noise ratio of 112 dB. The communication link is implemented using a dual-band radio frequency transceiver offering a half-duplex 800 kb/s data rate, 16.5 mW power consumption and less than 10(-10) post-correction Bit-Error Rate (BER). The designed system can be accessed and controlled by a computer with a user-friendly graphical interface. The proposed wireless implantable recording device was tested in vitro using real icEEG signals from two patients with refractory epilepsy. The wirelessly recorded signals were compared to the original signals recorded using wired-connection, and measured normalized root-mean square deviation was under 2%. PMID:23853301

  14. Alpha-1 Antitrypsin Deficiency

    MedlinePLUS

    ... Liver Disease Information > Alpha-1 Antitrypsin Deficiency Alpha-1 Antitrypsin Deficiency Explore this section to learn more about alpha-1 antitrypsin deficiency, including a description of the disorder ...

  15. Multivariate genetic determinants of EEG oscillations in schizophrenia and psychotic bipolar disorder from the BSNIP study

    PubMed Central

    Narayanan, B; Soh, P; Calhoun, V D; Ruaño, G; Kocherla, M; Windemuth, A; Clementz, B A; Tamminga, C A; Sweeney, J A; Keshavan, M S; Pearlson, G D

    2015-01-01

    Schizophrenia (SZ) and psychotic bipolar disorder (PBP) are disabling psychiatric illnesses with complex and unclear etiologies. Electroencephalogram (EEG) oscillatory abnormalities in SZ and PBP probands are heritable and expressed in their relatives, but the neurobiology and genetic factors mediating these abnormalities in the psychosis dimension of either disorder are less explored. We examined the polygenic architecture of eyes-open resting state EEG frequency activity (intrinsic frequency) from 64 channels in 105 SZ, 145 PBP probands and 56 healthy controls (HCs) from the multisite BSNIP (Bipolar-Schizophrenia Network on Intermediate Phenotypes) study. One million single-nucleotide polymorphisms (SNPs) were derived from DNA. We assessed eight data-driven EEG frequency activity derived from group-independent component analysis (ICA) in conjunction with a reduced subset of 10?422 SNPs through novel multivariate association using parallel ICA (para-ICA). Genes contributing to the association were examined collectively using pathway analysis tools. Para-ICA extracted five frequency and nine SNP components, of which theta and delta activities were significantly correlated with two different gene components, comprising genes participating extensively in brain development, neurogenesis and synaptogenesis. Delta and theta abnormality was present in both SZ and PBP, while theta differed between the two disorders. Theta abnormalities were also mediated by gene clusters involved in glutamic acid pathways, cadherin and synaptic contact-based cell adhesion processes. Our data suggest plausible multifactorial genetic networks, including novel and several previously identified (DISC1) candidate risk genes, mediating low frequency delta and theta abnormalities in psychoses. The gene clusters were enriched for biological properties affecting neural circuitry and involved in brain function and/or development. PMID:26101851

  16. Multivariate genetic determinants of EEG oscillations in schizophrenia and psychotic bipolar disorder from the BSNIP study.

    PubMed

    Narayanan, B; Soh, P; Calhoun, V D; Ruaño, G; Kocherla, M; Windemuth, A; Clementz, B A; Tamminga, C A; Sweeney, J A; Keshavan, M S; Pearlson, G D

    2015-01-01

    Schizophrenia (SZ) and psychotic bipolar disorder (PBP) are disabling psychiatric illnesses with complex and unclear etiologies. Electroencephalogram (EEG) oscillatory abnormalities in SZ and PBP probands are heritable and expressed in their relatives, but the neurobiology and genetic factors mediating these abnormalities in the psychosis dimension of either disorder are less explored. We examined the polygenic architecture of eyes-open resting state EEG frequency activity (intrinsic frequency) from 64 channels in 105 SZ, 145 PBP probands and 56 healthy controls (HCs) from the multisite BSNIP (Bipolar-Schizophrenia Network on Intermediate Phenotypes) study. One million single-nucleotide polymorphisms (SNPs) were derived from DNA. We assessed eight data-driven EEG frequency activity derived from group-independent component analysis (ICA) in conjunction with a reduced subset of 10?422 SNPs through novel multivariate association using parallel ICA (para-ICA). Genes contributing to the association were examined collectively using pathway analysis tools. Para-ICA extracted five frequency and nine SNP components, of which theta and delta activities were significantly correlated with two different gene components, comprising genes participating extensively in brain development, neurogenesis and synaptogenesis. Delta and theta abnormality was present in both SZ and PBP, while theta differed between the two disorders. Theta abnormalities were also mediated by gene clusters involved in glutamic acid pathways, cadherin and synaptic contact-based cell adhesion processes. Our data suggest plausible multifactorial genetic networks, including novel and several previously identified (DISC1) candidate risk genes, mediating low frequency delta and theta abnormalities in psychoses. The gene clusters were enriched for biological properties affecting neural circuitry and involved in brain function and/or development. PMID:26101851

  17. Integrating EEG and fMRI in epilepsy.

    PubMed

    Formaggio, Emanuela; Storti, Silvia Francesca; Bertoldo, Alessandra; Manganotti, Paolo; Fiaschi, Antonio; Toffolo, Gianna Maria

    2011-02-14

    Integrating electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies enables to non-invasively investigate human brain function and to find the direct correlation of these two important measures of brain activity. Presurgical evaluation of patients with epilepsy is one of the areas where EEG and fMRI integration has considerable clinical relevance for localizing the brain regions generating interictal epileptiform activity. The conventional analysis of EEG-fMRI data is based on the visual identification of the interictal epileptiform discharges (IEDs) on scalp EEG. The convolution of these EEG events, represented as stick functions, with a model of the fMRI response, i.e. the hemodynamic response function, provides the regressor for general linear model (GLM) analysis of fMRI data. However, the conventional analysis is not automatic and suffers of some subjectivity in IEDs classification. Here, we present an easy-to-use and automatic approach for combined EEG-fMRI analysis able to improve IEDs identification based on Independent Component Analysis and wavelet analysis. EEG signal due to IED is reconstructed and its wavelet power is used as a regressor in GLM. The method was validated on simulated data and then applied on real data set consisting of 2 normal subjects and 5 patients with partial epilepsy. In all continuous EEG-fMRI recording sessions a good quality EEG was obtained allowing the detection of spontaneous IEDs and the analysis of the related BOLD activation. The main clinical finding in EEG-fMRI studies of patients with partial epilepsy is that focal interictal slow-wave activity was invariably associated with increased focal BOLD responses in a spatially related brain area. Our study extends current knowledge on epileptic foci localization and confirms previous reports suggesting that BOLD activation associated with slow activity might have a role in localizing the epileptogenic region even in the absence of clear interictal spikes. PMID:21109007

  18. Emotional Stress Recognition System Using EEG and Psychophysiological Signals: Using New Labelling Process of EEG Signals in Emotional Stress State

    Microsoft Academic Search

    Seyyed Abed Hosseini; Mohammad Ali Khalilzadeh

    2010-01-01

    This paper proposes a new emotional stress recognition system using multi-modal bio-signals. Since electroencephalogram (EEG) is the reflection of brain activity and is widely used in clinical diagnosis and biomedical research, it is used as the main signal. In order to choose the proper EEG channels we used the cognitive model of the brain under emotional stress. We designed an

  19. Folate receptor {alpha} regulates cell proliferation in mouse gonadotroph {alpha}T3-1 cells

    SciTech Connect

    Yao, Congjun; Evans, Chheng-Orn [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States)] [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States); Stevens, Victoria L. [Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia (United States)] [Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia (United States); Owens, Timothy R. [Emory University, School of Medicine, Atlanta, Georgia (United States)] [Emory University, School of Medicine, Atlanta, Georgia (United States); Oyesiku, Nelson M., E-mail: noyesik@emory.edu [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States)

    2009-11-01

    We have previously found that the mRNA and protein levels of the folate receptor alpha (FR{alpha}) are uniquely over-expressed in clinically human nonfunctional (NF) pituitary adenomas, but the mechanistic role of FR{alpha} has not fully been determined. We investigated the effect of FR{alpha} over-expression in the mouse gonadotroph {alpha}T3-1 cell line as a model for NF pituitary adenomas. We found that the expression and function of FR{alpha} were strongly up-regulated, by Western blotting and folic acid binding assay. Furthermore, we found a higher cell growth rate, an enhanced percentage of cells in S-phase by BrdU assay, and a higher PCNA staining. These observations indicate that over-expression of FR{alpha} promotes cell proliferation. These effects were abrogated in the same {alpha}T3-1 cells when transfected with a mutant FR{alpha} cDNA that confers a dominant-negative phenotype by inhibiting folic acid binding. Finally, by real-time quantitative PCR, we found that mRNA expression of NOTCH3 was up-regulated in FR{alpha} over-expressing cells. In summary, our data suggests that FR{alpha} regulates pituitary tumor cell proliferation and mechanistically may involve the NOTCH pathway. Potentially, this finding could be exploited to develop new, innovative molecular targeted treatment for human NF pituitary adenomas.

  20. Evidence of a Faster Posterior Dominant EEG Rhythm in Children with Autism

    ERIC Educational Resources Information Center

    Gregory, Michael D.; Mandelbaum, David E.

    2012-01-01

    Multiple electroencephalography (EEG) abnormalities have been associated with autism. In the course of clinical work, we have observed a posterior dominant EEG rhythm at higher frequency in children with autism. To test this observation, 56 EEG tracings of children with autism were compared to the EEGs of age-matched controls. Children with autism…

  1. Slow and fast EEG sleep spindle component extraction using Independent Component Analysis

    Microsoft Academic Search

    Errikos M. Ventouras; Periklis Y. Ktonas; Hara Tsekou; Thomas Paparrigopoulos; Ioannis Kalatzis; Constantin R. Soldatos

    2008-01-01

    Sleep spindles are groups of rhythmic activity, with a waxing-waning morphology, and are considered a hallmark of stage 2 of the sleep electroencephalogram (EEG). They are present predominantly in stages 2, 3 and 4 of the sleep EEG. Spatial analysis of sleep spindle scalp EEG and EEG inverse problem solutions have provided evidence for the existence of two distinct sleep

  2. The $\\alpha-\\alpha$ fishbone potential revisited

    E-print Network

    Day, J P; Elhanafy, M; Smith, E; Woodhouse, R; Papp, Z

    2011-01-01

    The fishbone potential of composite particles simulates the Pauli effect by nonlocal terms. We determine the $\\alpha-\\alpha$ fishbone potential by simultaneously fitting to two-$\\alpha$ resonance energies, experimental phase shifts and three-$\\alpha$ binding energies. We found that essentially a simple gaussian can provide a good description of two-$\\alpha$ and three-$\\alpha$ experimental data without invoking three-body potentials.

  3. Correlations between EEG and chemical changes in uremia.

    PubMed

    Hughes, J R

    1980-05-01

    This study investigated correlations between the EEG and 10 different chemical indices in 23 uremic patients, tested over long periods of time (up to 18 months). An abnormal EEG was recorded at least once in 70% of these patients, but among the 362 tracings from all patients, 36% were considered abnormal. Slow wave abnormalities, mainly mild in degree and frontal in location, were found in 97% of abnormal records and epileptiform patterns in the form of bilateral spike and wave complexes were seen in 14%. Patients with these EEG abnormalities had a significantly slower frequency of background rhythm than patients with normal EEGs. Compared to those with normal records, patients with abnormal EEGs had a significantly higher BUN and Cl and lower Ca, as determined by standard (absolute) mean values. With relative changes, based on the percentage change from the previous value, the BUN, Ca, Cl, K, PO4 and CO2 showed significant relationships with a deteriorating EEG and the Ca, Cl, K and CO2 with an improving record. A deteriorating EEG was usually associated with an increasing BUN, Cr, K, Cl and Na and a decreasing Ca, PO4, Hct, Alb and CO2. Significant absolute changes in the chemical indices were more often seen than relative ones, especially with a deteriorating EEG. With either absolute or relatives values, the BUN showed the closest relationship with EEG deterioration and the Cr, Cl and Hct with EEG improvement. Changes were often seen in a combination of chemical indices, most often involving the BUN and to a lesser extent the Cr. With combined changes the one with the greatest change was especially the BUN and PO4. Variations in the amount of epileptiform activity were most closely related to changes in the BUN. The main conclusions of this study are that the BUN correlated best with the EEG among the 10 different serum values using various indices, especially standard (absolute) values with a deteriorating recording. The second highest number of correlations were found with the Cl, especially absolute values with an improving EEG. The Ca and K showed the best correlation with relative changes. Thus, correlations of various chemical indices with electrographic changes in uremic patients depend upon whether absolute or relative values are used and whether EEGs are deteriorating or improving. PMID:6153966

  4. Spatiotemporal analysis of multichannel EEG: CARTOOL.

    PubMed

    Brunet, Denis; Murray, Micah M; Michel, Christoph M

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way. PMID:21253358

  5. Spatiotemporal Analysis of Multichannel EEG: CARTOOL

    PubMed Central

    Brunet, Denis; Murray, Micah M.; Michel, Christoph M.

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way. PMID:21253358

  6. EEG microstates during resting represent personality differences.

    PubMed

    Schlegel, Felix; Lehmann, Dietrich; Faber, Pascal L; Milz, Patricia; Gianotti, Lorena R R

    2012-01-01

    We investigated the spontaneous brain electric activity of 13 skeptics and 16 believers in paranormal phenomena; they were university students assessed with a self-report scale about paranormal beliefs. 33-channel EEG recordings during no-task resting were processed as sequences of momentary potential distribution maps. Based on the maps at peak times of Global Field Power, the sequences were parsed into segments of quasi-stable potential distribution, the 'microstates'. The microstates were clustered into four classes of map topographies (A-D). Analysis of the microstate parameters time coverage, occurrence frequency and duration as well as the temporal sequence (syntax) of the microstate classes revealed significant differences: Believers had a higher coverage and occurrence of class B, tended to decreased coverage and occurrence of class C, and showed a predominant sequence of microstate concatenations from A to C to B to A that was reversed in skeptics (A to B to C to A). Microstates of different topographies, putative "atoms of thought", are hypothesized to represent different types of information processing.The study demonstrates that personality differences can be detected in resting EEG microstate parameters and microstate syntax. Microstate analysis yielded no conclusive evidence for the hypothesized relation between paranormal belief and schizophrenia. PMID:21644026

  7. Alpha One Foundation

    MedlinePLUS

    ... Support Find Doctor 20th Anniversary What Is Alpha-1? Alpha-1 Antitrypsin Deficiency (Alpha-1) is a ... daily treatment for COPD More News Our Number One Goal: Find a cure for Alpha-1. Website ...

  8. Mobile Collection and Automated Interpretation of EEG Data

    NASA Technical Reports Server (NTRS)

    Mintz, Frederick; Moynihan, Philip

    2007-01-01

    A system that would comprise mobile and stationary electronic hardware and software subsystems has been proposed for collection and automated interpretation of electroencephalographic (EEG) data from subjects in everyday activities in a variety of environments. By enabling collection of EEG data from mobile subjects engaged in ordinary activities (in contradistinction to collection from immobilized subjects in clinical settings), the system would expand the range of options and capabilities for performing diagnoses. Each subject would be equipped with one of the mobile subsystems, which would include a helmet that would hold floating electrodes (see figure) in those positions on the patient s head that are required in classical EEG data-collection techniques. A bundle of wires would couple the EEG signals from the electrodes to a multi-channel transmitter also located in the helmet. Electronic circuitry in the helmet transmitter would digitize the EEG signals and transmit the resulting data via a multidirectional RF patch antenna to a remote location. At the remote location, the subject s EEG data would be processed and stored in a database that would be auto-administered by a newly designed relational database management system (RDBMS). In this RDBMS, in nearly real time, the newly stored data would be subjected to automated interpretation that would involve comparison with other EEG data and concomitant peer-reviewed diagnoses stored in international brain data bases administered by other similar RDBMSs.

  9. Usability of four commercially-oriented EEG systems.

    PubMed

    David Hairston, W; Whitaker, Keith W; Ries, Anthony J; Vettel, Jean M; Cortney Bradford, J; Kerick, Scott E; McDowell, Kaleb

    2014-08-01

    Electroencephalography (EEG) holds promise as a neuroimaging technology that can be used to understand how the human brain functions in real-world, operational settings while individuals move freely in perceptually-rich environments. In recent years, several EEG systems have been developed that aim to increase the usability of the neuroimaging technology in real-world settings. Here, the usability of three wireless EEG systems from different companies are compared to a conventional wired EEG system, BioSemi's ActiveTwo, which serves as an established laboratory-grade 'gold standard' baseline. The wireless systems compared include Advanced Brain Monitoring's B-Alert X10, Emotiv Systems' EPOC and the 2009 version of QUASAR's Dry Sensor Interface 10-20. The design of each wireless system is discussed in relation to its impact on the system's usability as a potential real-world neuroimaging system. Evaluations are based on having participants complete a series of cognitive tasks while wearing each of the EEG acquisition systems. This report focuses on the system design, usability factors and participant comfort issues that arise during the experimental sessions. In particular, the EEG systems are assessed on five design elements: adaptability of the system for differing head sizes, subject comfort and preference, variance in scalp locations for the recording electrodes, stability of the electrical connection between the scalp and electrode, and timing integration between the EEG system, the stimulus presentation computer and other external events. PMID:24980915

  10. TMS-EEG: From basic research to clinical applications

    NASA Astrophysics Data System (ADS)

    Hernandez-Pavon, Julio C.; Sarvas, Jukka; Ilmoniemi, Risto J.

    2014-11-01

    Transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) is a powerful technique for non-invasively studying cortical excitability and connectivity. The combination of TMS and EEG has widely been used to perform basic research and recently has gained importance in different clinical applications. In this paper, we will describe the physical and biological principles of TMS-EEG and different applications in basic research and clinical applications. We will present methods based on independent component analysis (ICA) for studying the TMS-evoked EEG responses. These methods have the capability to remove and suppress large artifacts, making it feasible, for instance, to study language areas with TMS-EEG. We will discuss the different applications and limitations of TMS and TMS-EEG in clinical applications. Potential applications of TMS are presented, for instance in neurosurgical planning, depression and other neurological disorders. Advantages and disadvantages of TMS-EEG and its variants such as repetitive TMS (rTMS) are discussed in comparison to other brain stimulation and neuroimaging techniques. Finally, challenges that researchers face when using this technique will be summarized.

  11. Diagnostic Role of ECG Recording Simultaneously With EEG Testing.

    PubMed

    Kendirli, Mustafa Tansel; Aparci, Mustafa; Kendirli, Nurten; Tekeli, Hakan; Karaoglan, Mustafa; Senol, Mehmet Guney; Togrol, Erdem

    2015-07-01

    Arrhythmia is not uncommon in the etiology of syncope which mimics epilepsy. Data about the epilepsy induced vagal tonus abnormalities have being increasingly reported. So we aimed to evaluate what a neurologist may gain by a simultaneous electrocardiogram (ECG) and electroencephalogram (EEG) recording in the patients who underwent EEG testing due to prediagnosis of epilepsy. We retrospectively evaluated and detected ECG abnormalities in 68 (18%) of 376 patients who underwent EEG testing. A minimum of 20 of minutes artifact-free recording were required for each patient. Standard 1-channel ECG was simultaneously recorded in conjunction with the EEG. In all, 28% of females and 14% of males had ECG abnormalities. Females (mean age 49 years, range 18-88 years) were older compared with the male group (mean age 28 years, range 16-83 years). Atrial fibrillation was more frequent in female group whereas bradycardia and respiratory sinus arrhythmia was higher in male group. One case had been detected a critical asystole indicating sick sinus syndrome in the female group and treated with a pacemaker implantation in the following period. Simultaneous ECG recording in conjunction with EEG testing is a clinical prerequisite to detect and to clarify the coexisting ECG and EEG abnormalities and their clinical relevance. Potentially rare lethal causes of syncope that mimic seizure or those that could cause resistance to antiepileptic therapy could effectively be distinguished by detecting ECG abnormalities coinciding with the signs and abnormalities during EEG recording. PMID:25253437

  12. Pre-stimulus BOLD-network activation modulates EEG spectral activity during working memory retention

    PubMed Central

    Kottlow, Mara; Schlaepfer, Anthony; Baenninger, Anja; Michels, Lars; Brandeis, Daniel; Koenig, Thomas

    2015-01-01

    Working memory (WM) processes depend on our momentary mental state and therefore exhibit considerable fluctuations. Here, we investigate the interplay of task-preparatory and task-related brain activity as represented by pre-stimulus BOLD-fluctuations and spectral EEG from the retention periods of a visual WM task. Visual WM is used to maintain sensory information in the brain enabling the performance of cognitive operations and is associated with mental health. We tested 22 subjects simultaneously with EEG and fMRI while performing a visuo-verbal Sternberg task with two different loads, allowing for the temporal separation of preparation, encoding, retention and retrieval periods. Four temporally coherent networks (TCNs)—the default mode network (DMN), the dorsal attention, the right and the left WM network—were extracted from the continuous BOLD data by means of a group ICA. Subsequently, the modulatory effect of these networks' pre-stimulus activation upon retention-related EEG activity in the theta, alpha, and beta frequencies was analyzed. The obtained results are informative in the context of state-dependent information processing. We were able to replicate two well-known load-dependent effects: the frontal-midline theta increase during the task and the decrease of pre-stimulus DMN activity. As our main finding, these two measures seem to depend on each other as the significant negative correlations at frontal-midline channels suggested. Thus, suppressed pre-stimulus DMN levels facilitated later task related frontal midline theta increases. In general, based on previous findings that neuronal coupling in different frequency bands may underlie distinct functions in WM retention, our results suggest that processes reflected by spectral oscillations during retention seem not only to be “online” synchronized with activity in different attention-related networks but are also modulated by activity in these networks during preparation intervals. PMID:25999828

  13. Mean-field thalamocortical modeling of longitudinal EEG acquired during intensive meditation training.

    PubMed

    Saggar, Manish; Zanesco, Anthony P; King, Brandon G; Bridwell, David A; MacLean, Katherine A; Aichele, Stephen R; Jacobs, Tonya L; Wallace, B Alan; Saron, Clifford D; Miikkulainen, Risto

    2015-07-01

    Meditation training has been shown to enhance attention and improve emotion regulation. However, the brain processes associated with such training are poorly understood and a computational modeling framework is lacking. Modeling approaches that can realistically simulate neurophysiological data while conforming to basic anatomical and physiological constraints can provide a unique opportunity to generate concrete and testable hypotheses about the mechanisms supporting complex cognitive tasks such as meditation. Here we applied the mean-field computational modeling approach using the scalp-recorded electroencephalogram (EEG) collected at three assessment points from meditating participants during two separate 3-month-long shamatha meditation retreats. We modeled cortical, corticothalamic, and intrathalamic interactions to generate a simulation of EEG signals recorded across the scalp. We also present two novel extensions to the mean-field approach that allow for: (a) non-parametric analysis of changes in model parameter values across all channels and assessments; and (b) examination of variation in modeled thalamic reticular nucleus (TRN) connectivity over the retreat period. After successfully fitting whole-brain EEG data across three assessment points within each retreat, two model parameters were found to replicably change across both meditation retreats. First, after training, we observed an increased temporal delay between modeled cortical and thalamic cells. This increase provides a putative neural mechanism for a previously observed reduction in individual alpha frequency in these same participants. Second, we found decreased inhibitory connection strength between the TRN and secondary relay nuclei (SRN) of the modeled thalamus after training. This reduction in inhibitory strength was found to be associated with increased dynamical stability of the model. Altogether, this paper presents the first computational approach, taking core aspects of physiology and anatomy into account, to formally model brain processes associated with intensive meditation training. The observed changes in model parameters inform theoretical accounts of attention training through meditation, and may motivate future study on the use of meditation in a variety of clinical populations. PMID:25862265

  14. The effect of linear mixing in the EEG on Hurst exponent estimation.

    PubMed

    Blythe, Duncan A J; Haufe, Stefan; Müller, Klaus-Robert; Nikulin, Vadim V

    2014-10-01

    Although the long-range temporal correlation (LRTC) of the amplitude fluctuations of neuronal EEG/MEG oscillations is widely acknowledged, the majority of studies to date have been performed in sensor space, disregarding the mixing effects implied by volume conduction and confounding noise. While the effect of mixing on the evaluation of evoked responses and connectivity measures has been extensively studied, there are, to date, no studies reporting on the differences in the values of the estimated Hurst exponents when moving between sensor and source space representations of the multivariate data or on the effect of noise. Such differences, if not duly acknowledged, may lead to erroneous data interpretations. We show in simulations and in theory that measuring Hurst exponents in sensor space may lead to an incomplete picture of the LRTC properties of the underlying data and that noise may significantly bias the estimate of the Hurst exponent of the underlying signal. Moreover, these predictions are confirmed in real data, where we analyze the amplitude dynamics of neuronal oscillations in the resting state from EEG data. By moving either to an independent components representation or to a source representation which maximizes the signal to noise ratio in the alpha frequency range, we observe greater variance, skewness and kurtosis over measured Hurst exponents than in sensor space. We confirm the suitability of conventional source separation methodology by introducing a novel algorithm HeMax which obtains a source maximizing the Hurst exponent in the amplitude dynamics of narrow band oscillations. Our findings imply that the long-range correlative properties of the EEG should be studied in source space, in such a way that the SNR is maximized, or at least with spatial decomposition techniques approximating source activities, rather than in sensor space. PMID:24862080

  15. Utility of Independent Component Analysis for Interpretation of Intracranial EEG

    PubMed Central

    Whitmer, Diane; Worrell, Gregory; Stead, Matt; Lee, Il Keun; Makeig, Scott

    2010-01-01

    Electrode arrays are sometimes implanted in the brains of patients with intractable epilepsy to better localize seizure foci before epilepsy surgery. Analysis of intracranial EEG (iEEG) recordings is typically performed in the electrode channel domain without explicit separation of the sources that generate the signals. However, intracranial EEG signals, like scalp EEG signals, could be linear mixtures of local activity and volume-conducted activity arising in multiple source areas. Independent component analysis (ICA) has recently been applied to scalp EEG data, and shown to separate the signal mixtures into independently generated brain and non-brain source signals. Here, we applied ICA to unmix source signals from intracranial EEG recordings from four epilepsy patients during a visually cued finger movement task in the presence of background pathological brain activity. This ICA decomposition demonstrated that the iEEG recordings were not maximally independent, but rather are linear mixtures of activity from multiple sources. Many of the independent component (IC) projections to the iEEG recording grid were consistent with sources from single brain regions, including components exhibiting classic movement-related dynamics. Notably, the largest IC projection to each channel accounted for no more than 20–80% of the channel signal variance, implying that in general intracranial recordings cannot be accurately interpreted as recordings of independent brain sources. These results suggest that ICA can be used to identify and monitor major field sources of local and distributed functional networks generating iEEG data. ICA decomposition methods are useful for improving the fidelity of source signals of interest, likely including distinguishing the sources of pathological brain activity. PMID:21152349

  16. On the "dependence" of "independent" group EEG sources; an EEG study on two large databases.

    PubMed

    Congedo, Marco; John, Roy E; De Ridder, Dirk; Prichep, Leslie; Isenhart, Robert

    2010-06-01

    The aim of this work is to study the coherence profile (dependence) of robust eyes-closed resting EEG sources isolated by group blind source separation (gBSS). We employ a test-retest strategy using two large sample normative databases (N = 57 and 84). Using a BSS method in the complex Fourier domain, we show that we can rigourously study the out-of-phase dependence of the extracted components, albeit they are extracted so as to be in-phase independent (by BSS definition). Our focus on lagged communication between components effectively yields dependence measures unbiased by volume conduction effects, which is a major concern about the validity of any dependence measures issued by EEG measurements. We are able to show the organization of the extracted components in two networks. Within each network components oscillate coherently with multiple-frequency dynamics, whereas between networks they exchange information at non-random multiple time-lag rates. PMID:19802727

  17. SlimQuick™ - associated hepatotoxicity in a woman with alpha-1 antitrypsin heterozygosity

    PubMed Central

    Weinstein, Douglas H; Twaddell, William S; Raufman, Jean-Pierre; Philosophe, Benjamin; Mindikoglu, Ayse L

    2012-01-01

    Green tea (Camellia sinensis)-associated hepatotoxicity is reported. However, the presence of alpha-1 antitrypsin MZ phenotype as a predisposing factor to green tea-associated drug-induced liver injury (DILI) is unknown. A previously healthy woman with alpha-1 antitrypsin MZ phenotype who took SlimQuick™, an herbal supplement containing green tea extract, developed severe hepatotoxicity requiring corticosteroid treatment. Green tea-associated hepatotoxicity is reviewed and alpha-1 antitrypsin MZ phenotype as a predisposing factor to green tea-associated DILI is discussed. Liver biopsy demonstrated marked inflammation with necrosis suggestive of toxic injury with diffuse alpha-1 antitrypsin globule deposition on immunostaining. Corticosteroid therapy resulted in rapid clinical improvement. Alpha-1 antitrypsin MZ phenotype may increase vulnerability to herbal hepatotoxicity. PMID:22567188

  18. Gelastic seizures: incidence, clinical and EEG features in adult patients undergoing video-EEG telemetry.

    PubMed

    Kovac, Stjepana; Diehl, Beate; Wehner, Tim; Fois, Chiara; Toms, Nathan; Walker, Matthew C; Duncan, John S

    2015-01-01

    This study aimed to determine clinical features of adult patients with gelastic seizures recorded on video -electroencephalography (EEG) over a 5-year period. We screened video-EEG telemetry reports for the occurrence of the term "gelastic" seizures, and assessed the semiology, EEG features, and duration of those seizures. Gelastic seizures were identified in 19 (0.8%) of 2,446 admissions. The presumed epileptogenic zone was in the hypothalamus in one third of the cases, temporal lobe epilepsy was diagnosed in another third, and the remainder of the cases presenting with gelastic seizures were classified as frontal, parietal lobe epilepsy or remained undetermined or were multifocal. Gelastic seizures were embedded in a semiology, with part of the seizure showing features of automotor seizures. A small proportion of patients underwent epilepsy surgery. Outcome of epilepsy surgery was related to the underlying pathology; two patients with hippocampal sclerosis had good outcomes following temporal lobe resection and one of four patients with hypothalamic hamartomas undergoing gamma knife surgery had a good outcome. PMID:25516460

  19. A novel self-guided approach to alpha activity training.

    PubMed

    van Boxtel, Geert J M; Denissen, Ad J M; Jäger, Mark; Vernon, David; Dekker, Marian K J; Mihajlovi?, Vojkan; Sitskoorn, Margriet M

    2012-03-01

    Fifty healthy participants took part in a double-blind placebo-controlled study in which they were either given auditory alpha activity (8-12Hz) training (N=18), random beta training (N=12), or no training at all (N=20). A novel wireless electrode system was used for training without instructions, involving water-based electrodes mounted in an audio headset. Training was applied approximately at central electrodes. Post-training measurement using a conventional full-cap EEG system revealed a 10% increase in alpha activity at posterior sites compared to pre-training levels, when using the conventional index of alpha activity and a non-linear regression fit intended to model individual alpha frequency. This statistically significant increase was present only in the group that received the alpha training, and remained evident at a 3 month follow-up session, especially under eyes open conditions where an additional 10% increase was found. In an exit interview, approximately twice as many participants in the alpha training group (53%) mentioned that the training was relaxing, compared to those in either the beta (20%) or no training (21%) control groups. Behavioural measures of stress and relaxation were indicative of effects of alpha activity training but failed to reach statistical significance. These results are discussed in terms of a lack of statistical power. Overall, results suggest that self-guided alpha activity training using this novel system is feasible and represents a step forward in the ease of instrumental conditioning of brain rhythms. PMID:22119661

  20. Effects of Galvanic Vestibular Stimulation on Visual Memory Recall and EEG

    PubMed Central

    Lee, Jeong-Woo; Lee, Gi-Eun; An, Ji-Hyang; Yoon, Se-Won; Heo, Myoung; Kim, Hwang-Yong

    2014-01-01

    [Purpose] This study aimed to examine the effects of galvanic vestibular stimulation (GVS) on visual memory recall and EEG. [Subjects and Methods] In the present study, 42 adults were selected and divided equally into two groups of 21 adults, the GVS group and the Sham group. The error rate was calculated as a percentage based on the total number of errors in the answers to 24 questions after stimulation, while the reaction time was measured in intervals between the time the questions were asked and the time it took the subjects to answer the questions. EEG data were obtained by attaching electrodes to the Fz, Cz, and Pz points during the question and answer phase. [Results] The error rate showed statistically significant differences in the interaction involving the time of response and group. The reaction time showed no statistically significant differences in the interaction involving the time of response and group. When relative band power parameters were analyzed, alpha waves showed no statistically significant differences in the interaction involving the time of response and group, but only the Fz area of beta waves showed statistically significant differences in the interaction involving the time of response and group. [Conclusion] GVS may improve visual memory recall in relation to a flower, a person, an animal, or a building. PMID:25276011

  1. EEG neural oscillatory dynamics reveal semantic and response conflict at difference levels of conflict awareness.

    PubMed

    Jiang, Jun; Zhang, Qinglin; Van Gaal, Simon

    2015-01-01

    Although previous work has shown that conflict can be detected in the absence of awareness, it is unknown how different sources of conflict (i.e., semantic, response) are processed in the human brain and whether these processes are differently modulated by conflict awareness. To explore this issue, we extracted oscillatory power dynamics from electroencephalographic (EEG) data recorded while human participants performed a modified version of the Stroop task. Crucially, in this task conflict awareness was manipulated by masking a conflict-inducing color word preceding a color patch target. We isolated semantic from response conflict by introducing four color words/patches, of which two were matched to the same response. We observed that both semantic as well as response conflict were associated with mid-frontal theta-band and parietal alpha-band power modulations, irrespective of the level of conflict awareness (high vs. low), although awareness of conflict increased these conflict-related power dynamics. These results show that both semantic and response conflict can be processed in the human brain and suggest that the neural oscillatory mechanisms in EEG reflect mainly "domain general" conflict processing mechanisms, instead of conflict source specific effects. PMID:26169473

  2. EEG neural oscillatory dynamics reveal semantic and response conflict at difference levels of conflict awareness

    PubMed Central

    Jiang, Jun; Zhang, Qinglin; Van Gaal, Simon

    2015-01-01

    Although previous work has shown that conflict can be detected in the absence of awareness, it is unknown how different sources of conflict (i.e., semantic, response) are processed in the human brain and whether these processes are differently modulated by conflict awareness. To explore this issue, we extracted oscillatory power dynamics from electroencephalographic (EEG) data recorded while human participants performed a modified version of the Stroop task. Crucially, in this task conflict awareness was manipulated by masking a conflict-inducing color word preceding a color patch target. We isolated semantic from response conflict by introducing four color words/patches, of which two were matched to the same response. We observed that both semantic as well as response conflict were associated with mid-frontal theta-band and parietal alpha-band power modulations, irrespective of the level of conflict awareness (high vs. low), although awareness of conflict increased these conflict-related power dynamics. These results show that both semantic and response conflict can be processed in the human brain and suggest that the neural oscillatory mechanisms in EEG reflect mainly “domain general” conflict processing mechanisms, instead of conflict source specific effects. PMID:26169473

  3. EEG dynamics of experienced Zen meditation practitioners probed by complexity index and spectral measure.

    PubMed

    Huang, H-Y; Lo, P-C

    2009-01-01

    Changes in the electroencephalogram (EEG) characteristics in experienced Zen meditation practitioners (n = 23) during 40 minutes of meditation were compared with those in the matched controls (n = 23) taking a rest for 40 minutes. Averaged complexity index ([image omitted] ) evaluation and spectral analysis were measured in three intervals: the first, middle and the last 5-min segments of Zen meditation or relaxing rest. Significant increase in frontal alpha-1 (8-10 Hz) and occipital beta power was found during meditation as compared with the EEG under the rest, whereas an average increase of theta power was observed in the controls. In meditation, brain dynamics exhibited high [image omitted] , which correlated with more beta activity. Control subjects showed no significant change in [image omitted] level. This distinction became more significant during the last 5 minutes of meditation over most electrodes. Deeper meditation state has been reported as having implications of increased beta power that can be more prominent by the approach of [image omitted] estimation. Our results substantiate the idea that long-term training with Zen-Buddhist meditation induces changes in the electro-cortical activity of the brain. PMID:19384707

  4. A review on epilepsy in the horse and the potential of Ambulatory EEG as a diagnostic tool.

    PubMed

    van der Ree, Marleen; Wijnberg, Inge

    2012-01-01

    Epilepsy in the horse is diagnosed based on clinical signs, but diagnosing can be difficult if a grand mal is not present. The future prospects of the horse and potentially the safety of the owner depend on an accurate diagnosis. This review presents information on epilepsy and focuses on the diagnostic potential of (Ambulatory) electroencephalography ((A) EEG). An epileptic seizure is a brain disorder, which expresses itself as a recurrent episode of involuntary abnormal behaviour. The aetiology can originate from inside or outside the brain or is idiopathic. Besides those categories, seizures can be classified as generalised or partial. A typical generalised tonic-clonic seizure is characterised by the prodrome, the ictus and the post-ictal phase. EEG is the graphic recording of rhythmic bioelectric activity which originates predominantly from the cerebral cortex. In human medicine, the 10/20 international basis system for electrode placement is used. This makes comparison more reliable and consistent. The normal human brainwaves recorded are alpha, beta, theta and delta waves. In the horse, fewer descriptions of normal signals are available. In humans suffering from epilepsy, spikes, complexes, spike-and-wave discharges and rhythmical multi-spike activity are seen. In horses suffering from epilepsy, spikes, sharp waves and spike-and-wave discharges are seen. In humans, AEEG has numerous advantages above short-duration EEG in diagnosing epilepsy or intracranial pathology. In future, AEEG might be useful to record brain signals in awake horses expressing their behaviour under natural circumstances. PMID:23163553

  5. Biolog phenotype microarrays.

    PubMed

    Shea, April; Wolcott, Mark; Daefler, Simon; Rozak, David A

    2012-01-01

    Phenotype microarrays nicely complement traditional genomic, transcriptomic, and proteomic analysis by offering opportunities for researchers to ground microbial systems analysis and modeling in a broad yet quantitative assessment of the organism's physiological response to different metabolites and environments. Biolog phenotype assays achieve this by coupling tetrazolium dyes with minimally defined nutrients to measure the impact of hundreds of carbon, nitrogen, phosphorous, and sulfur sources on redox reactions that result from compound-induced effects on the electron transport chain. Over the years, we have used Biolog's reproducible and highly sensitive assays to distinguish closely related bacterial isolates, to understand their metabolic differences, and to model their metabolic behavior using flux balance analysis. This chapter describes Biolog phenotype microarray system components, reagents, and methods, particularly as they apply to bacterial identification, characterization, and metabolic analysis. PMID:22639219

  6. A comparative study of the diagnostic value of drug-induced sleep EEGs and sleep EEGs following sleep deprivation in patients with complex partial seizures

    Microsoft Academic Search

    R. Degen; H.-E. Degen

    1981-01-01

    The purpose of the study was to investigate whether the sleep EEG after sleep deprivation has a stronger provocative effect than the drug-induced sleep EEG. For this purpose a sleep EEG, induced by 2 mg\\/kg body weight of promazine hydrochloride, was recorded. On the following day a sleep EEG of the same patient was recorded after sleep deprivation of 24–26

  7. Double-Blind Single-Session Neurofeedback Training in Upper-Alpha for Cognitive Enhancement of Healthy Subjects

    E-print Network

    Minguez, Javier

    tests. Results of EEG analysis show the key role of the feedback: only the NF group enhanced upper alpha performing better in almost all measurements but many of them without statistical significance. I in a variety of neurological and psychological disorders such as epilepsy, attention deficit hyperactivity

  8. Skilled Motor Learning and EEG with PacMan

    Microsoft Academic Search

    Malcolm Mills; Don Brinkworth

    The brain activity changes that accompany motor learning in both the skill and the cognitive development stages were monitored at 21 locations on the scalp by the electroencephalograph (EEG) during the playing of a simple \\

  9. Lossless Multi-channel EEG Compression Yodchanan Wongsawat

    E-print Network

    Oraintara, Soontorn

    @uta.edu Abstract-- This paper presents a method for losslessly compressing multi-channel electroencephalogram redundancy. I. INTRODUCTION Nowadays, electroencephalogram (EEG) has become one of the useful signals

  10. Evaluation of driver fatigue on two channels of EEG data.

    PubMed

    Li, Wei; He, Qi-chang; Fan, Xiu-min; Fei, Zhi-min

    2012-01-11

    Electroencephalogram (EEG) data is an effective indicator to evaluate driver fatigue. The 16 channels of EEG data are collected and transformed into three bands (?, ?, and ?) in the current paper. First, 12 types of energy parameters are computed based on the EEG data. Then, Grey Relational Analysis (GRA) is introduced to identify the optimal indicator of driver fatigue, after which, the number of significant electrodes is reduced using Kernel Principle Component Analysis (KPCA). Finally, the evaluation model for driver fatigue is established with the regression equation based on the EEG data from two significant electrodes (Fp1 and O1). The experimental results verify that the model is effective in evaluating driver fatigue. PMID:22116020

  11. EEG (ELECTROENCEPHALOGRAM) AS A CROSS SPECIES INDICATOR OF NEUROTOXICITY

    EPA Science Inventory

    The electroencephalogram (EEG) is a promising measure in the field of neurotoxicology. It can be well quantified by techniques which can be interpreted both physically and statistically. Such quantification schemes are briefly discussed in this paper. However, the quantification ...

  12. EEG compression of scalp recordings based on dipole fitting.

    PubMed

    Daou, Hoda; Labeau, Fabrice

    2015-05-01

    A novel technique for electroencephalogram (EEG) compression is proposed in this paper. This technique models the intrinsic dependence inherent between the different EEG channels. It is based on methods borrowed from dipole fitting that is usually used in order to find a solution to the classic problems in EEG analysis: inverse and forward problems. To compress the EEG signals, the forward model based on approximated source dipoles is first used to provide an approximation of the recorded signals. Then, (based on a smoothness factor) appropriate coding techniques are suggested to compress the residuals of the fitting process. Results show that this technique works well for different recordings and for different patients, and is even able to provide near-lossless compression for certain types of recordings. PMID:25122606

  13. EEG-based Drowsiness Detection using Support Vector Machine 

    E-print Network

    Yu, Shaoda

    2014-08-07

    -person differences, definition of sleep stages, definition of the common frequency bands, and the nature of drowsiness. This section will provide a thorough overview of EEG related to drowsiness as well as cover the various phenomena mentioned above. In order...

  14. Coercively Adjusted Auto Regression Model for Forecasting in Epilepsy EEG

    PubMed Central

    Kim, Sun-Hee; Faloutsos, Christos; Yang, Hyung-Jeong

    2013-01-01

    Recently, data with complex characteristics such as epilepsy electroencephalography (EEG) time series has emerged. Epilepsy EEG data has special characteristics including nonlinearity, nonnormality, and nonperiodicity. Therefore, it is important to find a suitable forecasting method that covers these special characteristics. In this paper, we propose a coercively adjusted autoregression (CA-AR) method that forecasts future values from a multivariable epilepsy EEG time series. We use the technique of random coefficients, which forcefully adjusts the coefficients with ?1 and 1. The fractal dimension is used to determine the order of the CA-AR model. We applied the CA-AR method reflecting special characteristics of data to forecast the future value of epilepsy EEG data. Experimental results show that when compared to previous methods, the proposed method can forecast faster and accurately. PMID:23710252

  15. EEG comparisons in early Alzheimer's disease, dementia with Lewy bodies and Parkinson's disease with dementia patients with a 2-year follow-up.

    PubMed

    Bonanni, Laura; Thomas, Astrid; Tiraboschi, Pietro; Perfetti, Bernardo; Varanese, Sara; Onofrj, Marco

    2008-03-01

    EEG abnormalities have been reported for both dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Although it has been suggested that variations in mean EEG frequency are greater in the former, the existence of meaningful differences remains controversial. No evidence is as yet available for Parkinson's disease with dementia (PDD). The aim of this study was to evaluate whether EEG abnormalities can discriminate between DLB, AD and PDD in the earliest stages of dementia and to do this 50 DLB, 50 AD and 40 PDD patients with slight cognitive impairment at first visit (MMSE > or = 20) were studied. To improve clinical diagnostic accuracy, special emphasis was placed on identifying cognitive fluctuations and REM-sleep behaviour disorder. EEG variability was assessed by mean frequency analysis and compressed spectral arrays (CSA) in order to detect changes over time from different scalp derivations. Patients' initial diagnoses were revised at a 2-year follow-up visit with neuroimaging evaluation. Initial diagnoses were confirmed in 36 DLB, 40 AD and 35 PDD patients. The most relevant group differences were observed between the AD and DLB patients in EEGs from posterior derivations (P<0.001). Dominant frequencies were 8.3 +/- 0.6 Hz for the AD group and 7.4 +/- 1.6 Hz for the DLB group, in which most of the patients (88%) exhibited a frequency band of 5.6-7.9 Hz. Dominant frequency variability also differed between the AD (1.1 +/- 0.4 Hz) and DLB groups (1.8 +/- 1.2 Hz, P<0.001). Of note, less than a half (46%) of the patients with PDD exhibited the EEG abnormalities seen in those with DLB. Graded according to the presence of alpha activity, five different patterns were identified on EEG CSA from posterior derivations. A pattern with dominant alpha bands was observed in patients with AD alone while, in those with DLB and PDD, the degree to which residual alpha and 5.6-7.9 bands appeared was related to the presence and severity of cognitive fluctuations. At follow-up, EEG abnormalities from posterior leads were seen in all subjects with DLB and in three-quarters of those with PDD. Of interest, in four patients initially labelled as having AD, in whom the occurrence of fluctuations and/or REM-sleep behaviour disorder during the 2-year follow-up had made the diagnosis of AD questionable, the initial EEG was characterized by the features observed in the DLB group. If revised consensus criteria for DLB diagnosis are properly applied (i.e. emphasizing the diagnostic weight of fluctuations and REM sleep behaviour disorder), EEG recording may act to support discrimination between AD and DLB at the earliest stages of dementia, since characteristic abnormalities may even precede the appearance of distinctive clinical features. PMID:18202105

  16. Measuring presence during the navigation in a virtual environment using EEG.

    PubMed

    Clemente, Miriam; Rodríguez, Alejandro; Rey, Beatriz; Alcañiz, Mariano

    2013-01-01

    In the Virtual Reality field, presence refers to the sense of "being there" in the virtual world. Our aim in this work is to evaluate the usefulness of the Emotiv EPOC EEG device to measure the brain activations due to the sense of presence during the navigation in a Virtual Environment (VE), using for the analysis the sLORETA tool. We compare between two experimental conditions: free and automatic navigation through a VE. In this preliminary step, we monitored 9 healthy subjects, obtaining significant differences between the free and automatic navigation conditions in the activity of the right insula for the Theta and Alpha bands. The insula activation is related to stimulus attention and selfawareness processes, directly related with the sense of presence. PMID:23792860

  17. Effectiveness of multiple EEGs in supporting the diagnosis of epilepsy: an operational curve.

    PubMed

    Salinsky, M; Kanter, R; Dasheiff, R M

    1987-01-01

    Interictal epileptiform activity (IIEA) on EEG may be useful in the diagnosis and characterization of epilepsy. A single scalp EEG may fail to detect this abnormality, which is then discovered on repeat recordings. Since many people with epilepsy have persistently normal EEGs, a practical question arises concerning the yield of multiple EEGs. To determine the probability of finding IIEA with serial EEGs (the operational curve), we reviewed data from 1,201 EEGs on 429 adult patients, most with definite epilepsy presenting in adulthood. The diagnosis was made either clinically or with the support of the EEG. In 50% of our patients with IIEA, the abnormality is present on the first record, in 84% by the third EEG, and in 92% by the fourth. There is relatively little yield to serial EEGs beyond this point. PMID:3622408

  18. Networking Property During Epileptic Seizure with Multichannel EEG Recordings

    Microsoft Academic Search

    Huihua Wu; Xiaoli Li; Xinping Guan

    2006-01-01

    \\u000a EEG recordings are widely used in epilepsy research. We intend to address a question whether small world network property\\u000a exists in neural networks when epileptic seizures occur. In this paper, we introduce a bispectrum analysis to calculate the\\u000a interaction between two EEG recordings; then, a suitable threshold is chosen to convert the interaction of the six channels\\u000a at five frequency

  19. Metrological verification of FPGA based device for measuring EEG signal

    Microsoft Academic Search

    Platon Sovilj; V. Vujic?ic?; N. Pjevalica

    2010-01-01

    The paper presents a field-programmable gate array (FPGA) based model for measurement of electroencephalography (EEG) signal. The novelty of this system is implementation of digital stochastic block based on stochastic analog-to-digital (A\\/D) conversion and accumulation, with a novel hardware structure tailored for harmonic measurements. Metrologically verified stochastic measurement EEG system measured DC component of the signal and 15 harmonics with

  20. Evaluation of the workload and drowsiness during car driving by using high resolution EEG activity and neurophysiologic indices.

    PubMed

    Maglione, A; Borghini, G; Aricò, P; Borgia, F; Graziani, I; Colosimo, A; Kong, W; Vecchiato, G; Babiloni, F

    2014-01-01

    Sleep deprivation and/or a high workload situation can adversely affect driving performance, decreasing a driver's capacity to respond effectively in dangerous situations. In this context, to provide useful feedback and alert signals in real time to the drivers physiological and brain activities have been increasingly investigated in literature. In this study, we analyze the increase of cerebral workload and the insurgence of drowsiness during car driving in a simulated environment by using high resolution electroencephalographic techniques (EEG) as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). The simulated drive tasks were modulated with five levels of increasing difficulty. A workload index was then generated by using the EEG signals and the related HR and EBR signals. Results suggest that the derived workload index is sensitive to the mental efforts of the driver during the different drive tasks performed. Such workload index was based on the estimation the variation of EEG power spectra in the theta band over prefrontal cortical areas and the variation of the EEG power spectra over the parietal cortical areas in alpha band. In addition, results suggested as HR increases during the execution of the difficult driving tasks while instead it decreases at the insurgence of the drowsiness. Finally, the results obtained showed as the EBR variable increases of its values when the insurgence of drowsiness in the driver occurs. The proposed workload index could be then used in a near future to assess on-line the mental state of the driver during a drive task. PMID:25571422

  1. [The role of non-NMDA glutamate receptors in the EEG effects of chronic administration of noopept GVS-111 in awake rats].

    PubMed

    Kovalev, G I; Vorob'ev, V V

    2002-01-01

    Participation of the non-NMDA glutamate receptor subtype in the formation of the EEG frequency spectrum was studied in wakeful rats upon a long-term (10 x 0.2 mg/kg, s.c.) administration of the nootropic dipeptide GVS-111 (noopept or N-phenylacetyl-L-prolyglycine ethylate). The EEGs were measured with electrodes implanted into somatosensor cortex regions, hippocampus, and a cannula in the lateral ventricle. The acute reactions (characteristic of nootropes) in the alpha and beta ranges of EEG exhibited inversion after the 6th injection of noopept and almost completely vanished after the 9th injection. Preliminary introduction of the non-NMDA antagonist GDEE (glutamic acid diethyl ester) in a dose of 1 mumole into the lateral ventricle restored the EEG pattern observed upon the 6th dose of GVS-111. The role of glutamate receptors in the course of a prolonged administration of nootropes, as well as the possible mechanisms accounting for a difference in the action of GVS-111 and piracetam are discussed. PMID:12596524

  2. Multimodal detection of head-movement artefacts in EEG.

    PubMed

    O'Regan, Simon; Marnane, William

    2013-08-15

    Artefacts arising from head movements have been a considerable obstacle in the deployment of automatic event detection systems in ambulatory EEG. Recently, gyroscopes have been identified as a useful modality for providing complementary information to the head movement artefact detection task. In this work, a comprehensive data fusion analysis is conducted to investigate how EEG and gyroscope signals can be most effectively combined to provide a more accurate detection of head-movement artefacts in the EEG. To this end, several methods of combining these physiological and physical signals at the feature, decision and score fusion levels are examined. Results show that combination at the feature, score and decision levels is successful in improving classifier performance when compared to individual EEG or gyroscope classifiers, thus confirming that EEG and gyroscope signals carry complementary information regarding the detection of head-movement artefacts in the EEG. Feature fusion and the score fusion using the sum-rule provided the greatest improvement in artefact detection. By extending multimodal head-movement artefact detection to the score and decision fusion domains, it is possible to implement multimodal artefact detection in environments where gyroscope signals are intermittently available. PMID:23685269

  3. Bluetooth Communication Interface for EEG Signal Recording in Hyperbaric Chambers.

    PubMed

    Pastena, Lucio; Formaggio, Emanuela; Faralli, Fabio; Melucci, Massimo; Rossi, Marco; Gagliardi, Riccardo; Ricciardi, Lucio; Storti, Silvia F

    2015-07-01

    Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression. PMID:25608308

  4. Risk factors for EEG seizures in neonates treated with hypothermia

    PubMed Central

    Wusthoff, Courtney J.; Shellhaas, Renée A.; Tsuchida, Tammy N.; Bonifacio, Sonia Lomeli; Cordeiro, Malaika; Sullivan, Joseph; Abend, Nicholas S.; Chang, Taeun

    2014-01-01

    Objective: To assess the risk factors for electrographic seizures among neonates treated with therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE). Methods: Three-center observational cohort study of 90 term neonates treated with hypothermia, monitored with continuous video-EEG (cEEG) within the first day of life (median age at onset of recording 9.5 hours, interquartile range 6.3–14.5), and continued for >24 hours (total recording 93.3 hours, interquartile range 80.1–112.8 among survivors). A pediatric electroencephalographer at each site reviewed cEEGs for electrographic seizures and initial EEG background category. Results: A total of 43 (48%) had electrographic seizures, including 9 (10%) with electrographic status epilepticus. Abnormal initial EEG background classification (excessively discontinuous, depressed and undifferentiated, burst suppression, or extremely low voltage), but not clinical variables (including pH <6.8, base excess ??20, or 10-minute Apgar ?3), was strongly associated with seizures. Conclusions: Electrographic seizures are common among neonates with HIE undergoing hypothermia and are difficult to predict based on clinical features. These results justify the recommendation for cEEG monitoring in neonates treated with hypothermia. PMID:24610326

  5. Early effect of NEURAPAS® balance on current source density (CSD) of human EEG

    PubMed Central

    2011-01-01

    Psychiatric patients often suffer from stress, anxiety and depression. Various plant extracts are known to fight stress (valerian), anxiety (passion flower) or depression (St. John's wort). NEURAPAS® balance is a mixture of these three extracts and has been designed to cover this complex of psychiatric conditions. The study was initiated to quantitatively assess the effect of this combination on brain electric activity. Method Quantitative electroencephalogram (EEG) current source density (CSD) recording from 16 healthy male and female human volunteers (average age 49 years) was used in a randomized, placebo-controlled cross over study. Recordings were performed 0. 5, 1. 5, 3 and 4 hours after administration of the preparations under the conditions of 6 min eyes open and 5 min d2 concentration test, mathematical calculation test and memory test, respectively. All variables (electric power within 6 frequency ranges at 17 electrode positions) were fed into a linear discriminant analysis (eyes open condition). In the presence of mental load these variables were used to construct brain maps of frequency changes. Results Under the condition of mental load, centro-parietal spectral power remained statistically significantly lower within alpha1, alpha2 and beta1 frequencies in the presence of verum in comparison to placebo. Discriminant analysis revealed a difference to placebo 3 and 4 hours after intake of 6 tablets of NEURAPAS® balance. Data location within the polydimensional space was projected into the area of the effects of sedative and anti-depressive reference drugs tested earlier under identical conditions. Results appeared closer to the effects of fluoxetine than to St. John's wort. Conclusions Analysis of the neurophysiological changes following the intake of NEURAPAS® balance revealed a similarity of frequency changes to those of calming and anti-depressive drugs on the EEG without impairment of cognition. Trial registration ClinicalTrials.gov: NCT01047605 PMID:21810233

  6. Object-based attentional selection modulates anticipatory alpha oscillations.

    PubMed

    Knakker, Balázs; Weiss, Béla; Vidnyánszky, Zoltán

    2014-01-01

    Visual cortical alpha oscillations are involved in attentional gating of incoming visual information. It has been shown that spatial and feature-based attentional selection result in increased alpha oscillations over the cortical regions representing sensory input originating from the unattended visual field and task-irrelevant visual features, respectively. However, whether attentional gating in the case of object based selection is also associated with alpha oscillations has not been investigated before. Here we measured anticipatory electroencephalography (EEG) alpha oscillations while participants were cued to attend to foveal face or word stimuli, the processing of which is known to have right and left hemispheric lateralization, respectively. The results revealed that in the case of simultaneously displayed, overlapping face and word stimuli, attending to the words led to increased power of parieto-occipital alpha oscillations over the right hemisphere as compared to when faces were attended. This object category-specific modulation of the hemispheric lateralization of anticipatory alpha oscillations was maintained during sustained attentional selection of sequentially presented face and word stimuli. These results imply that in the case of object-based attentional selection-similarly to spatial and feature-based attention-gating of visual information processing might involve visual cortical alpha oscillations. PMID:25628554

  7. Potential for unreliable interpretation of EEG recorded with microelectrodes

    PubMed Central

    Stacey, William C.; Kellis, Spencer; Greger, Bradley; Butson, Christopher R.; Patel, Paras R.; Assaf, Trevor; Mihaylova, Temenuzhka; Glynn, Simon

    2013-01-01

    SUMMARY PURPOSE Recent studies in epilepsy, cognition, and brain machine interfaces have shown the utility of recording intracranial EEG (iEEG) with greater spatial resolution. Many of these studies utilize microelectrodes connected to specialized amplifiers that are optimized for such recordings. We recently measured the impedances of several commercial microelectrodes and demonstrated that they will distort iEEG signals if connected to clinical EEG amplifiers commonly used in most centers. In this study we demonstrate the clinical implications of this effect and identify some of the potential difficulties in using microelectrodes. METHODS Human iEEG data were digitally filtered to simulate the signal recorded by a hybrid grid (2 macro- and 8 microelectrodes) connected to a standard EEG amplifier. The filtered EEG data were read by three trained epileptologists, and high frequency oscillations (HFOs) detected with a well-known algorithm. The filtering method was verified experimentally by recording an injected EEG signal in a saline bath with the same physical acquisition system used to generate the model. Several electrodes underwent scanning electron microscopy (SEM). KEY FINDINGS Macroelectrode recordings were unaltered compared to the source iEEG signal, but microelectrodes attenuated low frequencies. The attenuated signals were difficult to interpret: all three clinicians changed their clinical scoring of slowing and seizures when presented with the same data recorded on different electrodes. The HFO detection algorithm was oversensitive with microelectrodes, classifying many more HFOs than when the same data were recorded with macroelectrodes. In addition, during experimental recordings the microelectrodes produced much greater noise as well as large baseline fluctuations, creating sharply-contoured transients, and superimposed “false” HFOs. SEM of these microelectrodes demonstrated marked variability in exposed electrode surface area, lead fractures, and sharp edges. SIGNIFICANCE Microelectrodes should not be used with low impedance (< 1G?) amplifiers due to severe signal attenuation and variability that changes clinical interpretations. The current method of preparing microelectrodes can leave sharp edges and nonuniform amounts of exposed wire. Even when recorded with higher impedance amplifiers, microelectrode data is highly prone to artifacts that are difficult to interpret. Great care must be taken when analyzing iEEG from high impedance microelectrodes. PMID:23647099

  8. [Intercentral correlations in the cerebral cortex according to the EEG coherence index after restoration of consciousness and speech following prolonged coma].

    PubMed

    Grindel', O M

    1985-01-01

    Power spectra and coherence function of EEG of various cortical areas of both hemispheres were analyzed in 9 patients with extremely protracted loss of consciousness. Five patients were in the state of posttraumatic apallic syndrome lasting for more than 4 years in one patient, and 4-9 months with successive lethal outcome in 4 patients. One patient for more than 2 years was in a state of areactivity to external signals. In 3 patients the process of recovery of consciousness and speech began in 1-2 months. At the apallic syndrome, only low-frequency EEG components were present in spectrograms, and the values of coherence function were sharply decreased. With recovering consciousness and speech, a gradual appearance of alpha-activity was observed as well as an increase of coherence values at the frequency of the alpha-rhythm. The recovery of intercentral EEG relations in the motor-verbal cortical area was shown to play a special role in further normalization of connections in the cerebral cortex. PMID:3984511

  9. Alpha-1 Antitrypsin Deficiency

    MedlinePLUS

    ... from the NHLBI on Twitter. What Is Alpha-1 Antitrypsin Deficiency? Alpha-1 antitrypsin (an-tee-TRIP-sin) deficiency, or AAT ... as it relates to lung disease. Overview Alpha-1 antitrypsin, also called AAT, is a protein made ...

  10. Abstract--The Electroencephalogram (EEG) is a non-invasive technique used in the medical field to record and

    E-print Network

    Slatton, Clint

    Abstract-- The Electroencephalogram (EEG) is a non- invasive technique used in the medical field the rehabilitation process through providing biofeedback and keeping them motivated. Electroencephalogram (EEG

  11. Familial Aggregation of Dyslexia Phenotypes

    Microsoft Academic Search

    Wendy H. Raskind; Li Hsu; Virginia W. Berninger; Jennifer B. Thomson; Ellen M. Wijsman

    2000-01-01

    There is evidence for genetic contributions to reading disability, but the phenotypic heterogeneity associated with the clinical diagnosis may make identification of the underlying genetic basis difficult. In order to elucidate distinct phenotypic features that may be contributing to the genotypic heterogeneity, we assessed the familial aggregation patterns of Verbal IQ and 24 phenotypic measures associated with dyslexia in 102

  12. EEG artifact removal—state-of-the-art and guidelines

    NASA Astrophysics Data System (ADS)

    Urigüen, Jose Antonio; Garcia-Zapirain, Begoña

    2015-06-01

    This paper presents an extensive review on the artifact removal algorithms used to remove the main sources of interference encountered in the electroencephalogram (EEG), specifically ocular, muscular and cardiac artifacts. We first introduce background knowledge on the characteristics of EEG activity, of the artifacts and of the EEG measurement model. Then, we present algorithms commonly employed in the literature and describe their key features. Lastly, principally on the basis of the results provided by various researchers, but also supported by our own experience, we compare the state-of-the-art methods in terms of reported performance, and provide guidelines on how to choose a suitable artifact removal algorithm for a given scenario. With this review we have concluded that, without prior knowledge of the recorded EEG signal or the contaminants, the safest approach is to correct the measured EEG using independent component analysis—to be precise, an algorithm based on second-order statistics such as second-order blind identification (SOBI). Other effective alternatives include extended information maximization (InfoMax) and an adaptive mixture of independent component analyzers (AMICA), based on higher order statistics. All of these algorithms have proved particularly effective with simulations and, more importantly, with data collected in controlled recording conditions. Moreover, whenever prior knowledge is available, then a constrained form of the chosen method should be used in order to incorporate such additional information. Finally, since which algorithm is the best performing is highly dependent on the type of the EEG signal, the artifacts and the signal to contaminant ratio, we believe that the optimal method for removing artifacts from the EEG consists in combining more than one algorithm to correct the signal using multiple processing stages, even though this is an option largely unexplored by researchers in the area.

  13. EEG artifact removal-state-of-the-art and guidelines.

    PubMed

    Urigüen, Jose Antonio; Garcia-Zapirain, Begoña

    2015-06-01

    This paper presents an extensive review on the artifact removal algorithms used to remove the main sources of interference encountered in the electroencephalogram (EEG), specifically ocular, muscular and cardiac artifacts. We first introduce background knowledge on the characteristics of EEG activity, of the artifacts and of the EEG measurement model. Then, we present algorithms commonly employed in the literature and describe their key features. Lastly, principally on the basis of the results provided by various researchers, but also supported by our own experience, we compare the state-of-the-art methods in terms of reported performance, and provide guidelines on how to choose a suitable artifact removal algorithm for a given scenario. With this review we have concluded that, without prior knowledge of the recorded EEG signal or the contaminants, the safest approach is to correct the measured EEG using independent component analysis-to be precise, an algorithm based on second-order statistics such as second-order blind identification (SOBI). Other effective alternatives include extended information maximization (InfoMax) and an adaptive mixture of independent component analyzers (AMICA), based on higher order statistics. All of these algorithms have proved particularly effective with simulations and, more importantly, with data collected in controlled recording conditions. Moreover, whenever prior knowledge is available, then a constrained form of the chosen method should be used in order to incorporate such additional information. Finally, since which algorithm is the best performing is highly dependent on the type of the EEG signal, the artifacts and the signal to contaminant ratio, we believe that the optimal method for removing artifacts from the EEG consists in combining more than one algorithm to correct the signal using multiple processing stages, even though this is an option largely unexplored by researchers in the area. PMID:25834104

  14. Signal distortion from microelectrodes in clinical EEG acquisition systems

    PubMed Central

    Stacey, William C.; Kellis, Spencer; Patel, Paras R.; Greger, Bradley; Butson, Christopher R.

    2012-01-01

    Many centers are now using high-density microelectrodes during traditional intracranial EEG (iEEG) both for research and clinical purposes. These microelectrodes are FDA-approved and integrate into clinical EEG acquisition systems. However, the electrical characteristics of these electrodes are poorly described and clinical systems were not designed to use them; thus it is possible that this shift into clinical practice could have unintended consequences. In this study, we characterized the impedance of over 100 commercial macro- and microelectrodes using electrochemical impedance spectroscopy (EIS) to determine how electrode properties could affect signal acquisition and interpretation. The EIS data were combined with the published specifications of several commercial EEG systems to design digital filters that mimic the behavior of the electrodes and amplifiers. These filters were used to analyze simulated brain signals that contain a mixture of characteristic features commonly observed in iEEG. Each output was then processed with several common quantitative EEG measurements. Our results show that traditional macroelectrodes had low impedances and produced negligible distortion of the original signal. Brain tissue and electrical wiring also had negligible filtering effects. However, microelectrode impedances were much higher and more variable than the macroelectrodes. When connected to clinical amplifiers, higher impedance electrodes produced considerable distortion of the signal at low frequencies (< 60 Hz), which caused significant changes in amplitude, phase, variance, and spectral band power. In contrast, there were only minimal changes to the signal content for frequencies above 100 Hz. In order to minimize distortion with microelectrodes, we determined that an acquisition system should have an input impedance of at least 1 G?, which is much higher than most clinical systems. These results show that it is critical to account for variations in impedance when analyzing EEG from different-sized electrodes. Data from microelectrodes may yield misleading results unless recorded with high-impedance amplifiers. PMID:22878608

  15. The allergic asthma phenotype.

    PubMed

    Schatz, Michael; Rosenwasser, Lanny

    2014-01-01

    Allergic asthma is the most common asthma phenotype. It usually is defined by the presence of sensitization to environmental allergens, although a clinical correlation between exposure and symptoms further supports the diagnosis. The average age of onset of allergic asthma is younger than that of nonallergic asthma. Although the spectrum of allergic asthma may vary from mild to severe, studies have reported that allergic versus nonallergic asthma is less severe. There is an increased prevalence of allergic rhinoconjunctivitis and atopic dermatitis in patients with allergic asthma. Total IgE levels usually are higher in allergic versus nonallergic asthma, but levels substantially overlap between the 2 groups. Increased Th2 cytokines have been demonstrated in secretions and peripheral blood of patients with allergic asthma. Atopy has been reported to be inversely associated with persistent airflow obstruction and airway remodeling. Clusters with a high prevalence of early onset atopic asthma have been frequently reported in statistical phenotyping studies, but the various clusters of patients with atopy were quite heterogeneous in terms of symptom severity, pulmonary function, and tendency for exacerbations. Implications for future research regarding the allergic asthma phenotype are described. PMID:25439351

  16. AFFECTIVE JUKEBOX: A CONFIRMATORY STUDY OF EEG EMOTIONAL CORRELATES IN RESPONSE

    E-print Network

    Miranda, Eduardo Reck

    -valence correlates determined from electroencephalogram (EEG) readings can be used to select music based. An experiment was conducted in or- der to validate the electroencephalogram (EEG) readings of the affective

  17. Bayesian Learning Algorithm for Compressive Sensing of Non-Sparse (EEG) Signals

    E-print Network

    de Freitas, Nando

    is very small and needs to be efficiently used. In the case of electroencephalogram (EEG) signals that is monitored is health related, such as electrocardiograms (ECG) or electroencephalogram (EEG) [1

  18. Using EEG in Knowledge Tracing Yanbo Xu Kai-min Chang Yueran Yuan Jack Mostow

    E-print Network

    Mostow, Jack

    by incorporating input from inexpensive EEG devices. EEG sensors record brainwaves, which result from coordinated neural activity. Patterns in these recorded brainwaves have been shown to correlate with a number

  19. EEG anomalies in adult ADHD subjects performing a working memory task.

    PubMed

    Missonnier, P; Hasler, R; Perroud, N; Herrmann, F R; Millet, P; Richiardi, J; Malafosse, A; Giannakopoulos, P; Baud, P

    2013-06-25

    Functional imaging studies have revealed differential brain activation patterns in attention deficit hyperactivity disorder (ADHD) adult patients performing working memory (WM) tasks. The existence of alterations in WM-related cortical circuits during childhood may precede executive dysfunctions in this disorder in adults. To date, there is no study exploring the electrophysiological activation of WM-related neural networks in ADHD. To address this issue, we carried out an electroencephalographic (EEG) activation study associated with time-frequency (TF) analysis in 15 adults with ADHD and 15 controls performing two visual N-back WM tasks, as well as oddball detection and passive fixation tasks. Frontal transient (phasic) theta event-related synchronization (ERS, 0-500 msec) was significantly reduced in ADHD as compared to control subjects. Such reduction was equally present in a task-independent manner. In contrast, the power of the later sustained (?500-1200 msec) theta ERS for all tasks was comparable in ADHD and control groups. In active WM tasks, ADHD patients displayed lower alpha event-related desynchronization (ERD, ?200-900 msec) and higher subsequent alpha ERS (?900-2400 msec) compared to controls. The time course of alpha ERD/ERS cycle was modified in ADHD patients compared to controls, suggesting that they are able to use late compensatory mechanisms in order to perform this WM task. These findings support the idea of an ADHD-related dysfunction of neural generators sub-serving attention directed to the incoming visual information. ADHD cases may successfully face WM needs depending on the preservation of sustained theta ERS and prolonged increase of alpha ERS at later post-stimulus time points. PMID:23518223

  20. Nonlinear EEG Decoding Based on a Particle Filter Model

    PubMed Central

    Hong, Jun

    2014-01-01

    While the world is stepping into the aging society, rehabilitation robots play a more and more important role in terms of both rehabilitation treatment and nursing of the patients with neurological diseases. Benefiting from the abundant contents of movement information, electroencephalography (EEG) has become a promising information source for rehabilitation robots control. Although the multiple linear regression model was used as the decoding model of EEG signals in some researches, it has been considered that it cannot reflect the nonlinear components of EEG signals. In order to overcome this shortcoming, we propose a nonlinear decoding model, the particle filter model. Two- and three-dimensional decoding experiments were performed to test the validity of this model. In decoding accuracy, the results are comparable to those of the multiple linear regression model and previous EEG studies. In addition, the particle filter model uses less training data and more frequency information than the multiple linear regression model, which shows the potential of nonlinear decoding models. Overall, the findings hold promise for the furtherance of EEG-based rehabilitation robots. PMID:24949420

  1. Uncorrelated multiway discriminant analysis for motor imagery EEG classification.

    PubMed

    Liu, Ye; Zhao, Qibin; Zhang, Liqing

    2015-06-01

    Motor imagery-based brain-computer interfaces (BCIs) training has been proved to be an effective communication system between human brain and external devices. A practical problem in BCI-based systems is how to correctly and efficiently identify and extract subject-specific features from the blurred scalp electroencephalography (EEG) and translate those features into device commands in order to control external devices. In real BCI-based applications, we usually define frequency bands and channels configuration that related to brain activities beforehand. However, a steady configuration usually loses effects due to individual variability among different subjects in practical applications. In this study, a robust tensor-based method is proposed for a multiway discriminative subspace extraction from tensor-represented EEG data, which performs well in motor imagery EEG classification without the prior neurophysiologic knowledge like channels configuration and active frequency bands. Motor imagery EEG patterns in spatial-spectral-temporal domain are detected directly from the multidimensional EEG, which may provide insights to the underlying cortical activity patterns. Extensive experiment comparisons have been performed on a benchmark dataset from the famous BCI competition III as well as self-acquired data from healthy subjects and stroke patients. The experimental results demonstrate the superior performance of the proposed method over the contemporary methods. PMID:25986750

  2. [EEG-correlates of consciousness recovery after traumatic brain injury].

    PubMed

    Sharova, E V; Chelyapina, M V; Korobkova, E V; Kulikov, M A; Zaitsev, O S

    2014-01-01

    The aim of studies of patients in long-term posttraumatic unconscious state (PUS) was to outline prognostically significant EEG-markers of consciousness condition and an assessment of its dynamics orientation. We analysed outcomes of dynamic (from days to 16 years after trauma) EEG studies in 196 patients in TBI-caused PUS and different degrees of mental recovery: from chronic unconscious state up to clear consciousness. These results were compared to clinical protocols and data of MRI. It is revealed that dynamic features of EEC pattern (with the analysis of equivalent dipolar sources of separate components) allow to characterize the severity of patient's current state, to reveal the brain structures with the most expressed dysfunction, to define a zone of local cortical damage, and also the general direction of development of a traumatic illness (as though dynamics of a homeostasis of a brain). Frequency characteristics of EEG power spectrum (average frequency--an effective frequency strip) in a background and at reactions find the greatest predictive importance, especially at their assessment in 2-3 months after a trauma. The background interhemispheric EEG coherence (first of all, frontal) as the integrative characteristic of system brain activity, and its change at reactions to external incentives most reflect degree of consciousness oppression, dynamics and potential of its restoration. It was shown the high informational of the researches EEG changes to indifferent and functionally significant signs for an assessment of CNS functionality, and also of PUS pathogenesis. PMID:24761592

  3. Mutual information measures applied to EEG signals for sleepiness characterization.

    PubMed

    Melia, Umberto; Guaita, Marc; Vallverdú, Montserrat; Embid, Cristina; Vilaseca, Isabel; Salamero, Manel; Santamaria, Joan

    2015-03-01

    Excessive daytime sleepiness (EDS) is one of the main symptoms of several sleep related disorders with a great impact on the patient lives. While many studies have been carried out in order to assess daytime sleepiness, the automatic EDS detection still remains an open problem. In this work, a novel approach to this issue based on non-linear dynamical analysis of EEG signal was proposed. Multichannel EEG signals were recorded during five maintenance of wakefulness (MWT) and multiple sleep latency (MSLT) tests alternated throughout the day from patients suffering from sleep disordered breathing. A group of 20 patients with excessive daytime sleepiness (EDS) was compared with a group of 20 patients without daytime sleepiness (WDS), by analyzing 60-s EEG windows in waking state. Measures obtained from cross-mutual information function (CMIF) and auto-mutual-information function (AMIF) were calculated in the EEG. These functions permitted a quantification of the complexity properties of the EEG signal and the non-linear couplings between different zones of the scalp. Statistical differences between EDS and WDS groups were found in ? band during MSLT events (p-value < 0.0001). WDS group presented more complexity than EDS in the occipital zone, while a stronger nonlinear coupling between occipital and frontal zones was detected in EDS patients than in WDS. The AMIF and CMIF measures yielded sensitivity and specificity above 80% and AUC of ROC above 0.85 in classifying EDS and WDS patients. PMID:25638417

  4. Exploring Sampling in the Detection of Multicategory EEG Signals

    PubMed Central

    Siuly, Siuly; Kabir, Enamul; Wang, Hua; Zhang, Yanchun

    2015-01-01

    The paper presents a structure based on samplings and machine leaning techniques for the detection of multicategory EEG signals where random sampling (RS) and optimal allocation sampling (OS) are explored. In the proposed framework, before using the RS and OS scheme, the entire EEG signals of each class are partitioned into several groups based on a particular time period. The RS and OS schemes are used in order to have representative observations from each group of each category of EEG data. Then all of the selected samples by the RS from the groups of each category are combined in a one set named RS set. In the similar way, for the OS scheme, an OS set is obtained. Then eleven statistical features are extracted from the RS and OS set, separately. Finally this study employs three well-known classifiers: k-nearest neighbor (k-NN), multinomial logistic regression with a ridge estimator (MLR), and support vector machine (SVM) to evaluate the performance for the RS and OS feature set. The experimental outcomes demonstrate that the RS scheme well represents the EEG signals and the k-NN with the RS is the optimum choice for detection of multicategory EEG signals. PMID:25977705

  5. Identifying preseizure state in intracranial EEG data using diffusion kernels.

    PubMed

    Duncan, Dominique; Talmon, Ronen; Zaveri, Hitten P; Coifman, Ronald R

    2013-06-01

    The goal of this study is to identify preseizure changes in intracranial EEG (icEEG). A novel approach based on the recently developed diffusion map framework, which is considered to be one of the leading manifold learning methods, is proposed. Diffusion mapping provides dimensionality reduction of the data as well as pattern recognition that can be used to distinguish different states of the patient, for example, interictal and preseizure. A new algorithm, which is an extension of diffusion maps, is developed to construct coordinates that generate efficient geometric representations of the complex structures in the icEEG data. In addition, this method is adapted to the icEEG data and enables the extraction of the underlying brain activity. The algorithm is tested on icEEG data recorded from several electrode contacts from a patient being evaluated for possible epilepsy surgery at the Yale-New Haven Hospital. Numerical results show that the proposed approach provides a distinction between interictal and preseizure states. PMID:23906137

  6. Quantitative change of EEG and respiration signals during mindfulness meditation

    PubMed Central

    2014-01-01

    Background This study investigates measures of mindfulness meditation (MM) as a mental practice, in which a resting but alert state of mind is maintained. A population of older people with high stress level participated in this study, while electroencephalographic (EEG) and respiration signals were recorded during a MM intervention. The physiological signals during meditation and control conditions were analyzed with signal processing. Methods EEG and respiration data were collected and analyzed on 34 novice meditators after a 6-week meditation intervention. Collected data were analyzed with spectral analysis, phase analysis and classification to evaluate an objective marker for meditation. Results Different frequency bands showed differences in meditation and control conditions. Furthermore, we established a classifier using EEG and respiration signals with a higher accuracy (85%) at discriminating between meditation and control conditions than a classifier using the EEG signal only (78%). Conclusion Support vector machine (SVM) classifier with EEG and respiration feature vector is a viable objective marker for meditation ability. This classifier should be able to quantify different levels of meditation depth and meditation experience in future studies. PMID:24939519

  7. Feature extraction of EEG signals from epilepsy patients based on Gabor Transform and EMD Decomposition

    Microsoft Academic Search

    Lisheng Chen; Erbo Zhao; Dahui Wang; Zhangang Han; Shouwen Zhang; Cuiping Xu

    2010-01-01

    Electroencephalograph (EEG) has been considered as a practical media to explore human brain activities. It is believed that EEG signals have lots of information carried still unknown. The non-stationary, non-linear traits of EEG signals make the information detection a hard task. While time-frequency methods, for their superiority to process such data, were widely studied and applied to this research. EEG

  8. Macrostructural EEG characterization based on nonparametric change point segmentation: application to sleep analysis

    Microsoft Academic Search

    A. Kaplan; J. Röschke; B. Darkhovsky; J. Fell

    2001-01-01

    In the present investigation a new methodology for macrostructural EEG characterization based on automatic segmentation has been applied to sleep analysis. A nonparametric statistical approach for EEG segmentation was chosen, because it minimizes the need for a priori information about a signal. The method provides the detection of change-points i.e. boundaries between quasi-stationary EEG segments based on the EEG characteristics

  9. Phase shifts in alpha-frequency rhythm detected in electroencephalograms influence reaction time.

    PubMed

    Naruse, Yasushi; Takiyama, Ken; Okada, Masato; Umehara, Hiroaki; Sakaguchi, Yutaka

    2015-02-01

    Although the phase shifts in ongoing oscillations seen in electroencephalograms (EEGs) and magnetoencephalograms are an important factor in discussions of phase dynamics, such as synchrony and reset, few studies have focused specifically on the phase shift. Here we investigate the relationship between phase shifts in alpha-frequency rhythms and reaction times during a visual simple reaction task by applying our previously described method (Naruse et al., 2013), which enables detection of phase shifts from a single EEG trial. In the left, parietal, and occipital areas, the reaction times in the trials in which phase shifts were detected before the button press were significantly longer than in those in which phase shifts were not so detected. These results indicate that phase shifts in the alpha and mu rhythms relate to variability in reaction times. PMID:25150125

  10. Opposite effects of the acute promyelocytic leukemia PML-retinoic acid receptor alpha (RAR alpha) and PLZF-RAR alpha fusion proteins on retinoic acid signalling.

    PubMed Central

    Ruthardt, M; Testa, U; Nervi, C; Ferrucci, P F; Grignani, F; Puccetti, E; Grignani, F; Peschle, C; Pelicci, P G

    1997-01-01

    Fusion proteins involving the retinoic acid receptor alpha (RAR alpha) and the PML or PLZF nuclear protein are the genetic markers of acute promyelocytic leukemias (APLs). APLs with the PML-RAR alpha or the PLZF-RAR alpha fusion protein are phenotypically indistinguishable except that they differ in their sensitivity to retinoic acid (RA)-induced differentiation: PML-RAR alpha blasts are sensitive to RA and patients enter disease remission after RA treatment, while patients with PLZF-RAR alpha do not. We here report that (i) like PML-RAR alpha expression, PLZF-RAR alpha expression blocks terminal differentiation of hematopoietic precursor cell lines (U937 and HL-60) in response to different stimuli (vitamin D3, transforming growth factor beta1, and dimethyl sulfoxide); (ii) PML-RAR alpha, but not PLZF-RAR alpha, increases RA sensitivity of hematopoietic precursor cells and restores RA sensitivity of RA-resistant hematopoietic cells; (iii) PML-RAR alpha and PLZF-RAR alpha have similar RA binding affinities; and (iv) PML-RAR alpha enhances the RA response of RA target genes (those for RAR beta, RAR gamma, and transglutaminase type II [TGase]) in vivo, while PLZF-RAR alpha expression has either no effect (RAR beta) or an inhibitory activity (RAR gamma and type II TGase). These data demonstrate that PML-RAR alpha and PLZF-RAR alpha have similar (inhibitory) effects on RA-independent differentiation and opposite (stimulatory or inhibitory) effects on RA-dependent differentiation and that they behave in vivo as RA-dependent enhancers or inhibitors of RA-responsive genes, respectively. Their different activities on the RA signalling pathway might underlie the different responses of PML-RAR alpha and PLZF-RAR alpha APLs to RA treatment. The PLZF-RAR alpha fusion protein contains an approximately 120-amino-acid N-terminal motif (called the POZ domain), which is also found in a variety of zinc finger proteins and a group of poxvirus proteins and which mediates protein-protein interactions. Deletion of the PLZF POZ domain partially abrogated the inhibitory effect of PLZF-RAR alpha on RA-induced differentiation and on RA-mediated type II TGase up-regulation, suggesting that POZ-mediated protein interactions might be responsible for the inhibitory transcriptional activities of PLZF-RAR alpha. PMID:9234742

  11. Learning from M/EEG data with variable brain activation delays

    E-print Network

    Paris-Sud XI, Université de

    the electromagnetic fields induced by brain activity. Typically, when collecting M/EEG data in neurosciences, the same- and electroencephalography (M/EEG) measure the electromagnetic signals produced by brain activity. In order to ad- dressLearning from M/EEG data with variable brain activation delays Wojciech Zaremba1,2 , M. Pawan Kumar

  12. Analysis of the EEG during the sleeping by the rhythmic component extraction

    Microsoft Academic Search

    Yohei Tomita; Yasue Mitsukura; Toshihisa Tanaka; Jianting Cao

    2009-01-01

    In this experiment, we record the EEG data during the sleeping and the awakening for the drowsiness cognition. As is well known, analyzing the frequency components of the EEG is important for the sleeping. There are many studies to analyze the EEG frequency data for recognizing the sleeping quality, and so on. However, there is no established method for the

  13. Recognition of Anticipatory Behavior from Human EEG G. Gangadhar1,2

    E-print Network

    . To the best of our knowledge, anticipation related potentials in human EEG are well studied in the contextRecognition of Anticipatory Behavior from Human EEG G. Gangadhar1,2 , R. Chavarriaga1 , J. del. R of Electroencephalogram (EEG) correlates of this ac- tivation on single trials as a first step towards building such a BCI

  14. Subliminal display of action words interferes with motor planning: a combined EEG and kinematic study

    E-print Network

    Paris-Sud XI, Université de

    1 Subliminal display of action words interferes with motor planning: a combined EEG and kinematic movement, using words that were presented too fast to be consciously perceived (subliminally). Encephalogram (EEG) and movement kinematics were recorded. EEG recordings of the "Readiness Potential" ("RP

  15. Subliminal display of action words interferes with motor planning: A combined EEG and kinematic study

    E-print Network

    Institut des Sciences Cognitives, CNRS

    Subliminal display of action words interferes with motor planning: A combined EEG and kinematic presented too fast to be consciously perceived (subliminally). Encephalogram (EEG) and movement kinematics Readiness potential Language processes Interference EEG Kinematics a b s t r a c t Recent evidence has shown

  16. Eigenvector Methods for Analysis of Human PPG, ECG and EEG Signals

    Microsoft Academic Search

    Elif Derya Übeyli; Dean Cvetkovic; Irena Cosic

    2007-01-01

    This paper presents eigenvector methods for analysis of the photoplethysmogram (PPG), eigenvector methods for analysis of human PPG, ECG and EEG signals Electrocardiogram (ECG), electroencephalogram (EEG) signals recorded in order to examine the effects of pulsed electromagnetic field (PEMF) at extremely low frequency (ELF) upon the human electrophysiological signal behavior. The features representing the PPG, ECG, EEG signals were obtained

  17. Reflection of the Intelligence Structure in the Spatiotemporal Features of the Baseline EEG

    Microsoft Academic Search

    O. M. Razoumnikova

    2003-01-01

    The EEG correlates of the verbal, numerical, and figural IQ components according to the power and coherence characteristics of the baseline EEG in six frequency bands were studied taking into account personality traits of subjects (extroversion, neuroticism, psychoticism, and anxiety). Analysis of variance and correlation showed that a decreased power of the low-frequency ?1, 2and a1 rhythms and increased EEG

  18. EEG feature selection using mutual information and support vector machine: A comparative analysis

    E-print Network

    Verleysen, Michel

    EEG feature selection using mutual information and support vector machine: A comparative analysis of the study, we carry out 1000 independent runs using a bootstrap approach, and evaluate the statistical be different de- pending of the application, i.e., EEG epilepsy detection, EEG prediction and brain computer

  19. A Tutorial on EEG Signal Processing Techniques for Mental State Recognition in Brain-Computer

    E-print Network

    Boyer, Edmond

    Chapter 7 A Tutorial on EEG Signal Processing Techniques for Mental State Recognition in Brain processing techniques that can be used to recognize mental states from electroen- cephalographic (EEGEncephaloGraphy (EEG) is to process and analyse such EEG signals in real-time, in order to identify the mental state

  20. Does Frontal EEG Beta Have Application in Anxiety Monitoring during Computer-Based Learning?

    ERIC Educational Resources Information Center

    Macaulay, M.; Edmonds, E.

    2004-01-01

    One of the psychological states that can be monitored and influenced during learning in order to improve its various aspects is the state of anxiety, and one possible index of this state is frontal EEG beta. However, frontal EEG beta has also been associated with mental activities. This may imply that frontal EEG beta would not be a reliable index…

  1. EEG denoising with a recurrent quantum neural network for a brain-computer interface

    Microsoft Academic Search

    Vaibhav Gandhi; Vipul Arora; Laxmidhar Behera; Girijesh Prasad; Damien Coyle; TM McGinnity

    2011-01-01

    Brain-computer interface (BCI) technology is a means of communication that allows individuals with severe movement disability to communicate with external assistive devices using the electroencephalogram (EEG) or other brain signals. This paper presents an alternative neural information processing architecture using the Schrwave equation (SWE) for enhancement of the raw EEG signal. The raw EEG signal obtained during the motor imagery

  2. A Brain-Machine Interface using Dry-Contact, Low-Noise EEG Sensors

    E-print Network

    Cauwenberghs, Gert

    A Brain-Machine Interface using Dry-Contact, Low-Noise EEG Sensors Thomas J. Sullivan, Stephen R the need for conductive gel and creating sensors that fit into a scalable array architecture. The EEG dry are detected, and an eye-blink study is demonstrated. I. INTRODUCTION Electroencephalograph (EEG) systems

  3. Sex Differences in Genetic Architecture of Complex Phenotypes?

    PubMed Central

    Vink, Jacqueline M.; Bartels, Meike; van Beijsterveldt, Toos C. E. M.; van Dongen, Jenny; van Beek, Jenny H. D. A.; Distel, Marijn A.; de Moor, Marleen H. M.; Smit, Dirk J. A.; Minica, Camelia C.; Ligthart, Lannie; Geels, Lot M.; Abdellaoui, Abdel; Middeldorp, Christel M.; Hottenga, Jouke Jan; Willemsen, Gonneke; de Geus, Eco J. C.; Boomsma, Dorret I.

    2012-01-01

    We examined sex differences in familial resemblance for a broad range of behavioral, psychiatric and health related phenotypes (122 complex traits) in children and adults. There is a renewed interest in the importance of genotype by sex interaction in, for example, genome-wide association (GWA) studies of complex phenotypes. If different genes play a role across sex, GWA studies should consider the effect of genetic variants separately in men and women, which affects statistical power. Twin and family studies offer an opportunity to compare resemblance between opposite-sex family members to the resemblance between same-sex relatives, thereby presenting a test of quantitative and qualitative sex differences in the genetic architecture of complex traits. We analyzed data on lifestyle, personality, psychiatric disorder, health, growth, development and metabolic traits in dizygotic (DZ) same-sex and opposite-sex twins, as these siblings are perfectly matched for age and prenatal exposures. Sample size varied from slightly over 300 subjects for measures of brain function such as EEG power to over 30,000 subjects for childhood psychopathology and birth weight. For most phenotypes, sample sizes were large, with an average sample size of 9027 individuals. By testing whether the resemblance in DZ opposite-sex pairs is the same as in DZ same-sex pairs, we obtain evidence for genetic qualitative sex-differences in the genetic architecture of complex traits for 4% of phenotypes. We conclude that for most traits that were examined, the current evidence is that same the genes are operating in men and women. PMID:23272036

  4. Classification of independent components of EEG into multiple artifact classes.

    PubMed

    Frølich, Laura; Andersen, Tobias S; Mørup, Morten

    2015-01-01

    In this study, we aim to automatically identify multiple artifact types in EEG. We used multinomial regression to classify independent components of EEG data, selecting from 65 spatial, spectral, and temporal features of independent components using forward selection. The classifier identified neural and five nonneural types of components. Between subjects within studies, high classification performances were obtained. Between studies, however, classification was more difficult. For neural versus nonneural classifications, performance was on par with previous results obtained by others. We found that automatic separation of multiple artifact classes is possible with a small feature set. Our method can reduce manual workload and allow for the selective removal of artifact classes. Identifying artifacts during EEG recording may be used to instruct subjects to refrain from activity causing them. PMID:25048104

  5. Brain-computer interfaces for EEG neurofeedback: peculiarities and solutions.

    PubMed

    Huster, René J; Mokom, Zacharais N; Enriquez-Geppert, Stefanie; Herrmann, Christoph S

    2014-01-01

    Neurofeedback training procedures designed to alter a person's brain activity have been in use for nearly four decades now and represent one of the earliest applications of brain-computer interfaces (BCI). The majority of studies using neurofeedback technology relies on recordings of the electroencephalogram (EEG) and applies neurofeedback in clinical contexts, exploring its potential as treatment for psychopathological syndromes. This clinical focus significantly affects the technology behind neurofeedback BCIs. For example, in contrast to other BCI applications, neurofeedback BCIs usually rely on EEG-derived features with only a minimum of additional processing steps being employed. Here, we highlight the peculiarities of EEG-based neurofeedback BCIs and consider their relevance for software implementations. Having reviewed already existing packages for the implementation of BCIs, we introduce our own solution which specifically considers the relevance of multi-subject handling for experimental and clinical trials, for example by implementing ready-to-use solutions for pseudo-/sham-neurofeedback. PMID:24012908

  6. The transliminal brain at rest: baseline EEG, unusual experiences, and access to unconscious mental activity.

    PubMed

    Fleck, Jessica I; Green, Deborah L; Stevenson, Jennifer L; Payne, Lisa; Bowden, Edward M; Jung-Beeman, Mark; Kounios, John

    2008-01-01

    Transliminality reflects individual differences in the threshold at which unconscious processes or external stimuli enter into consciousness. Individuals high in transliminality possess characteristics such as magical ideation, belief in the paranormal, and creative personality traits, and also report the occurrence of manic/mystic experiences. The goal of the present research was to determine if resting brain activity differs for individuals high versus low in transliminality. We compared baseline EEG recordings (eyes-closed) between individuals high versus low in transliminality, assessed using The Revised Transliminality Scale of Lange et al. (2000). Identifying reliable differences at rest between high- and low-transliminality individuals would support a predisposition for transliminality-related traits. Individuals high in transliminality exhibited lower alpha, beta, and gamma power than individuals low in transliminality over left posterior association cortex and lower high alpha, low beta, and gamma power over the right superior temporal region. In contrast, when compared to individuals low in transliminality, individuals high in transliminality exhibited greater gamma power over the frontal-midline region. These results are consistent with prior research reporting reductions in left temporal/parietal activity, as well as the desynchronization of right temporal activity in schizotypy and related schizophrenia spectrum disorders. Further, differences between high- and low-transliminality groups extend existing theories linking altered hemispheric asymmetries in brain activity to a predisposition toward schizophrenia, paranormal beliefs, and unusual experiences. PMID:18814870

  7. EEG predictors of covert vigilant attention

    NASA Astrophysics Data System (ADS)

    Martel, Adrien; Dähne, Sven; Blankertz, Benjamin

    2014-06-01

    Objective. The present study addressed the question whether neurophysiological signals exhibit characteristic modulations preceding a miss in a covert vigilant attention task which mimics a natural environment in which critical stimuli may appear in the periphery of the visual field. Approach. Subjective, behavioural and encephalographic (EEG) data of 12 participants performing a modified Mackworth Clock task were obtained and analysed offline. The stimulus consisted of a pointer performing regular ticks in a clockwise sequence across 42 dots arranged in a circle. Participants were requested to covertly attend to the pointer and press a response button as quickly as possible in the event of a jump, a rare and random event. Main results. Significant increases in response latencies and decreases in the detection rates were found as a function of time-on-task, a characteristic effect of sustained attention tasks known as the vigilance decrement. Subjective sleepiness showed a significant increase over the duration of the experiment. Increased activity in the ?-frequency range (8-14 Hz) was observed emerging and gradually accumulating 10 s before a missed target. Additionally, a significant gradual attenuation of the P3 event-related component was found to antecede misses by 5 s. Significance. The results corroborate recent findings that behavioural errors are presaged by specific neurophysiological activity and demonstrate that lapses of attention can be predicted in a covert setting up to 10 s in advance reinforcing the prospective use of brain-computer interface (BCI) technology for the detection of waning vigilance in real-world scenarios. Combining these findings with real-time single-trial analysis from BCI may pave the way for cognitive states monitoring systems able to determine the current, and predict the near-future development of the brain's attentional processes.

  8. Neural decoding of expressive human movement from scalp electroencephalography (EEG)

    PubMed Central

    Cruz-Garza, Jesus G.; Hernandez, Zachery R.; Nepaul, Sargoon; Bradley, Karen K.; Contreras-Vidal, Jose L.

    2014-01-01

    Although efforts to characterize human movement through electroencephalography (EEG) have revealed neural activities unique to limb control that can be used to infer movement kinematics, it is still unknown the extent to which EEG can be used to discern the expressive qualities that influence such movements. In this study we used EEG and inertial sensors to record brain activity and movement of five skilled and certified Laban Movement Analysis (LMA) dancers. Each dancer performed whole body movements of three Action types: movements devoid of expressive qualities (“Neutral”), non-expressive movements while thinking about specific expressive qualities (“Think”), and enacted expressive movements (“Do”). The expressive movement qualities that were used in the “Think” and “Do” actions consisted of a sequence of eight Laban Effort qualities as defined by LMA—a notation system and language for describing, visualizing, interpreting and documenting all varieties of human movement. We used delta band (0.2–4 Hz) EEG as input to a machine learning algorithm that computed locality-preserving Fisher's discriminant analysis (LFDA) for dimensionality reduction followed by Gaussian mixture models (GMMs) to decode the type of Action. We also trained our LFDA-GMM models to classify all the possible combinations of Action Type and Laban Effort quality (giving a total of 17 classes). Classification accuracy rates were 59.4 ± 0.6% for Action Type and 88.2 ± 0.7% for Laban Effort quality Type. Ancillary analyses of the potential relations between the EEG and movement kinematics of the dancer's body, indicated that motion-related artifacts did not significantly influence our classification results. In summary, this research demonstrates that EEG has valuable information about the expressive qualities of movement. These results may have applications for advancing the understanding of the neural basis of expressive movements and for the development of neuroprosthetics to restore movements. PMID:24782734

  9. EEG effects of ECT: implications for rTMS.

    PubMed

    Krystal, A D; West, M; Prado, R; Greenside, H; Zoldi, S; Weiner, R D

    2000-01-01

    Electroconvulsive therapy (ECT) involves the use of electrical stimulation to elicit a series of generalized tonic-clonic seizures for therapeutic purposes and is the most effective treatment known for major depression. These treatments have significant neurophysiologic effects, many of which are manifest in the electroencephalogram (EEG). The relationship between EEG data and the response to ECT has been studied since the 1940s, but for many years no consistent correlates were found. Recent studies indicate that a number of specific EEG features recorded during the induced seizures (ictal EEG) as well as before and after a course of treatment (interictal EEG) are related to both the therapeutic efficacy and cognitive side effects. Similar to ECT, repetitive transcranial magnetic stimulation (rTMS), which involves focal electromagnetic stimulation of cortical neurons, has also been studied as an antidepressant therapy and also appears to have neurophysiologic effects, although these have not been as fully investigated as is the case with ECT. Given the similarity of these treatments, it is natural to consider whether advances in understanding the electrophysiologic correlates of the ECT response might have implications for rTMS. The present article reviews the literature on the EEG effects of ECT and discusses the implications in terms of the likely efficacy and side effects associated with rTMS in specific anatomic locations, the potential for producing an antidepressant response with rTMS without eliciting seizure activity, eliciting focal seizures with rTMS, and the possibility of using rTMS to focally modulate seizure induction and spread with ECT to optimize treatment. PMID:11126190

  10. Monitoring sedation levels by EEG spectral analysis.

    PubMed Central

    Griffiths, M. J.; Preece, A. W.; Green, J. L.

    1991-01-01

    Real-time electroencephalographic power spectra were obtained for a group of 37 volunteers undergoing sedation with enflurane at different concentrations in air. In part one, 17 subjects were given 0.5%, 0.75%, and 1.0% for 4 min at each level, and recovery after 5 min was assessed by the Trieger method. There was considerable variation in subject response to the different doses, but adequate sedation was indicated by the presence of a strong alpha rhythm (9-11 Hz) and suppression of frequencies below 5 Hz. Overdose was indicated by an initial shift in the alpha frequency to a lower value (6-7 Hz) followed by the appearance of delta waves (0.5-4 Hz) and loss of alpha waves. In part two, 20 volunteers inhaled enflurane at 0.5% for 10 min to allow adequate absorption, followed by a 10-min recovery period. Equal numbers showed sedation or a failure to respond to enflurane at this concentration. In the responders, sedation was accompanied by a marked shift in the ratio of the power in two frequency bands: 1-4 Hz and 8-12 Hz. Progress of the frequency band power ratio followed closely the state of the subject into sedation, overdose, and recovery. This measure was further improved by the use of multivariate analysis, which showed good discrimination of the alert, sedated, and overdosed states of the subject. PMID:1842161

  11. Subspace techniques to remove artifacts from EEG: a quantitative analysis.

    PubMed

    Teixeira, A R; Tome, A M; Lang, E W; Martins da Silva, A

    2008-01-01

    In this work we discuss and apply projective subspace techniques to both multichannel as well as single channel recordings. The single-channel approach is based on singular spectrum analysis(SSA) and the multichannel approach uses the extended infomax algorithm which is implemented in the opensource toolbox EEGLAB. Both approaches will be evaluated using artificial mixtures of a set of selected EEG signals. The latter were selected visually to contain as the dominant activity one of the characteristic bands of an electroencephalogram (EEG). The evaluation is performed both in the time and frequency domain by using correlation coefficients and coherence function, respectively. PMID:19163688

  12. Yield of intermittent versus continuous EEG in comatose survivors of cardiac arrest treated with hypothermia

    PubMed Central

    2013-01-01

    Introduction Electroencephalography (EEG) has a central role in the outcome prognostication in subjects with anoxic/hypoxic encephalopathy following a cardiac arrest (CA). Continuous EEG monitoring (cEEG) has been consistently developed and studied; however, its yield as compared to repeated standard EEG (sEEG) is unknown. Methods We studied a prospective cohort of comatose adults treated with therapeutic hypothermia (TH) after a CA. cEEG data regarding background activity and epileptiform components were compared to two 20-minute sEEGs extracted from the cEEG recording (one during TH, and one in early normothermia). Results Thirty-four recordings were studied. During TH, the agreement between cEEG and sEEG was 97.1% (95% CI: 84.6 to 99.9%) for background discontinuity and reactivity evaluation, while it was 94.1% (95% CI 80.3 to 99.2%) regarding epileptiform activity. In early normothermia, we did not find any discrepancies. Thus, concordance results were very good during TH (kappa 0.83), and optimal during normothermia (kappa = 1). The median delay between CA and the first EEG reactivity testing was 18 hours (range: 4.75 to 25) for patients with perfect agreement and 10 hours (range: 5.75 to 10.5) for the three patients with discordant findings (P = 0.02, Wilcoxon). Conclusions Standard intermittent EEG has comparable performance with continuous EEG both for variables important for outcome prognostication (EEG reactivity) and identification of epileptiform transients in this relatively small sample of comatose survivors of CA. This finding has an important practical implication, especially for centers where EEG resources are limited. PMID:24007625

  13. From Phenotype to Genotype

    PubMed Central

    2014-01-01

    The progress in phenotype descriptions, measurements, and analyses has been remarkable in the last 50 years. Biomarkers (proteins, carbohydrates, lipids, hormones, various RNAs and cDNAs, microarrays) have been discovered and correlated with diseases and disorders, as well as physiological responses to disease, injury, stress, within blood, urine, and saliva. Three-dimensional digital imaging advanced how we “see” and utilize phenotypes toward diagnosis, treatment, and prognosis. In each example, scientific discovery led to inform clinical health care. In tandem, genetics evolved from Mendelian inheritance (single gene mutations) to include Complex Human Diseases (multiple gene-gene and gene-environment interactions). In addition, epigenetics blossomed with new insights about gene modifiers (e.g., histone and non-histone chromosomal protein methylation, acetylation, sulfation, phosphorylation). We are now at the beginning of a new era using human and microbial whole-genome sequencing to make significant healthcare decisions as to risk, stratification of patients, diagnosis, treatments, and outcomes. Are we as clinicians, scientists, and educators prepared to expand our scope of practice, knowledge base, integration into primary health care (medicine, pharmacy, nursing, and allied health science professions), and clinical approaches to craniofacial-oral-dental health care? The time is now. PMID:24799423

  14. Ab initio alpha-alpha scattering

    E-print Network

    Serdar Elhatisari; Dean Lee; Gautam Rupak; Evgeny Epelbaum; Hermann Krebs; Timo A. Lähde; Thomas Luu; Ulf-G. Meißner

    2015-06-11

    Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.

  15. Ab initio alpha-alpha scattering

    E-print Network

    Elhatisari, Serdar; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-01-01

    Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.

  16. Event-related synchronization of alpha activity in early Alzheimer's disease and mild cognitive impairment: An MEG study combining beamformer and group comparison

    Microsoft Academic Search

    Ryu Kurimoto; Ryouhei Ishii; Leonides Canuet; Koji Ikezawa; Michiyo Azechi; Masao Iwase; Tetsuhiko Yoshida; Hiromitsu Kazui; Toshiki Yoshimine; Masatoshi Takeda

    2008-01-01

    In patients with Alzheimer's disease (AD), it is sometimes challenging to identify typical findings in electroencephalography (EEG) or magnetoencephalography (MEG) such as a slowing of the posterior dominant activity or an increase in slow activity. In this MEG study, we evaluated the event-related synchronization (ERS) of alpha activity after eye closing in patients with early AD and mild cognitive impairment

  17. Alpha band cortico-muscular coherence occurs in healthy individuals during mechanically-induced tremor.

    PubMed

    Budini, Francesco; McManus, Lara M; Berchicci, Marika; Menotti, Federica; Macaluso, Andrea; Di Russo, Francesco; Lowery, Madeleine M; De Vito, Giuseppe

    2014-01-01

    The present work aimed at investigating the effects of mechanically amplified tremor on cortico-muscular coherence (CMC) in the alpha band. The study of CMC in this specific band is of particular interest because this coherence is usually absent in healthy individuals and it is an aberrant feature in patients affected by pathological tremors; understanding its mechanisms is therefore important. Thirteen healthy volunteers (23±4 years) performed elbow flexor sustained contractions both against a spring load and in isometric conditions at 20% of maximal voluntary isometric contraction (MVC). Spring stiffness was selected to induce instability in the stretch reflex servo loop. 64 EEG channels, surface EMG from the biceps brachii muscle and force were simultaneously recorded. Contractions against the spring resulted in greater fluctuations of the force signal and EMG amplitude compared to isometric conditions (p<.05). During isometric contractions CMC was systematically found in the beta band and sporadically observed in the alpha band. However, during the contractions against the spring load, CMC in the alpha band was observed in 12 out of 13 volunteers. Partial directed coherence (PDC) revealed an increased information flow in the EMG to EEG direction in the alpha band (p<.05). Therefore, coherence in the alpha band between the sensory-motor cortex and the biceps brachii muscle can be systematically induced in healthy individuals by mechanically amplifying tremor. The increased information flow in the EMG to EEG direction may reflect enhanced afferent activity from the muscle spindles. These results may contribute to the understanding of the presence of alpha band CMC in tremor related pathologies by suggesting that the origin of this phenomenon may not only be at cortical level but may also be affected by spinal circuit loops. PMID:25514444

  18. EEG feature comparison and classification of simple and compound limb motor imagery

    PubMed Central

    2013-01-01

    Background Motor imagery can elicit brain oscillations in Rolandic mu rhythm and central beta rhythm, both originating in the sensorimotor cortex. In contrast with simple limb motor imagery, less work was reported about compound limb motor imagery which involves several parts of limbs. The goal of this study was to investigate the differences of the EEG patterns between simple limb motor imagery and compound limb motor imagery, and discuss the separability of multiple types of mental tasks. Methods Ten subjects participated in the experiment involving three tasks of simple limb motor imagery (left hand, right hand, feet), three tasks of compound limb motor imagery (both hands, left hand combined with right foot, right hand combined with left foot) and rest state. Event-related spectral perturbation (ERSP), power spectral entropy (PSE) and spatial distribution coefficient were adopted to analyze these seven EEG patterns. Then three algorithms of modified multi-class common spatial patterns (CSP) were used for feature extraction and classification was implemented by support vector machine (SVM). Results The induced event-related desynchronization (ERD) affects more components within both alpha and beta bands resulting in more broad ERD bands at electrode positions C3, Cz and C4 during left/right hand combined with contralateral foot imagery, whose PSE values are significant higher than that of simple limb motor imagery. From the topographical distribution, simultaneous imagination of upper limb and contralateral lower limb certainly contributes to the activation of more areas on cerebral cortex. Classification result shows that multi-class stationary Tikhonov regularized CSP (Multi-sTRCSP) outperforms other two multi-class CSP methods, with the highest accuracy of 84% and mean accuracy of 70%. Conclusions The work implies that there exist the separable differences between simple limb motor imagery and compound limb motor imagery, which can be utilized to build a multimodal classification paradigm in motor imagery based brain-computer interface (BCI) systems. PMID:24119261

  19. Single trial prediction of self-paced reaching directions from EEG signals

    PubMed Central

    Lew, Eileen Y. L.; Chavarriaga, Ricardo; Silvoni, Stefano; Millán, José del R.

    2014-01-01

    Early detection of movement intention could possibly minimize the delays in the activation of neuroprosthetic devices. As yet, single trial analysis using non-invasive approaches for understanding such movement preparation remains a challenging task. We studied the feasibility of predicting movement directions in self-paced upper limb center-out reaching tasks, i.e., spontaneous movements executed without an external cue that can better reflect natural motor behavior in humans. We reported results of non-invasive electroencephalography (EEG) recorded from mild stroke patients and able-bodied participants. Previous studies have shown that low frequency EEG oscillations are modulated by the intent to move and therefore, can be decoded prior to the movement execution. Motivated by these results, we investigated whether slow cortical potentials (SCPs) preceding movement onset can be used to classify reaching directions and evaluated the performance using 5-fold cross-validation. For able-bodied subjects, we obtained an average decoding accuracy of 76% (chance level of 25%) at 62.5 ms before onset using the amplitude of on-going SCPs with above chance level performances between 875 to 437.5 ms prior to onset. The decoding accuracy for the stroke patients was on average 47% with their paretic arms. Comparison of the decoding accuracy across different frequency ranges (i.e., SCPs, delta, theta, alpha, and gamma) yielded the best accuracy using SCPs filtered between 0.1 to 1 Hz. Across all the subjects, including stroke subjects, the best selected features were obtained mostly from the fronto-parietal regions, hence consistent with previous neurophysiological studies on arm reaching tasks. In summary, we concluded that SCPs allow the possibility of single trial decoding of reaching directions at least 312.5 ms before onset of reach. PMID:25136290

  20. A review of the usefulness of the standard EEG in psychiatry.

    PubMed

    Hughes, J R

    1996-01-01

    The goal of this paper is to draw conclusions about the usefulness of the standard EEG in psychiatry. In general, two thirds of psychiatric referrals for an EEG are expected to provide useful information. The emphasis in schizophrenia is placed on left-sided abnormalities, especially on the left temporal area. In mood disorders the emphasis is on right-sided foci, in addition to the controversial 6/sec spike and wave complexes, small sharp spikes and positive spikes. In the acute stage of alcoholism, a relationship is seen between the degree of intoxication and the amount of slow activity, while in the chronic stage an increase in slow activity is seen, but another change is fast activity on the temporal areas. During withdrawal a low seizure threshold can be seen as irregular bilateral spike and wave complexes. During abstinence 2-4 yr may be required before slow wave sleep is normal in all regards. Among the organic mental syndromes, delirium shows slow activity, except in delirium tremens, which often is associated with a normal record with fast activity. In dementia the prevalence of EEG abnormalities is related to the degree of impairment. After five sessions of ECT diffuse slow waves are often seen. In other conditions, among developmental disorders about one half of autistic children show abnormalities and epileptiform activity is not uncommon. Mild nonspecific abnormalities are seen in about 40% of dyslexics and also in behavior disorders. Anxiety disorders include anorexia nervosa, showing abnormal background activity related to the effect of starvation on cerebral metabolism. In panic attacks paroxysmal activity can be seen. In borderline personality positive spikes have been (again) associated with impulsivity and 6/sec spike and wave complexes with interpersonal problems. Of the drugs of abuse psilocybin and phencyclidine are often associated with generalized epileptiform patterns and with marijuana the alpha shows a decreased frequency with increased amplitude. Typically, an increase in slow activity is seen with psychotropic drugs if there is a change in the level of awareness. Finally, distinctive personality traits are, at times, seen in temporal lobe epilepsy and the phenomenon of "forced normalization" may appear when seizures stop and psychotic symptoms appear. PMID:8719500

  1. SYNGAP1 Mutation in Focal and Generalized Epilepsy: A Literature Overview and A Case Report with Special Aspects of the EEG.

    PubMed

    von Stülpnagel, Celina; Funke, Claudia; Haberl, Caroline; Hörtnagel, Konstanze; Jüngling, Jerome; Weber, Yvonne G; Staudt, Martin; Kluger, Gerhard

    2015-08-01

    Background?SYNGAP1, which encodes a RAS-GTPase-activating protein, is located on the short arm of chromosome 6. Heterozygous SYNGAP1 gene mutations have been associated with autism spectrum disorders, delay of psychomotor development, acquired microcephaly, and several forms of idiopathic generalized epilepsy. Here, we report a patient with a new SYNGAP1 stop mutation, and compare the phenotype with published cases with SYNGAP1 mutations and epilepsy. Patient?This 15-year-old nondysmorphic girl with intellectual disability developed drop attacks at the age of 2 years, later clonic and clonic-tonic as well as myoclonic seizures predominantly during sleep. The epilepsy was well-controlled by valproic acid (VPA) and later on with levetiracetam. Electroencephalogram (EEG) showed a complete EEG-normalization with eye opening as well as photosensitivity. Magnetic resonance imaging was normal. Genetic analysis revealed a de novo heterozygous stop mutation (c.348C?>?A, p.Y116*) in exon 4 of the SYNGAP1 gene. Discussion?The main clinical features of our patient (i.e., intellectual disability and idiopathic epilepsy) are compatible with previous reports on patients with SYNGAP1 mutations. The unusual feature of complete EEG normalization with eye opening has not been reported yet for this genetic abnormality. Furthermore, our case provides further support for efficacy of VPA in patients with SYNGAP1 mutation-related epilepsy. PMID:26110312

  2. Phenyl-/alpha/,/alpha/,/omega/-trihydropolyfluoroalkyliodonium fluoroborates

    SciTech Connect

    Mironova, A.A.; Soloshonok, I.V.; Maletina, I.I.; Orda, V.V.; Yagupol'skii, L.M.

    1988-08-20

    The reaction of difluoroiodo-/alpha/,/alpha/,/omega/-trihydrofluoroalkanes (I) with boron trifluoride and benzene gave phenyl-/alpha/,/alpha/,/omega/-trihydropolyfluoroalkyliodonium fluoroborates (II). It was established that the polyfluoroalkyl radical adds at the sulfur atom in reaction with p-chlorothiophenol, the N-polyfluoroalkylation product is formed with aniline, pyridine is polyfluoroalkylated at the nitrogen atom with the formation of a quaternary salt, and a mixture of products from polyfluoroalkylation at the nitrogen atom of the dimethylamino group and at the para position of the benzene ring is formed with dimethylaniline.

  3. EHR Big Data Deep Phenotyping

    PubMed Central

    Lenert, L.; Lopez-Campos, G.

    2014-01-01

    Summary Objectives Given the quickening speed of discovery of variant disease drivers from combined patient genotype and phenotype data, the objective is to provide methodology using big data technology to support the definition of deep phenotypes in medical records. Methods As the vast stores of genomic information increase with next generation sequencing, the importance of deep phenotyping increases. The growth of genomic data and adoption of Electronic Health Records (EHR) in medicine provides a unique opportunity to integrate phenotype and genotype data into medical records. The method by which collections of clinical findings and other health related data are leveraged to form meaningful phenotypes is an active area of research. Longitudinal data stored in EHRs provide a wealth of information that can be used to construct phenotypes of patients. We focus on a practical problem around data integration for deep phenotype identification within EHR data. The use of big data approaches are described that enable scalable markup of EHR events that can be used for semantic and temporal similarity analysis to support the identification of phenotype and genotype relationships. Conclusions Stead and colleagues’ 2005 concept of using light standards to increase the productivity of software systems by riding on the wave of hardware/processing power is described as a harbinger for designing future healthcare systems. The big data solution, using flexible markup, provides a route to improved utilization of processing power for organizing patient records in genotype and phenotype research. PMID:25123744

  4. Surgical Treatment of Patients with Lennox-Gastaut Syndrome Phenotype

    PubMed Central

    Liu, Shi-Yong; An, Ning; Fang, Xiang; Singh, Prabhdeep; Oommen, Joseph; Yin, Qing; Yang, Mei-Hua; Liu, Yong; Liao, Wei; Gao, Chang-Qing; Yang, Hui

    2012-01-01

    Lennox-Gastaut syndrome (LGS) is a devastating and refractory generalized epilepsy affecting children and adolescents. In this study we report the results of resective surgery in 18 patients with LGS phenotype who underwent single-lobe/lesionectomy or multilobe resection plus multiple subpial transection and/or callosotomy. After surgery, seven patients became completely seizure-free (Engel Class I) and five almost seizure-free (Engel Class II). Additional four had significant seizure control (Engel Class III), and two had no change in seizure frequency (Engel Class IV). Of the 4 patients without any lesion on brain MRI, 2 ended with Engel Class II, 1 with III and the other with IV in Engels' classification. Mean intelligence quotient (IQ) increased from 56.1?±?8.1 (mean?±?SD) before operation to 67.4?±?8.2 (mean?±?SD) after operation, a significant improvement (P = 0.001). Results also indicated that the younger the patient at surgery, or the shorter the interval between onset of seizure and resective operation, the better the intellectual outcome. Our data suggest that resective epilepsy surgery can be successful in patients with LGS phenotype as long as the EEG shows dominance of discharges in one hemisphere and corresponding ipsilateral imaging findings, even with contralateral ictal discharges. PMID:22629163

  5. Pharmaco-EEG: A Study of Individualized Medicine in Clinical Practice.

    PubMed

    Swatzyna, Ronald J; Kozlowski, Gerald P; Tarnow, Jay D

    2015-07-01

    Pharmaco-electroencephalography (Pharmaco-EEG) studies using clinical EEG and quantitative EEG (qEEG) technologies have existed for more than 4 decades. This is a promising area that could improve psychotropic intervention using neurological data. One of the objectives in our clinical practice has been to collect EEG and quantitative EEG (qEEG) data. In the past 5 years, we have identified a subset of refractory cases (n = 386) found to contain commonalities of a small number of electrophysiological features in the following diagnostic categories: mood, anxiety, autistic spectrum, and attention deficit disorders, Four abnormalities were noted in the majority of medication failure cases and these abnormalities did not appear to significantly align with their diagnoses. Those were the following: encephalopathy, focal slowing, beta spindles, and transient discharges. To analyze the relationship noted, they were tested for association with the assigned diagnoses. Fisher's exact test and binary logistics regression found very little (6%) association between particular EEG/qEEG abnormalities and diagnoses. Findings from studies of this type suggest that EEG/qEEG provides individualized understanding of pharmacotherapy failures and has the potential to improve medication selection. PMID:25420624

  6. Continuous EEG monitoring in adults in the intensive care unit (ICU).

    PubMed

    André-Obadia, N; Parain, D; Szurhaj, W

    2015-03-01

    Continuous EEG monitoring in the ICU is different from planned EEG due to the rather urgent nature of the indications, explaining the fact that recording is started in certain cases by the clinical team in charge of the patient's care. Close collaboration between neurophysiology teams and intensive care teams is essential. Continuous EEG monitoring can be facilitated by quantified analysis systems. This kind of analysis is based on certain signal characteristics, such as amplitude or frequency content, but raw EEG data should always be interpreted if possible, since artefacts can sometimes impair quantified EEG analysis. It is preferable to work within a tele-EEG network, so that the neurophysiologist has the possibility to give an interpretation on call. Continuous EEG monitoring is thus useful in the diagnosis of non-convulsive epileptic seizures or purely electrical discharges and in the monitoring of status epilepticus when consciousness disorders persist after initial treatment. A number of other indications are currently under evaluation. PMID:25639999

  7. Pseudomonas Aeruginosa Resistance Phenotypes and Phenotypic Highlighting Methods

    PubMed Central

    B?L??OIU, MARIA; B?L??OIU, A.T.; M?NESCU, RODICA; AVRAMESCU, CARMEN; IONETE, OANA

    2014-01-01

    Pseudomonas aeruginosa genus bacteria are well known for their increased drug resistance (phenotypic ang genotypic resistance). The most important resistance mechanisms are: enzyme production, reduction of pore expression, reduction of the external membrane proteins expression, efflux systems, topoisomerase mutations. These mechanisms often accumulate and lead to multidrug ressitance strains emergence. The most frequent acquired resistance mechanisms are betalactamase-type enzyme production (ESBLs, AmpC, carbapenemases), which determine variable phenotypes of betalactamines resistance, phenotypes which are associated with aminoglycosides and quinolones resistance. The nonenzymatic drug resistance mechanisms are caused by efflux systems, pore reduction and penicillin-binding proteins (PBP) modification, which are often associated to other resistance mechanisms. Phenotypic methods used for testing these mechanisms are based on highlighting these phenotypes using Kirby Bauer antibiogram, clinical breakpoints, and “cut off” values recommended by EUCAST 2013 standard, version 3.1. PMID:25729587

  8. Pseudomonas aeruginosa resistance phenotypes and phenotypic highlighting methods.

    PubMed

    B?l??oiu, Maria; B?l??oiu, A T; M?nescu, Rodica; Avramescu, Carmen; Ionete, Oana

    2014-01-01

    Pseudomonas aeruginosa genus bacteria are well known for their increased drug resistance (phenotypic ang genotypic resistance). The most important resistance mechanisms are: enzyme production, reduction of pore expression, reduction of the external membrane proteins expression, efflux systems, topoisomerase mutations. These mechanisms often accumulate and lead to multidrug ressitance strains emergence. The most frequent acquired resistance mechanisms are betalactamase-type enzyme production (ESBLs, AmpC, carbapenemases), which determine variable phenotypes of betalactamines resistance, phenotypes which are associated with aminoglycosides and quinolones resistance. The nonenzymatic drug resistance mechanisms are caused by efflux systems, pore reduction and penicillin-binding proteins (PBP) modification, which are often associated to other resistance mechanisms. Phenotypic methods used for testing these mechanisms are based on highlighting these phenotypes using Kirby Bauer antibiogram, clinical breakpoints, and "cut off" values recommended by EUCAST 2013 standard, version 3.1. PMID:25729587

  9. Characterization of putative stem cell phenotype in human limbal epithelia.

    PubMed

    Chen, Zhuo; de Paiva, Cintia S; Luo, Lihui; Kretzer, Francis L; Pflugfelder, Stephen C; Li, De-Quan

    2004-01-01

    This study evaluated proposed molecular markers related to stem cell (SC) properties with the intention of characterizing a putative SC phenotype in human limbal epithelia. Human corneal and limbal tissues were cut in the vertical and horizontal meridians for histology, transmission electron microscopy (TEM), and immunostaining. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization were used to evaluate gene expression. TEM showed that the limbal basal cells were small primitive cells. Immunostaining disclosed that p63, ABCG2 and integrin alpha9 were primarily expressed by the basal epithelial cells of limbus. Antibodies against integrin beta1, epidermal growth factor receptor (EGFR), K19, enolase-alpha, and CD71 stained the basal cells of the limbus more brightly than the suprabasal epithelia. Integrin alpha6, nestin, E-cadherin and connexin 43 did not stain the limbal basal cells, but the suprabasal epithelia of the cornea and limbus showed strong immunoreactivity. K3 and involucrin stained only corneal and limbal superficial cells. RT-PCR showed higher levels of p63, ABCG2 and integrin alpha9 mRNA, but lower levels of K3, K12 and connexin 43 expressed in the limbal epithelia than the corneal epithelia. In situ hybridization showed that p63 transcripts were located in basal layer of the limbal epithelium. This work suggests that the basal epithelial cells of the limbus are p63, ABCG2 and integrin alpha9 positive, and nestin, E-cadherin, connexin 43, involucrin, K3, and K12 negative, with relatively higher expression of integrin beta1, EGFR, K19, and enolase-alpha. This putative SC phenotype may facilitate the identification and isolation of limbal epithelial SCs. PMID:15153612

  10. KCNQ2 encephalopathy: delineation of the electroclinical phenotype and treatment response.

    PubMed

    Numis, Adam L; Angriman, Marco; Sullivan, Joseph E; Lewis, Ann J; Striano, Pasquale; Nabbout, Rima; Cilio, Maria R

    2014-01-28

    Neonatal-onset epilepsies are rare conditions, mostly genetically determined, that can have a benign or severe phenotype.(1,2) There is recent recognition of de novo KCNQ2 mutations in patients with severe neonatal-onset epilepsy with intractable seizures and severe psychomotor impairment, termed KCNQ2 encephalopathy.(3,4) This is a rare condition and all patients reported so far were diagnosed well after the neonatal period.(3,4) We report on 3 new cases of KCNQ2 encephalopathy diagnosed in the neonatal period and studied with continuous video-EEG recording. We describe a distinct electroclinical phenotype and report on efficacy of antiepileptic drug (AED) therapies. PMID:24371303

  11. Behavioral phenotype in five individuals with de novo mutations within the GRIN2B gene

    PubMed Central

    2013-01-01

    Background Intellectual disability (ID) is often associated with behavioral problems or disorders. Mutations in the GRIN2B gene (MRD6, MIM613970) have been identified as a common cause of ID (prevalence of 0.5 – 1% in individuals with ID) associated with EEG and behavioral problems. Methods We assessed five GRIN2B mutation carriers aged between 3 and 14 years clinically and via standardized questionnaires to delineate a detailed behavioral phenotype. Parents and teachers rated problem behavior of their affected children by completing the Developmental Behavior Checklist (DBC) and the Conners’ Rating Scales Revised (CRS-R:L). Results All individuals had mild to severe ID and needed guidance in daily routine. They showed characteristic behavior problems with prominent hyperactivity, impulsivity, distractibility and a short attention span. Stereotypies, sleeping problems and a friendly but boundless social behavior were commonly reported. Conclusion Our observations provide an initial delineation of the behavioral phenotype of GRIN2B mutation carriers. PMID:23718928

  12. A Matter of Time: The Influence of Recording Context on EEG Spectral Power in Adolescents and Young Adults with ADHD.

    PubMed

    Kitsune, Glenn L; Cheung, Celeste H M; Brandeis, Daniel; Banaschewski, Tobias; Asherson, Philip; McLoughlin, Gráinne; Kuntsi, Jonna

    2015-07-01

    Elevated theta or theta/beta ratio is often reported in attention deficit hyperactivity disorder (ADHD), but the consistency across studies and the relation to hypoarousal are increasingly questioned. Reports of elevated delta related to maturational lag and of attenuated beta activity are less well replicated. Some critical inconsistencies could relate to differences in recording context. We examined if resting-state EEG power or global field synchronization (GFS) differed between recordings made at the beginning and end of a 1.5 h testing session in 76 adolescents and young adults with ADHD, and 85 controls. In addition, we aimed to examine the effect of IQ on any potential group differences. Both regional and midline electrodes yielded group main effects for delta, trends in theta, but no differences in alpha or theta/beta ratio. An additional group difference in beta was detected when using regions. Group by time interactions in delta and theta became significant when controlling for IQ. The ADHD group had higher delta and theta power at time-1, but not at time-2, whereas beta power was elevated only at time-2. GFS did not differ between groups or condition. We show some ADHD-control differences on EEG spectral power varied with recording time within a single recording session, with both IQ and electrode selection having a small but significant influence on observed differences. Our findings demonstrate the effect of recording context on resting-state EEG, and highlight the importance of accounting for these variables to ensure consistency of results in future studies. PMID:25200165

  13. Longitudinal study of perception of structured optic flow and random visual motion in infants using high-density EEG.

    PubMed

    Agyei, Seth B; Holth, Magnus; van der Weel, F R Ruud; van der Meer, Audrey L H

    2015-05-01

    Electroencephalogram (EEG) was used in infants at 3-4 months and 11-12 months to longitudinally study brain electrical activity as the infants were exposed to structured forwards and reversed optic flow, and non-structured random visual motion. Analyses of visual evoked potential (VEP) and temporal spectral evolution (TSE, time-dependent amplitude changes) were performed on EEG data recorded with a 128-channel sensor array. VEP results showed infants to significantly differentiate between the radial motion conditions, but only at 11-12 months where they showed shortest latency for forwards optic flow and longest latency for random visual motion. When the TSE results of the motion conditions were compared with those of a static non-flow dot pattern, infants at 3-4 and 11-12 months both showed significant differences in induced activity. A decrease in amplitudes at 5-7 Hz was observed as desynchronized theta-band activity at both 3-4 and 11-12 months, while an increase in amplitudes at 9-13 Hz was observed as synchronized alpha-band activity only at 11-12 months. It was concluded that brain electrical activities related to visual motion perception change during the first year of life, and these changes can be observed both in the VEP and induced activities of EEG. With adequate neurobiological development and locomotor experience infants around 1 year of age rely, more so than when they were younger, on structured optic flow and show a more adult-like specialization for motion where faster oscillating cell assemblies have fewer but more specialized neurons, resulting in improved visual motion perception. PMID:25145649

  14. Do Respiratory Cycle-Related EEG Changes or Arousals from Sleep Predict Neurobehavioral Deficits and Response to Adenotonsillectomy in Children?

    PubMed Central

    Chervin, Ronald D.; Garetz, Susan L.; Ruzicka, Deborah L.; Hodges, Elise K.; Giordani, Bruno J.; Dillon, James E.; Felt, Barbara T.; Hoban, Timothy F.; Guire, Kenneth E.; O'Brien, Louise M.; Burns, Joseph W.

    2014-01-01

    Study Objectives: Pediatric obstructive sleep apnea (OSA) is associated with hyperactive behavior, cognitive deficits, psychiatric morbidity, and sleepiness, but objective polysomnographic measures of OSA presence or severity among children scheduled for adenotonsillectomy have not explained why. To assess whether sleep fragmentation might explain neurobehavioral outcomes, we prospectively assessed the predictive value of standard arousals and also respiratory cycle-related EEG changes (RCREC), thought to reflect inspiratory microarousals. Methods: Washtenaw County Adenotonsillectomy Cohort II participants included children (ages 3-12 years) scheduled for adenotonsillectomy, for any clinical indication. At enrollment and again 7.2 ± 0.9 (SD) months later, children had polysomnography, a multiple sleep latency test, parent-completed behavioral rating scales, cognitive testing, and psychiatric evaluation. The RCREC were computed as previously described for delta, theta, alpha, sigma, and beta EEG frequency bands. Results: Participants included 133 children, 109 with OSA (apnea-hypopnea index [AHI] ? 1.5, mean 8.3 ± 10.6) and 24 without OSA (AHI 0.9 ± 0.3). At baseline, the arousal index and RCREC showed no consistent, significant associations with neurobehavioral morbidities, among all subjects or the 109 with OSA. At follow-up, the arousal index, RCREC, and neurobehavioral measures all tended to improve, but neither baseline measure of sleep fragmentation effectively predicted outcomes (all p > 0.05, with only scattered exceptions, among all subjects or those with OSA). Conclusion: Sleep fragmentation, as reflected by standard arousals or by RCREC, appears unlikely to explain neurobehavioral morbidity among children who undergo adenotonsillectomy. Clinical Trial Registration: ClinicalTrials.gov, ID: NCT00233194 Citation: Chervin RD, Garetz SL, Ruzicka DL, Hodges EK, Giordani BJ, Dillon JE, Felt BT, Hoban TF, Guire KE, O'Brien LM, Burns JW. Do respiratory cycle-related EEG changes or arousals from sleep predict neurobehavioral deficits and response to adenotonsillectomy in children?. J Clin Sleep Med 2014;10(8):903-911. PMID:25126038

  15. Preoperational radiation surveillance of the WIPP project by EEG during 1992

    SciTech Connect

    Kenney, J.W.

    1994-02-01

    The purpose of the EEG preoperational monitoring program is to document the existing concentrations of selected radionuclides in various environmental media collected from the vicinity of the WIPP site to provide a basis of comparison of any effects of future WT-PP operations. The basic methodology for conducting environmental surveillance both on-site and off-site was outlined by Spiegler (1984). This report represents a continuation of the EEG baseline data beginning in 1985, previously reported in EEG-43, EEG-47, EEG-49 and EEG-51. Such radionuclide baseline data are important in order to determine whether future WIPP operations with radioactive waste have affected concentrations of these radionuclides in the environment. EEG data are consistent with similar environmental measurements obtained by DOE beginning in 1985. Since late 1985, the EEG has collected or received as split samples 2 443 air filters with particulates, 202 water samples, 16 biota samples and 13 soil/sediment samples. A total of 5,946 specific radionuclide analyses have been performed on these samples. As reported previously by EEG (EEG-43, EEG-47, EEG-49 and EEG-51), observed concentrations of U-238 daughter radionuclides were not in equilibrium with the parent radionuclide in water samples. This observation is consistent with different radionuclide mobility in the environment. In a notice of proposed rule making for 40 CFR 141 (US EPA 1991), the Environmental Protection Agency (EPA) National Primary Drinking Water Regulations reflect this in the calculated activity-to-mass ratio of 1.3 pCi/{mu}g of uranium using a geometric mean of the U-234:U-238 ratio in water supplies of 2.7. Ra-226 and Ra- 228 were reported in a number of water samples in concentrations similar to those previously published by EEG and DOE.

  16. Assessment of EEG synchronization based on state-space analysis

    Microsoft Academic Search

    Cristian Carmeli; Maria G. Knyazeva; Giorgio M. Innocenti; Oscar De Feo

    2005-01-01

    Cortical computation involves the formation of cooperative neuronal assemblies characterized by synchronous oscillatory activity. A traditional method for the identification of synchronous neuronal assemblies has been the coherence analysis of EEG signals. Here, we suggest a new method called S estimator, whereby cortical synchrony is defined from the embedding dimension in a state-space. We first validated the method on clusters

  17. A Wearable UHF RFID-Based EEG System Artem Dementyev

    E-print Network

    Hochberg, Michael

    , there is a clinical need for continuos EEG monitoring to alert the patient and health- care providers during the onset monitoring system that is battery-free; is powered by a standard UHF RFID reader; and uses backscatter could be used for mental-work load detection to alert distracted or drowsy car drivers [3]. Furthermore

  18. Multilevel neural network system for EEG spike detection

    Microsoft Academic Search

    Ozcan Ozdamar; Ilker Yaylali; P. Jayaker; Carlos N. Lopez

    1991-01-01

    The design and evaluation of an artificial neural network system for the detection of epileptogenic spikes is described. The system is composed of smaller neural network modules which are trained individually and organized in two levels. The first-level modules are trained to recognize candidate spikes in single referential electroencephalogram (EEG) channels. Original digitized data with a running window of 100

  19. [Diagnostic significance of sleep EEG in children with febrile seizures].

    PubMed

    Kovelenova, M V; Rozhkov, V P; Guzeva, V I

    2002-01-01

    To obtain effective criteria for febrile seizures (FS) differential diagnosis and prognosis, clinical examination and EEG recorded during wakefulness and daytime sleep were studied in 75 FS children and 15 controls aged from 6 months to 6 years. According to duration, frequency and complications of FS, all patients were divided into three groups: "simple" FS (n = 35), "complex" FS (n = 25) and "afebrile seizures" (AFS), i.e. those who developed non-febrile seizures after febrile ones (n = 15). In waking state EEG, epileptic activity was found in only 60% of AFS patients. During sleep stages I-III, in 84% of the patients with complex FS as well as in all AFS patients generalized discharges of (poly) spike-waves and (or) focal spikes were detected. Paroxysmal changes, atypical scalp distribution, vertex-potentials and sleep spindles generalization as well as insertion of spikes into arousal-rhythms were determined as additional criteria for unfavorable FS course. In the patients with main features of sympathetic-adrenal reaction during febrile paroxysms, complicated FS course was not found. EEG examination during sleep in children with FS increases an efficacy of differential disease diagnosis. Epileptic discharge detection, along with exposure of paroxysmal transformation of physiological sleep EEG transients, that may be earlier sign of epileptic dysfunction, are recommended for proper prevention and treatment of FS. PMID:11915706

  20. Dynamic causal modeling of evoked responses in EEG and MEG

    Microsoft Academic Search

    Olivier David; Stefan J. Kiebel; Lee M. Harrison; Jérémie Mattout; James M. Kilner; Karl J. Friston

    2006-01-01

    Neuronally plausible, generative or forward models are essential for understanding how event-related fields (ERFs) and potentials (ERPs) are generated. In this paper, we present a new approach to modeling event-related responses measured with EEG or MEG. This approach uses a biologically informed model to make inferences about the underlying neuronal networks generating responses. The approach can be regarded as a

  1. Imipramine and EEG sleep in children with depressive symptoms

    Microsoft Academic Search

    David J. Kupfer; Patricia Coble; Judith Kane; Theodore Petti; C. Keith Conners

    1979-01-01

    Depression in children is currently an area of considerable controversy, as is the use of potent psychopharmacologic agents in children. Since EEG sleep techniques have proven to be useful in under-standing the mechanisms of depression in adults and in predicting their response to antidepressants, a pilot study employing these techniques was undertaken in a population of hospitalized children.

  2. Characteristics of human EEG sleep spindles assessed by Gabor transform

    Microsoft Academic Search

    Suzana V. Schönwald; Günther J. L. Gerhardt; Emerson L. de Santa-Helena; Márcia L. F. Chaves

    2003-01-01

    The aim of this study is to show an application of the Gabor transform on the detection and characterization of human sleep EEG spindles in a sample of 10 healthy young adults, trying to identify the most useful parameters that can be used for the automatic detection and characterization of such events.

  3. EFFECT OF DAYTIME EXERCISE ON SLEEP EEG AND SUBJECTIVE SLEEP

    Microsoft Academic Search

    Y. Sasazawa; T. Kawada; Y. Kiryu

    1997-01-01

    This study was designed to assess the effects of daytime physical exercise on the quality of objective and subjective sleep by examining all-night sleep EEGs. The subjects were five male students, aged 19 to 20 years, who were in the habit of performing regular daytime exercise. The sleep polygraphic parameters in this study were sleep stage time as a percentage

  4. Automated EEG-sleep analyses and neonatal neurointensive care

    Microsoft Academic Search

    Mark S. Scher

    2004-01-01

    Clinical applications of neonatal EEG-sleep studies can improve neurointensive care for preterm and fullterm infants. Behavioral and physiologic assessments of neonatal sleep by nursing and physician personnel can result in more developmentally appropriate state regulation for infants, particularly for those who require medical care for many weeks to months in the intensive care unit. Secondly, prediction of altered expressions of

  5. Characteristics of human EEG sleep spindles assessed by Gabor transform

    NASA Astrophysics Data System (ADS)

    Schönwald, Suzana V.; Gerhardt, Günther J. L.; de Santa-Helena, Emerson L.; Chaves, Márcia L. F.

    2003-09-01

    The aim of this study is to show an application of the Gabor transform on the detection and characterization of human sleep EEG spindles in a sample of 10 healthy young adults, trying to identify the most useful parameters that can be used for the automatic detection and characterization of such events.

  6. A unified Bayesian framework for MEG\\/EEG source imaging

    Microsoft Academic Search

    David Wipf; Srikantan Nagarajan

    2009-01-01

    The ill-posed nature of the MEG (or related EEG) source localization problem requires the incorporation of prior assumptions when choosing an appropriate solution out of an infinite set of candidates. Bayesian approaches are useful in this capacity because they allow these assumptions to be explicitly quantified using postulated prior distributions. However, the means by which these priors are chosen, as

  7. A stochastic model for EEG microstate sequence analysis.

    PubMed

    Gärtner, Matthias; Brodbeck, Verena; Laufs, Helmut; Schneider, Gaby

    2015-01-01

    The analysis of spontaneous resting state neuronal activity is assumed to give insight into the brain function. One noninvasive technique to study resting state activity is electroencephalography (EEG) with a subsequent microstate analysis. This technique reduces the recorded EEG signal to a sequence of prototypical topographical maps, which is hypothesized to capture important spatio-temporal properties of the signal. In a statistical EEG microstate analysis of healthy subjects in wakefulness and three stages of sleep, we observed a simple structure in the microstate transition matrix. It can be described with a first order Markov chain in which the transition probability from the current state (i.e., map) to a different map does not depend on the current map. The resulting transition matrix shows a high agreement with the observed transition matrix, requiring only about 2% of mass transport (1/2 L1-distance). In the second part, we introduce an extended framework in which the simple Markov chain is used to make inferences on a potential underlying time continuous process. This process cannot be directly observed and is therefore usually estimated from discrete sampling points of the EEG signal given by the local maxima of the global field power. Therefore, we propose a simple stochastic model called sampled marked intervals (SMI) model that relates the observed sequence of microstates to an assumed underlying process of background intervals and thus, complements approaches that focus on the analysis of observable microstate sequences. PMID:25451473

  8. Amplitude suppression and chaos control in epileptic EEG signals

    E-print Network

    Bandyopadhyay, Antar

    to improve patient specific dosage titration during vagus nerve stimulation therapy has been outlined Lyapunov exponent (ASLE); Vagus nerve stimulation (VNS) 1. Introduction Amplitude suppression in a signal in a sampled EEG signal can help to determine dosage titration in electrical stimulation therapy to control

  9. Realistically Coupled Neural Mass Models Can Generate EEG Rhythms

    Microsoft Academic Search

    Roberto C. Sotero; Nelson J. Trujillo-barreto; Yasser Iturria-medina; Felix Carbonell; Juan C. Jimenez

    2007-01-01

    We study the generation of EEG rhythms by means of realistically coupled neural mass models. Previous neural mass models were used to model cortical voxels and the thalamus. Interactions between voxels of the same and other cortical areas and with the thalamus were taken into account. Voxels within the same cortical area were coupled (short-range connections) with both excitatory and

  10. A longitudinal study of EEG sleep in schizophrenia

    Microsoft Academic Search

    Matcheri S Keshavan; Charles F Reynolds; Jean M Miewald; Debra M Montrose

    1996-01-01

    Several abnormalities in sleep architecture have been described in schizophrenia. However, the question of whether sleep electroencephalographic (EEG) changes are influenced by treatment and phase of illness remains unclear. To examine the longitudinal stability of sleep data, we compared baseline sleep measures with measures obtained approximately 4 weeks and 1 year after the beginning of treatment in a series of

  11. The EEG and Incidence of Epilepsy in Down's Syndrome.

    ERIC Educational Resources Information Center

    Tangye, Sheila R.

    1979-01-01

    It was found, among other things, that neither the presence of congenital heart disease, nor diabetes, nor intercurrent illness appeared to have any effect on the development of seizures. The age groups with the lowest proportion of EEG abnormalities were 25-34 years (48.7 percent abnormal) and 35-44 years (54.1 percent abnormal). (Author/DLS)

  12. [Wavelet entropy analysis of spontaneous EEG signals in Alzheimer's disease].

    PubMed

    Zhang, Meiyun; Zhang, Benshu; Chen, Ying

    2014-08-01

    Wavelet entropy is a quantitative indexto describe the complexity of signals. Continuous wavelet transform method was employed to analyze the spontaneous electroencephalogram (EEG) signals of mild, moderate and severe Alzheimer's disease (AD) patients and normal elderly control people in this study. Wavelet power spectrums of EEG signals were calculated based on wavelet coefficients. Wavelet entropies of mild, moderate and severe AD patients were compared with those of normal controls. The correlation analysis between wavelet entropy and MMSE score was carried out. There existed significant difference on wavelet entropy among mild, moderate, severe AD patients and normal controls (PEEG and the MMSE score were significantly correlated (r= 0. 601-0. 799, PEEG signals. Wavelet entropy is likely to be an electrophysiological index for AD diagnosis and severity assessment. PMID:25508413

  13. [Wavelet entropy analysis of spontaneous EEG signals in Alzheimer's disease].

    PubMed

    Zhang, Meiyun; Zhang, Benshu; Chen, Ying

    2014-08-01

    Wavelet entropy is a quantitative index to describe the complexity of signals. Continuous wavelet transform method was employed to analyze the spontaneous electroencephalogram (EEG) signals of mild, moderate and severe Alzheimer's disease (AD) patients and normal elderly control people in this study. Wavelet power spectrums of EEG signals were calculated based on wavelet coefficients. Wavelet entropies of mild, moderate and severe AD patients were compared with those of normal controls. The correlation analysis between wavelet entropy and MMSE score was carried out. There existed significant difference on wavelet entropy among mild, moderate, severe AD patients and normal controls (P<0.01). Group comparisons showed that wavelet entropy for mild, moderate, severe AD patients was significantly lower than that for normal controls, which was related to the narrow distribution of their wavelet power spectrums. The statistical difference was significant (P<0.05). Further studies showed that the wavelet entropy of EEG and the MMSE score were significantly correlated (r= 0. 601-0. 799, P<0.01). Wavelet entropy is a quantitative indicator describing the complexity of EEG signals. Wavelet entropy is likely to be an electrophysiological index for AD diagnosis and severity assessment. PMID:25464782

  14. EEG phase patterns reflect the selectivity of neural firing.

    PubMed

    Ng, Benedict Shien Wei; Logothetis, Nikos K; Kayser, Christoph

    2013-02-01

    Oscillations are pervasive in encephalographic signals and supposedly reflect cognitive processes and sensory representations. While the relation between oscillation amplitude (power) and sensory-cognitive variables has been extensively studied, recent work reveals that the dynamic oscillation signature (phase pattern) can carry information about such processes to a greater degree than amplitude. To elucidate the neural correlates of oscillatory phase patterns, we compared the stimulus selectivity of neural firing rates and auditory-driven electroencephalogram (EEG) oscillations. We employed the same naturalistic sound stimuli in 2 experiments, one recording scalp EEGs in humans and one recording intracortical local field potentials (LFPs) and single neurons in macaque auditory cortex. Using stimulus decoding techniques, we show that stimulus selective firing patterns imprint on the phase rather than the amplitude of slow (theta band) oscillations in LFPs and EEG. In particular, we find that stimuli which can be discriminated by firing rates can also be discriminated by phase patterns but not by oscillation amplitude and that stimulus-specific phase patterns also persist in the absence of increases of oscillation power. These findings support a neural basis for stimulus selective and entrained EEG phase patterns and reveal a level of interrelation between encephalographic signals and neural firing beyond simple amplitude covariations in both signals. PMID:22345353

  15. Synchronization and information flow in EEGs of epileptic patients

    Microsoft Academic Search

    M. Paulus; V. Komarek; T. Prochazka; Z. Hrncir; K. Sterbova

    2001-01-01

    An information-theoretic approach suitable for studying synchronization phenomena in experimental time series has been applied in analysis of EEG recordings of epileptic patients. Transient phenomena leading to seizures have been characterized by increased synchronization (local and between areas) and asymmetry in information flow (the area of the epileptogenic focus drives and synchronizes adjacent areas). Although the results should be regarded

  16. GABAA Agonist Reduces Visual Awareness: A Masking–EEG Experiment

    Microsoft Academic Search

    Anouk M. van Loon; H. Steven Scholte; Simon van Gaal; Björn J. J. van der Hoort; Victor A. F. Lamme

    2012-01-01

    Consciousness can be manipulated in many ways. Here, we seek to understand whether two such ways, visual masking and pharmacological intervention, share a common pathway in manipulating visual consciousness. We recorded EEG from human participants who performed a backward-masking task in which they had to detect a masked figure form its background (masking strength was varied across trials). In a

  17. Conducting Art Therapy Research Using Quantitative EEG Measures

    ERIC Educational Resources Information Center

    Belkofer, Christopher M.; Konopka, Lukasz M.

    2008-01-01

    This study presents a modified, single subject design that measured the patterns of electrical activity of a participant's brain following an hour spent painting and drawing. Paired t tests were used to compare pre and post art-making electroencephalograph (EEG) data. The results indicated that neurobiological activity after drawing and painting…

  18. Internal Noise of Eeg-Measurements and Certain Boson Systems

    NASA Astrophysics Data System (ADS)

    Fichtner, Karl-Heinz; Fichtner, Lars; Inoue, Kei; Ohya, Masanori

    2013-01-01

    Based on classical models of brain activities it seems to be difficult to explain the internal noise related to EEG-measurements. In this paper using a quantum model of the recognition process we consider the asymptotic behaviour of that internal noise.

  19. The complete ellipsoidal shell-model in EEG imaging

    Microsoft Academic Search

    S. N. Giapalaki; F. Kariotou

    2006-01-01

    This work provides the solution of the direct Electroencephalography (EEG) problem for the complete ellipsoidal shell-model of the human head. The model involves four confocal ellipsoids that represent the successive interfaces between the brain tissue, the cerebrospinal fluid, the skull, and the skin characterized by different conductivities. The electric excitation of the brain is due to an equivalent electric dipole,

  20. Probabilistic Common Spatial Patterns for Multichannel EEG Analysis

    PubMed Central

    Chen, Zhe; Gao, Xiaorong; Li, Yuanqing; Brown, Emery N.; Gao, Shangkai

    2015-01-01

    Common spatial patterns (CSP) is a well-known spatial filtering algorithm for multichannel electroencephalogram (EEG) analysis. In this paper, we cast the CSP algorithm in a probabilistic modeling setting. Specifically, probabilistic CSP (P-CSP) is proposed as a generic EEG spatio-temporal modeling framework that subsumes the CSP and regularized CSP algorithms. The proposed framework enables us to resolve the overfitting issue of CSP in a principled manner. We derive statistical inference algorithms that can alleviate the issue of local optima. In particular, an efficient algorithm based on eigendecomposition is developed for maximum a posteriori (MAP) estimation in the case of isotropic noise. For more general cases, a variational algorithm is developed for group-wise sparse Bayesian learning for the P-CSP model and for automatically determining the model size. The two proposed algorithms are validated on a simulated data set. Their practical efficacy is also demonstrated by successful applications to single-trial classifications of three motor imagery EEG data sets and by the spatio-temporal pattern analysis of one EEG data set recorded in a Stroop color naming task. PMID:26005228

  1. EEG seizure detection and prediction algorithms: a survey

    NASA Astrophysics Data System (ADS)

    Alotaiby, Turkey N.; Alshebeili, Saleh A.; Alshawi, Tariq; Ahmad, Ishtiaq; Abd El-Samie, Fathi E.

    2014-12-01

    Epilepsy patients experience challenges in daily life due to precautions they have to take in order to cope with this condition. When a seizure occurs, it might cause injuries or endanger the life of the patients or others, especially when they are using heavy machinery, e.g., deriving cars. Studies of epilepsy often rely on electroencephalogram (EEG) signals in order to analyze the behavior of the brain during seizures. Locating the seizure period in EEG recordings manually is difficult and time consuming; one often needs to skim through tens or even hundreds of hours of EEG recordings. Therefore, automatic detection of such an activity is of great importance. Another potential usage of EEG signal analysis is in the prediction of epileptic activities before they occur, as this will enable the patients (and caregivers) to take appropriate precautions. In this paper, we first present an overview of seizure detection and prediction problem and provide insights on the challenges in this area. Second, we cover some of the state-of-the-art seizure detection and prediction algorithms and provide comparison between these algorithms. Finally, we conclude with future research directions and open problems in this topic.

  2. Hemodynamic and EEG Time-Courses During Unilateral Hand Movement in Patients with Cortical Myoclonus. An EEG-fMRI and EEG-TD-fNIRS Study.

    PubMed

    Visani, E; Canafoglia, L; Gilioli, I; Sebastiano, D Rossi; Contarino, V E; Duran, D; Panzica, F; Cubeddu, R; Contini, D; Zucchelli, L; Spinelli, L; Caffini, M; Molteni, E; Bianchi, A M; Cerutti, S; Franceschetti, S; Torricelli, A

    2014-09-25

    Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TD-fNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated O2Hb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the ? and ? bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TD-fNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in O2Hb and the decrease in BOLD. The post-movement ? rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG ?-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies. PMID:25253050

  3. A stable pattern of EEG spectral coherence distinguishes children with autism from neuro-typical controls - a large case control study

    PubMed Central

    2012-01-01

    Background The autism rate has recently increased to 1 in 100 children. Genetic studies demonstrate poorly understood complexity. Environmental factors apparently also play a role. Magnetic resonance imaging (MRI) studies demonstrate increased brain sizes and altered connectivity. Electroencephalogram (EEG) coherence studies confirm connectivity changes. However, genetic-, MRI- and/or EEG-based diagnostic tests are not yet available. The varied study results likely reflect methodological and population differences, small samples and, for EEG, lack of attention to group-specific artifact. Methods Of the 1,304 subjects who participated in this study, with ages ranging from 1 to 18 years old and assessed with comparable EEG studies, 463 children were diagnosed with autism spectrum disorder (ASD); 571 children were neuro-typical controls (C). After artifact management, principal components analysis (PCA) identified EEG spectral coherence factors with corresponding loading patterns. The 2- to 12-year-old subsample consisted of 430 ASD- and 554 C-group subjects (n = 984). Discriminant function analysis (DFA) determined the spectral coherence factors' discrimination success for the two groups. Loading patterns on the DFA-selected coherence factors described ASD-specific coherence differences when compared to controls. Results Total sample PCA of coherence data identified 40 factors which explained 50.8% of the total population variance. For the 2- to 12-year-olds, the 40 factors showed highly significant group differences (P < 0.0001). Ten randomly generated split half replications demonstrated high-average classification success (C, 88.5%; ASD, 86.0%). Still higher success was obtained in the more restricted age sub-samples using the jackknifing technique: 2- to 4-year-olds (C, 90.6%; ASD, 98.1%); 4- to 6-year-olds (C, 90.9%; ASD 99.1%); and 6- to 12-year-olds (C, 98.7%; ASD, 93.9%). Coherence loadings demonstrated reduced short-distance and reduced, as well as increased, long-distance coherences for the ASD-groups, when compared to the controls. Average spectral loading per factor was wide (10.1 Hz). Conclusions Classification success suggests a stable coherence loading pattern that differentiates ASD- from C-group subjects. This might constitute an EEG coherence-based phenotype of childhood autism. The predominantly reduced short-distance coherences may indicate poor local network function. The increased long-distance coherences may represent compensatory processes or reduced neural pruning. The wide average spectral range of factor loadings may suggest over-damped neural networks. PMID:22730909

  4. The effects of a single session of upper alpha neurofeedback for cognitive enhancement: a sham-controlled study.

    PubMed

    Escolano, C; Navarro-Gil, M; Garcia-Campayo, J; Minguez, J

    2014-12-01

    The minimization of the non-specific factors of neurofeedback (NF) is an important aspect to further advance in the understanding of the effects of these types of procedures. This paper investigates the NF effects of a single session (25 min) of individual upper alpha enhancement following a sham-controlled experimental design (19 healthy participants). We measured immediate effects after the training and 1-day lasting EEG effects (eyes closed resting state and task-related activity), as well as the event-locked EEG effects during the execution of a mental rotation task. These metrics were computed in trained (upper alpha) and non-trained EEG parameters (lower alpha and lower beta). Several cognitive functions were assessed such as working memory and mental rotation abilities. The NF group showed increased upper alpha power after training in task-related activity (not significantly sustained 1 day after) and higher pre-stimulus power during the mental rotation task. Both groups improved cognitive performance, with a more prominent improvement for the NF group, however a single session seems to be insufficient to yield significant differences between groups. A higher number of training sessions seems necessary to achieve long-lasting effects on the electrophysiology and to enhance the behavioral effects. PMID:25267413

  5. Functional role of frontal alpha oscillations in creativity.

    PubMed

    Lustenberger, Caroline; Boyle, Michael R; Foulser, A Alban; Mellin, Juliann M; Fröhlich, Flavio

    2015-06-01

    Creativity, the ability to produce innovative ideas, is a key higher-order cognitive function that is poorly understood. At the level of macroscopic cortical network dynamics, recent electroencephalography (EEG) data suggests that cortical oscillations in the alpha frequency band (8-12 Hz) are correlated with creative thinking. However, whether alpha oscillations play a functional role in creativity has remained unknown. Here we show that creativity is increased by enhancing alpha power using 10 Hz transcranial alternating current stimulation (10 Hz-tACS) of the frontal cortex. In a study of 20 healthy participants with a randomized, balanced cross-over design, we found a significant improvement of 7.4% in the Creativity Index measured by the Torrance Test of Creative Thinking (TTCT), a comprehensive and most frequently used assay of creative potential and strengths. In a second similar study with 20 subjects, 40 Hz-tACS was used instead of 10 Hz-tACS to rule out a general "electrical stimulation" effect. No significant change in the Creativity Index was found for such frontal 40 Hz stimulation. Our results suggest that alpha activity in frontal brain areas is selectively involved in creativity; this enhancement represents the first demonstration of specific neuronal dynamics that drive creativity and can be modulated by non-invasive brain stimulation. Our findings agree with the model that alpha recruitment increases with internal processing demands and is involved in inhibitory top-down control, which is an important requirement for creative ideation. PMID:25913062

  6. The Broad Autism Phenotype Questionnaire

    ERIC Educational Resources Information Center

    Hurley, Robert S. E.; Losh, Molly; Parlier, Morgan; Reznick, J. Steven; Piven, Joseph

    2007-01-01

    The broad autism phenotype (BAP) is a set of personality and language characteristics that reflect the phenotypic expression of the genetic liability to autism, in non-autistic relatives of autistic individuals. These characteristics are milder but qualitatively similar to the defining features of autism. A new instrument designed to measure the…

  7. Untangling asthma phenotypes and endotypes.

    PubMed

    Agache, I; Akdis, C; Jutel, M; Virchow, J C

    2012-07-01

    Asthma phenotypes have been developed to address the complexities of the disease. However, owing to a lack of longitudinal studies, little is known about the onset as well as the stability of phenotypes. Distinguishing phenotypes with regard to the severity or duration of the disease is essential. A phenotype covers the clinically relevant properties of the disease, but does not show the direct relationship to disease etiology and pathophysiology. Different pathogenetic mechanisms might cause similar asthma symptoms and might be operant in a certain phenotype. These putative mechanisms are addressed by the term 'endotype'. Classification of asthma based on endotypes provides advantages for epidemiological, genetic, and drug-related studies. A successful definition of endotypes should link key pathogenic mechanisms with the asthma phenotype. Thus, the identification of corresponding molecular biomarkers for individual pathogenic mechanism underlying phenotypes or subgroups within a phenotype is important. Whether newly defined asthma endotypes predict the individual course of asthma has to be validated in longitudinal studies. The accurate endotyping reflects natural history of asthma and should help to predict treatment response. Thus, understanding asthma endotypes might be useful in clinical practice. PMID:22594878

  8. Phenotypic concordance in 70 families with IGE-implications for genetic studies of epilepsy

    PubMed Central

    Kinirons, Peter; Rabinowitz, Daniel; Gravel, Micheline; Long, James; Winawer, Melodie; Sénéchal, Geneviève; Ottman, Ruth; Cossette, Patrick

    2009-01-01

    Summary Introduction A crucial issue in the genetic analysis of idiopathic generalized epilepsy (IGE) is deciding on the phenotypes that are likely to give the greatest power to detect predisposing variants. A complex inheritance pattern and unclear nature of the genotype—phenotype correlation makes this task difficult. In the absence of much definitive genetic information to clarify this correlation, we inferred the putative effects of predisposing genes by studying the clustering of various phenotypic features, both clinical and electrophysiological, within families. Methods We examined the distribution of clinical features among relatives of a proband in 70 French—Canadian families with a minimum of two affected individuals with a clear diagnosis of IGE and then, using concordance analysis, identified the relative genetic influences on IGE syndrome, seizure type, age-at-onset, and EEG features. Results The mean number of affected individuals with IGE per family was three. One-third of relatives had the same syndrome as the proband. 16—22.5% of relatives of a proband with one of the absence syndromes had juvenile myoclonic epilepsy (JME). Conversely, 27% of relatives of probands with JME had an absence syndrome. 15% of relatives displayed the exact constellation of seizure types as the proband. Concordance analysis demonstrated greater clustering within families of IGE syndrome, seizure type, and age-at-onset than would be expected by chance. Significant concordance was not evident for EEG features. Discussion There was a large degree of clinical heterogeneity present within families. However we found evidence for clustering of a number of clinical features. Further refinement of the phenotypes used in genetic studies of complex IGE is necessary for progress to be made. PMID:18723325

  9. Correntropy measures to detect daytime sleepiness from EEG signals.

    PubMed

    Melia, Umberto; Guaita, Marc; Vallverdú, Montserrat; Montserrat, Josep M; Vilaseca, Isabel; Salamero, Manel; Gaig, Carles; Caminal, Pere; Santamaria, Joan

    2014-10-01

    Excessive daytime sleepiness (EDS) is one of the main symptoms of several sleep related disorders and has a great impact on patients' lives. While many studies have been carried out in order to assess daytime sleepiness, automatic EDS detection still remains an open problem. In this work, a novel approach to this issue based on correntropy function analysis of EEG signals was proposed in order to detect patients suffering from EDS. Multichannel EEG signals were recorded during five Maintenance of Wakefulness Tests (MWT) and Multiple Sleep Latency Tests (MSLT) alternated throughout the day for patients suffering from sleep disordered breathing (SDB). A group of 20 patients with EDS was compared with a group of 20 patients without daytime sleepiness (WDS), by analyzing 60?s EEG windows in a waking state. Measures obtained from the cross-correntropy function (CCORR) and auto-correntropy function (ACORR) were calculated in the EEG frequency bands: ?, 0.1-4?Hz; ?, 4-8?Hz; ?, 8-12?Hz; ?, 12-30?Hz; total band TB, 0.1-45?Hz. These functions permitted the quantification of complex signal properties and the non-linear couplings between different areas of the scalp. Statistical differences between EDS and WDS groups were mainly found in the ? band during MSLT events (p-value < 0.0001). The WDS group presented more complexity in the occipital zone than the EDS group, while a stronger nonlinear coupling between the occipital and frontal regions was detected in EDS patients than in the WDS group. At best, ACORR and CCORR measures yielded sensitivity and specificity above 80% and the area under ROC curve (AUC) was above 0.85 in classifying EDS and WDS patients. These performances represent an improvement with respect to classical EEG indices applied in the same database (sensitivity and specificity were never above 80% and AUC was under 0.75). PMID:25237837

  10. Emotion recognition from EEG using higher order crossings.

    PubMed

    Petrantonakis, Panagiotis C; Hadjileontiadis, Leontios J

    2010-03-01

    Electroencephalogram (EEG)-based emotion recognition is a relatively new field in the affective computing area with challenging issues regarding the induction of the emotional states and the extraction of the features in order to achieve optimum classification performance. In this paper, a novel emotion evocation and EEG-based feature extraction technique is presented. In particular, the mirror neuron system concept was adapted to efficiently foster emotion induction by the process of imitation. In addition, higher order crossings (HOC) analysis was employed for the feature extraction scheme and a robust classification method, namely HOC-emotion classifier (HOC-EC), was implemented testing four different classifiers [quadratic discriminant analysis (QDA), k-nearest neighbor, Mahalanobis distance, and support vector machines (SVMs)], in order to accomplish efficient emotion recognition. Through a series of facial expression image projection, EEG data have been collected by 16 healthy subjects using only 3 EEG channels, namely Fp1, Fp2, and a bipolar channel of F3 and F4 positions according to 10-20 system. Two scenarios were examined using EEG data from a single-channel and from combined-channels, respectively. Compared with other feature extraction methods, HOC-EC appears to outperform them, achieving a 62.3% (using QDA) and 83.33% (using SVM) classification accuracy for the single-channel and combined-channel cases, respectively, differentiating among the six basic emotions, i.e., happiness, surprise, anger, fear, disgust, and sadness. As the emotion class-set reduces its dimension, the HOC-EC converges toward maximum classification rate (100% for five or less emotions), justifying the efficiency of the proposed approach. This could facilitate the integration of HOC-EC in human machine interfaces, such as pervasive healthcare systems, enhancing their affective character and providing information about the user's emotional status (e.g., identifying user's emotion experiences, recurring affective states, time-dependent emotional trends). PMID:19858033

  11. Adolescence & Parental History of Alcoholism: Insights from the Sleep EEG

    PubMed Central

    Van Reen, Eliza; Acebo, Christine; LeBourgeois, Monique; Seifer, Ronald; Fallone, Gahan; Carskadon, Mary A.

    2014-01-01

    Background Disrupted sleep is a common complaint of individuals with alcohol use disorder and in abstinent alcoholics. Furthermore, among recovering alcoholics, poor sleep predicts relapse to drinking. Whether disrupted sleep in these populations results from prolonged alcohol use or precedes the onset of drinking is not known. The aim of the present study was to examine the sleep EEG in alcohol naïve, parental history positive (PH+) and negative (PH?) boys and girls. Methods All-night sleep EEG recordings in two longitudinal cohorts (child and teen) followed at 1.5 – 3 year intervals were analyzed. The child and teen participants were 9/10 and 15/16 years old at the initial assessment, respectively. Parental history status was classified by DSM-IV criteria applied to structured interviews (CDIS-IV) resulting in 14 PH? and 10 PH+ children and 14 PH? and 10 PH+ teens. Sleep data were visually scored in 30-second epochs using standard criteria. Power spectra were calculated for EEG derivations C3/A2, C4/A1, O2/A1, O1/A2 for NREM and REM sleep. Results We found no difference between PH+ and PH? individuals in either cohort for any visually scored sleep stage variable. Spectral power declined in both cohorts across assessments for NREM and REM sleep in all derivations and across frequencies independent of parental history status. With regard to parental history, NREM sleep EEG power was lower for the delta band in PH+ teens at both assessments for the central derivations. Furthermore, power in the sigma band for the right occipital derivation in both NREM and REM sleep was lower in PH+ children only at the initial assessment. Conclusions We found no gross signs of sleep disruption as a function of parental history. Modest differences in spectral EEG power between PH+ and PH? children and teens indicate that a marker of parental alcohol history may detectable in teens at risk for problem drinking. PMID:22486223

  12. Malignant histiocytosis. A phenotypic and genotypic investigation.

    PubMed Central

    Cattoretti, G.; Villa, A.; Vezzoni, P.; Giardini, R.; Lombardi, L.; Rilke, F.

    1990-01-01

    Ten cases of malignant histiocytosis (MH) were evaluated for clinical and histopathologic features, phenotype, and rearrangement of T cell receptor (TCR) beta, gamma, and alpha and immunoglobulin (Ig) genes (7/10). All cases were HLA-DR+ and CD30-positive. Four cases had molecular evidence of T cell lineage such as TCR beta, gamma, and alpha rearrangements, and one additional case synthesized the cytoplasmic TCR beta chain. The remaining five cases did not show unequivocal T, B, natural killer (NK) cell, or macrophagic origin, and three of them had germline TCR and Ig genes. Ultrastructural analysis was not helpful for the definition of the cell lineage. Most myelomonocytic markers (MAC387, CD13, CD14, CD64, CD68) were either negative on the MH cells or were expressed on cells with rearranged TCR gene. Precursor (CD34, CD7) and NK (CD16, CD56, and CD57) cell markers were not found. The lineage of a number of cases of MH remains unresolved. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:2349962

  13. Childhood asthma-predictive phenotype.

    PubMed

    Guilbert, Theresa W; Mauger, David T; Lemanske, Robert F

    2014-01-01

    Wheezing is a fairly common symptom in early childhood, but only some of these toddlers will experience continued wheezing symptoms in later childhood. The definition of the asthma-predictive phenotype is in children with frequent, recurrent wheezing in early life who have risk factors associated with the continuation of asthma symptoms in later life. Several asthma-predictive phenotypes were developed retrospectively based on large, longitudinal cohort studies; however, it can be difficult to differentiate these phenotypes clinically as the expression of symptoms, and risk factors can change with time. Genetic, environmental, developmental, and host factors and their interactions may contribute to the development, severity, and persistence of the asthma phenotype over time. Key characteristics that distinguish the childhood asthma-predictive phenotype include the following: male sex; a history of wheezing, with lower respiratory tract infections; history of parental asthma; history of atopic dermatitis; eosinophilia; early sensitization to food or aeroallergens; or lower lung function in early life. PMID:25439355

  14. Correction of ocular artifacts in EEGs using an autoregressive model to describe the EEG; a pilot study.

    PubMed

    Van den Berg-Lenssen, M M; Brunia, C H; Blom, J A

    1989-07-01

    The basic idea in eye movement (EM) artifact corrections is that the actual recording is the summation of brain potentials (true EEG) and artifact. Often a regression analysis is performed, using simultaneous EEG and EOG data, to find the parameters describing the relationship between artifact and EOG derivations (EOGs). Our method uses a maximum likelihood parameter estimation and considers data from preceding sample moments as well, since there may be a delay in the artifact transferring over the scalp. For the error term (true EEG) an autoregressive function is used. Results from estimations on data from one volunteer indicate that a delay need not be considered and that 3 autoregressive parameters are sufficient. For F3 4 EOGs give only somewhat better results than 2 EOGs. For C3 and C4 2 EOGs are sufficient. For practical reasons for each of these 3 EEG recordings, 2 EOGs were used to perform corrections. Corrections were performed using either the parameters estimated for EMs and blinks together, or the parameters estimated for EMs only (used for EMs), or the parameters estimated for blinks only (used for blinks). For EMs the differences between these corrections are very small. For blinks the differences are much larger. Parameters estimated for one trial may be used to correct other trials, recorded within a period of about 15 min preceding or following that trial. PMID:2472954

  15. Effects of a new slow release formulation of caffeine on EEG, psychomotor and cognitive functions in sleep-deprived subjects.

    PubMed

    Patat, Alain; Rosenzweig, Pierre; Enslen, Marc; Trocherie, Suzanne; Miget, Nathalie; Bozon, Marie-Christine; Allain, Hervé; Gandon, Jean-Marc

    2000-04-01

    Caffeine is a widely-consumed psychoactive substance whose stimulant effects on mood, attention and performance are largely recognised. The central nervous system pharmacodynamic profile of a single oral dose of a new slow release (SR) caffeine formulation (600 mg) was assessed in a randomised, double-blind, crossover, placebo-controlled study. Twelve young, health, male, sleep-deprived (for 36 h) subjects were studied using EEG and various measures of psychomotor and cognitive functions, including critical flicker fusion (CFF), choice reaction task (CRT), tracking, continuous performance task (CPT), Stroop test, body sway and subjective evaluation (Stanford Sleepiness Scale). Caffeine significantly ( < 0/05) antagonised the detrimental effects of sleep-deprivation on EEG (i.e. produced a significant decrease in delta and theta relative power and a significant increase in alpha and beta (12-40 Hz) relative power) and psychomotor performance (significant increase in speed of reaction on the CRT and Stroop tests, significant decrease in body sway, significant increase in accuracy of the CPT and significant reduction in subjective sedation) compared to placebo. The effect peaked 4 h after dosing and was maintained until the end of sleep deprivation (i.e. 24 h after dosing). In conclusion, the present results demonstrate that a single dose of caffeine SR possesses alerting effects which are able to reverse the deleterious effect of 36 h sleep deprivation for at least 24 h. Copyright 2000 John Wiley & Sons, Ltd. PMID:12404329

  16. The effects of individual upper alpha neurofeedback in ADHD: an open-label pilot study.

    PubMed

    Escolano, C; Navarro-Gil, M; Garcia-Campayo, J; Congedo, M; Minguez, J

    2014-12-01

    Standardized neurofeedback (NF) protocols have been extensively evaluated in attention-deficit/hyperactivity disorder (ADHD). However, such protocols do not account for the large EEG heterogeneity in ADHD. Thus, individualized approaches have been suggested to improve the clinical outcome. In this direction, an open-label pilot study was designed to evaluate a NF protocol of relative upper alpha power enhancement in fronto-central sites. Upper alpha band was individually determined using the alpha peak frequency as an anchor point. 20 ADHD children underwent 18 training sessions. Clinical and neurophysiological variables were measured pre- and post-training. EEG was recorded pre- and post-training, and pre- and post-training trials within each session, in both eyes closed resting state and eyes open task-related activity. A power EEG analysis assessed long-term and within-session effects, in the trained parameter and in all the sensors in the (1-30) Hz spectral range. Learning curves over sessions were assessed as well. Parents rated a clinical improvement in children regarding inattention and hyperactivity/impulsivity. Neurophysiological tests showed an improvement in working memory, concentration and impulsivity (decreased number of commission errors in a continuous performance test). Relative and absolute upper alpha power showed long-term enhancement in task-related activity, and a positive learning curve over sessions. The analysis of within-session effects showed a power decrease ("rebound" effect) in task-related activity, with no significant effects during training trials. We conclude that the enhancement of the individual upper alpha power is effective in improving several measures of clinical outcome and cognitive performance in ADHD. This is the first NF study evaluating such a protocol in ADHD. A controlled evaluation seems warranted due to the positive results obtained in the current study. PMID:25199660

  17. Biolog Phenotype Microarrays for phenotypic characterization of microbial cells.

    PubMed

    Mackie, Amanda M; Hassan, Karl A; Paulsen, Ian T; Tetu, Sasha G

    2014-01-01

    Biolog Phenotype MicroArrays for microorganisms provide a high-throughput method for the global analysis of microbial growth phenotypes. Using a colorimetric reaction that is indicative of respiration, these microplate assays measure the response of an individual strain or microbial community to a large and diverse range of nutrients and chemicals. Phenotype MicroArrays have been used to study gene function and to improve genome annotation in single microorganisms and for physiological profiling of bacterial communities. The microplate system can be used to obtain a comprehensive overview of metabolic capability, or it can be tailored, through the use of subsets of plates, to address specific research needs. PMID:24515365

  18. Electrophysiological correlates of the BOLD signal for EEG-informed fMRI

    PubMed Central

    Murta, Teresa; Leite, Marco; Carmichael, David W; Figueiredo, Patrícia; Lemieux, Louis

    2015-01-01

    Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG–fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological–haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG–fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG–fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG–fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations. PMID:25277370

  19. Plant Phenotype Characterization System

    SciTech Connect

    Daniel W McDonald; Ronald B Michaels

    2005-09-09

    This report is the final scientific report for the DOE Inventions and Innovations Project: Plant Phenotype Characterization System, DE-FG36-04GO14334. The period of performance was September 30, 2004 through July 15, 2005. The project objective is to demonstrate the viability of a new scientific instrument concept for the study of plant root systems. The root systems of plants are thought to be important in plant yield and thus important to DOE goals in renewable energy sources. The scientific study and understanding of plant root systems is hampered by the difficulty in observing root activity and the inadequacy of existing root study instrumentation options. We have demonstrated a high throughput, non-invasive, high resolution technique for visualizing plant root systems in-situ. Our approach is based upon low-energy x-ray radiography and the use of containers and substrates (artificial soil) which are virtually transparent to x-rays. The system allows us to germinate and grow plant specimens in our containers and substrates and to generate x-ray images of the developing root system over time. The same plant can be imaged at different times in its development. The system can be used for root studies in plant physiology, plant morphology, plant breeding, plant functional genomics and plant genotype screening.

  20. EEG-informed fMRI analysis during a hand grip task: estimating the relationship between EEG rhythms and the BOLD signal

    PubMed Central

    Sclocco, Roberta; Tana, Maria G.; Visani, Elisa; Gilioli, Isabella; Panzica, Ferruccio; Franceschetti, Silvana; Cerutti, Sergio; Bianchi, Anna M.

    2014-01-01

    In the last decade, an increasing interest has arisen in investigating the relationship between the electrophysiological and hemodynamic measurements of brain activity, such as EEG and (BOLD) fMRI. In particular, changes in BOLD have been shown to be associated with changes in the spectral profile of neural activity, rather than with absolute power. Concurrently, recent findings showed that different EEG rhythms are independently related to changes in the BOLD signal: therefore, it would be also important to distinguish between the contributions of the different EEG rhythms to BOLD fluctuations when modeling the relationship between the two signals. Here we propose a method to perform EEG-informed fMRI analysis where the changes in the spectral profile are modeled, and, at the same time, the distinction between rhythms is preserved. We compared our model with two other frequency-dependent regressors modeling using simultaneous EEG-fMRI data from healthy subjects performing a motor task. Our results showed that the proposed method better captures the correlations between BOLD signal and EEG rhythms modulations, identifying task-related, well localized activated volumes. Furthermore, we showed that including among the regressors also EEG rhythms not primarily involved in the task enhances the performance of the analysis, even when only correlations with BOLD signal and specific EEG rhythms are explored. PMID:24744720

  1. EEG power asymmetry and functional connectivity as a marker of treatment effectiveness in DBS surgery for depression.

    PubMed

    Quraan, Maher A; Protzner, Andrea B; Daskalakis, Zafiris J; Giacobbe, Peter; Tang, Chris W; Kennedy, Sidney H; Lozano, Andres M; McAndrews, Mary P

    2014-04-01

    Recently, deep brain stimulation (DBS) has been evaluated as an experimental therapy for treatment-resistant depression. Although there have been encouraging results in open-label trials, about half of the patients fail to achieve meaningful benefit. Although progress has been made in understanding the neurobiology of MDD, the ability to characterize differences in brain dynamics between those who do and do not benefit from DBS is lacking. In this study, we investigated EEG resting-state data recorded from 12 patients that have undergone DBS surgery. Of those, six patients were classified as responders to DBS, defined as an improvement of 50% or more on the 17-item Hamilton Rating Scale for Depression (HAMD-17). We compared hemispheric frontal theta and parietal alpha power asymmetry and synchronization asymmetry between responders and non-responders. Hemispheric power asymmetry showed statistically significant differences between responders and non-responders with healthy controls showing an asymmetry similar to responders but opposite to non-responders. This asymmetry was characterized by an increase in frontal theta in the right hemisphere relative to the left combined with an increase in parietal alpha in the left hemisphere relative to the right in non-responders compared with responders. Hemispheric mean synchronization asymmetry showed a statistically significant difference between responders and non-responders in the theta band, with healthy controls showing an asymmetry similar to responders but opposite to non-responders. This asymmetry resulted from an increase in frontal synchronization in the right hemisphere relative to the left combined with an increase in parietal synchronization in the left hemisphere relative to the right in non-responders compared with responders. Connectivity diagrams revealed long-range differences in frontal/central-parietal connectivity between the two groups in the theta band. This pattern was observed irrespective of whether EEG data were collected with active DBS or with the DBS stimulation turned off, suggesting stable functional and possibly structural modifications that may be attributed to plasticity. PMID:24285211

  2. The use of single-electrode wireless EEG in biobehavioral investigations.

    PubMed

    Poltavski, Dmitri V

    2015-01-01

    The purpose of this chapter is to introduce novice and intermediate EEG researchers to a convenient and user-friendly EEG system from NeuroSky, Inc. In our recent study we were interested in changes in the frontal cortical EEG activity of healthy adults as a function of accommodative stress during performance of a sustained attention task. We used a commercially available low-cost wireless EEG device from NeuroSky (MindSet), which has a single active Fp1 dry electrode capable of recording research-grade EEG coupled with powerful noise-filtering and data software support. The convenience and ease-of-use of MindSet is further enhanced with validated eSense meters of Attention and Meditation. In this chapter we also provide additional data analytic support for EEG power spectrum using SPSS syntax commonly used in many biobehavioral sciences. PMID:25626552

  3. Peak High-Frequency HRV and Peak Alpha Frequency Higher in PTSD

    PubMed Central

    Oken, Barry S.

    2012-01-01

    Posttraumatic stress disorder (PTSD) is difficult to treat and current PTSD treatments are not effective for all people. Despite limited evidence for its efficacy, some clinicians have implemented biofeedback for PTSD treatment. As a first step in constructing an effective biofeedback treatment program, we assessed respiration, electroencephalography (EEG) and heart rate variability (HRV) as potential biofeedback parameters for a future clinical trial. This cross-sectional study included 86 veterans; 59 with and 27 without PTSD. Data were collected on EEG measures, HRV, and respiration rate during an attentive resting state. Measures were analyzed to assess sensitivity to PTSD status and the relationship to PTSD symptoms. Peak alpha frequency was higher in the PTSD group (F(1,84) = 6.14, p = 0.01). Peak high-frequency HRV was lower in the PTSD group (F(2,78) = 26.5, p<0.00005) when adjusting for respiration rate. All other EEG and HRV measures and respiration were not different between groups. Peak high-frequency HRV and peak alpha frequency are sensitive to PTSD status and may be potential biofeedback parameters for future PTSD clinical trials. PMID:23178990

  4. Finding Our Way through Phenotypes

    PubMed Central

    Deans, Andrew R.; Lewis, Suzanna E.; Huala, Eva; Anzaldo, Salvatore S.; Ashburner, Michael; Balhoff, James P.; Blackburn, David C.; Blake, Judith A.; Burleigh, J. Gordon; Chanet, Bruno; Cooper, Laurel D.; Courtot, Mélanie; Csösz, Sándor; Cui, Hong; Dahdul, Wasila; Das, Sandip; Dececchi, T. Alexander; Dettai, Agnes; Diogo, Rui; Druzinsky, Robert E.; Dumontier, Michel; Franz, Nico M.; Friedrich, Frank; Gkoutos, George V.; Haendel, Melissa; Harmon, Luke J.; Hayamizu, Terry F.; He, Yongqun; Hines, Heather M.; Ibrahim, Nizar; Jackson, Laura M.; Jaiswal, Pankaj; James-Zorn, Christina; Köhler, Sebastian; Lecointre, Guillaume; Lapp, Hilmar; Lawrence, Carolyn J.; Le Novère, Nicolas; Lundberg, John G.; Macklin, James; Mast, Austin R.; Midford, Peter E.; Mikó, István; Mungall, Christopher J.; Oellrich, Anika; Osumi-Sutherland, David; Parkinson, Helen; Ramírez, Martín J.; Richter, Stefan; Robinson, Peter N.; Ruttenberg, Alan; Schulz, Katja S.; Segerdell, Erik; Seltmann, Katja C.; Sharkey, Michael J.; Smith, Aaron D.; Smith, Barry; Specht, Chelsea D.; Squires, R. Burke; Thacker, Robert W.; Thessen, Anne; Fernandez-Triana, Jose; Vihinen, Mauno; Vize, Peter D.; Vogt, Lars; Wall, Christine E.; Walls, Ramona L.; Westerfeld, Monte; Wharton, Robert A.; Wirkner, Christian S.; Woolley, James B.; Yoder, Matthew J.; Zorn, Aaron M.; Mabee, Paula

    2015-01-01

    Despite a large and multifaceted effort to understand the vast landscape of phenotypic data, their current form inhibits productive data analysis. The lack of a community-wide, consensus-based, human- and machine-interpretable language for describing phenotypes and their genomic and environmental contexts is perhaps the most pressing scientific bottleneck to integration across many key fields in biology, including genomics, systems biology, development, medicine, evolution, ecology, and systematics. Here we survey the current phenomics landscape, including data resources and handling, and the progress that has been made to accurately capture relevant data descriptions for phenotypes. We present an example of the kind of integration across domains that computable phenotypes would enable, and we call upon the broader biology community, publishers, and relevant funding agencies to support efforts to surmount today's data barriers and facilitate analytical reproducibility. PMID:25562316

  5. Phenotypic variability in myotonia congenita.

    PubMed

    Colding-Jørgensen, Eskild

    2005-07-01

    Myotonia congenita is a hereditary chloride channel disorder characterized by delayed relaxation of skeletal muscle (myotonia). It is caused by mutations in the skeletal muscle chloride channel gene CLCN1 on chromosome 7. The phenotypic spectrum of myotonia congenita ranges from mild myotonia disclosed only by clinical examination to severe and disabling myotonia with transient weakness and myopathy. The most severe phenotypes are seen in patients with two mutated alleles. Heterozygotes are often asymptomatic but for some mutations heterozygosity is sufficient to cause pronounced myotonia, although without weakness and myopathy. Thus, the phenotype depends on the mutation type to some extent, but this does not explain the fact that severity varies greatly between heterozygous family members and may even vary with time in the individual patient. In this review, existing knowledge about phenotypic variability is summarized, and the possible contributing factors are discussed. PMID:15786415

  6. Finding our way through phenotypes.

    PubMed

    Deans, Andrew R; Lewis, Suzanna E; Huala, Eva; Anzaldo, Salvatore S; Ashburner, Michael; Balhoff, James P; Blackburn, David C; Blake, Judith A; Burleigh, J Gordon; Chanet, Bruno; Cooper, Laurel D; Courtot, Mélanie; Csösz, Sándor; Cui, Hong; Dahdul, Wasila; Das, Sandip; Dececchi, T Alexander; Dettai, Agnes; Diogo, Rui; Druzinsky, Robert E; Dumontier, Michel; Franz, Nico M; Friedrich, Frank; Gkoutos, George V; Haendel, Melissa; Harmon, Luke J; Hayamizu, Terry F; He, Yongqun; Hines, Heather M; Ibrahim, Nizar; Jackson, Laura M; Jaiswal, Pankaj; James-Zorn, Christina; Köhler, Sebastian; Lecointre, Guillaume; Lapp, Hilmar; Lawrence, Carolyn J; Le Novère, Nicolas; Lundberg, John G; Macklin, James; Mast, Austin R; Midford, Peter E; Mikó, István; Mungall, Christopher J; Oellrich, Anika; Osumi-Sutherland, David; Parkinson, Helen; Ramírez, Martín J; Richter, Stefan; Robinson, Peter N; Ruttenberg, Alan; Schulz, Katja S; Segerdell, Erik; Seltmann, Katja C; Sharkey, Michael J; Smith, Aaron D; Smith, Barry; Specht, Chelsea D; Squires, R Burke; Thacker, Robert W; Thessen, Anne; Fernandez-Triana, Jose; Vihinen, Mauno; Vize, Peter D; Vogt, Lars; Wall, Christine E; Walls, Ramona L; Westerfeld, Monte; Wharton, Robert A; Wirkner, Christian S; Woolley, James B; Yoder, Matthew J; Zorn, Aaron M; Mabee, Paula

    2015-01-01

    Despite a large and multifaceted effort to understand the vast landscape of phenotypic data, their current form inhibits productive data analysis. The lack of a community-wide, consensus-based, human- and machine-interpretable language for describing phenotypes and their genomic and environmental contexts is perhaps the most pressing scientific bottleneck to integration across many key fields in biology, including genomics, systems biology, development, medicine, evolution, ecology, and systematics. Here we survey the current phenomics landscape, including data resources and handling, and the progress that has been made to accurately capture relevant data descriptions for phenotypes. We present an example of the kind of integration across domains that computable phenotypes would enable, and we call upon the broader biology community, publishers, and relevant funding agencies to support efforts to surmount today's data barriers and facilitate analytical reproducibility. PMID:25562316

  7. Two new alpha1-globin gene point mutations: Hb Nedlands (HBA1:c.86C>T) [alpha28(B9)Ala-->Val] and Hb Queens Park (HBA1:c.98T>A) [alpha32(B13)Met-->Lys].

    PubMed

    Phylipsen, Marion; Prior, John F; Lim, Erna; Lingam, Neela; Finlayson, Jill; Arkesteijn, Sandra G J; Harteveld, Cornelis L; Giordano, Piero C

    2010-01-01

    We report two new point mutations of the alpha1-globin gene found in a Greek and a Burmese patient, both living in Western Australia. The patients were initially selected for their microcytic hypochromic parameters as belonging to a group suspected for uncommon (deletion) defects. Gap-polymerase chain reaction (gap-PCR) and multiplex ligation-dependent probe amplification (MLPA) technologies were applied, and in those cases not showing deletions, direct sequencing was performed. We have found 1) HBA1:c.86C>T, Hb Nedlands [alpha28(B9)Ala-->Val] which, based on the red cell indices and phenotype prediction scores, is presumed to be clinically silent, and 2) HBA1:c.98T>A, Hb Queens Park [alpha32(B13)Met-->Lys] which seems to be associated with a mild alpha-thalassemia (alpha-thal) phenotype. The phenotype/genotype correlation is briefly described. PMID:20353346

  8. MNE software for processing MEG and EEG data

    PubMed Central

    Gramfort, A.; Luessi, M.; Larson, E.; Engemann, D.; Strohmeier, D.; Brodbeck, C.; Parkkonen, L.; Hämäläinen, M.

    2013-01-01

    Magnetoencephalography and electroencephalography (M/EEG) measure the weak electromagnetic signals originating from neural currents in the brain. Using these signals to characterize and locate brain activity is a challenging task, as evidenced by several decades of methodological contributions. MNE, whose name stems from its capability to compute cortically-constrained minimum-norm current estimates from M/EEG data, is a software package that provides comprehensive analysis tools and workflows including preprocessing, source estimation, time–frequency analysis, statistical analysis, and several methods to estimate functional connectivity between distributed brain regions. The present paper gives detailed information about the MNE package and describes typical use cases while also warning about potential caveats in analysis. The MNE package is a collaborative effort of multiple institutes striving to implement and share best methods and to facilitate distribution of analysis pipelines to advance reproducibility of research. Full documentation is available at http://martinos.org/mne. PMID:24161808

  9. EEG and eye-tracking based measures for enhanced training.

    PubMed

    Soussou, Walid; Rooksby, Michael; Forty, Charles; Weatherhead, James; Marshall, Sandra

    2012-01-01

    This paper describes a project whose goal was to establish the feasibility of using unobtrusive cognitive assessment methodologies in order to optimize efficiency and expediency of training. QUASAR, EyeTracking, Inc. (ETI), and Safe Passage International (SPI), teamed to demonstrate correlation between EEG and eye-tracking based cognitive workload, performance assessment and subject expertise on X-Ray screening tasks. Results indicate significant correlation between cognitive workload metrics based on EEG and eye-tracking measurements recorded during a simulated baggage screening task and subject expertise and error rates in that same task. These results suggest that cognitive monitoring could be useful in improving training efficiency by enabling training paradigms that adapts to increasing expertise. PMID:23366217

  10. Field deployable EEG monitor for nerve agent casualties.

    PubMed

    McDonnall, Daniel; Hiatt, Scott; Yatsenko, Dimitri; Guillory, K Shane

    2009-01-01

    Early recognition and aggressive management of seizure activity is important in the treatment of patients with nerve agent exposure. However, these patients can experience non-convulsive seizures that are difficult to identify without EEG monitoring. In this paper, we discuss the development and testing of a low-cost, field-deployable device that records and displays patient EEG trends over time. The device is optimized for early levels of care for military and mass casualty patients until they can be relocated to medical facilities with more comprehensive monitoring. The device also records pulse oximetry and acceleration information, and patient data are available for later analysis and improvement of treatment protocols. PMID:19964118

  11. Joint optimization of algorithmic suites for EEG analysis.

    PubMed

    Santana, Eder; Brockmeier, Austin J; Principe, Jose C

    2014-01-01

    Electroencephalogram (EEG) data analysis algorithms consist of multiple processing steps each with a number of free parameters. A joint optimization methodology can be used as a wrapper to fine-tune these parameters for the patient or application. This approach is inspired by deep learning neural network models, but differs because the processing layers for EEG are heterogeneous with different approaches used for processing space and time. Nonetheless, we treat the processing stages as a neural network and apply backpropagation to jointly optimize the parameters. This approach outperforms previous results on the BCI Competition II - dataset IV; additionally, it outperforms the common spatial patterns (CSP) algorithm on the BCI Competition III dataset IV. In addition, the optimized parameters in the architecture are still interpretable. PMID:25570621

  12. Boxers--computed tomography, EEG, and neurological evaluation

    SciTech Connect

    Ross, R.J.; Cole, M.; Thompson, J.S.; Kim, K.H.

    1983-01-14

    During the last three years, 40 ex-boxers were examined to determine the effects of boxing in regard to their neurological status and the computed tomographic (CT) appearance of the brain. Thirty-eight of these patients had a CT scan of the brain, and 24 had a complete neurological examination including an EEG. The results demonstrate a significant relationship between the number of bouts fought and CT changes indicating cerebral atrophy. Positive neurological findings were not significantly correlated with the number of bouts. Electroencephalographic abnormalities were significantly correlated with the number of bouts fought. Computed tomography and EEG of the brain should be considered as part of a regular neurological examination for active boxers and, if possible, before and after each match, to detect not only the effects of acute life-threatening brain trauma such as subdural hematomas and brain hemorrhages, but the more subtle and debilitating long-term changes of cerebral atrophy.

  13. Real-Time EEG-Based Happiness Detection System

    PubMed Central

    2013-01-01

    We propose to use real-time EEG signal to classify happy and unhappy emotions elicited by pictures and classical music. We use PSD as a feature and SVM as a classifier. The average accuracies of subject-dependent model and subject-independent model are approximately 75.62% and 65.12%, respectively. Considering each pair of channels, temporal pair of channels (T7 and T8) gives a better result than the other area. Considering different frequency bands, high-frequency bands (Beta and Gamma) give a better result than low-frequency bands. Considering different time durations for emotion elicitation, that result from 30 seconds does not have significant difference compared with the result from 60 seconds. From all of these results, we implement real-time EEG-based happiness detection system using only one pair of channels. Furthermore, we develop games based on the happiness detection system to help user recognize and control the happiness. PMID:24023532

  14. Identical mutations and phenotypic variation

    Microsoft Academic Search

    Ulrich Wolf

    1997-01-01

    The relationship between pathogenetic mutations and disease phenotype is becoming increasingly complex. Well-delineated clinical\\u000a entities can be genetically heterogeneous, and mutations in a particular gene may result in fundamental clinical differences.\\u000a Genetic heterogeneity includes mutations at different gene loci or allelic mutations within a single gene, resulting in a\\u000a similar phenotype. However, one and the same mutation is expected to

  15. Design of a Wireless EEG System for Point-of-Care Applications

    PubMed Central

    Jia, Wenyan; Bai, Yicheng; Sun, Mingui; Sclabassi, Robert J.

    2014-01-01

    This study aims to develop a wireless EEG system to provide critical point-of-care information about brain electrical activity. A novel dry electrode, which can be installed rapidly, is used to acquire EEG from the scalp. A wireless data link between the electrode and a data port (i.e., a smartphone) is established based on the Bluetooth technology. A prototype of this system has been implemented and its performance in acquiring EEG has been evaluated. PMID:25419099

  16. Recording EEG in immature rats with a novel miniature telemetry system

    PubMed Central

    Zayachkivsky, A.; Lehmkuhle, M. J.; Fisher, J. H.; Ekstrand, J. J.

    2013-01-01

    Serial EEG recordings from immature rat pups are extremely difficult to obtain but important for analyzing animal models of neonatal seizures and other pediatric neurological conditions as well as normal physiology. In this report, we describe the features and applications of a novel miniature telemetry system designed to record EEG in rat pups as young as postnatal day 6 (P6). First, we have recorded electrographic seizure activity in two animal models of neonatal seizures, hypoxia- and kainate-induced seizures at P7. Second, we describe a viable approach for long-term continuous EEG monitoring of naturally reared rat pups implanted with EEG at P6. Third, we have used serial EEG recordings to record age-dependent changes in the background EEG signal as the animals matured from P7 to P11. The important advantages of using miniature wireless EEG technology are: 1) minimally invasive surgical implantation; 2) a device form-factor that is compatible with housing of rat pups with the dam and littermates; 3) serial recordings of EEG activity; and 4) low power consumption of the unit, theoretically allowing continuous monitoring for up to 2 yr without surgical reimplantation. The miniature EEG telemetry system provides a technical advance that allows researchers to record continuous and serial EEG recordings in neonatal rodent models of human neurological disorders, study the progression of the disease, and then assess possible therapies using quantitative EEG as an outcome measure. This new technical approach should improve animal models of human conditions that rely on EEG monitoring for diagnosis and therapy. PMID:23114207

  17. Automatic Removal of Eye-Movement and Blink Artifacts from EEG Signals

    Microsoft Academic Search

    Jun Feng Gao; Yong Yang; Pan Lin; Pei Wang; Chong Xun Zheng

    2010-01-01

    Frequent occurrence of electrooculography (EOG) artifacts leads to serious problems in interpreting and analyzing the electroencephalogram\\u000a (EEG). In this paper, a robust method is presented to automatically eliminate eye-movement and eye-blink artifacts from EEG\\u000a signals. Independent Component Analysis (ICA) is used to decompose EEG signals into independent components. Moreover, the\\u000a features of topographies and power spectral densities of those components

  18. Maturational trends of EEG-sleep measures in the healthy preterm neonate

    Microsoft Academic Search

    Mark S. Scher; Doris A. Steppe; David L. Banks; Robert D. Guthrie; Robert J. Sclabassi

    1995-01-01

    Five physiologic groupings of 45 EEG-sleep measures were acquired from serial 24-channel EEG-sleep recordings (i.e., sleep architecture, continuity, EEG spectral, phasic, and autonomic measures), utilizing 129 studies on 56 healthy preterm infants from 28 to 43 weeks postconceptional age (PCA) who were neurodevelopmentally normal on follow-up. Regression analyses chose the least number of measures that best reflected maturation. Four of

  19. Study of EEGs following 24Hour Sleep Deprivation in Patients with Posttraumatic Epilepsy

    Microsoft Academic Search

    T. N. Thomaides; E. P. Kerezoudi; Ray Chaudhuri; C. Cheropoulos

    1992-01-01

    Routine and awake EEGs following 24-hour sleep deprivation were studied in 119 patients with closed head injury, 64 epileptics without any history of head injury and 53 healthy controls. The results were compared to CT brain scan findings. There were no epileptic discharges in routine EEGs, while EEGs after 24-hour sleep deprivation showed considerable activation, ranging from 28 to 37.5%

  20. Functional brain maturation in neonates as measured by EEG-sleep analyses

    Microsoft Academic Search

    Mark S. Scher; Bobby L. Jones; Doris A. Steppe; Daniel L. Cork; Howard J. Seltman; David L. Banks

    2003-01-01

    Objective: Seven measures of neonatal EEG-sleep behavior were evaluated using multivariate analyses to ascertain if physiologic differences exist between healthy full- and preterm cohorts.Methods: A total of 381 24-channel EEG-sleep studies were analyzed, including 125 recordings on 50 healthy fullterm and 256 recordings on 59 asymptomatic preterm infants between 28 and 70.6 weeks post-conceptional age. One EEG study for each

  1. Investigation of non-linear properties of multichannel EEG in the early stages of Parkinson's disease

    Microsoft Academic Search

    Laurent Pezard; Robert Jech; Evžen R?ži?ka

    2001-01-01

    Objectives: Modifications of brain activity in the early stages of Parkinson's disease (PD) are difficult to detect using electroencephalography (EEG) signals and are often biased by l-DOPA treatment. We compare here the performances of both linear and non-linear methods in differentiating EEG of l-DOPA naive PD patients from that of control subjects.Methods: Resting multichannel EEG (20 electrodes, 30 s epochs)

  2. Treatment of Lithium-Pilocarpine Induced Status Epilepticus Rat Models According to EEG Stage

    Microsoft Academic Search

    Mi-Young Jeon

    Background: EEG shows a sequence of progressive changes in status epilepticus (SE). Timely antiepileptic drug treatment is an important factor for the prognosis of SE. Here we investigated the effect of treatment according to EEG staging in a lithium-pilocarpine SE rat model. Methods: By analyzing the on-going EEG of SE, we injected propofol (PF) or propofol and valproate (PF+VA) on

  3. Functional mapping of human sensorimotor cortex with electrocorticographic spectral analysis. I. Alpha and beta event- related desynchronization

    Microsoft Academic Search

    Nathan E. Crone; Diana L. Miglioretti; Barry Gordon; Jeffrey M. Sieracki; Michael T. Wilson; Sumio Uematsu; Ronald P. Lesser

    1998-01-01

    Summary Human scalp EEG studies have shown that event-related desynchronization (ERD) in the alpha (8-13 Hz) and beta (15-25 Hz) bands may be used to detect functional activation of sensorimotor cortex. However, in most previous studies somatotopy has not been examined in detail and brief, self-paced movements, focusing on the planning of motor output, have been used. We recorded electrocorticographic

  4. Smoking cessation a byproduct of EEG telemetry monitoring.

    PubMed

    Ahmed, Syed Nizamuddin; Quigley, Daphne; Siddiqi, Zaeem A

    2005-04-01

    Smoking is a common problem in epilepsy patients. The inpatient video-EEG monitoring (VEEG) unit provides a unique and conducive environment for epilepsy patients to participate actively in a smoking-cessation program. The restrictions and confinement to the telemetry bed impose a forced abstinence from smoking. It has been suggested that patients who are hospitalized may be more receptive to smoking-cessation advice. We report two patients who were successfully able to quit smoking after admission for VEEG. PMID:15816961

  5. Sleep and EEG features in genetic models of Down syndrome

    Microsoft Academic Search

    Damien Colas; Janice S. Valletta; Ryoko Takimoto-Kimura; Seiji Nishino; Nobuhiro Fujiki; William C. Mobley; Emmanuel Mignot

    2008-01-01

    Down syndrome is characterized by a host of behavioral abnormalities including sleep disturbances. Sleep and EEG was studied at the age of 3 months in two mouse models of the condition, Ts65Dn and Ts1Cje, carrying one extra copy of partially overlapping segments of the mmu chromosome 16 (equivalent to the human chromosome 21). We found that the Ts65Dn mice showed increased

  6. Bicoherence of intracranial EEG in sleep, wakefulness and seizures

    Microsoft Academic Search

    T. H. Bullock; J. Z. Achimowicz; R. B. Duckrow; S. S. Spencer; V. J. Iragui-Madoz

    1997-01-01

    The hypothesis that the intracranial EEG has local structure and short-term non-stationarity is tested with a little-studied measure of nonlinear phase coupling, the bicoherence in human subdural and deep temporal lobe probe data from 11 subjects during sleeping, waking and seizure states. This measure of cooperativity estimates the proportion of energy in every possible pair of frequency components, F1, F2

  7. Wireless communication interface for EEG/PSG Holter monitor.

    PubMed

    Velarde Reyes, Ernesto; Marante Rizo, Francisco; Santos, Belkis Morgalo; Jorge, Jorge Garrote; Martin Gonzalez, Francisco

    2010-04-01

    Communication interfaces for medical devices are normally wired. For long-term monitoring applications, wired devices limit patient mobility. In this paper a wireless communication interface for an EEG/PSG Holter monitor is presented. Selection of broadcasting band, communication standard, available hardware, and connection algorithm to use are discussed before making a choice. Results of experimental tests carried out on the prototype demonstrate the functionality of the implemented interface. PMID:20121457

  8. A multichannel EEG telemetry system utilizing a PCM subcarrier

    NASA Technical Reports Server (NTRS)

    Fryer, T. B.

    1974-01-01

    A multichannel personal-type telemetry system is described that utilizes PCM encoding for the most effective range with minimum RF bandwidth and noise interference. Recent IC developments (COS MOS) make it possible to implement a sophisticated encoding system (PCM) within the low power and size constraints necessary for a personal biotelemetry system. This system includes low-level high-impedance preamplifiers to make the system suitable for EEG recording.

  9. Noninvasive Neural Prostheses Using Mobile and Wireless EEG

    E-print Network

    Makeig, Scott

    -Tung University, Hsinchu, Taiwan, R.O.C. (e-mail: ctlin@mail.nctu.edu.tw; lwko@mail.nctu.edu.tw; chiouINVITED P A P E R Noninvasive Neural Prostheses Using Mobile and Wireless EEG A system using micro an automobile driving simulator. By Chin-Teng Lin, Fellow IEEE, Li-Wei Ko, Jin-Chern Chiou, Member IEEE, Jeng

  10. EEG/MEG Source Imaging: Methods, Challenges, and Open Issues

    PubMed Central

    Wendel, Katrina; Väisänen, Outi; Malmivuo, Jaakko; Gencer, Nevzat G.; Vanrumste, Bart; Durka, Piotr; Magjarevi?, Ratko; Supek, Selma; Pascu, Mihail Lucian; Fontenelle, Hugues; Grave de Peralta Menendez, Rolando

    2009-01-01

    We present the four key areas of research—preprocessing, the volume conductor, the forward problem, and the inverse problem—that affect the performance of EEG and MEG source imaging. In each key area we identify prominent approaches and methodologies that have open issues warranting further investigation within the community, challenges associated with certain techniques, and algorithms necessitating clarification of their implications. More than providing definitive answers we aim to identify important open issues in the quest of source localization. PMID:19639045

  11. The Research of Rehabilitation Robots BCI Technology Based on EEG

    Microsoft Academic Search

    Yuran Zhu; Ran Zhen; Hongwei Liu; Shang Meng

    2008-01-01

    Brain-computer interface (BCI) is a new type of man-machine interfaces and one of the key technologies of rehabilitation robot. In this paper, the BCI system structure, working principle and the key technology are discussed. The dummy matrix based on event-related potential P300 is designed, used the stimulation by the character matrix sequence, subjects produced the evoked electroencephalograph (EEG). The evoked

  12. EEG, CT and neurosonographic findings in patients with postischemic seizures

    Microsoft Academic Search

    Susanna Horner; Xiu-Shi Ni; Margret Duft; Kurt Niederkorn; Helmut Lechner

    1995-01-01

    Seventy-two patients with postischemic seizures were evaluated with electroencephalography (EEG), computerized tomography (CT) and neurosonography. There were 24% early-onset and 76% late-onset initial seizures. Early-onset seizure was more likely to be simple partial (53%), whereas late-onset seizure was more likely to be primarily generalized (56%). 76% early-onset and 80% late-onset seizures were single. Status epilepticus was more frequent in early-onset

  13. Dynamic peripheral visual performance relates to alpha activity in soccer players

    PubMed Central

    Nan, Wenya; Migotina, Daria; Wan, Feng; Lou, Chin Ian; Rodrigues, João; Semedo, João; Vai, Mang I; Pereira, Jose Gomes; Melicio, Fernando; Da Rosa, Agostinho C.

    2014-01-01

    Many studies have demonstrated the relationship between the alpha activity and the central visual ability, in which the visual ability is usually assessed through static stimuli. Besides static circumstance, however in the real environment there are often dynamic changes and the peripheral visual ability in a dynamic environment (i.e., dynamic peripheral visual ability) is important for all people. So far, no work has reported whether there is a relationship between the dynamic peripheral visual ability and the alpha activity. Thus, the objective of this study was to investigate their relationship. Sixty-two soccer players performed a newly designed peripheral vision task in which the visual stimuli were dynamic, while their EEG signals were recorded from Cz, O1, and O2 locations. The relationship between the dynamic peripheral visual performance and the alpha activity was examined by the percentage-bend correlation test. The results indicated no significant correlation between the dynamic peripheral visual performance and the alpha amplitudes in the eyes-open and eyes-closed resting condition. However, it was not the case for the alpha activity during the peripheral vision task: the dynamic peripheral visual performance showed significant positive inter-individual correlations with the amplitudes in the alpha band (8–12 Hz) and the individual alpha band (IAB) during the peripheral vision task. A potential application of this finding is to improve the dynamic peripheral visual performance by up-regulating alpha activity using neuromodulation techniques. PMID:25426058

  14. Estimating workload using EEG spectral power and ERPs in the n-back task

    NASA Astrophysics Data System (ADS)

    Brouwer, Anne-Marie; Hogervorst, Maarten A.; van Erp, Jan B. F.; Heffelaar, Tobias; Zimmerman, Patrick H.; Oostenveld, Robert

    2012-08-01

    Previous studies indicate that both electroencephalogram (EEG) spectral power (in particular the alpha and theta band) and event-related potentials (ERPs) (in particular the P300) can be used as a measure of mental work or memory load. We compare their ability to estimate workload level in a well-controlled task. In addition, we combine both types of measures in a single classification model to examine whether this results in higher classification accuracy than either one alone. Participants watched a sequence of visually presented letters and indicated whether or not the current letter was the same as the one (n instances) before. Workload was varied by varying n. We developed different classification models using ERP features, frequency power features or a combination (fusion). Training and testing of the models simulated an online workload estimation situation. All our ERP, power and fusion models provide classification accuracies between 80% and 90% when distinguishing between the highest and the lowest workload condition after 2 min. For 32 out of 35 participants, classification was significantly higher than chance level after 2.5 s (or one letter) as estimated by the fusion model. Differences between the models are rather small, though the fusion model performs better than the other models when only short data segments are available for estimating workload.

  15. Contrasting losses and gains increases the predictability of behavior by frontal EEG asymmetry

    PubMed Central

    Telpaz, Ariel; Yechiam, Eldad

    2014-01-01

    Frontal asymmetry measured at rest using EEG is considered a stable marker of approach-avoidance behaviors and risk taking. We examined whether without salient cues of attention in the form of losses, predictability is reduced. Fifty-seven participants performed an experiential decision task in a gain-only, loss-only, and mixed (gains and losses) condition. Increased risk taking on the part of individuals with relatively high left frontal activation, as denoted by the Alpha band, was only observed in the task involving both gains and losses. Event-related potential analysis sheds light on the processes leading to this pattern. Left-frontal dominant individuals had increased fronto-central P300 activation following risky compared to safe outcomes, while right-frontal dominant individuals did not show a P300 difference following safe and risky outcomes. This interaction also only emerged when losses were contrasted with gains. The findings highlight the sensitivity of behavioral predictability to cues of valence. PMID:24817845

  16. Wavelet analysis of the EEG during the neurocognitive evaluation of invalidly cued targets.

    PubMed

    Digiacomo, Marcia R; Marco-Pallarés, Josep; Flores, Angélica B; Gómez, Carlos M

    2008-10-01

    In a spatial central cueing paradigm, positions in the horizontal meridian were cued to evaluate the neurocognitive processing of validly (V) and invalidly cued (I) targets. ERPs were obtained from 20 EEG channel recordings. Complex Morlet wavelets were applied for computing event-related spectral power (ERSP) modulations and inter-trial phase coherence (ITC). P3a and P3b responses were increased in a statistically significant manner in I targets with regard to V targets. This increase seems to be generated only by phase resetting without enhancement of spectral power. Comparing ERSP modulations between I and V target trials we found a major effect centred in the alpha range. The following results were obtained for invalid condition in relation to valid condition: 6-12Hz ERSP decrease topographically widespread over the scalp, starting around 450 ms and peaking around 650 ms; 10-14Hz ERSP increase peaking around 200 ms at fronto-central electrodes; and 10-14Hz ERSP decrease occurring from 400 to 600 ms at posterior electrodes. Therefore, the invalidity effect indeed produces salient changes in the stimulus related and ongoing neuronal activity leading to a brain state of comparative higher activity both excitatory and inhibitory with respect to the validly cued target processing. PMID:18708032

  17. Subliminal salience search illustrated: EEG identity and deception detection on the fringe of awareness.

    PubMed

    Bowman, Howard; Filetti, Marco; Janssen, Dirk; Su, Li; Alsufyani, Abdulmajeed; Wyble, Brad

    2013-01-01

    We propose a novel deception detection system based on Rapid Serial Visual Presentation (RSVP). One motivation for the new method is to present stimuli on the fringe of awareness, such that it is more difficult for deceivers to confound the deception test using countermeasures. The proposed system is able to detect identity deception (by using the first names of participants) with a 100% hit rate (at an alpha level of 0.05). To achieve this, we extended the classic Event-Related Potential (ERP) techniques (such as peak-to-peak) by applying Randomisation, a form of Monte Carlo resampling, which we used to detect deception at an individual level. In order to make the deployment of the system simple and rapid, we utilised data from three electrodes only: Fz, Cz and Pz. We then combined data from the three electrodes using Fisher's method so that each participant was assigned a single p-value, which represents the combined probability that a specific participant was being deceptive. We also present subliminal salience search as a general method to determine what participants find salient by detecting breakthrough into conscious awareness using EEG. PMID:23372697

  18. Intensive training induces longitudinal changes in meditation state-related EEG oscillatory activity

    PubMed Central

    Saggar, Manish; King, Brandon G.; Zanesco, Anthony P.; MacLean, Katherine A.; Aichele, Stephen R.; Jacobs, Tonya L.; Bridwell, David A.; Shaver, Phillip R.; Rosenberg, Erika L.; Sahdra, Baljinder K.; Ferrer, Emilio; Tang, Akaysha C.; Mangun, George R.; Wallace, B. Alan; Miikkulainen, Risto; Saron, Clifford D.

    2012-01-01

    The capacity to focus one's attention for an extended period of time can be increased through training in contemplative practices. However, the cognitive processes engaged during meditation that support trait changes in cognition are not well characterized. We conducted a longitudinal wait-list controlled study of intensive meditation training. Retreat participants practiced focused attention (FA) meditation techniques for three months during an initial retreat. Wait-list participants later undertook formally identical training during a second retreat. Dense-array scalp-recorded electroencephalogram (EEG) data were collected during 6 min of mindfulness of breathing meditation at three assessment points during each retreat. Second-order blind source separation, along with a novel semi-automatic artifact removal tool (SMART), was used for data preprocessing. We observed replicable reductions in meditative state-related beta-band power bilaterally over anteriocentral and posterior scalp regions. In addition, individual alpha frequency (IAF) decreased across both retreats and in direct relation to the amount of meditative practice. These findings provide evidence for replicable longitudinal changes in brain oscillatory activity during meditation and increase our understanding of the cortical processes engaged during meditation that may support long-term improvements in cognition. PMID:22973218

  19. Modeling epileptic brain states using EEG spectral analysis and topographic mapping.

    PubMed

    Direito, Bruno; Teixeira, César; Ribeiro, Bernardete; Castelo-Branco, Miguel; Sales, Francisco; Dourado, António

    2012-09-30

    Changes in the spatio-temporal behavior of the brain electrical activity are believed to be associated to epileptic brain states. We propose a novel methodology to identify the different states of the epileptic brain, based on the topographic mapping of the time varying relative power of delta, theta, alpha, beta and gamma frequency sub-bands, estimated from EEG. Using normalized-cuts segmentation algorithm, points of interest are identified in the topographic mappings and their trajectories over time are used for finding out relations with epileptogenic propagations in the brain. These trajectories are used to train a Hidden Markov Model (HMM), which models the different epileptic brain states and the transition among them. Applied to 10 patients suffering from focal seizures, with a total of 30 seizures over 497.3h of data, the methodology shows good results (an average point-by-point accuracy of 89.31%) for the identification of the four brain states--interictal, preictal, ictal and postictal. The results suggest that the spatio-temporal dynamics captured by the proposed methodology are related to the epileptic brain states and transitions involved in focal seizures. PMID:22850556

  20. EEG and MEG Data Analysis in SPM8

    PubMed Central

    Litvak, Vladimir; Mattout, Jérémie; Kiebel, Stefan; Phillips, Christophe; Henson, Richard; Kilner, James; Barnes, Gareth; Oostenveld, Robert; Daunizeau, Jean; Flandin, Guillaume; Penny, Will; Friston, Karl

    2011-01-01

    SPM is a free and open source software written in MATLAB (The MathWorks, Inc.). In addition to standard M/EEG preprocessing, we presently offer three main analysis tools: (i) statistical analysis of scalp-maps, time-frequency images, and volumetric 3D source reconstruction images based on the general linear model, with correction for multiple comparisons using random field theory; (ii) Bayesian M/EEG source reconstruction, including support for group studies, simultaneous EEG and MEG, and fMRI priors; (iii) dynamic causal modelling (DCM), an approach combining neural modelling with data analysis for which there are several variants dealing with evoked responses, steady state responses (power spectra and cross-spectra), induced responses, and phase coupling. SPM8 is integrated with the FieldTrip toolbox , making it possible for users to combine a variety of standard analysis methods with new schemes implemented in SPM and build custom analysis tools using powerful graphical user interface (GUI) and batching tools. PMID:21437221