Intrahemispheric Coherence Research Articles

Electrocortical Profiles in Relation to Childhood Adversity and Depression Severity: A Preliminary Report.

Objective: Assessment of electroencephalographic (EEG) activity in depression has provided insights into neural profiles of the illness. However, there is limited understanding on how symptom severity and risk factors, such as childhood adversity, influence EEG features. Methods: Eyes-closed EEG was acquired in N = 28 depressed individuals being treated in a tertiary psychiatric setting. Absolute alpha, beta, theta, and delta power and inter-/intra-hemispheric coherence were examined. Relations between the Montgomery-Åsberg Depression Scale (MADRS) and Adverse Childhood Experience (ACE) Questionnaire and EEG features were assessed. Results: Individuals in the high (MADRS≥30) versus lower (MADRS ≤ 29) symptom severity group exhibited greater overall beta power, and lower Fp1-Fp2 delta and theta coherence. Those with high (≥3) versus lower (≤2) ACE scores exhibited greater T7-T8 beta coherence. Lowest F3-F4 beta coherence was observed in those with high ACE/high depression severity. A negative correlation existed between F8-P8 alpha coherence and symptom severity. Conclusions: Those with higher depression severity exhibit increased beta power, possibly reflecting a hyper-vigilant state. Depression severity and ACE history may produce subtle alterations in frontal delta/theta and temporal/frontal beta coherence regions. Significance: This is the first study to examine the neural impact of depression severity and ACE-assessed childhood trauma in depressed individuals receiving treatment in a tertiary setting, accounting for the clinical reality of the prevalence of their co-occurrence.

Investigating the effects of chiropractic care on resting-state EEG of MCI patients.

Mild cognitive impairment (MCI) is a stage between health and dementia, with various symptoms including memory, language, and visuospatial impairment. Chiropractic, a manual therapy that seeks to improve the function of the body and spine, has been shown to affect sensorimotor processing, multimodal sensory processing, and mental processing tasks. In this paper, the effect of chiropractic intervention on Electroencephalogram (EEG) signals in patients with mild cognitive impairment was investigated. EEG signals from two groups of patients with mild cognitive impairment (n = 13 people in each group) were recorded pre- and post-control and chiropractic intervention. A comparison of relative power was done with the support vector machine (SVM) method and non-parametric cluster-based permutation test showing the two groups could be separately identified with high accuracy. The highest accuracy was obtained in beta2 (25-35 Hz) and theta (4-8 Hz) bands. A comparison of different brain areas with the SVM method showed that the intervention had a greater effect on frontal areas. Also, interhemispheric coherence in all regions increased significantly after the intervention. The results of the Wilcoxon test showed that intrahemispheric coherence changes in frontal-occipital, frontal-temporal and right temporal-occipital regions were significantly different in two groups. Comparison of the results obtained from chiropractic intervention and previous studies shows that chiropractic intervention can have a positive effect on MCI disease and using this method may slow down the progression of mild cognitive impairment to Alzheimer's disease.

QEEG findings in nonsyndromic sagittal craniosynostosis

Despite the undertaken treatment, children with nonsyndromic sagittal craniosynostosis (NSC) are burdened with problems with speech development, visuospatial and other cognitive deficits. The electroencephalographic assessment has not influenced the diagnostics and treatment strategy of craniosynostosis so far but the introduction of quantitative EEG (QEEG) protocols renewed an interest in the functional aspect of this disease. In this study we retrospectively assessed the QEEG records of 25 children with NSC aged 1–18 months (mean age 9.62 months) before and after surgery. In each case, the amplitude, interhemispheric (ICoh) and intrahemispheric (HCoh) coherence indices were calculated. Obtained data were compared to age-matched control group of 25 normocephalic children. Children with NSC presented significantly lower values of amplitudes and intrahemispheric coherence in occipital, posterior parietal and posterior temporal regions than normocephalic children. The values of amplitudes, ICoh and HCoh in pre- and postoperative QEEG records mostly remained unchanged, with a slight improvement in HCoh in centro-parietal area. These findings suggest that NSC children present their own QEEG profile. The operative treatment improves an intrahemispheric connectivity, but there still exists a significant difference in the occipitotemporal, frontotemporal and centro-frontal areas, which may be considered as a functional substrate of reported speech and neurocognitive problems. QEEG findings in nonsyndromic sagittal craniosynostosis.

Comparing executive functions in children with attention deficit hyperactivity disorder with or without reading disability: A resting‐state EEG study

As numerous studies have shown, executive dysfunction is the main impairment in attention-deficit/hyperactivity disorder. According to recent neuroimaging studies, the frontoparietal coherence plays a key role in overall cognitive functions. Therefore, the aim of this study was to compare executive functions during resting-state EEG by monitoring brain connectivity (coherence) patterns in children with attention deficit hyperactivity disorder (ADHD) with or without reading disability (RD). The statistical sample of the study consisted of 32 children with ADHD aged between 8 and 12 years old with or without specific RD. Each group consisted of 11 boys and 5 girls that were matched on chronological age and gender. EEG was recorded during eyes-opened condition and brain connectivity within and between frontal and parietal regions was analyzed within theta, alpha, and beta bands. The results revealed that across the frontal regions, the comorbid group showed a significant reduction in the left intrahemispheric coherence in the alpha and beta bands. The ADHD-alone group exhibited increased theta and decreased alpha and beta coherence in frontal regions. In the frontoparietal regions, children in the comorbid group showed lower coherence between frontal and parietal networks compared to children without comorbid RD. The findings indicate that brain connectivity (coherence) patterns of children with ADHD with comorbid RD were more abnormal and lend support to more disrupted cortical connectivity in the comorbid group. Thus, these findings can be a useful marker for better recognizing ADHD and comorbid disabilities.

Neurofeedback Effects on EEG Connectivity among Children with Reading Disorders: I. Coherence

Electroencephalograms (EEGs) of children with reading disorders (RDs) are characterized by a higher theta and a lower alpha than those of typically developing children. Neurofeedback (NFB) may be helpful for treating learning disorders by reinforcing a reduction in the theta/alpha ratio. Several studies have suggested that NFB may lead to EEG power normalization and cognitive improvements. To further explore brain changes in isolated areas, the aim of this study was to explore the effects of an NFB protocol on functional connectivity (coherence) among children with RDs. Twenty children with an RD and an abnormally high theta/alpha ratio underwent 30 NFB sessions, and five children with the same characteristics received a sham NFB treatment. On average, the children in the NFB group showed an increase in reading accuracy and comprehension scores; their coherence diminished in the delta, theta, and beta bands and increased in the alpha band, primarily the theta intrahemispheric coherences of the left hemisphere, which is closely associated with reading. In contrast, children who received the sham NFB treatment did not show reading changes and had few changes in their coherence patterns. These preliminary results suggest that NFB can positively impact reading-related functions in the brain networks of children with RDs.

Coherence of the electroencephalogram and peripheral markers of nerve tissue damage in depressive disorders

To evaluate the coherence parameters of the electroencephalogram and the level of peripheral markers of nerve tissue damage in patients with depressive disorders. Thirty patients with a diagnosis from a cluster of mood disorders: affective disorder within a single depressive episode and recurrent depressive disorder were examined. A control group consisted of 30 healthy individuals, comparable in sex and age to the main group. The bioelectric activity of the brain was recorded and analyzed with the calculation of the averaged coefficients of intra- and interhemispheric coherence. The concentration of calcium-binding protein S100b, the main protein of myelin MBP and glial fibrillar acid protein GFAP was determined in blood sera by solid-phase enzyme immunoassay. Patients with depressive disorders showed signi cantly lower coefficients of interhemispheric coherence of alpha (p=0.003), beta (p=0.042) and theta rhythms (p=0.041), as well as intrahemispheric coherence of alpha rhythm in the left (p=0.016) and right hemispheres (p=0.026), beta rhythm in the right hemisphere (p=0.034) compared to the control group. Patients with depressive disorders showed a higher concentration of MBP compared to the control group (p=0.008). Additionally, we identified statistically significant correlations between EEG coherence coefficients and serum markers in patients with depressive disorders. The results clearly confirm the presence of inflammatory changes in the brain in patients with depression, which is reflected in structural and functional changes.

Differential resting-state neurophysiological activity associated with game usage patterns and genres in Internet gaming disorder.

We investigated differences in quantitative electroencephalogram (EEG) patterns associated with game usage patterns and genre among patients with Internet gaming disorder (IGD). Data from 140 participants (76 IGD patients and 64 healthy controls) were analysed. The IGD group was divided into subgroups based on game usage patterns (single game [SG] or multiple games [MGs]) and genre (multiplayer online battle arena, first-person shooter [FPS], or massively multiplayer online role-playing game [MMORPG; hereafter, MMG]). A resting-state, eye-closed quantitative EEG was recorded, and the absolute power and coherence of brain waves were analysed. IGD patients who played SGs showed increased beta activity compared with those who played MGs and controls. Increased absolute beta power was significantly associated with higher tendencies towards behavioural inhibition compared with controls. FPS gamers showed increased delta power in the frontal region compared with controls, which was related to the severity of IGD. Furthermore, decreased intrahemispheric coherence in the left frontoparietal region was observed in the MMG and FPS groups compared with controls. This decreased coherence was observed in the theta (MMG and FPS), delta (MMG), and beta (FPS) bands. These features were related to impairment in visuospatial working memory. Unique neurophysiological features related to preoccupation with an SG may be associated with the inhibition of behavioural changes. The present study suggests that the underlying neurophysiological networks in IGD differ according to game usage patterns and genre.

Open monitoring meditation alters the EEG gamma coherence in experts meditators: The expert practice exhibit greater right intra-hemispheric functional coupling

AimThis study investigated the differences in frontoparietal EEG gamma coherence between expert meditators (EM) and naïve meditators (NM). Material and methodsThis is a cross-sectional study with a sample of twenty-one healthy adults divided under two groups (experts meditators vs. naive-meditators), with analyzing the intra-hemispheric coherence of frontoparietal gamma oscillations by electroencephalography during the study steps: EEG resting-state 1, during the open presence meditation practice, and EEG resting-state 2. ResultsThe findings demonstrated greater frontoparietal EEG coherence in gamma for experts meditators in the Fp1-P3, F4-P4, F8-P4 electrode pairs during rest 1 and rest 2 (p ≤ 0.0083). In addition, we evidenced differences in the frontoparietal EEG coherence for expert meditators in F4-P4, F8-P4 during the meditation (p ≤ 0.0083). ConclusionOur results can support evidence that the connectivity of the right frontoparietal network acts as a biomarker of the enhanced Open monitoring meditation training.

Comparison of resting electroencephalogram coherence in patients with mild cognitive impairment and normal elderly subjects

Mild cognitive impairment (MCI) was a condition beginning before more serious deterioration, leading to Alzheimer’s dementia (AD). MCI detection was needed to determine the patient's therapeutic management. Analysis of electroencephalogram (EEG) coherence is one of the modalities for MCI detection. Therefore, this study investigated the inter and intra-hemispheric coherence over 16 EEG channels in the frequency range of 1-30 Hz. The simulation results showed that most of the electrode pair coherence in MCI patients have decreased compared to normal elderly subjects. In inter hemisphere coherence, significant differences (p<0.05) were found in the FP1-FP2 electrode pairs. Meanwhile, significant differences (p<0.05) were found in almost all pre-frontal area connectivity of the intra-hemisphere coherence pairs. The electrode pairs were FP2-F4, FP2-T4, FP1-F3, FP1-F7, FP1-C3, FP1-T3, FP1-P3, FP1-T5, FP1-O1, F3-O1, and T3-T5. The decreased coherence in MCI patients showed the disconnection of cortical connections as a result of the death of the neurons. Furthermore, the coherence value can be used as a multimodal feature in normal elderly subjects and MCI. It is hoped that current studies may be considered for early detection of Alzheimer’s in a larger population.

Electroencephalogram (EEG) With or Without Transcranial Magnetic Stimulation (TMS) as Biomarkers for Post-stroke Recovery: A Narrative Review.

Stroke is one of the leading causes of death and disability. Despite the high prevalence of stroke, characterizing the acute neural recovery patterns that follow stroke and predicting long-term recovery remains challenging. Objective methods to quantify and characterize neural injury are still lacking. Since neuroimaging methods have a poor temporal resolution, EEG has been used as a method for characterizing post-stroke recovery mechanisms for various deficits including motor, language, and cognition as well as predicting treatment response to experimental therapies. In addition, transcranial magnetic stimulation (TMS), a form of non-invasive brain stimulation, has been used in conjunction with EEG (TMS-EEG) to evaluate neurophysiology for a variety of indications. TMS-EEG has significant potential for exploring brain connectivity using focal TMS-evoked potentials and oscillations, which may allow for the system-specific delineation of recovery patterns after stroke. In this review, we summarize the use of EEG alone or in combination with TMS in post-stroke motor, language, cognition, and functional/global recovery. Overall, stroke leads to a reduction in higher frequency activity (≥8 Hz) and intra-hemispheric connectivity in the lesioned hemisphere, which creates an activity imbalance between non-lesioned and lesioned hemispheres. Compensatory activity in the non-lesioned hemisphere leads mostly to unfavorable outcomes and further aggravated interhemispheric imbalance. Balanced interhemispheric activity with increased intrahemispheric coherence in the lesioned networks correlates with improved post-stroke recovery. TMS-EEG studies reveal the clinical importance of cortical reactivity and functional connectivity within the sensorimotor cortex for motor recovery after stroke. Although post-stroke motor studies support the prognostic value of TMS-EEG, more studies are needed to determine its utility as a biomarker for recovery across domains including language, cognition, and hemispatial neglect. As a complement to MRI-based technologies, EEG-based technologies are accessible and valuable non-invasive clinical tools in stroke neurology.

Дослідження ЕЕГ-предикторів нейромедіаторної і нейрогліальної активності, особливостей перебудови міжцентральних відносин мозку у пацієнтів з тяжкою ЧМТ

Метою цього дослідження було вивчення впливу Цитофлавіну на перебудову міжцентральних відносин мозку, зміни нейромедіаторної і нейрогліальної активності в пацієнтів із тяжкою черепно-мозковою травмою (ЧМТ). Матеріал і методи дослідження. Дослідження проводилося в 2011–2014 роках у ДОКТМО на базі кафедри анестезіології та інтенсивної терапії ФПО Донецького національного медичного університету ім. Горького. Обстежено 60 пацієнтів із діагнозом «тяжка черепно-мозкова травма». Дизайн дослідження: відкрите проспективне дослідження за типом «випадок-контроль», що проводиться в групі пацієнтів із тяжкою ЧМТ. Рівень порушення свідомості при надходженні до стаціонару від 4 до 8 балів за шкалою коми Глазго, вік від 20 до 70 років. 1-ша група складалася з 30 пацієнтів, які отримували терапію за стандартним протоколом. 2-га група — з 30 хворих, які отримували, крім терапії по протоколу, препарат Цитофлавін із першої доби після отримання травми у вигляді інфузійного розчину 5 мл в 100 мл фізіологічного розчину 1 раз на добу (в 1-й групі — плацебо) внутрішньовенно повільно крапельно протягом 7 діб. Досліджували електричну активність мозку у хворих із тяжкою ЧМТ методами кількісної електроенцефалографії за допомогою інтегрального кількісного аналізу, внутрішьно- і міжпівкульної когерентності досліджуваних частотних діапазонів. Результати та обговорення. На першому етапі дослідження падіння рівнів міжпівкульної когерентності, виявлене в обох групах хворих із тяжкою ЧМТ, з вираженою синхронізацією біопотенціалів неокортексу справа (посилення внутрішньопівкульної когерентності потиличної кори з центральними і фронтальними ділянками (С4-О2 і Fр2-T4)) відображало крайню напруженість гомеостазу ЦНС і домінування неспецифічної аварійної адаптації з ознаками зриву адаптаційних можливостей. У хворих із тяжкою ЧМТ встановлено нейрофізіологічні ЕЕГ-предиктори феномена функціонального роз’єднання півкуль: істотне ослаблення міжпівкульної взаємодії в альфа-частотному діапазоні ЕЕГ у всіх симетричних відділах мозку — Fp1-Fp2, T3-T4, C3-C4, O1-O2 відведеннях, що відображає гальмівний стан кори. Проявом феномена роз’єднання зв’язків між підкірковими гангліями і корою головного мозку є виражене зниження рівнів міжпівкульної когерентності в симетричних лобових відведеннях (Fp1-Fp2), центральних (С3-С4) і потиличних відділах (О1-О2) в діапазонах тета-, альфа1-, альфаS-, бета1-, бета2-хвиль, що свідчить про дисфункцію регуляторних систем медіобазальних відділів фронтальної кори і про падіння напруженості в системах диенцефального рівня. На першому етапі дослідження в обох групах хворих із тяжкою ЧМТ встановлено вихідне зниження активності всіх досліджуваних нейромедіаторних систем практично у всіх досліджуваних відділах кори, що відображає глибоке виснаження стресреалізуючих і стреслімітуючих реакцій ЦНС. У хворих із тяжкою ЧМТ, які отримували Цитофлавін, предикторами трансформації стрес-реакції з періоду аварійної адаптації в період довгострокової адаптації є збільшення значення когерентності в альфа-діапазоні ЕЕГ-частот в центральній корі (С3-С4), проекційній зоні неспецифічного таламуса, відновлення активності верхньостовбурових структур мозку і лімбічної системи (посилення міжпівкульних діагональних когерентних зв’язків (C3-О2, С4-O1) фонової ЕЕГ в альфа-діапазоні). У хворих із тяжкою ЧМТ інтенсивна терапія з застосуванням Цитофлавіну протягом тижня відновлювала нейромедіаторний баланс, поетапно модулюючи активність адренергічної, серотонінергічної і дофамінергічної, холінергічної нейромедіаторних систем, коли стресреалізуючі реакції в процесі відновлення функцій ЦНС змінювалися стреслімітуючими реакціями, більш відповідними необхідному рівню гомеостазу. Висновки. Застосування Цитофлавіну забезпечувало енергетичну складову адекватних стресреалізуючих і стреслімітуючих процесів при тяжкій ЧМТ, їх поетапне включення у відновлення гомеостазу ЦНС. У групі пацієнтів із тяжкою ЧМТ, які отримували додатково до стандартного протоколу лікування Цитофлавін, значуще зростав шанс відновлення свідомості до 11 і більше балів за шкалою коми Глазго (ОR ± 95% ДІ = 0,22 (0,054–0,914)), значуще знижувався ризик смерті ((RR) ± 95% ДІ = 3 (1,09–8,2)) вже на 3-тю добу терапії.

Quantitative Analysis of Inter- and Intrahemispheric Coherence on Epileptic Electroencephalography Signal.

When an epileptic seizure occurs, the neuron's activity of the brain is dynamically changed, which affects the connectivity between brain regions. The connectivity of each brain region can be quantified by electroencephalography (EEG) coherence, which measures the statistical correlation between electrodes spatially separated on the scalp. Previous studies conducted a coherence analysis of all EEG electrodes covering all parts of the brain. However, in an epileptic condition, seizures occur in a specific region of the brain then spreading to other areas. Therefore, this study applies an energy-based channel selection process to determine the coherence analysis in the most active brain regions during the seizure. This paper presents a quantitative analysis of inter- and intrahemispheric coherence in epileptic EEG signals and the correlation with the channel activity to glean insights about brain area connectivity changes during epileptic seizures. The EEG signals are obtained from ten patients’ data from the CHB-MIT dataset. Pair-wise electrode spectral coherence is calculated in the full band and five sub-bands of EEG signals. The channel activity level is determined by calculating the energy of each channel in all patients. The EEG coherence observation in the preictal (Cohpre) and ictal (Cohictal) conditions showed a significant decrease of Cohictal in the most active channel, especially in the lower EEG sub-bands. This finding indicates that there is a strong correlation between the decrease of mean spectral coherence and channel activity. The decrease of coherence in epileptic conditions (Cohictal <Cohpre) indicates low neuronal connectivity. There are some exceptions in some channel pairs, but a constant pattern is found in the high activity channel. This shows a strong correlation between the decrease of coherence and the channel activity. The finding in this study demonstrates that the neuronal connectivity of epileptic EEG signals is suitable to be analyzed in the more active brain regions.

Hemispheric Coherence Analysis of Wide Band EEG Signals for Characterization of Post-Stroke Patients with Dementia

Post-stroke dementia (PSD) is a type of vascular dementia (VaD) that might be occurred in post-stroke patients. Memory, language and behavior tests can be used for the analysis of cognitive impairment caused by PSD. Often a supporting clinical examination such as an electroencephalogram (EEG) is used to support the diagnosis or analyze the characteristic changes that occur in the brain. Conventional analysis or visual inspection of EEG signals can be very difficult, since the nature of the signal tends to be non-stationer. Therefore, this study proposes a quantitative analysis for the characterization of EEG signals in stroke survivors with dementia. It is thought that it has different characteristics with the normal subject so that this study can be used as a reference in supporting dementia detection in post-stroke survivors. The quantitative analysis used in this study is coherence analysis. Coherence analysis was performed on EEG signals recorded from six poststroke patients with dementia and then compared with ten normal healthy subjects. Analysis of coherence between brain areas includes inter and intra-hemispheric coherence. Validation was carried out by using the independent t-test where the confidence level was 95%, indicating that the p-value &lt;0.05 had a significant difference. The test results show that in general the coherence of the electrode pairs in patients with dementia is lower than in the normal healthy group. It is notably, i) In interhemispheric, the C3-C4, T3-T4, and T5-T6 pairs generate significant differences, ii) the highest decrease in intrahemispheric coherence was found in C3-T5 with p = 0.0005. The coherence study presented in this paper is expected to be used for early detection of PSD in the future.

Neurophysiological mechanisms and features of autonomic support of productive cognitive activity of intuitive type in young adults

Is intuition a conscious or subconscious process, a “sixth sense” or a product of learning? This article contains an answer to this question which is based on the disclosure of neurophysiological mechanisms of one of the least understandable types of human cognitive activity. For the first time with the use of cerebral cortex electrical activity mapping, a comprehensive study of the organization of cortical neural networks and the functional state of the autonomic nervous system of female biology students engaged in intuitive thinking has been conducted. The productivity of intuitive thinking is associated with increasing the spectral power of beta2-, delta-, theta-components of the electroencephalogram. The synchronization of the activity of most frequency bands is manifested in the frontal and motor areas of the cortex, which have close connections with the basal ganglia, which are responsible for the formation of skills. In the beta1-band there are probable intrahemispheric long coherences between the anterior and posterior parts of the right hemisphere, at the frequency of beta1,2- and theta-bands of the electroencephalogram they are combined into large cellular ensembles that cover the central-parietal-temporal loci of the cortex. Synchronization of biopotentials in the delta range covers large areas of the cerebral cortex. It has been established that in intuitive thinking the female students with a low standard of efficiency had a high level of central rhythm regulation, and the female students with a high standard of efficiency had a high level of autonomous regulation. Higher performance under intuitive thinking negatively correlated with low frequency findings and positively correlated with high frequency and the value of the square root of the mean squares of the intervals between heartbeats (rMSSD) in the structure of cardiorhythm. Correlation analysis found that productive mental activity is conditioned by the specific integration of cortico-visceral processes: productive intuitive thinking is associated with the activation of autonomic regulation of heart rate variability and coherence in the evolutionarily older delta and delta-theta systems of the brain. Thus, intuition is a scientific set of skills and knowledge, and the topographic signs of synchronization of electrical processes of the cerebral cortex can serve as objective criteria for successful intuitive thinking, which allow one to predict both individual abilities and the state that contributes to their realization.

Abnormalities in cortical pattern of coherence in migraine detected using ultra high-density EEG.

Individuals with migraine generally experience photophobia and/or phonophobia during and between migraine attacks. Many different mechanisms have been postulated to explain these migraine phenomena including abnormal patterns of connectivity across the cortex. The results, however, remain contradictory and there is no clear consensus on the nature of the cortical abnormalities in migraine. Here, we uncover alterations in cortical patterns of coherence (connectivity) in interictal migraineurs during the presentation of visual and auditory stimuli and during rest. We used a high-density EEG system, with 128 customized electrode locations, to compare inter- and intra-hemispheric coherence in the interictal period from 17 individuals with migraine (12 female) and 18 age- and gender-matched healthy control subjects. During presentations of visual (vertical grating pattern) and auditory (modulated tone) stimulation which varied in temporal frequency (4 and 6 Hz), and during rest, participants performed a colour detection task at fixation. Analyses included characterizing the inter- and intra-hemisphere coherence between the scalp EEG channels over 2-s time intervals and over different frequency bands at different spatial distances and spatial clusters. Pearson’s correlation coefficients were estimated at zero-lag. Repeated measures analyses-of-variance revealed that, relative to controls, migraineurs exhibited significantly (i) faster colour detection performance, (ii) lower spatial coherence of alpha-band activity, for both inter- and intra-hemisphere connections, and (iii) the reduced coherence occurred predominantly in frontal clusters during both sensory conditions, regardless of the stimulation frequency, as well as during the resting-state. The abnormal patterns of EEG coherence in interictal migraineurs during visual and auditory stimuli, as well as at rest (eyes open), may be associated with the cortical hyper-responsivity that is characteristic of abnormal sensory processing in migraineurs.

Aerobic Exercise Mediates Neural Inefficiency Among Adolescents At Risk for Suicide.

This study examined the electroencephalograpy (EEG) coherence and working memory performance effects of a 9-week exercise program on a small group of adolescents at high suicide risk. We randomly assigned 26 adolescents at high suicide risk (based on their scores on the Adolescents Mental Health Inventory- AMHI) into equal sized exercise and no-exercise groups. Before and after the 9-week exercise program, all participants performed the Sternberg working memory task, during which we recorded their EEGs, with electrodes placed at F3, F4, C3, C4, P3, P4, T3, T4, O1, and O2 regions (using the International 10-20 system of EEG electrode placement). We measured working memory performance and inter-hemispheric (F3-F4, C3-C4, T3-T4, P3-P4, O1-O2) and intra-hemispheric (F3-C3, F3-T3, F3-P3, F3-O1, F4-C4, F4-T4, F4-P4, F4-O2) EEG coherence as an index of the participants' underlying neural efficiency. While we found no significant group differences in working memory performances, the exercise group, relative to the no-exercise group, exhibited lower inter- and intra-hemispheric EEG coherence while performing the working memory task. These EEG differences may reflect a mediating effect of aerobic exercise on these participants' neural efficiency.

Power and Coherence in the EEG of the Rat: Impact of Behavioral States, Cortical Area, Lateralization and Light/Dark Phases.

The sleep-wake cycle is constituted by three behavioral states: wakefulness (W), non-REM (NREM) and REM sleep. These states are associated with drastic changes in cognitive capacities, mostly determined by the function of the thalamo-cortical system, whose activity can be examined by means of intra-cranial electroencephalogram (iEEG). With the purpose to study in depth the basal activity of the iEEG in adult rats, we analyzed the spectral power and coherence of the iEEG during W and sleep in the paleocortex (olfactory bulb), and in neocortical areas. We also analyzed the laterality of the signals, as well as the influence of the light and dark phases. We found that the iEEG power and coherence of the whole spectrum were largely affected by behavioral states and highly dependent on the cortical areas recorded. We also determined that there are night/day differences in power and coherence during sleep, but not in W. Finally, we observed that, during REM sleep, intra-hemispheric coherence differs between right and left hemispheres. We conclude that the iEEG dynamics are highly dependent on the cortical area and behavioral states. Moreover, there are light/dark phases disparities in the iEEG during sleep, and intra-hemispheric connectivity differs between both hemispheres during REM sleep.

The influence of wrist tapping based on the author’s methodology on the dynamics of intrahemispheric integration and ‘internal’ rhythm in healthy adults

The goal The goal is to study the lateralization of changes in intrahemispheric coherence in accordance with the basic rhythms of electroen- cephalography in healthy young people under the influence of tapping on the wrist in accordance with the author’s technique.Materials and methods: The conduct of this study was approved by the ethics com- mittee of KrasGMU. prof. V. F. Voyno-Yasenetsky (protocol No. 77/2017 of 06/26/2017). The study of the infl of wrist tapping according to the author’s technique on the coefficient of intrahemispheric coherence of the cerebral cortex in healthy volunteers (n2=63). Wrist tapping was carried out using the original technique (RF patent No. 2606489 of 01/10/2017). The analysis of intrahemispheric coherence in the pairs F3–T5, T5–O1, F3–O1, F4–T6, T6–O2, F4–O2 was carried out using a com- puter encephalographic complex (Neurocartograph, MBN Moscow).Results and discussions: According to the studies, it was shown that under the influence of tapping the hand according to the author’s technique, the state of sensory deprivation (closed eyes), statistically signifi changes in hemisphere coherence in theta and beta rhythms were not found, p&gt;0.05, however, we showed a statistically significant (p&lt;0.05) de- crease in hemisphere alpha-rhythm coherence in the right hemisphere in pairs F4–T4 (p=0.0000793) and F4–O2 (p=0.01711824), while the median coherence coeffi before and after tapping changed from 0.27 to 0.315 and from 0.13 to 0.175, respectively. At that time, we did not find statistically significant changes in the coherence of the hemisphere in similar pairs of the left hemisphere p&gt;0.05. As a result of this study, when the wrist tapping was opened with the eyes of the subjects open, statistically significant changes in the coherence of the hemispheric alpha rhythm were detected only in the F3–O1 pair of the left hemisphere (p = 0.0000147), but not in the right hemisphere. At the same time, when the eyes of the volunteers were closed, there were no statistically significant changes in the coherence of the hemisphere in the theta and beta rhythms in both the left and right hemispheres.Conclusion. Thus, the use of tapping the wrist according to the author’s technique with the left hand in right-handed people in a state of sensory deprivation is promising for practical use in neurological practice, in particular in the management of patients with epilepsy and panic attacks, since a patient previously trained by the attending physician — neurorehabilitation, can use this the author’s program on his smartphone, in the case of an epileptic aura of focal epileptic seizures or precursors of panic attacks. However, the clinical application of the author’s technique needs detailed research.

QEEG coherence patterns related to mathematics ability in children

The current study investigates the utility of resting-state EEG coherence values in predicting standardized math scores in children. Quantitative EEG and standardized academic achievement analyses were performed on 60 school-aged children. Analyses assessing intrahemispheric coherence at rest were conducted across the sample of participants and several coherence networks were extracted and compared to standardized math achievement values. Specifically, networks that included Brodmann area 40 (a brain region involved in the cognitive processes responsible for mathematics performance) and whose coherence values were significantly correlated with standardized math scores were examined. Results indicate a total of four coherence networks, two in each hemisphere, that have utility in predicting general math skills in children. In addition to BA 40, these coherence networks include BAs in the right temporal lobe, right frontoparietal lobe, left superior temporal lobe, and the left medial prefrontal cortex. These findings address the current dearth of research on the neurological connectivity patterns that are foundational for mathematics abilities in children. Further, these results lay a foundation for the supplementary use of EEG in the assessment and identification practices surrounding math learning disabilities in children and additionally provide a neurocognitive framework upon which intervention research may be targeted.

Intra-Hemisphere Gamma Band Coherence as an EEG Marker of Negative Self-Referential Thinking

Intra-Hemisphere Gamma Band Coherence as an EEG Marker of Negative Self-Referential Thinking