Relative Beta Power Research Articles

Evaluating Acupuncture Point and Nonacupuncture Point Stimulation with EEG: A High-Frequency Power Spectrum Analysis.

To identify physical and sensory responses to acupuncture point stimulation (APS), nonacupuncture point stimulation (NAPS) and no stimulation (NS), changes in the high-frequency power spectrum before and after stimulation were evaluated with electroencephalography (EEG). A total of 37 healthy subjects received APS at the LI4 point, NAPS, or NS with their eyes closed. Background brain waves were measured before, during, and after stimulation using 8 channels. Changes in the power spectra of gamma waves and high beta waves before, during, and after stimulation were comparatively analyzed. After NAPS, absolute high beta power (AHBP), relative high beta power (RHBP), absolute gamma power (AGP), and relative gamma power (RGP) tended to increase in all channels. But no consistent notable changes were found for APS and NS. NAPS is believed to cause temporary reactions to stress, tension, and sensory responses of the human body, while APS responds stably compared to stimulation of other parts of the body.

Functional Connectivity and Quantitative EEG in Women with Alcohol Use Disorders: A Resting-State Study.

This study was aimed at exploring the electroencephalographic features associated with alcohol use disorders (AUD) during a resting-state condition, by using quantitative EEG and Functional Connectivity analyses. In addition, we explored whether EEG functional connectivity is associated with trait impulsivity. Absolute and relative powers and Synchronization Likelihood (SL) as a measure of functional connectivity were analyzed in 15 AUD women and fifteen controls matched in age, gender and education. Correlation analysis between self-report impulsivity as measured by the Barratt impulsiveness Scale (BIS-11) and SL values of AUD patients were performed. Our results showed increased absolute and relative beta power in AUD patients compared to matched controls, and reduced functional connectivity in AUD patients predominantly in the beta and alpha bands. Impaired connectivity was distributed at fronto-central and occipito-parietal regions in the alpha band, and over the entire scalp in the beta band. We also found that impaired functional connectivity particularly in alpha band at fronto-central areas was negative correlated with non-planning dimension of impulsivity. These findings suggest that functional brain abnormalities are present in AUD patients and a disruption of resting-state EEG functional connectivity is associated with psychopathological traits of addictive behavior.

V40. Deep brain recordings using an implanted pulse generator in Parkinson’s disease

Introduction Deep brain stimulation (DBS) in the subthalamic nucleus (STN) for Parkinson’s disease (PD) has been shown to be a safe and effective treatment. Recent studies suggest that oscillatory beta activity could be used as a biomarker in patients with PD for subthalamic closed-loop stimulation leading to improved clinical benefit and reduced energy consumption. The aim of the present study was to evaluate the feasibility of local field potential (LFP) recordings for closed-loop stimulation using a new generation of implantable stimulators that also can record LFPs. Materials and methods Eight patients with PD (2 female, mean age 66.1 ± [SEM] 1.5 years; disease duration 10.5 ± 1.4 years) who underwent bilateral implantation of DBS electrodes in the STN were included in the study. LFP recordings were conducted at rest ON and OFF subthalamic high frequency stimulation (140 Hz) via DBS electrodes using the new stimulator device (bipolar recordings from contact pair 0–2, monopolar stimulation at contact 1). FFT based power spectra were calculated ON and OFF DBS, normalized to total power and compared between conditions. Results We recorded subthalamic oscillatory activity from 15 out of 16 DBS electrodes using the stimulator’s sensing function. We found discrete peaks in the beta band in 12 out of 15 electrodes (mean peak frequency 17 Hz). A significant reduction in averaged beta band power (13–30 Hz) of 14% was found ON compared to OFF DBS condition ( p = 0.002). No difference was found in the alpha band (7–13 Hz; p > 0.05). Direct comparison of beta peak frequency aligned power spectra across the group revealed a significant DBS related beta power reduction in a frequency range from −1.4 Hz to +5.8 Hz ( p ⩽ 0.03, FWE corrected) surrounding the individual peaks. Discussion We demonstrate for the first time recordings of human deep brain activity from a new generation of fully implantable pulse generators with sensing function. Discrete peaks in beta activity were obtained from the subthalamic area from 12 out of 15 electrodes when patients were OFF medication, moreover the new device could identify a significant suppression of beta band activity during DBS. The present results give further evidence for beta band activity being a useful biomarker in PD patients that can be followed with implantable systems.

Sports Concussion And Mild Traumatic Brain Injury Assessment Is Enhanced With Portable, Non-invasive Biosensor Arrays

PURPOSE: To determine the degree that sports concussion may be identified by predictive multivariate models including neuropsychological testing data, single-lead electroenceplographic (EEG) data, and other modes of biosensor data. METHODS: Collegiate athletes who suffered traumatic brain injury (concussion; N=30) while participating in varsity sports were assessed in a longitudinal study design during the symptomatic and asymptomatic phase of recovery. These data were compared to an equal number of non-injured, age matched, comparator subjects. Each participant was tested using a novel single-lead EEG device during a series of cognitive and behavioral tasks, including eyes closed (EC) and eyes open (EO) resting task and a five word immediate recall task under IRB supervision. Behavioral measures (e.g. error-rate/task duration) and EEG spectral and wavelet features were extracted from EC/EO baseline and neuropsychological test epochs. Univariate and multivariate logistic regression, linear discriminant analysis and random forest models were compared for the ability to predict a concussive event as well as to develop signatures of Return-to-Learn and Return-to-Play decisions. RESULTS: EEG spectral density power features (e.g. relative beta power), relative to overall power, had an overall predictive accuracy of 65% (p<0.004). Additionally, total read times alone were 62% accurate (p<0.015) in a neuro-ophthalmologic saccade test. In a multivariate model, these two modes were found to be 70% accurate (p<0.006). However, inclusion of covariates increased discriminant power to 76% accurate at differentiating concussed from control subjects (p<0.003). CONCLUSIONS: Neuropsychological testing benefits by the addition of other objective biosensor modalities in the predictive performance of concussion / TBI testing for both the identification and management in Return-to-Learn and Return-to-Play decision making. These results suggest the use of multivariate signatures for concussion/TBI testing. Nonetheless, these preliminary findings must be independently replicated, validated, and expanded in sample size across multiple clinical settings such as team sports and emergency department use.

Resting state cortical oscillations of patients with Parkinson disease and with and without subthalamic deep brain stimulation: a magnetoencephalography study.

In this study, we investigate the modification to cortical oscillations of patients with Parkinson disease (PD) by subthalamic deep brain stimulation (STN-DBS). Spontaneous cortical oscillations of patients with PD were recorded with magnetoencephalography during on and off subthalamic nucleus deep brain stimulation states. Several features such as average frequency, average power, and relative subband power in regions of interest were extracted in the frequency domain, and these features were correlated with Unified Parkinson Disease Rating Scale III evaluation. The same features were also investigated in patients with PD without surgery and healthy controls. Patients with Parkinson disease without surgery compared with healthy controls had a significantly lower average frequency and an increased average power in 1 to 48 Hz range in whole cortex. Higher relative power in theta and simultaneous decrease in beta and gamma over temporal and occipital were also observed in patients with PD. The Unified Parkinson Disease Rating Scale III rigidity score correlated with the average frequency and with the relative power of beta and gamma in frontal areas. During subthalamic nucleus deep brain stimulation, the average frequency increased significantly when stimulation was on compared with off state. In addition, the relative power dropped in delta, whereas it rose in beta over the whole cortex. Through the course of stimulation, the Unified Parkinson Disease Rating Scale III rigidity and tremor scores correlated with the relative power of alpha over left parietal. Subthalamic nucleus deep brain stimulation improves the symptoms of PD by suppressing the synchronization of alpha rhythm in somatomotor region.

Quantitative Electroencephalography in Autistic Children

there are regions of brain dysfunction associated with neural connectivity anomalies in autism. Aim is to study the quantitative EEG findings in autistic and normal children. EEG was done for 21 autistic children compared to 21 controls. topographical differences in cerebral functioning were examined using estimates of absolute relative power asymmetry as wel as theta beta ratio, delta alpha ratio and intra- and inter-hemispheric coherence. there were significant differences in EEG power, symmetry, delta alpha ratio and coherence between autistic and control groups with excessive absolute of delta and theta power especially at frontal region. global reduction in relative alpha and beta power in frontal, central and posterior regions in autistic children. there is pattern of under-connectivity and over-connectivity in autistic children.

Особенности биоэлектрической активности мозга детей раннего возраста, воспитывающихся в детском доме

We investigated whether the electroencephalogram (EEG) during visual fixation in institutionalized children shows the altered oscillation properties. EEG was recorded in the "eyes open" situation with visual attention fixed on a cartoon in 51 2-3.5 years old children living in Simferopol orphanage, Crimea and in 53 age-matched children living in families. Oscillation properties were measured using the relative power (RP) indices of theta-, alpha-, beta- and gamma-rhythms. Institutionalized children showed higher RP of alpha rhythm in seven loci (frontal polar, anterior temporal, posterior temporal and left occipital derivations), lower RP of theta rhythm in eight loci (frontal polar, frontal, anterior temporal and posterior temporal derivations). In addition, RP of beta- and gamma-rhythms were decreased in the left anterior temporal area. These results suggest that institutionalized children show impaired development of CNS, in particular development of limbic system and neocortex, probably are caused by early social deprivation.

Quantitative EEG in autistic children

Background Autism spectrum disorder is a neurodevelopmental disorder that is characterized mainly by difficulties in social interaction and communication. Studies have suggested abnormal neural connectivity patterns in the brains of patients with autism. Objective The current work aimed to study the quantitative electroencephalography (EEG) findings in autistic children and compare it with those of normal controls. Methods The EEG recordings of 21 autistic children between 4 and 12 years of age were compared with those of 21 age-matched and sex-matched controls under an eyes-opened condition. Differences in cerebral functioning were examined using measurements of absolute and relative power and intrahemispheric and interhemispheric coherence. Results There were statistically significant differences in EEG power between the autistic and control groups, with greater absolute of delta and theta power especially at the frontal region in autistic children. There was also global reduction in relative alpha and beta power especially in the frontal, central, and posterior regions in autistic children. In addition, there was a pattern of underconnectivity and overconnectivity when measuring the intrahemispheric and interhemispheric coherence in the autistic compared with the control group. Conclusion These results suggested regional dysfunction of the brain in autistic children, along with a pattern of abnormal neural connectivity, which could explain the autistic symptomatology.

The rotenone-induced rat model of Parkinson's disease: Behavioral and electrophysiological findings

Exposure to rotenone leads to parkinsonian features, such as loss of dopaminergic neurons in the substantia nigra and motor impairment, however, the validity of this model has recently been questioned. In rodent and monkey models of Parkinson's disease (PD) abnormal neuronal activity in the basal ganglia motor loop has been described, with hyperactivity of the subthalamic nucleus (STN) similar to that found in PD. The present study aims at providing new and more specific evidence for the validity of the rotenone rat model of PD by examining whether neuronal activity in the STN is altered.Male Sprague Dawley rats were treated with rotenone injections (2.5mg/kg bodyweight intraperitoneally) for 60 days. Behavioral analysis showed an impairment in the rotarod and hanging wire test in the rotenone group (p<0.05), accompanied by a decline in tyrosine hydroxylase immunoreactive neurons in the nigro-striatal region (p<0.001). Thereafter, single unit (SU) activities and local field potentials were recorded in the STN in urethane anesthetized rats. The SU analysis revealed a higher neuronal discharge rate (p<0.001), more bursts per minute (p=0.006) and a higher oscillatory activity (p=0.008) in the STN of rotenone treated rats. Spectral analysis showed an increase of relative beta power in the STN as well as in the motor cortex.We found electrophysiological key features of PD pathology and pathophysiology in the STN of rotenone treated rats. Therefore, the rotenone-induced rat model of PD deserves further attention since it covers more aspects than dopamine depletion and implies the reproducibility of PD specific features.

Study on effect and mechanism of cinnabaris and realgar in promoting awake of endotoxin-induced brain injury rat applied with Angong Niuhuang Wan

To explore the effect and mechanism of cinnabaris and realgar in promoting awake effect of endotoxin- induced brain injury rat applied with Angong Niuhuang Wan. Normal rats implanted cortical electrode in advance were divided into 6 groups: control, model, the Angong Niuhuang Wan (AGNH, 0.4, 0.2 g · kg(-1)), the Angong Niuhuang Wan without cinnabaris and realgar (QZX-AGNH, 0.32, 0.16 g · kg(-1)). Rats in the control and model groups were given distilled water. After three days of intragastric administration, the brain injury model was injected with endotoxin through tail vein. Then trace electro-corticogram (EcoG) 1-6 h after LPS injection, and compare the power and relative power of beta (β) and delta-waves (δ) at 6 h of these groups. The content of acetylcholine (Ach) and the affinity of M-receptor (M-R) in cortex and brainstem were detected by alkaline hydroxylamine colorimetric method and radioactive ligand binding assay, respectively. AGNH (0.4, 0.2 g · kg(-1)) could increase the power and relative power of β and AGNH (0.4 g · kg(-1)) showed better action on brain electrical activation. QZX-AGNH showed weak effect on it. AGNH (0.4 g · kg(-1)) could increase the affinity of M-R in cortex and the content of Ach in brainstem. The action of QZX-AGNH was not obvious. In endotoxin-induced brain injury rats, AGNH can raise the cholinergic system function of cortex, and strengthen the uplink of cortex activation of brainstem cholinergic system, improve the level of cortical activity and enhance the activation of EcoG to promote the body's awakening. QZX-AGNH show weak effect. Cinnabaris and realgar play an important role in promoting awake effect in endotoxin-induced brain injury applied with Angong Niuhuang Wan. The mechanism may be related to cortical and brainstem cholinergic system function.

Event related beta and gamma oscillatory responses during perception of affective pictures

Several studies reveal that unpleasant pictures elicit higher beta and gamma responses than pleasant and/or neutral pictures; however, the effect of stimulation design (block or random) has not been studied before. The aim of the study is to analyze the common and distinct parameters of affective picture perception in block and random designs by means of analysis of high frequency oscillatory dynamics (beta and gamma). EEG of 22 healthy subjects was recorded at 32 locations. The participants passively viewed 120 emotional pictures (10×4 unpleasant, 10×4 pleasant, 10×4 neutral) in block and random designs. The phase-locking and power of event related beta (14–28Hz) and gamma (29–48Hz) oscillations were analyzed for two different time windows (0–200ms/200–400ms). Statistical analysis showed that in the 0–200ms time window, during the block design, unpleasant stimulation elicited higher beta phase-locking and beta power than the pleasant and neutral stimulation (p<0.05). In the 200–400ms time window, during the block design, over occipital electrodes unpleasant stimulation elicited higher gamma response power than the pleasant stimulation and neutral stimulation (p<0.05). Unpleasant stimulation did not elicit higher beta or gamma responses in the random design. The present study showed that experimental design highly influences the perception of IAPS pictures. Unpleasant stimulation elicited higher event related beta and gamma phase-locking and power only in block design but not in random design. It seems that longer blocks of aversive pictures affect the brain more than the rapid observation of these pictures.

Is 1/f sound more effective than simple resting in reducing stress response?

It has been previously demonstrated that listening to 1/f sound effectively reduces stress. However, these findings have been inconsistent and further study on the relationship between 1/f sound and the stress response is consequently necessary. The present study examined whether sound with 1/f properties (1/f sound) affects stress-induced electroencephalogram (EEG) changes. Twenty-six subjects who voluntarily participated in the study were randomly assigned to the experimental or control group. Data from four participants were excluded because of EEG artifacts. A mental arithmetic task was used as a stressor. Participants in the experiment group listened to 1/f sound for 5 minutes and 33 seconds, while participants in the control group sat quietly for the same duration. EEG recordings were obtained at various points throughout the experiment. After the experiment, participants completed a questionnaire on the affective impact of the 1/f sound. The results indicated that the mental arithmetic task effectively induced a stress response measurable by EEG. Relative theta power at all electrode sites was significantly lower than baseline in both the control and experimental group. Relative alpha power was significantly lower, and relative beta power was significantly higher in the T3 and T4 areas. Secondly, 1/f sound and simple resting affected task-associated EEG changes in a similar manner. Finally, participants reported in the questionnaire that they experienced a positive feeling in response to the 1/f sound. Our results suggest that a commercialized 1/f sound product is not more effective than simple resting in alleviating the physiological stress response.

Resting electroencephalogram in attention deficit hyperactivity disorder: Developmental course and diagnostic value

This study investigated electroencephalographic (EEG) activity and its developmental course in attention deficit hyperactivity disorder (ADHD) throughout the lifespan, as well as the accuracy of EEG parameters in distinguishing ADHD patients from typically developing individuals. Three minutes eyes closed resting EEG was compared between 62 individuals with ADHD (36 children, 26 adults) and 55 typically developing individuals (30 children, 25 adults). EEG activity and maturation did not differ between individuals with ADHD and typically developing individuals. However, despite comparable developmental course between clinical groups, persistent elevated theta/beta ratio and reduced relative beta power were observed in the ADHD inattentive subtype compared to the ADHD combined subtype and controls across the lifespan. Therefore, a maturational deviation rather than a maturational delay may underlie a subgroup of ADHD. EEG based classification failed for ADHD but proved successful for age. These findings emphasize heterogeneity in ADHD throughout the lifespan and question clinical utility of conventional EEG approaches for diagnostic purposes in ADHD.

Differences in Brain Waves of Normal Persons and Stroke Patients during Action Observation and Motor Imagery

[Purpose] The purpose of this study was to examine the changes in brain waves between action observation and motor imagery of stroke patients and normal subjects, and to compare them. [Methods] Twelve stroke patients and twelve normal persons participated in this research. Each group executed action observation and the motor imagery training for 3 minutes, and before and during each intervention the brain waves were measured for 3 minutes, and the relative alpha power and relative beta power analyzed. [Results] Both normal persons and stroke patients showed significant differences in relative alpha power during action observation, but no significant difference in relative alpha power was found during motor imagery. The relative beta power increased similarly in both groups but it was more significantly different during action observation than during motor imagery. [Conclusion] Both action observation and motor imagery can be used as a therapeutic method for motor learning. However, action observation induces stronger cognitive activity, so for the stroke patients who have difficulty with fine motor representation, action observation might be a more effective therapy.

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

ObjectiveWhile 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.MethodEEG 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.ResultsBehaviorally, 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.ConclusionThese distributed spectral powers in different frequency bands might provide meaningful information about emotional processing in PD patients.

Effect of Deep Brain Stimulation on Levodopa-Induced Dyskinesias and Striatal Oscillatory Local Field Potentials in a Rat Model of Parkinson's Disease

BackgroundIn Parkinson's disease (PD) dyskinesias appear after long-term dopaminergic treatment. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or the globus pallidus internus (GPi) is a well-established treatment option for both PD symptoms and complications of medication. ObjectiveTo elucidate physiological mechanisms of the effect of DBS on levodopa-induced dyskinesias (LID) we investigated both DBS in the GPi and the centromedian-parafascicular complex (CM-Pf), which are part of an internal basal ganglia loop connecting with the dorsolateral striatum. In particular, we focused on changes of oscillatory activity in the dorsolateral striatum, which also presents the entrance region of the basal ganglia (BG). Methods6-Hydroxydopamine (6-OHDA) hemiparkinsonian (HP) rats and 6-OHDA lesioned HP rats with LID (HP-LID) were used to compare the effect of DBS in the entopeduncular nucleus (EPN, the equivalent to the human GPi) and the thalamic parafascicular nucleus (Pf, the equivalent of the human CM-Pf) on dyskinesias and neuronal oscillatory activity of selected frequency bands in the dorsolateral striatum on and off levodopa. ResultsIn HP-LID rats the relative beta and gamma power was lower, while relative theta power was higher as compared to HP rats. Chronic DBS of either the EPN or the Pf improved dyskinesia scores in HP-LID rats, and no differences in oscillatory activity were observed between groups. ConclusionsStimulation of the Pf has a specific impact on dyskinesias, which is similar to that found after EPN stimulation, and which is accompanied by changes of oscillatory activity.

Neurofeedback Training Aimed to Improve Focused Attention and Alertness in Children With ADHD

Neurofeedback is a nonpharmacological treatment for attention-deficit hyperactivity disorder (ADHD). We propose that operant conditioning of electroencephalogram (EEG) in neurofeedback training aimed to mitigate inattention and low arousal in ADHD, will be accompanied by changes in EEG bands' relative power. Patients were 18 children diagnosed with ADHD. The neurofeedback protocol ("Focus/Alertness" by Peak Achievement Trainer) has a focused attention and alertness training mode. The neurofeedback protocol provides one for Focus and one for Alertness. This does not allow for collecting information regarding changes in specific EEG bands (delta, theta, alpha, low and high beta, and gamma) power within the 2 to 45 Hz range. Quantitative EEG analysis was completed on each of twelve 25-minute-long sessions using a custom-made MatLab application to determine the relative power of each of the aforementioned EEG bands throughout each session, and from the first session to the last session. Additional statistical analysis determined significant changes in relative power within sessions (from minute 1 to minute 25) and between sessions (from session 1 to session 12). Analysis was of relative power of theta, alpha, low and high beta, theta/alpha, theta/beta, and theta/low beta and theta/high beta ratios. Additional secondary measures of patients' post-neurofeedback outcomes were assessed, using an audiovisual selective attention test (IVA + Plus) and behavioral evaluation scores from the Aberrant Behavior Checklist. Analysis of data computed in the MatLab application, determined that theta/low beta and theta/alpha ratios decreased significantly from session 1 to session 12, and from minute 1 to minute 25 within sessions. The findings regarding EEG changes resulting from brain wave self-regulation training, along with behavioral evaluations, will help elucidate neural mechanisms of neurofeedback aimed to improve focused attention and alertness in ADHD.

Comparison of auditory P300 responses in healthy elderly, people with mild cognitive impairment and people with Alzheimer's disease

Background: The role of beta responses in cognitive load was least understood in comparison to other frequency bands. The aim of the present study is to investigate the role of beta response oscillations upon cognitive load in healthy subjects and in subjects with mild cognitive impairment (MCI). Methods: Seventeen consecutive patients with MCI (mean age 70,76 65,62years) according to Petersen’s criteria and Seventeen ageand education-matched normal elderly controls (mean age 68,49 65,48 years) were included in the study. Visual oddball paradigm was used in the experiments. Oscillatory responses were recorded from F 3, F z, F 4, C 3, C z, C 4, TP 7, TP 8, P 3, P z, P 4, O 1, O z and O 2 scalp electrodes. EEG-evoked power, inter-trial phase synchronization and event related beta responses filtered in 15-20 Hz were obtained in response to target and non-target stimuli for both groups of subjects. Results: EEG-evoked beta power, inter-trial phase synchronization of beta responses and event related filtered beta responses were significantly higher in response target stimulation in comparison to non-target stimulation in healthy subjects (p<0,05). On the other hand, there were no evoked beta power differences between target and non target stimuli in MCI patients. Furthermore, upon presentation of visual oddball paradigm occipital electrodes enhanced higher beta response in comparison to other electrode sites (p< 0,0001). Conclusions: The results of the present study clearly indicated that target stimulation elicited higher event related beta power, event related beta phase locking and event related filtered beta responses than non-target stimulation in all electrode sites in healthy subjects. Event related beta increase could be related to attention and cognitive activity. The increased beta response upon presentation of target stimuli in healthy subjects implies that beta oscillations could shift the system to an attention state and had important function in cognitive activity. This may, in future, open the way to consider the beta activity as universal operator in the brain in cognitive processes.

ELECTROENCEPHALOGRAPHIC BIOFEEDBACK IMPROVES FOCUSED ATTENTION IN ATTENTION DEFICIT/HYPERACTIVITY DISORDER

EEG biofeedback (so called neurofeedback) is considered as an efficacious treatment for ADHD. We propose that operant conditioning of EEG in neurofeedback training mode, aimed to mitigate inattention and low arousal in ADHD, will be accompanied by changes in EEG bands' relative power. Patients were 18 children diagnosed with ADHD. The neurofeedback protocol (“Focus/Alertness” by Peak Achievement Trainer, Neurotek, KY) used to train patients has focused attention training procedure, which according to specifications, represents wide band EEG amplitude suppression training. Quantitative EEG analysis was completed on each of 25 min long twelve sessions to determine the relative power of each of the EEG bands of interest throughout each session, and from the first session to the last session. Additional statistical analysis was performed to determine significant changes in relative power within sessions (from minute 1 to minute 25), and between sessions (from session 1 to session 12) for an individual patient. We performed analysis of relative power of Theta, Alpha, Low and High Beta, Theta/Alpha, Theta/Beta, and Theta/Low Beta and Theta/High Beta ratios. We performed also analysis between the “Focus”measure and changes in relative power of above EEG rhythms and their ratios. Additional secondary measures of patients’ post-neurofeedback outcomes were assessed using an audio-visual selective attention test (IVA + Plus) and behavioral evaluation scores from Aberrant Behavior Checklist. We found that, as expected, Theta/Low Beta and Theta/Alpha ratios decreased significantly from Session 1 to Session 12 and from minute 1 to minute 25 within sessions. The ‘Focus” measure of protocol showed high negative correlation with both Theta/Alpha and Theta/Beta ratios. The findings regarding EEG changes resulting from self-regulation training along with behavioral evaluations will help in elucidation of neural mechanisms of neurofeedback aimed to improve focused attention and alertness in ADHD.

Electroencephalogram beta power assay: A promising diagnosis tool of cognitive impairment in early time after cerebral hemorrhage

Cerebral hemorrhage (CH) could affect the cerebral function on specific cognitive abilities and lead to the cognitive decline or cognitive dysfunction. Electroencephalogram (EEG) is a relatively cheap and easy usable tool, which could reflect the cerebral function of the patients. A total of 170 patients (patients with and without cognitive impairment) with CH and 120 normal healthy controls were recruited from September 2008 to June 2012 at the Department of Neurology. EEG studies were carried out to analyze the cerebral function in all the subjects. Correlation, clustering and concordance analysis were performed to analyze the relationship between EEG power and Montreal cognitive assessment (MoCA) scores. The effects of EEG analysis were assessed to diagnosis the cognitive impairment. The results were showed that patients with cognitive impairment had a significantly decreased EEG beta power (0.771 ± 0.149 μV 2 ) compared with the normal cognitive function (1.654 ± 0.186 μV 2 , P < 0.01) or normal healthy controls (1.703 ± 0.216 μV 2 , P < 0.01). Significantly positive correlation (r = 0.90174, P < 0.001) was discovered between relative beta power and hemorrhage type, while significantly negative correlations between the relative beta power and hemorrhage size and amount were also observed (r =-0.81235 and r =-0.90136, respectively, all P < 0.001). There was a better concordance between K-means clustering algorithm calculating of the relative beta power and MoCA scores (κ =0.913, P < 0.001). The cognitive impairment post hemorrhage was positively correlated to hemorrhage type and negatively correlated with hemorrhage size and amount. The analysis method of EEG beta power abnormality holds a promise to assess the cognitive impairment post CH.