Frequência Alfa na meditação Gurdjieff / Alpha Frequency in Gurdjieff Meditation

Introdução: a meditação é uma prática que visa regular o estado mental e as emoções, podendo induzir a estados alterados de consciência. Dentre inúmeras técnicas de meditação, o trabalho proposto por George I. Gurdjieff, inclui práticas voltadas para o recolhimento da atenção e o equilíbrio entre a atividade do corpo, da mente e do sentimento. Estudos realizados com eletroencefalografia (EEG), avaliando o estado meditativo em geral, demonstraram um padrão cerebral caracterizado pelo aumento da amplitude dos ritmos eletroencefalográficos alfa e teta, bem como diferenças na atividade alfa entre a meditação e o relaxamento. Entretanto, isto não está caracterizado em meditadores da linha de G.I. Gurdjieff, que praticam, além de meditações sentadas, exercícios corporais acompanhados de uma música própria e exercícios de atenção durante a vida diária. Objetivo: comparar a atividade cerebral da frequência alfa durante os estágios de meditação e relaxamento e avaliar as diferenças entre as regiões frontal, central e occipital nesses dois estados, em meditadores experientes do grupo Gurdjieff, de Salvador-Bahia-Brasil. Metodologia: a coleta da atividade cerebral dos 8 voluntários foi realizada através do EEG. O protocolo de coleta adotado foi de 6 minutos de relaxamento e 12 minutos de meditação. Resultados: foi encontrado aumento significativo da potência alfa durante a meditação, quando comparada ao relaxamento. As regiões frontal e central não apresentaram diferenças entre si para a potência alfa, enquanto a região occipital apresentou aumento da potência alfa em comparação com as regiões frontal e central. Existe um aumento da densidade de alfa durante a meditação em todas as regiões cerebrais testadas, com maior densidade na região occipital. Conclusão: A frequência alfa comporta-se de forma diferente durante a meditação, comparada ao relaxamento, com um aumento da densidade de potência durante o estado meditativo em todas as regiões avaliadas, sendo a região occipital a que apresentou maior potência.

Introduction: meditation is a practice that aims to regulate the mental state and emotions, and can induce altered states of consciousness. Among numerous meditation techniques, the work proposed by George I. Gurdjieff, includes an attempt to balance activities from the body, the mind and the feelings. Studies conducted with electroencephalography (EEG), evaluating the meditative tate, demonstrated a brain pattern characterized by increased alpha and theta amplitude, as well as differences in alpha activity between meditation and relaxation. However, this is not characterized in Gurdjieff meditators, which practice beyond sitted meditations, body exercises with music, and attentional exercises during everyday life. Objective: comparing the brain activity of the alpha power during the meditation and relaxation stages and evaluate the differences between the frontal, central and occipital regions in these two states, in experienced meditators from the Gurdjieff group, in Salvador-Bahia-Brazil. Methodology: the data collection of the brain activity from 8 volunteers was performed by EEG. The collection protocol adopted was 6 minutes of relaxation and 12 minutes of meditation. Results: a significant increase in alpha power was found during meditation, when compared to relaxation. The frontal and central regions showed no differences between them for alpha power, while the occipital region showed an increase in alpha power compared to the frontal and central regions. Conclusion: the alpha frequency behaves differently during meditation, compared to relaxation, with an increase in alpha density during the meditative state in all evaluated regions, with the occipital region being the most potent.

Alfa no estado alterado de consciência: meditação Raja Yoga / Alpha density in altered state of consciousness: Raja Yoga meditation

Introdução: a meditação é uma técnica ancestral praticada por tradições religiosas e não religiosas, para alcançar benefícios espirituais e na saúde. É considerada um dos estados alterados de consciência. Estudos com ressonância magnética funcional e eletroencefalografia revelaram que existe diminuição da atividade cerebral no lóbulo parietal superior, durante a meditação. Na meditação, a frequência alfa aumenta no córtex cerebral quando comparada ao relaxamento e é caracterizada por ondas rítmicas associadas ao relaxamento e à diminuição de processo cognitivo. Objetivo: descrever e comparar a distribuição de potência da frequência cerebral alfa, nos estágios de MD e RL, nas regiões cerebrais frontal, central e occipital e, comparar as diferenças entre as regiões, de meditadores experientes da casa Brahma Kumaris, praticantes da meditação Raja Yoga, de Salvador ­ BA-Brasil. Metodologia: participaram 14 voluntários neste experimento. A coleta de dados foi realizada com EEG (21 eletrodos). O protocolo utilizado envolveu 6 minutos de relaxamento e 12 minutos de meditação. Os voluntários precisavam ter tido uma noite de sono adaptada à sua rotina e não terem ingerido bebidas estimulantes antes da coleta de dados. Resultados: encontrou-se aumento da densidade alfa na região occipital, na meditação para a média (µV2 / Hz), quando comparada às regiões frontal e central. Obteve-se um tamanho de efeito médio para alfa em relação às comparações entre as regiões frontal e central e um tamanho de efeito pequeno para alfa, entre as regiões central e occipital, durante o processo meditativo. Para as outras regiões, nenhum tamanho de efeito significativo para alfa foi encontrado. Conclusão: não foram encontradas diferenças significativas para alfa, entre os estados de meditação e relaxamento, porém a densidade de potência alfa foi maior na região occipital, quando comparada com as regiões frontal e central; entretanto, essa diferença não apresentou um tamanho de efeito do d de Cohen de relevante magnitude.

Introduction: meditation is an ancient technique practiced by religious and non-religious traditions to achieve spiritual and health benefits. It is considered one of the altered states of consciousness and studies with fMRI and EEG revealed that there is decreased brain activity in the upper parietal lobe during meditation. In meditation, alpha frequency increases in the cerebral cortex when compared to relaxation and is characterized by rhythmic waves associated with relaxation and decreased cognitive process. Objective: to describe and compare the EEG alpha power density distribution during the stages of meditation and relaxation in the frontal, central and occipital regions of experienced Brahma Kumaris Rajayoga meditators. Methodology: volunteers in number of 14 participated in this experiment. Data collection was performed with EEG (21 electrodes). The protocol used involved six minutes of relaxation and 12 minutes of meditation. Volunteers needed to have had a night's sleep suited to their routine and had not inhaled stimulant drinks prior to data collection. Results: we found an increase in alpha density in the occipital region in meditation for the general mean (µV2 / Hz), when compared to the frontal and central regions. A mean effect size for alpha was obtained relative to the comparisons between the frontal and central regions and a small effect size for alpha between the central and occipital regions during meditative process. For the other regions, no significant effect size for alpha was found. Conclusion: no significant differences were found for alpha between the states of meditation and relaxation, but the alpha potency density was higher in the occipital region, when compared with the frontal and central regions; however, this difference did not present a Cohen's d effect size of relevant magnitude

Traumatic brain injury: An EEG point of view / Lesão cerebral traumática: Um ponto de vista EEG

ABSTRACT Traumatic brain injury (TBI) is a silent epidemic. Mild traumatic brain injury (mTBI) causes brain injury that results in electrophysiologic abnormalities visible on electroencephalography (EEG) recordings. The purpose of this brief review was to discuss the importance of EEG findings in traumatic brain injury. Relevant articles published during the 1996-2016 period were retrieved from Medline (PubMed). The keywords were in English and included "traumatic brain injury", "EEG" and "quantitative EEG". We found 460 articles, analyzed 52 and selected 13 articles. EEG after TBI shows slowing of the posterior dominant rhythm and increased diffuse theta slowing, which may revert to normal within hours or may clear more slowly over many weeks. There are no clear EEG or quantitative EEG (qEEG) features unique to mild traumatic brain injury. Although the literature indicates the promise of qEEG in reaching a diagnosis and indicating prognosis of mTBI, further study is needed to corroborate and refine these methods.

RESUMO O trauma cranioencefálico (TCE) é uma epidemia silenciosa. O trauma cranioencefálico leve causa uma lesão cerebral que resulta em anormalidades eletrofisiológicas visíveis nos registros eletroencefalográficos (EEG). O intuito dessa revisão curta foi discutir a importância dos achados eletroencefalográficos no trauma cranioencefálico. Os artigos relevantes publicados durante o período 1996-2016 foram selecionados do Medline (PubMed). As palavras-chave estavam em inglês e incluíam "traumatic brain injury", "EEG" e "quantitative EEG". Foram encontrados 460 artigos, analisados 52 e selecionados 13 artigos. O EEG após o TCE mostra lentificação do ritmo posterior dominante e aumento difuso da atividade lenta teta, o que pode ser revertido dentro de horas ou semanas. Não há características únicas no EEG ou EEG quantitativo (EEGq) de pacientes com TCE leve. Apesar da literatura indicar que no futuro o EEGq será uma ferramenta para diagnosticar e estabelecer um prognóstico para o TCE, mais estudos são necessários para corroborar e refinar esses métodos.

Individual Alpha Frequency (IAF) Based Quantitative EEG Correlates of Psychological Stress.

Objectives: To explore the EEG changes associated with psychological stress state. Methods: The study was conducted on 34 healthy male student volunteers. The intervention consisted of psychological stress, which was induced by asking the participants to play a pre-decided stressful computer game. Physiological markers of psychological stress were assessed using galvanic skin response (GSR) and heart rate (HR). Electroencephalography (EEG) was recorded from 19 scalp locations according to 10- 20 international system of electrode placement. Results: Computer game served as model of lab stressor and was associated with a significant increase in physiological markers (GSR & heart rate) of stress response. Psychological stress was associated with increased absolute power in theta, lower 1 alpha and gamma bands & decreased power in upper alpha and beta bands. Lower 2 alpha band power remained unchanged. Conclusions: Certain types of computer games serve as a model of lab stressor and are associated with physiological and psychological stress and have unique electroencephalographic correlates. The EEG correlates of mental stress are unique superimposed pattern of various cognitive domains. With sustained and continuing stress resulting from computer game attention, alertness and performance starts declining.

Quantitative EEG analysis disease during resting and memory task in carriers and non-carriers of PS-1 E280A mutation of familial Alzheimer's / Análisis del EEG cuantitativo durante tareas de memoria y reposo en portadores y no portadores de la mutación PS-1 E280A de la enfermedad de Alzheimer

ABSTRACT Background: Alzheimer's disease is the most leading cause of dementia in the world; the mutation PS-1 E280A alters the gene of the Presenilin-1 and causes an early onset familial Alzheimer's disease. This mutation has been found in large kindred of Antioquia, Colombia. The objective of this study was to find differences revealed by electroencephalogram between healthy subjects and asymptomatic carriers that can be used as clinical markers of the disease in this population. Methods: EEG was recorded in 15 asymptomatic E280A carriers and 15 healthy non carriers during resting and a memory task using 64 channels amplifier. Two conditions in the memory task were analyzed: encoding and retrieval, the process of recording and evocating information, respectively. Power spectrum was calculated in delta (0. 5-4. 0 Hz), theta (4. 0-8. 0 Hz), alpha-1 (8. 0-10. 0 Hz), alpha-2 (10. 0-13. 0 Hz), beta (13. 0-25. 0 Hz) and gamma (25. 0-50 Hz) frequency bands for four regions of interest. Changes were evaluated in different conditions by ANOVA analysis.. Results: In resting condition a significant decrease was found in theta (p=0. 0001) and an increase in alpha-2 frequencies (p=0.037) in carriers compare with controls. During encoding of the memory task theta was significantly lower in carriers compared with controls (p=0. 008) and comparing resting versus retrieval process for each group, there was more theta synchronization in carriers. Conclusions: Early changes in theta frequencies were observed in the EEG recordings, it could be use as clinical markers in this population. Also it seems carriers activate additional cortical regions in order to conserve successful cognitive functions before clinical impairment.

RESUMEN Introducción: la enfermedad de Alzheimer es la principal causa de demencia en el mundo; la mutación PS-1 E280A altera el gen presenilin-1 y causa una variante familiar de la enfermedad que se caracteriza por una aparición temprana. La mutación se ha descubierto en un grupo de familias de Antioquia, Colombia. El objetivo de este estudio fue encontrar diferencias, a partir de registros electroencefalográficos de personas portadores de la mutación en una etapa asintomática y sujetos sanos para evaluar si pueden ser utilizadas como un marcador temprano de la enfermedad en la población portadora de la mutación. Metodología: se realizaron registros EEG en 15 portadores asintomáticos de la mutación E280A y 15 personas sanas no portadoras durante una tarea de memoria y en reposo utilizando un amplificador de 64 canales. En la tarea de memoria se evaluaron dos condiciones: codificación y evocación; el proceso de memorizar y recuperar la información, respectivamente. La potencia espectral fue calculada en las bandas de frecuencia delta (0,5-4,0 Hz), teta (4,0-8,0 Hz), alfa-1 (8,0-10,0 Hz), alfa-2 (10,0-13,0 Hz), beta (13,0-25,0 Hz) y gamma (25,0-50 Hz) para cuatro regiones de interés. Los cambios del espectro fueron evaluados por análisis de varianza ANOVA. Resultados: bajo la condición de reposo se encontró una disminución importante en la potencia de la banda teta (p=0,0001) y un incremento en la banda alfa-2 (p=0,037) en portadores comparados con controles. Durante la tarea de codificación, los portadores mostraron una disminución significativa en la banda teta (p=0,008). Al comparar reposo contra memoria de evocación se encontró una mayor sincronización en teta en los portadores de la mutación. Conclusión: se encontraron cambios tempranos de la potencia en la banda teta que pueden ser utilizados como un marcador clínico de la enfermedad en esta población. Una hipótesis adicional basada en los resultados es que los portadores necesitan ...

Effects of Psychotropic Drugs on Quantitative EEG among Patients with Schizophrenia-spectrum Disorders

OBJECTIVE: We examined how psychotropic medications affected quantitative EEG (qEEG) results among patients with a schizophrenia-spectrum disorder. METHODS: The drugs were clustered into nine groups depending on their mechanism. We hypothesized that drugs would affect the relative power shown in qEEG results independently and investigated the effect of each drug group on relative power using multiple linear regression analysis and independent samples t-tests. RESULTS: We found that antipsychotics other than clozapine induced an increase in the relative power of alpha activity. Clozapine markedly increased slow waves and decreased alpha activity in the occipital area. The main findings for antidepressants and antiepileptic drugs were the beta increment and lithium increased the power of delta and theta activity. However, we found no evident changes in power due to benzodiazepine. CONCLUSION: Our results are generally consistent with previous pharmaco-EEG studies, despite some differences. Therefore, the EEG effect in each drug group could be singled out even under the polypharmacy condition, with the possible exception of benzodiazepines. Our results support using a new methodological approach to identify the qEEG effects of various psychotropic drugs in clinical settings.

The Clinical use of quantitative EEG in cognitive disorders / A utilização clínica do EEG quantitativo nos transtornos cognitivos

Abstract: The primary diagnosis of most cognitive disorders is clinically based, but the EEG plays a role in evaluating, classifying and following some of these disorders. There is an ongoing debate over routine use of qEEG. Although many findings regarding the clinical use of quantitative EEG are awaiting validation by independent investigators while confirmatory clinical follow-up studies are also needed, qEEG can be cautiously used by a skilled neurophysiologist in cognitive dysfunctions to improve the analysis of background activity, slow/fast focal activity, subtle asymmetries, spikes and waves, as well as in longitudinal follow-ups.

Resumo: O uso clínico do EEG Quantitativo nas doenças cognitivas. O diagnóstico das doenças cognitivas geralmente é clínico mas o EEG é importante como exame auxiliar na avaliação, diagnóstico e classificação de algumas delas. O debate atual refere-se ao uso clínico do EEGq. Embora muitos achados no EEGq ainda aguardem validação, o EEGq pode ser usado cautelosamente em situações específicas e por um neurofisiologista experiente. Nas doenças cognitivas ele pode contribuir na análise da atividade de base, em atividades focais lentas ou rápidas, assimetrias sutís, pontas e ondas e no acompanhamento longitudinal dos pacientes.

The influence of bromazepam on cortical power distribution

The EEG has been widely employed in the assessment of electrophysiological changes induced by distinct medications. Its sensibility in detecting alterations produced by a specific substance may be enhanced by methods of quantitative analyses (qEEG). The present study aimed at investigating the modulatory effects of bromazepam on brain dynamics. The effects of bromazepam (3mg) on EEG power distribution were tested in 10 healthy individuals, in a double-blind experiment. The electrophysiological measure was analyzed across experimental conditions, moments, and electrodes, in the delta, theta, alpha and beta frequency bands separately. A significant decrease of relative power was observed in delta and theta (main effect of condition). No interactions were observed. Although the expected anxiolytic EEG profile was not observed (increased beta and decreased alpha activity), this specific result may be related to other factors such as dosage used and the subjects' general physiological state, and not necessarily to the drug itself.

O EEG tem sido amplamente empregado na avaliação de mudanças eletrofisiológicas induzidas por medicações distintas.A sensibilidade desta técnica em detectar alterações produzidas por uma substância pode ser aprimorada por métodos de análise quantitativa (EEGq). O presente estudo teve por objetivo investigar os efeitos modulatórios do bromazepam na dinâmica cerebral. Os efeitos de 3mg de bromazepam na distribuição de potência cortical foram observados em 10 indivíduos sadios, em um desenho duplo-cego. A medida eletrofisiológica foi analisada nas diferentes condições experimentais, momentos e eletrodos, em delta, teta, alfa e beta separadamente. Uma diminuição significativa de potência relativa foi observada em delta e teta (efeito principal para condição). Não foram observadas interações. Embora o perfil ansiolítico do EEG (aumento de beta e diminuição de alfa) não tenha sido observado, esteresultado específico pode estar relacionado a outros fatores, tais como dose utilizada e estado fisiológico dos sujeitos, e não necessariamente à droga propriamente dita.

Usefulness of Quantified-EEG in Alzheimer's Disease

BACKGROUND: The conventional electroencephalography (EEG) is commonly used as an aid in the diagnosis of Alzhiemer's disease (AD). Recently developed quantitative electroencephalography (qEEG) provides data that are not achievable by conventional EEG. Nevertheless, the clinical reliability and usefulness of spectral analysis and topographic mapping is still a matter of controversy in the diagnosis of Alzheimer's disease. The aim of this study was to compare the topographical quantitative EEG (qEEG) changes between elderly controls and AD patients. METHODS: We analyzed the absolute, relative spectra power and occipital peak frequency taken from 16 derivations by averaging twenty-2-sec epoch in elderly controls and AD patients. After logarithmic transformations of absolute and relative power, a statistical test was done and occipital peak frequency was compared with each other. RESULTS: (1) Compared with normal controls, AD patients had a significantly lower alpha and beta spectra power as well as a significant higher delta spectra power. (2) In AD patients, the peak frequency in occipital lead had a significantly lower frequency than that of elderly controls. (3) Korean Mini-Mental State Examination(K-MMSE) scores were closely related in delta and alpha band power in nearly all electric leads. (4) Compared to absolute power, relative power was a more sensitive tools in detecting changes of EEG in AD patients. CONCLUSIONS: This study suggests that qEEG is a useful tool for detecting the electroencephalographic changes of AD, and correlated with the severity of cognitive dysfunction. Moreover, absolute and relative spectra power is complementary in the clinical utility of qEEG.

Cerebral Functional Localization Related to Attentional Work in Patients with Attention-Deficit Hyperactivity Disorder / 신경정신의학

OBJECTIVES: The attentional deficit is a core symptom in attention deficit hyperactivity disorder. The major brain areas related to attention are frontal and parietal lobes. Abnormalities of frontal and parietal lobes in attention deficit hyperactivity disorder have been reported in previous researches. But, most of the researches are based on comparing patients and controls while they are in resting condition. Further research on funtional changes related to performance of attentional task is needed to understand the attentional dysfuntion in attention deficit hyperactivity disorder. In this study, the localized functional changes of the brains related to attentional task in patients with attention deficit hyperactivity disorder and the differences of them between patients and normal controls were examined. Also the effect of the methylphenidate on functional changes related to attentional task in patients with attention deficit hyperactivity disorder was examined. METHOD: Quantitative electroencephalography (QEEG) was applied to examine the fuctional changes related to attentional task. Subjects of this study consisted of 20 patients with attention deficit hyperactivity disorder and 20 controls who were matched age, sex, handedness, intelligence. QEEG was recorded on eye open resting condition, and on performing computerized attentional task. In cases of patients, after taking of methylphenidate, QEEG was recorded on both conditions. RESULTS: 1)In attention test, normal controls had better scores in response time and variabilities of response time than those of patients with attention deficit hyperactivity disorder without taking methylphenidate. After taking medication, scores of omission, response time and variabilities of response time were significantly improved, comparing to scores without taking medication. No differences were recognized between the controls and patients with taking medication in scores of attention test. 2)In resting condition, spectral EEG revealed baseline activity levels of patients were significantly increased comparing to those of controls. 3)Analysis of delta wave revealed that amplitudes of controls were significantly elevated in parieto-occipital area during performance of attentional task. But in patients, localized activated area related to attentional task was not remarkable. 4)Theta activity of controls were significantly elevated in right frontal, right temporal, and both parieto-occipital areas during performance of attentional task. But in patients without taking medication, localized activated area related to attentional work was not remarkable. After taking medication, right frontal, right temporal, and both parieto-occipital areas were significantly activated. 5)Alpha activities of controls were significantly increased in parieto-occipital area during performance of attentional task, but those of patients without taking medication were increased in broad area. 6)Beta activities of controls were significantly increased in frontal area during attentional performance, but those of patients without taking medication were significantly increased in most of the brain areas. After taking medication, significantly increased activities related to attentional task were recognized in left frontal, and both temporal areas. Localized activated patterns similar to those of controls were recognized. CONCLUSION: Based on the results of this research, it is suggested that patients with attention deficit hyperactivity disorder have increased baseline brain activity. In controls, brains showed localized response to a attentional stimuli, and functional changes related to attentional stimuli were recognized in frontal, and parieto-occipital areas. But, patients failed in showing appropriate localized activated response to attentional stimuli. It is concluded that frontal and parieto-occipital areas have some deficit responsible for the attentional dysfunction of attention deficit hyperactivity disorder.

Quantitative EEG Changes during Verbal Memory Task Performance in Schizophrenia / 대한정신약물학회지

OBJECTIVE: Under the hypothesis that activated brain regions of patients with schizophrenia differ from those of normal subjects during memory task performance, this study was aimed to investigate topographic changes related to memory functions in schizophrenia. METHOD: Subjects of this study consisted of 20 unmedicated patients with schizophrenia and 19 normal controls who were matched for age, sex, and handedness. Quantitative EEG(QEEG) with 32 channels was recorded with eyes closed(EEG0) and open(EEG1) in a resting condition and during computerized verbal encoding(EEG2) and recognition(EEG3) tasks. RESULTS: During EEG1, 2, and 3, there was a decrease in alpha activity in both groups compared to EEG0 and the change in alpha activity of patients was significantly lesser than normal controls in the occipital region. Pairwise comparison showed that the alpha activity of normal controls significantly increased from EEG1 to EEG2 in the parietal region and from EEG1 to EEG3 in all regions except both frontal regions while those of patients did not change. The beta activity of normal controls significantly increased from EEG1 to EEG2 in both temporal regions and from EEG1 to EEG3 in the frontal, temporal, and parietal regions while those of patients significantly increased only in the parieto-occipital region. CONCLUSION: These results indicate that the frontal lobe, temporal lobe, and thalamus are not appropriately activated during memory tasks in schizophrenia. It may be proposed that the learing of visually presented words in patients with schizophrenia depends on distinct memory process such as priming.

Computerized EEG and Neuropsychopharmacology / 대한정신약물학회지

In parallel to rapid popularization of personal computers, EEG studies in psychiatric field have become one of important and indispensable methods particularly because of appearance of topographical imaging of scalp EEG b ased on quantitative techaics of convational qualitative ones. Pharmaco-EEG has been an example of quantitative EEG, which is quite useful in objectively predicting clinical efficacies of newly developed substance in healthy subject before giving it to patient with supposed targel from animal experiments. It is also usable in predicting clinical outcomes of psychotic disorder only single dose administration of the drug selected for the treatment. It may be quite evident that we have not necessarily to interpret EEG tracings by replacing them with EEG imagings, which are comparable to the other brain imagings such as CT, SPECT, PET and MRl. The author has proposed the creation of tele-EEG network systems through telephone line in near future.