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Background High levels of physical conditioning are associated with improvements in cognitive performance. In this sense, electroencephalographic (ECG) correlates are used to investigate the enhancing role of physical exercise on executive functions. Oscillations in the β frequency range are proposed to be evident during sensorimotor activity.

Background The saccadic eye movement is responsible for providing focus to a visual object of interest to the retina. In sports like volleyball, identifying relevant targets quickly is essential to a masterful performance. The training improves cortical regions underlying saccadic action, enabling more automated processing in athletes.

Aim: The present study investigated the differences between the Panic Disorder (PD) patients groups’ and healthy controls for the EEG alpha dynamics under the frontal cortex and reaction time during the oddball task. Material and Methods: The reaction time during the oddball paradigm concomitant to EEG alpha power was tested in nine PD patients and ten healthy controls before and after a computer simulation presentation. Results: The findings revealed a decrease in EEG alpha power in PD patients concerning the control group (p ≤ 0.0125). However, both groups demonstrated an increased cortical oscillation after the computer simulation, except for the Fp1 electrode during M3 moment in the experimental group. The experimental group has a fast reaction time compared to healthy individuals during the oddball task (p = 0.002). Conclusions: We propose that the decrease in EEG alpha power in the PD patients may indicate an increase in processing related to an anxiogenic stimulus and interference of the anxiety state that compromises the inhibitory control. The reaction time task reveals cognitive symptoms in the experimental group, which may be related to the faster reactivity and high impulsivity to stimuli.

Abstract Background: Motor Imagery (MI) represents the cognitive component of the movement and recruits dopaminergic systems. Objective: To investigate the role of dopaminergic system through the action of methylphenidate and risperidone over beta coherence during execution, action observation and motor imagery. Methods: Electroencephalography (EEG) data were recorded before and after the substance intake. For statistical analysis, a three-way ANOVA was used to identify changes in beta coherence induced by the group, task and the moment variables. Statistical significance was set at p≤0.007. Results: We found a main effect for group for C3/CZ, and a main effect for task for CZ/C4 pairs of electrodes. Furthermore, significant differences were found in the post-drug administration between groups for C3/CZ pair of electrodes, and between task for C4/CZ pair of electrodes. Conclusion: The administration of methylphenidate and risperidone was able to produce electrocortical changes of the cortical central regions, even when featuring antagonistic effects on the dopaminergic pathways. Moreover, the execution task allowed beta-band modulation increase.

Cardiac responses to appetitive stimuli have been studied as indices of motivational states and attentional processes, the former being associated with cardiac acceleration and latter deceleration. Very few studies have examined heart rate changes in appetitive classical conditioning in humans. The current study describes the development and pilot testing of a classical conditioning task to assess cardiac responses to appetitive stimuli and cues that reliably precede them. Data from 18 adults were examined. They were shown initially neutral visual stimuli (putative CS) on a computer screen followed by pictures of high-caloric food (US). Phasic cardiac deceleration to food images was observed, consistent with an orienting response to motivationally significant stimuli. Similar responses were observed to non-appetitive stimuli when they were preceded by the cue associated with the food images, suggesting that attentional processes were engaged by conditioned stimuli. These autonomic changes provide significant information about classical conditioning effects in humans.

Ethanol (ET) is a substance that modulates the Central Nervous System (CNS). Frequently, ET intake occurs combined with energy drinks, which contain taurine (TA), an important amino acid found in the body (i.e brain and muscles). Although TA administration has been used in the improvement of physical performance, the impact of TA, ET and exercise remains unknown. This study aimed to analyze the acute effect of 6g of Taurine (TA), 0.6 mL∙kg-1 of Ethanol (ET), and Taurine combined with Ethanol (TA+ET) ingestion on the electrocortical activity before and after a moderate intensity exercise in 9 subjects, 5 women (counterbalanced experimental design). In each of the 4 treatments (Placebo-PL, TA, ET and TA+ET), electroencephalography (EEG) tests were conducted in order to analyze changes in absolute beta power (ABP) in the frontal lobe in 3 moments: baseline (before ingestion), peak (before exercise) and post-exercise. In the PL treatment, the frontal areas showed decrease in ABP after exercise. However, in the ET+TA treatment, ABP values were greater after exercise, except for Fp1. The ET treatment had no effect on the Superior Frontal Gyrus area (F3, Fz and F4) and ABP decreased after exercise in Fp1 and Fp2. In the TA treatment, ABP increased after exercise, while it decreased at the peak moment in most of the frontal regions, except for Fp1, F3 and Fz. We concluded that after a moderate intensity exercise, a decrease in cortical activity occurs in placebo treatment. Moreover, we found a inhibitory effect of TA on cortical activity before exercise and a increased in cortical activity after exercise. A small ET dose is not enough to alter ABP in all regions of the frontal cortex and, in combination with TA, it showed an increase in the frontal cortex activity at the post-exercise moment.

ABSTRACTObjective Our aim was to investigate and compare the neuromodulatory effects of bromazepam (6 mg) and modafinil (200 mg) during a sensorimotor task analyzing the changes produced in the absolute alpha power.Method The sample was composed of 15 healthy individuals exposed to three experimental conditions: placebo, modafinil and bromazepam. EEG data were recorded before, during and after the execution of the task. A three-way ANOVA was applied, in order to compare the absolute alpha power among the factors: Group (control, bromazepam and modafinil) Condition (Pre and Post-drug ingestion) and Moment (pre and post-stimulus).Results Interaction was found between the group and condition factors for Fp1, F4 and F3. We observed a main effect of moment and condition for the Fp2, F8 and Fz electrodes.Conclusion We concluded that drugs may interfere in sensorimotor processes, such as in the performance of tasks carried out in an unpredictable scenario.

The present study investigates the influence of bromazepam while executing a motor task. Specifically, we intend to analyze the changes in alpha absolute power under two experimental conditions, bromazepam and placebo. We also included analyses of theta and beta frequencies. We collected electroencephalographic data before, during, and after motor task execution. We used a Two Way ANOVA to investigate the condition (PL × Br6 mg) and moment (pre and post) variables for the following electrodes: Fp1, Fp2, F7, F3, Fz, F4, F8, C3, CZ and C4. We found a main effect for condition on the electrodes FP1, F7, F3, Fz, F4, C3 and CZ, for alpha and beta bands. For beta band we also found a main effect for condition on the electrodes Fp2, F8 and C4; for theta band we identified a main effect for condition on C3, Cz and C4 electrodes. This finding suggests that the motor task did not have any influence on the electrocortical activity in alpha, and that the existing modifications were a consequence due merely to the drug use. Despite its anxiolytic and sedative action, bromazepam did not show any significant changes when the individuals executed a finger extension motor task.

El procesamiento digital de la señal de electroencefalograma (EEG) ha tomado importancia en el monitoreo de profundidad anestésica, contribuyendo a una mejor técnica anestésica. El objetivo es realizar una revisión de métodos matemáticos no lineales aplicados recientemente al análisis de EEG la cual presenta características no lineales y no estacionarias. Una revisión fue desarrollada abarcando métodos matemáticos no lineales en el dominio del tiempo y frecuencia, los cuales han sido aplicados recientemente al análisis de EEG: Entropía Aproximada, Entropía Muestral, Entropía Espectral, Entropía Permutada, Transformada Wavelet, Entropía Wavelet, Bispectro, Bicoherencia y Transformada Hilbert Huang. Los algoritmos implementados fueron probados en un registro EEG de un paciente en la Clínica Universidad de La Sabana. Resultados publicados en la literatura a fin del tema son discutidos. Técnicas no lineales como el análisis de entropía, y la combinación con transformadas Wavelet y Hilbert Huang en el dominio de la frecuencia han presentado resultados prometedores en clasificación de estados de profundidad anestésica.

Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners’ ability to limit the processing of unnecessary information (e.g., discursive thought) and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.

Some studies have reported the importance of electroencephalography (EEG) as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD), discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals. Keywords: Electroencephalography, panic disorder, neurobiology, brain mapping.

The saccadic movement is an important behavioral measure used to investigate several cognitive processes, including attention and sensorimotor integration. The present study aimed at investigating changes in beta coherence over frontal, motor, occipital, and parietal cortices during the performance of two different conditions of a prosacadic paradigm. The conditions involved a different pattern of stimulus presentation: a fixed and random stimulus presentation. Twelve healthy volunteers (three male, mean age of 26.25 (SD=4.13) performed the task, while their brain activity pattern was recorded using quantitative electroencephalography. The results showed an interaction between factors condition and moment for the pair of electrode C3/C4. We observed a main effect for moment to CZ/C4, FZ/F3, and P3/PZ. We also found a main effect for condition to FZ/F4, P3/P4, and O1/O2. Our results demonstrated an important role of the inter-connection of the two hemispheres in visual search and movement preparation. The study demonstrates an automation of action and reduction of the focus of attention during the task. We also found that the inter-hemispheric beta coherence plays an important role in the differentiation of the two conditions, and that beta in the right frontal cortex is able to differentiate the conditions, demonstrating a greater involvement of procedural memory in fixed condition. Our results suggest a neuronal specialization in the execution of prosacadic paradigm involving motor task sequence.

The present study aimed at investigating changes in behavior (shooting precision) and electrophysiological variables (absolute alpha power) during the motor learning of practical pistol shooting. The sample was composed of 23 healthy subjects, right-handed, male, between 18 and 20 years of age. The task consisted of four learning blocks. A One-way ANOVA with repeated measures and a post hoc analysis were employed to observe modifications on behavioral and electrophysiological measures (pO presente estudo teve por objetivo investigar alterações nas variáveis comportamentais (precisão do tiro) e eletrofisiológicas (potência absoluta de alfa) durante o aprendizado motor do tiro prático de pistola. A amostra constituiu-se de 20 sujeitos saudáveis, destros, sexo masculino, faixa etária entre 18 e 20 anos. A tarefa consistiu de quatro blocos de aprendizagem. A análise estatística das variáveis comportamentais e eletrofisiológicas foram realizadas por meio de uma ANOVA one-way e uma análise post hoc (p

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.

The goal of the present study was to investigate electrophysiologic, qEEG, changes when individuals were exposed to a motor task. Subjects’ brain electrical activity was analyzed before and after the typewriting training task. For the neurophysiological variable asymmetry, a paired t-test was performed to compare each moment, pre and post-task, in the beta bands. The findings showed a change for the qEEG variable in each scalp site, F3/F4; C3/C4 and P3/P4. These results suggest an adaptation of pre-frontal, sensory-motor and parietal cortex, as a consequence of the typewriting training.O objetivo do presente estudo foi investigar mudanças eletrofisiológicas através do EEGq quando indivíduos são expostos a uma tarefa motora. A atividade elétrica no córtex dos sujeitos foi analisada antes e após o treinamento da tarefa motora. Para a variável neurofisiológica assimetria, um teste t foi implementado para comparar cada momento, pré e pós-tarefa, na banda beta. Os achados demonstraram mudança em assimetria para as seguintes regiões no escalpo: F3/F4, C3/C4 e P3/P4. Estes resultados sugerem uma adaptação das regiões pré-frontal, somatosensorial e parietal como conseqüência do treinamento de datilografia.

The aim of this study was to verify changes in absolute power (qEEG), in theta, during the catch of a free falling object. The sample consisted of 10 healthy individuals, of both genders, with ages between 25 and 40 years. A three-way ANOVA followed by Post-Hoc analysis was applied. The results demonstrated main effects for time and position. In conclusion, a motor task that involves expectation produces deactivation of non-relevant areas in the ipsilateral hemisphere of the active limb. On the other hand, the patterns of results showed activation in areas responsible for planning and selection of motor repertories in the contralateral hemisphere.O objetivo deste estudo foi verificar mudanças na potência absoluta (EEGq), em teta, durante a pegada de objeto em queda livre. A amostra consistiu de 20 indivíduos saudáveis, de ambos os gêneros, com idade entre 25 e 40 anos. Foi utilizada uma ANOVA three-way seguida de uma análise Post-Hoc. Os resultados demonstraram efeito principal para momento e posição. Concluindo, uma tarefa motora que envolve expectativa produz desativação de áreas não-relevantes no hemisfério ipsilateral do membro ativo. Por outro lado, o padrão dos resultados mostrou ativação em áreas responsáveis por planejamento e seleção de repertórios motores no hemisfério contralateral.

Exercise has been widely related to changes in cortical activation and enhanced brain functioning. Quantitative electroencephalography (qEEG) is frequently used to investigate normal and pathological conditions in the brain cortex. Therefore, the aim of the present study was to observe absolute power alterations in beta and alpha frequency bands after a maximal effort exercise. Ten healthy young volunteers were submitted to an eight-minute resting EEG (eyes closed) followed by a maximal exercise test using a mechanical cycle ergometer. Immediately after the exercise, another identical eight-minute EEG was recorded. Log transformation and paired student's t-test compared the pre and post exercise values (pA atividade física vem sendo relacionada com ativação cortical e melhor funcionamento do cérebro. A eletrencefalografia quantitativa (EEGq) é freqüentemente usada para investigar condições normais e patológicas do córtex cerebral. Sendo assim, o objetivo do presente estudo foi observar alterações na potência absoluta nas bandas de freqüência alfa e beta após um exercício de esforço máximo. Dez voluntários jovens e saudáveis foram submetidos a oito minutos de EEG antes e após um teste de esforço máximo em cicloergômetro. As transformações para o log e o teste t de Student foram utilizados para comparar as respostas eletrencefalográficas entre os momentos pré e pós exercício. Foi observado aumento significativo na potência absoluta de beta após o exercício nos eletrodos frontais (Fp1, F3, F4) e centrais (C4). Este resultado pode estar associado a alterações fisiológicas e ao aumento da ativação cortical.

The aim of this study is analyze possible modifications in the cerebral cortex, through quantitative electroencephalography (qEEG) in patients submitted to a tendon transfer procedure (posterior tibialis) by the Srinivasan's technique. Four subjects (2 men and 2 women), 49.25 age average (SD±21.4) were studied. All subjects have been through surgical procedure due to leprosy and had, at least, two years of drop foot condition. The qEEG measured the electrocortical activity (relative power) between 8 and 25 Hz frequencies pre and post surgery. A paired t test analyzed all data (pO objetivo deste estudo é analisar possíveis modificações no córtex cerebral, através da electrencefalografia quantitativa (EEGq), em pacientes submetidos a um procedimento de transferência de tendão (tibial posterior) pela técnica de Srinivasan. Quatro sujeitos (2 homens e 2 mulheres), com média de idade de 49,25 anos (±21,4 DP) foram estudados. Todos os sujeitos realizaram o procedimento cirúrgico devido a hanseníase e tinham, pelo menos, dois anos de pé caído. O EEGq mediu a atividade electrocortical (potencia relativa) entre freqüências de 8 e 25 Hz, no pré e pós-operatório. Um teste t pareado analisou todos os dados (p

The main goal of the present study was to analyze theta asymmetry through quantitative electroencephalography (qEEG) when individuals were exposed to a sequential motor task, i.e. catching a ball. The sample was composed of 23 healthy subjects, male and female, between 25 and 40 years of age. A two-way factor Anova was applied to compare pre and post moments related to the balls' drop and scalp regions (i.e., frontal and parieto-occipital cortices). The first analysis of the frontal region compared electrodes in the left, right and left/right hemispheres combined, with the frontal midline electrode (FZ) included in the analysis. The results showed moment and region main effects. The second analysis compared left versus right hemisphere without the FZ site. The findings demonstrated an interaction effect between moment and region. The first parieto-occipital analysis, comparing left, right and central regions, with PZ included in all regions, showed main effects of moment and region. The second analysis, comparing left, right (without Pz) and central regions strictly demonstrated a region main effect. Thus, we observed an asymmetric pattern in the frontal cortex (i.e., planning and response selection) when the subjects were waiting for the balls' drop. Moreover, the left hemisphere seems to engage differently from the other regions when the central nervous system needs to prepare for a motor action. On the other hand, the parieto-occipital cortex, which is related to attentive processes, demonstrated a more asymmetric activity towards the right region which implies a participation of this area in cognitive strategies in this particular task. Taken together, we concluded that the adopted experimental approach can be useful to explore several others directions combining sensorimotor integration tasks with different pathologies, such as depression, Alzheimer's and Parkinson's diseases.O objetivo do presente experimento foi avaliar medidas de assimetria na banda teta através da electroencefalografia quantitativa (EEGq) durante a realização da atividade motora de apreensão de uma bola em queda livre. A amostra constituiu-se de 23 sujeitos saudáveis de ambos os sexos, faixa etária entre 25 e 40 anos. Anova two-way foi utilizada para comparar os momentos pré e pós relacionados à queda da bola, e às regiões do escalpo (córtex frontal e parieto-occipital). A primeira análise da região frontal comparou eletrodos nos hemisférios esquerdo, direito e esquerdo/direito combinados, incluindo na análise o eletrodo frontal mediano (FZ). O resultado demonstrou um efeito principal para momento e região. A segunda análise comparou os hemisférios direito e esquerdo, sem o eletrodo FZ. Neste achado verificou-se um efeito principal para a interação entre os fatores momento e região. A primeira análise realizada na região parieto-occipital comparou as regiões esquerda, direita e central, com PZ incluídos em todas as áreas, demonstrou efeito principal para momento e região. A segunda análise comparou as regiões esquerda, direita (sem PZ) e central, e verificou-se um efeito principal para região. Tais achados indicaram um padrão de assimetria no córtex frontal (ex., planejamento e seleção de resposta) no momento em que os sujeitos esperavam a queda da bola. Além disso, o hemisfério esquerdo parece engajar-se diferentemente em relação às outras regiões quando o sistema nervoso central necessita se preparar para uma ação motora. Por outro lado, o córtex parieto-occipital, o qual está envolvido com processos de atenção, demonstrou uma maior assimetria no hemisfério direito, o que implica uma participação dessa área em estratégias cognitivas para uma tarefa particular. Então, podemos concluir que o procedimento experimental adotado pode ser utilizado para explorar diferentes direções combinando tarefas de integração sensório-motora com diferentes patologias, tais como depressão, doença de Alzheimer e mal de Parkinson.

The aim of the present study was to evaluate coherence measures at Theta through qEEG during the accomplishment of a specific motor task. The sample consisted of 23 healthy individuals, both sexes, with ages varying between 25 and 40 years old. All subjects were submmitted to a specific motor task of cacthing sequences of falling balls. A three-way ANOVA was employed for the statistical analysis, which demonstrated main effects for the following factors: time, block and position. However, there was no interection between the factors. A significant and generalized coherence reduction was observed during the task execution time. Coherence was also diminished at the left frontal cortex and contralateral hemisphere of the utilizing limb (comparing to the right frontal cortex). In conclusion, these findings suggest a certain specialization of the neural circuit, also according to previous investigations. The inter-coherence reduction suggests a spatial inter-electrode dependence during the task, rather than a neuronal specialization.O objetivo do presente experimento foi avaliar medidas de coerência na banda Teta através do EEGq durante a realização de uma atividade motora. A amostra constituiu-se de 23 sujeitos saudáveis, ambos os sexos, faixa etária entre 25 e 40 anos. Os sujeitos foram submetidos à tarefa motora de apreensão seqüencial de bolas em queda livre. Para análise estatística foi realizada uma ANOVA (Three-Way) que demonstrou efeito principal para os fatores: momento, tempo e posição. Porém não houve interação entre os fatores. Uma diminuição generalizada significativa da coerência ocorreu ao longo do tempo de execução da tarefa que também se apresentou reduzida no córtex frontal esquerdo, hemisfério contralateral ao membro utilizado (em comparação com o córtex frontal direito). Em conclusão, estes achados sugerem especialização do circuito neural que estão em consonância com experimentos prévios. A diminuição da coerência inter-hemisférica sugere uma dependência espacial inter-eletrodos durante a tarefa e não uma especialização neuronal.

The present study aimed at comparing frontal beta power between long-term (LTM) and first-time meditators (FTM), before, during and after a meditation session. We hypothesized that LTM would present lower beta power than FTM due to lower effort of attention and awareness.Twenty one participants were recruited, eleven of whom were long-term meditators. The subjects were asked to rest for 4 minutes before and after open monitoring (OM) meditation (40 minutes).The two-way ANOVA revealed an interaction between the group and moment factors for the Fp1 (p

Intermittent photic stimulation (IPS) is an important functional test, which can induce the photic driving in the electroencephalogram (EEG). It is capable of enhancing latent oscillation’s manifestations not present in the resting EEG. However, for adequate quantitative evaluation of the photic driving, these changes should be assessed on a statistical basis. With this aim, the sampling distribution of spectral F test was investigated. On this basis, confidence limits of the SFT-estimate could be obtained for different practical situations, in which the signal-to-noise ratio and the number of epochs used in the estimation may vary. The technique was applied to the EEG of 10 normal subjects during IPS, and allowed detecting responses not only at the fundamental IPS frequency but also at higher harmonics. It also permitted to assess the strength of the photic driving responses and to compare them in different derivations and in different subjects.A fotoestimulação intermitente (FEI) é um importante teste functional, que pode induzir o fotorecrutamento no eletroencefalograma (EEG), sendo capaz de realçar manifestações latentes de oscilações não observadas no EEG de repouso. Entretanto, para uma análise quantitativa adequada do fotorecrutamento, tais alterações devem ser avaliadas com base estatística. Assim, a distribuição de probabilidade do teste-F espectral (TFE) foi investigada. Neste sentido, limites de confiança para a estimativa do TFE puderam ser obtidos para diferentes situações práticas, nas quais a razão sinal-ruído e o número de épocas usadas na estimação podem variar. A técnica foi aplicada ao EEG de 10 sujeitos normais durante FEI, e permitiu a detecção de respostas não somente na freqüência fundamental da FEI como também em seus harmônicos. Além disso, permitiu avaliar o grau de fotorecrutamento entre derivações distintas e entre diferentes sujeitos.

The objective of the study was to describe seasonality of hospitalizations for heart failure in tropical climate as it has been described in cold climates. Seasonal Auto-regressive Integrated Moving-Average model was applied to time-series data of heart failure hospitalizations between 1996 and 2004 in Niteroi (Southeastern Brazil), collected from the Brazilian National Health Service Database. The standard seasonal variation was obtained by means of moving-average filtering and averaging data. The lowest and the highest annual hospital admissions were 507 (1997) and 849 (2002), respectively; the lowest and the highest monthly rates were 419 (December) and 681 (October), respectively. Peak admission rates were seen during the fall and winter. Although weak, the seasonality observed indicates that slight variations result in increased hospitalizations for heart failure.El objetivo del estudio fue describir la estacionalidad de las hospitalizaciones por insuficiencia cardiaca en climas tropicales, aspecto ya conocido en climas fríos. Se aplicó el Modelo Estacional Auto-Regresivo Integrado de Promedios Móviles a una serie histórica de 6.596 hospitalizaciones por insuficiencia cardiaca en el municipio de Niteroi, Sureste de Brasil, de 1996 a 2004, obtenida del Banco de Datos del Sistema Único de Salud. La variación estacional estándar fue obtenida por medio de la filtración y cálculo del promedio-móvil de los datos. El menor número de hospitalizaciones por año fue 507 (1997) y el mayor 849 (2002); e por mes 419 (diciembre) y 681 (octubre), respectivamente. Se observaron picos de internación en otoño e invierno. A pesar de que fue débil, la estacionalidad observada muestra que una pequeña variación puede llevar al aumento de hospitalizaciones.O objetivo do estudo foi descrever a sazonalidade das hospitalizações por insuficiência cardíaca em climas tropicais, aspecto já conhecido em climas frios. Aplicou-se o Modelo Sazonal Auto-Regressivo Integrado de Médias Móveis a uma série histórica de 6.596 hospitalizações por insuficiência cardíaca no município de Niterói, RJ, de 1996 a 2004, obtida do Banco de Dados do Sistema Único de Saúde. A variação sazonal padrão foi obtida por meio da filtragem e cálculo da média-móvel dos dados. O menor número de hospitalizações por ano foi 507 (1997) e o maior 849 (2002); e por mês 419 (dezembro) e 681 (outrubro), respectivamente. Foram observados picos de internação no outono e inverno. Ainda que fraca, a sazonalidade observada mostra que uma pequena variação pode levar ao aumento de hospitalizações.

This study aimed to elucidate electrophysiological and cortical mechanisms involved in anticipatory actions when individuals had to catch balls in free drop; specifically through quantitative electroencephalography (qEEG) alpha absolute power changes. The sample was composed for 23 health subjects, both sexes, with ages varying between 25 and 40 years, absence of mental and physical illness, right handed and don't make use of any psychoactive or psychotropic substance at the time of the study. The experiment consisted of a task of catching balls in free drop. The three-way ANOVA analysis demonstrated an interaction between moment and position factors in left parietal posterior cortex (PPC) (p=0.001). Through the experimental task employed, this area demonstrated a differentiated activity involving expectation, planning and preparedness in the ball's drop task.O estudo tentou elucidar mecanismos eletrofisiológicos e corticais envolvidos em ações antecipatórias quando os sujeitos testados tiveram que apreender bolas em queda livre; especificamente através de mudanças na potência absoluta na banda alfa da eletrencefalografia quantitativa (EEGq). A amostra foi composta por 23 sujeitos sadios, ambos os sexos, idade entre variando entre 25 e 40 anos, sem comprometimento físico e mental, destros, e não fazer uso de nenhuma substância psicoativa ou psicotrópicos até o momento do estudo. O experimento consistiu de uma tarefa de apreensão de bolas em queda livre. A análise three-way ANOVA demonstrou uma interação entre os fatores momento e posição no córtex parietal posterior (CPP) esquerdo (p=0,001). Através da tarefa experimental empregada, esta área demonstrou uma atividade diferenciada envolvendo expectativa, planejamento e prontidão na tarefa de queda de bolas.

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes.

The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2), N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) and the reaction time (RT). In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) was found. Therefore, we propose that if the secondary processing of visual input (P200 latency) occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency), motor response processing (PMP latency), reorganization of attention and working memory update (P300 latency), and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude).