Search

Our objective is to verify the modulatory effects of bromazepam on EEG theta absolute power when subjects were submitted to a visuomotor task (i.e., car driver task). Sample was composed of 14 students (9 males and 5 females), right handed, with ages varying between 23 and 42 years (mean = 32.5 ± 9.5), absence of mental or physical impairments, no psychoactive or psychotropic substance use and no neuromuscular disorders (screened by a clinical examination). The results showed an interaction between condition and electrodes (p = 0.034) in favor of F8 electrode compared with F7 in both experimental conditions (t-test; p = 0.001). Additionally, main effects were observed for condition (p = 0.001), period (p = 0.001) and electrodes (p = 0.031) in favor of F4 electrode compared with F3. In conclusion, Br 6 mg of bromazepam may interfere in sensorimotor processes in the task performance in an unpredictable scenario allowing that certain visuospatial factors were predominant. Therefore, the results may reflect that bromazepam effects influence the performance of the involved areas because of the acquisition and integration of sensory stimuli processes until the development of a motor behavior based on the same stimuli.

The study aimed to elucidate electrophysiological and cortical mechanisms involved in anticipatory actions when healthy subjects had to catch balls in free drop; specifically through quantitative electroencephalography (qEEG) alpha absolute power changes. Our hypothesis is that during the preparation of motor action (i.e., 2s before ball's drop) occurred integration among left medial frontal, left primary somatomotor and left posterior parietal cortices, showing a differentiated activity involving expectation, planning and preparedness. This hypothesis supports a lateralization of motor function. Although we contend that in right-handers the left hemisphere takes on a dominant role for the regulation of motor behavior. The sample was composed of 23 healthy subjects (13 male and 10 female), right handed, with ages varying between 25 and 40 years old (32.5+/-7.5), absence of mental and physical illness, right handed, and do not 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 in left medial frontal cortex (F3 electrode), somatomotor cortex (C3 electrode) and posterior parietal cortex (P3 electrode; p0.001). Summarizing, through experimental task employed, it was possible to observe integration among frontal, central and parietal regions. This integration appears to be more predominant in expectation, planning and motor preparation. In this way, it established an absolute predominance of this mechanism under the left hemisphere.

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 (p

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.

Objective: To examine the changes in slow (8–10 Hz) and fast (10–12 Hz) alpha bands of EEG in three groups of subjects submitted to different amounts of functional electrostimulation (FES). Our hypothesis is that different amounts of electrostimulation may cause different patterns of activation in the sensorimotor cortex. In particular, we expect to see an increase in alpha power due to habituation effects. We examine the two bands comprised by alpha rhythm (i.e., slow and fast alpha), since these two sub-rhythms are related to distinct aspects: general energy demands and specific motor aspects, respectively. Methods: The sample was composed of 27 students, both sexes, aging between 25 and 40 years old. The subjects were randomly distributed in three groups: control (n = 9), G24 (n = 9) and G36 (n = 9). A FES equipment (Neuro Compact-2462) was used to stimulate the right index finger extension. Simultaneously, the electroencephalographic signal was acquired. We investigated the absolute power in slow and fast alpha bands in the sensorimotor cortex. Results: The G36 indicated a significant increasing in absolute power values in lower and higher alpha components, respectively, when compared with the control group. Particularly, in the following regions: pre-motor cortex and primary motor cortex. Discussion: FES seems to promote cortical adaptations that are similar to those observed when someone learns a procedural task. FES application in the G36 was more effective in promoting such neural changes. The lower and higher components of alpha rhythms behave differently in their topographical distribution during FES application. These results suggest a somatotopic organization in primary motor cortex which can be represented by the fast alpha component.

Foi investigada a contribuição em potência na vizinhança do pico da banda alfa (BPA) do EEG durante imagética motora (IM). Sinais EEG (derivações occipitais e parietais) foram adquiridos em sujeitos destros (18-40 anos), durante repouso (ESP) e IM nas modalidades cinestésica (IMC) e visual (IMV), sendo 15 atletas de voleibol e 15 não-atletas. O Revised Movement Imagery Questionnaire não indicou diferenças entre grupos ou modalidades de IM; todavia os atletas imaginaram-se melhor que os não-atletas. Para ambos os grupos, a potência em BPA resultou menor em IM do que em ESP, sendo mais reduzida em IMC. Ativação cortical similar ocorreu em ambos os hemisférios de não-atletas e mais pronunciada no hemisfério esquerdo de atletas, principalmente durante IMC. Tais resultados sugerem que IM reduz a atividade de alfa de acordo com o conhecimento real da tarefa e a modalidade de IM. This study aims at statistically assessing the differences in alpha band power, particularly in the vicinity of the alpha peak (BPA), during motor imagery (MI). Multi-channel EEG (occipital and parietal regions) was acquired at rest condition (ESP) and MI kinesthetic (MIC) and visual (MIV) modalities from right-handed male subjects (18-40 years), 15 ‘athletes’ (experienced volleyball players) and 15 ‘non-athletes’. The Revised Movement Imagery Questionnaire indicated no differences between groups or MI modalities, but athletes imagine themselves more clearly than non-athletes during MI. The power within BPA reduces in both groups, but greater in MIC than in MIV. The cortical activation was similar in both hemispheres of non-athletes but more pronounced in left hemisphere of athletes, mainly in MIC. The findings suggest that MI reduces alpha activity according to individual knowledge of real execution of motor task and MI modalities.

The early stages of visual information processing, involving the detection and perception of simple visual stimuli, have been demonstrated to be sensitive to psychotropic agents. The present study investigated the effects of an acute dose of bromazepam (3 mg), compared with placebo, on the P100 component of the visual evoked potential and reaction time. The sample, consisting of 14 healthy subjects (6 male and 8 female), was submitted to a visual discrimination task, which employed the "oddball" paradigm. Results suggest that bromazepam (3 mg) impairs the initial stage of visual information processing, as observed by an increase in P100 latency.

The need for a better approach for auditory screening is due to pathologies that can affect higher auditory centers. Therefore, the Middle Latency Auditory Evoked Potential (MLAEP) was investigated by using the F SP statistical index. The EEG of ten adults during click stimulation with different sound pressure levels was collected. With the critical value for the statistical null hypothesis (absence of response), particularly considering EEG as a colored noise and fitting the number of degrees of freedom of the index distribution, objective detection of MLAEP resulted in a better performance than the threshold of 3.1, commonly employed in the literature. This finding suggests the F SP for detecting MLAEP response as an auxiliary tool for determining objectively the neurophysiologic acoustical threshold level.

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 (p

O objetivo deste estudo foi avaliar o fluxo sanguíneo cerebral no córtex cerebelar (4 sub-regiões) e no córtex pré-frontal, em repouso e durante uma tarefa motora. A amostra foi composta por 8 sujeitos saudáveis, ambos os sexos, entre 23 e 36 anos. O grupo foi submetido a tarefa visuo-motora (memória implícita) que consistia na ação de desviar um submarino de supostas minas que percorriam a tela do monitor. Para avaliar a perfusão, foi utilizado o método de análise semi-quantitativa para imagens de SPECT cerebral - 99mTc-ECD. Os resultados evidenciaram aumento de atividade nas áreas de interesse durante a realização da tarefa. Em conclusão, quatro sub-regiões do córtex cerebelar e ambos os hemisférios do córtex pré-frontal apontaram uma ativação simultânea durante a tarefa. Ainda, e conforme estudos prévios, nossos resultados sugerem um modo de operação em paralelo do sistema nervoso central, no intuito de integrar uma informação sensorial e motora. The objective of the present study was to evaluate the cerebral blood flow in the cerebellar (4 sub-regions) and pre-frontal cortex, when subjects were in rest and during a motor task performance. The sample consisted of 8 healthy subjects, male or female, between 23 and 36 of age. The visuo-motor task _ implicit memory _ requires the subjects to navigate and swerve a graphic submarine from missiles that run on the screen. Semi-quantitative analysis with brain SPECT (99mTc-ECD) was used to evaluate regional perfusion. The results revealed an increased activity in all areas of interest during motor task. In conclusion, four sub-regions of cerebellar cortex and both pre-frontal hemispheres showed a simultaneous activation during task. Moreover, our findings suggest as seen in previous experiments that the central nervous system operates in a parallel fashion, in order to integrate sensory and motor information.

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.

Current approaches for auditory screening are usually based on the Brainstem Auditory Evoked Potentials or on the Otoacoustic Emissions, and hence are not able to detect pathologies that affect higher auditory centers. Therefore, the Middle Latency Auditory Evoked Potential (MLAEP) was investigated as a neurophysiologic acoustic threshold measure by using the “Evoked Potential Detector” (EPD) as an Objective Response Detection technique. The EEG was collected from ten adults during monaural click stimulation (left ear, using contralateral masking noise) with different sound pressure levels. Based on the statistical distribution of EPD under the null hypothesis (absence of response), the use of the critical value considering EEG as a colored noise and fitting the shape parameters for a Beta distribution resulted in an objective detection of MLAEP with a better specificity and a similar sensitivity than considering EEG as a white noise. Full detection over all the casuistry occurred for stimulation levels as low as those found in literature using expert-based analysis, particularly for the derivation contralateral to the stimulation. This finding suggests the use of EPD for detecting MLAEP response as an auxiliary tool for determining objectively the neurophysiologic acoustical threshold level.

Although neurophysiological changes of aging are well known, there is still much to learn about cortical asymmetry in older depressed subjects. This study aimed at assessing differences between depressed and normal elderly subjects on alpha asymmetry, and to observe the correlations of this measure with depressive symptoms and quality of life. Thirty-six subjects (14 normal and 22 depressed) were assessed by EEG, depression rating scales, and SF-36. Despite the fact that compared to healthy elderly, depressive elderly subjects showed relatively greater right frontal activity (F4F3) and relatively greater left parietal activity (P4P3); this difference was not significant. The relationship between depression and frontal asymmetry was better observed in healthy elderly, where relatively greater left frontal activity was associated with less depressive symptoms.

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.

Benzodiazepines are among the most commonly prescribed medications due to their therapeutic efficacy in reducing anxiety and inducing sleep. Consequently, they have been widely employed in the pharmacological treatment of several disorders. Nevertheless, few studies have analyzed the effects of bromazepam in electroencephalographic activity (EEG). The present study aimed at investigating the modulatory effects of this drug on brain dynamics. Specifically, the effects of bromazepam (3mg) on EEG coherence were tested in a double-blind experiment. The sample, consisting of 10 healthy subjects (5 male and 5 female), was submitted to ten minutes of EEG recording. The electrophysiological measure (coherence) was analyzed across three experimental conditions: bromazepam, placebo 1, and placebo 2. Results indicate that bromazepam significantly increases cortical interhemispheric coherence. Benzodiazepínicos estão entre as medicações mais comumente prescritas devido à sua eficácia terapêutica para reduzir ansiedade e induzir sono. Conseqüentemente, eles têm sido amplamente empregados no tratamento de diversas desordens. No entanto, poucos estudos têm analisado os efeitos do bromazepam na atividade eletrencefalográfica (EEG). Assim, o presente estudo teve por objetivo investigar os efeitos modulatórios desta droga na dinâmica cerebral. Especificamente, os efeitos de 3 mg de bromazepam na coerência eletrocortical foram analisados em um experimento duplo-cego. A amostra consistiu de 10 sujeitos sadios (5 homens e 5 mulheres), submetidos a dez minutos de captação do sinal de EEG. A medida eletrofisiológica (coerência) foi analisada em três condições experimentais: bromazepam, placebo 1 e placebo 2. Os resultados sugerem que o bromazepam aumenta significativamente a coerência cortical inter-hemisférica.

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.

An interesting fact about language cognition is that stimulation involving incongruence in the merge operation between verb and complement has often been related to a negative event-related potential (ERP) of augmented amplitude and latency of ca. 400 ms - the N400. Using an automatic ERP latency and amplitude estimator to facilitate the recognition of waves with a low signal-to-noise ratio, the objective of the present study was to study the N400 statistically in 24 volunteers. Stimulation consisted of 80 experimental sentences (40 congruous and 40 incongruous), generated in Brazilian Portuguese, involving two distinct local verb-argument combinations (nominal object and pronominal object series). For each volunteer, the EEG was simultaneously acquired at 20 derivations, topographically localized according to the 10-20 International System. A computerized routine for automatic N400-peak marking (based on the ascendant zero-cross of the first waveform derivative) was applied to the estimated individual ERP waveform for congruous and incongruous sentences in both series for all ERP topographic derivations. Peak-to-peak N400 amplitude was significantly augmented (P < 0.05; one-sided Wilcoxon signed-rank test) due to incongruence in derivations F3, T3, C3, Cz, T5, P3, Pz, and P4 for nominal object series and in P3, Pz and P4 for pronominal object series. The results also indicated high inter-individual variability in ERP waveforms, suggesting that the usual procedure of grand averaging might not be considered a generally adequate approach. Hence, signal processing statistical techniques should be applied in neurolinguistic ERP studies allowing waveform analysis with low signal-to-noise ratio.

Benzodiazepines have been used in the pharmacological treatment of anxiety for over four decades. However, very few studies have combined bromazepam and event-related potentials (ERP). The present study aimed at investigating the modulatory effects of this drug on brain dynamics. Specifically, the effects of bromazepam (3mg) on the P300 component of the ERP were tested in a double-blind experiment. The sample, consisting of 15 healthy subjects (7 male and 8 female), was submitted to a visual discrimination task, which employed the "oddball" paradigm. Electrophysiological (P300) and behavioral measures (stroop, digit span, and reaction time) were analyzed across three experimental conditions: placebo 1, placebo 2, and bromazepam. Results suggest that the effects of bromazepam (3mg) on cognitive processes are not apparent. In spite of what seems irrefutable in current literature, bromazepam did not produce evident effects on the behavioral and electrophysiological variables analyzed. Benzodiazepínicos têm sido utilizados no tratamento farmacológico da ansiedade há mais de quatro décadas. No entanto, poucos estudos têm combinado bromazepam e potencial evocado relacionado a evento (PRE). O presente estudo teve por objetivo investigar os efeitos modulatórios desta droga na dinâmica cerebral. Especificamente, os efeitos de 3mg de bromazepam no componente P300 do PRE foram analisados em um experimento duplo-cego. A amostra consistiu de 15 sujeitos sadios (7 homens e 8 mulheres), submetidos a uma tarefa de discriminação visual utilizando o paradigma "oddball". Medidas eletrofisiológicas (P300) e comportamentais (stroop, digit span, e tempo de reação) foram analisadas em três condições experimentais: placebo 1, placebo 2 e bromazepam. Os resultados sugerem que os efeitos de 3mg de bromazepam em processos cognitivos não são aparentes. Apesar do que parece irrefutável na literatura, o bromazepam não produziu efeitos evidentes nas variáveis comportamentais e eletrofisiológicas analisadas.

El objetivo del presente estudio fue el de investigar alteraciones en los padrones electroencefalograficos de sujetos normales y diestros durante el aprendizaje motor de una tarea manual Estudios recientes tienen demostrado que en el cortex cervical es susceptible a varias modificaciones en varios aspectos durante el aprendizaje, y que tales alteraciones en los padrones electrocorticales son los resultados de la adquisicion de habilidades motoras y de la consodilacion de la memoria. Para tal, la actividad cortical electrica de los sujetos fue analizada antes y despues de la practica motora. Los datos fueron captados por el "Braintech" 3000 y analizados por el programa "Neurometrics". Para el analisis estadistico, variables del comportamiento tales como tiempo y error fueron observadas a traves de un ANOVA "one-way", bloques como efecto principal. En la variable neurofisiologica; potenbcia absoluta, fue utilizado el test-T pareado a fin de poder detectar alteraciones entre los momentos pre y post aprendizaje, en diferentes electrodos, CZ-C3/CZ-C4 en teta y alfa y O1-P3/T3-F7 en beta. Los resultados principales demonstraron un cambio en la performance a traves del tiempo y en el numero de errores Concomitantemente, fue observado y verificado un aumento de la potencia en la banda alfa sobre las areas centrales (CZ-C3/CZ-C4) y una diminuicion en beta localizada en el area temporo-parietal izquierda (O1-P3/T3-F7). Las alteraciones en la banda teta, como se han demostrado en otras experiencias, no ocurrieron en este estudiotales resultados sugieren una adapatacion del la corteza sensorio-motora en la que la alteracion de la actividad electrica cortical es coincidente con una transmicion al automatismo motor.

O objetivo do presente estudo foi investigar alterações nos padrões eletroencefalográficos de sujeitos normais e destros durante o aprendizado de uma tarefa motora (datilografia). Estudos têm demonstrado que o córtex cerebral é susceptível a modificações durante a aprendizagem e que alterações nos padrões elétricos corticais ocorrem em função da aquisição de uma habilidade motora e da consolidação da memória. Assim, a atividade elétrica cortical dos sujeitos foi analisada antes e depois da prática motora. Os dados foram captados pelo "Braintech" 3000 e analisados pelo programa "Neurometrics". Para a análise estatística, variáveis comportamentais tais como tempo e erro, foram analisadas através do teste ANOVA "one-way" (diferenças entre blocos). Em seguida, foi utilizado um Teste-t pareado para os pares de eletrodos CZ-C3/CZ-C4, nas bandas de freqüência teta e alfa. Os resultados principais demonstraram mudança na performance através das variáveis comportamentais "tempo" e "número de erros". Concomitantemente, não foram observadas alterações na variável neurofisiológica "Potência Absoluta" na banda teta. Em contrapartida, houve um aumento significativo na banda alfa em áreas centrais (CZ-C3/CZ-C4). Tais resultados sugerem uma adaptação do córtex sensório-motor em função do treinamento de datilografia. The present study aimed to investigate alterations in EEG patterns in normal, right-handed individuals, during the process of learning a specific motor skill (typewriting). Recent studies have shown that the cerebral cortex is susceptible to several changes during a learning process and that alterations in the brain's electrical patterns take place as a result of the acquisition of a motor skill and memory consolidation. In this context, subjects' brain electrical activity was analyzed before and after the motor task. EEG data were collected by a Braintech 3000 and analyzed by Neurometrics. For the statistical analysis, the behavioral variables "time" and "number of errors" were assessed by a one-way ANOVA. For the neurophysiological variable "Absolute Power", a paired t-Test was performed for each pair of electrodes CZ-C3/CZ-C4, in the theta and alpha frequency bands. The main results demonstrated a change in performance, through both behavioral variables ("time" and "number of errors"). At the same time, no changes were observed for the neurophysiological variable ("Absolute Power") in the theta band. On the other hand, a significant increase was observed in the alpha band in central areas (CZ-C3/CZ-C4). These results suggest an adaptation of the sensory-motor cortex, as a consequence of the typewriting training.

Trata-se de um experimento neurolingtiístico em português do Brasil, investigando aspectos da concatenação entre verbo e complemento, em três condições experimentais: Série 1 - concatenação verbo-complemento simples e local; Série 2 - concatenação verbocomplemento envolvendo herança de traços de nome pertencente a uma sentença anterior; Série 3 - concatenação do verbo e complemento envolvendo perguntas com sintagmas QU-. Foram geradas 240 sentenças experimentais (80 para cada condição) e 240 distrato res. A partir de um protocolo de apresentação cinética, as sentenças eram exibidas para cada um dos 25 sujeitos enquanto se fazia a aquisição de 20 derivações de EEG Empregaramse técnicas de processamento de sinais a fim de estimar-se a ERP individual para cada região anatômica. A série 1, envolvendo computações estritamente locais, resultou em N400s parietais clássicos, enquanto os estímulos relativos à herança nominal (Série 2) geraram dois picos nos ERPs da região central e parietal. Na Série 3, o deslocamento de QU- apresentou respostas corticais mais precoces e marcantes. As diferentes morfologías de ERP, resultantes de cada condição, são compatíveis com um modelo no qual o processamento lingüístico resulta de computações tarefa-específicas, talvez envolvendo diferentes subsistemas neurológicos.

The stimulant effects of caffeine on cognitive performance have been widely investigated. The visual evoked potential, specially the P300 component, has been used in studies that explain the stimulant mechanisms of caffeine through neurophysiological methods. In this context, the present study aimed to investigate electrophysiological changes (P300 latency) and modification of cognitive and motor performance produced by caffeine. Fifteen healthy volunteers, 9 women and 6 men (26 ± 5 years, 67 ± 12.5kg) were submitted three times to the following procedure: electroencefalographic recording, Word Color Stroop Test, and visual discrimination task. Subjects took a gelatin caffeine capsule (400 mg) or a placebo (P1 and P2), in a randomized, crossover, double-blind design. A one-factor ANOVA and Tukey’ post hoc test were used to compare dependent variables on the C, P1 and P2 moments. The statistical analyses indicated a non-significant decrease in reaction time, Stroop execution time and latency at Cz on the caffeine moment when compared to the others. Moreover, a non-significant increase in Stroop raw score and latency at Pz could be observed. The only significant result was found at Fz. These findings suggest that the positive tendency of caffeine to improve cognitive performance is probably associated with changes in the frontal cortex, a widely recognized attention area. Os efeitos estimulantes da cafeína no desempenho cognitivo vêm sendo amplamente investigados. O potencial evocado visual (P300) tem sido empregado em estudos recentes que buscam elucidar os mecanismos excitatórios da cafeína através de métodos neurofisiológicos. Neste contexto, o presente estudo objetivou examinar as variações geradas pela cafeína em respostas eletrofisiológicas (latência do P300) e determinar modificações no desempenho cognitivo e motor. Para tanto, 15 indivíduos hígidos, sendo 9 mulheres e 6 homens (26 ± 5 anos, 67 ± 12,5 kg) foram submetidos por três vezes à seguinte rotina: aquisição de sinais eletroencefalográficos, Word Color Stroop Test e tarefa de discriminação visual. Foi administrada uma cápsula gelatinosa de 400 mg de cafeína ou de placebo (P1 e P2) em um desenho randomizado duplo-cego cruzado. Foi empregada a ANOVA com um fator e post hoc de Tukey - HSD para a comparação das variáveis nos momentos C, P1 e P2. O momento cafeína apresentou redução não significativa no tempo de reação, no tempo de execução do Stroop e na latência em Cz. Observou-se também aumento não significativo no escore bruto do Stroop e na latência em Pz. O único resultado significativo encontrado foi na latência em Fz. Assim, pode-se concluir que a tendência favorável à ingestão de cafeína na melhora das respostas cognitivas pode estar relacionada a mudanças em regiões específicas do cérebro, como o córtex frontal, área amplamente relacionada com os processos de atenção.

Electroencephalography (EEG) can be a valuable technique to assess electrophysiological changes related to dementia. In patients suspected of having dementia, the EEG is often quite informative. The sensitivity of the EEG to detect correlates of psychiatric disorders has been enhanced by means of quantitative methods of analysis (quantitative EEG). Quantitative features are extracted from, at least, 2 minutes of artifact-free, eyes closed, resting EEG, log-transformed to obtain Gaussianity, age-regressed, and Z-transformed relative to population norms (Neurometrics database). Using a subset of quantitative EEG (qEEG) features, forward stepwise discriminant analyses are used to construct classifier functions. Along this vein, the main objective of this experiment is to distinguish profiles of qEEG, which differentiate depressive from demented patients (n = 125). The results showed that demented patients present deviations above the control group in variables associated to slow rhythms: Normed Monopolar Relative Power Theta for Cz and Normed Bipolar Relative Power Theta for Head. On the other hand, the deviation below the control group occurs with the variable associated to alpha rhythm: Normed Monopolar Relative Power Alpha for P3, in dementia. Using this method, the present investigation demonstrated high discriminant accuracy in separating Primary Degenerative Dementia from Major Depressive Disorder (Depression). A Eletroencefalografia (EEG) pode ser utilizada como uma técnica valiosa na avaliação de mudanças eletrofisiológicas relacionadas à demência. Em pacientes com suspeita de demência, o EEG é em geral bastante informativo. A sensibilidade do EEG em detectar correlatos de desordens psiquiátricas pode ser incrementada através de métodos de análise quantitativa (EEG quantitativo). Padrões quantitativos são extraídos de pelo menos 2 minutos de dados livres de artefatos, em que os sujeitos estão com olhos fechados e em estado de repouso. São aplicados métodos quantitativos, tais como: transformação logarítmica para obtenção de uma distribuição Gaussiana, regressão por faixa etária e o escore Z relativo a normas populacionais preestabelecidas (Neurometrics). Utilizando uma amostra de padrões de EEG quantitativo (EEGq), será implementada uma análise discriminante (forward stepwise) a fim de estabelecer funções classificatórias. Neste contexto, o objetivo principal deste estudo é distinguir perfis de EEGq que diferenciem pacientes com depressão de pacientes com demência (n = 125). Os resultados demonstraram que pacientes acometidos por demência apresentam desvios acima do grupo controle em variáveis associadas a ritmos lentos: Potência Monopolar Relativa Normalizada em Teta para Cz e Potência Bipolar Relativa Normalizada em Teta para Cabeça. Por outro lado, desvios abaixo do grupo controle ocorrem em variáveis associadas ao ritmo alfa: Potência Monopolar Relativa Normalizada em Alfa para P3. Através deste método, a presente investigação demonstrou uma alta acurácia em discriminar pacientes com Demência Degenerativa Primária de pacientes com Transtorno Depressivo Maior.

Functional imaging of brain electrical activity was performed in 25 chronic medicated schizophrenics and 40 controls, analyzing the classical frequency bands (delta, theta, alpha, and beta) of 19-channel EEG during resting state to identify brain regions with deviant activity of different functional significances, using LORETA (Low Resolution Tomography) and SPM99 (Statistical Parametric Mapping). Patients differed from controls due to an excess of slow activity comprising delta + theta frequency bands (inhibitory pattern) located at the right middle frontal gyrus, right inferior frontal gyrus, and right insula, as well as at the bilateral anterior cingulum with a left preponderance. The high temporal resolution of EEG enables the specification of the deviations not only as an excess or a deficit of brain electrical activity, but also as inhibitory (delta, theta), normal (alpha), and excitatory (beta) activities. These deviations point out to an impaired functional brain state consisting of inhibited frontal and prefrontal areas that may result in inadequate treatment of externally or internally generated information. Imagens funcionais da atividade elétrica cerebral de 25 esquizofrênicos crônicos medicados e de 40 controles foram obtidas através do registro (19 canais) e da análise das faixas tradicionais (delta, teta, alfa e beta) do EEG, durante o repouso vigil. O objetivo foi identificar regiões do cérebro que apresentassem desvios com diferentes significados funcionais na 'Low Resolution Electromagnetic Tomography' (LORETA) e no 'Statistical Parametric Mapping' (SPM). Observou-se excesso de atividade lenta nas faixas delta + teta (padrão inibitório) nos pacientes esquizofrênicos, localizado no giro frontal médio direito, no giro frontal inferior direito e na insula direita e, também, na porção anterior do giro do cíngulo, bilateralmente, mas com predomínio à esquerda. A alta resolução temporal do EEG permite especificar os desvios em termos de excesso ou déficit de atividade elétrica cerebral, bem como de atividades com um padrão inibitório (delta, teta), normal (alfa) e excitatório (beta). Os desvios encontrados apontam para comprometimento funcional cerebral que consiste no predomínio de atividade inibitória nas áreas frontais e pré-frontais que pode causar processamento inadequado de informações, quer de origem externa quanto interna.

Introduction Hypertension is a major risk factor for cardiovascular disease. Despite the availability of various classes of anti-hypertensive medications, blood pressure (BP) control often remains poor. Lifestyle changes, if adopted, are effective at reducing BP. The aim of this study was to estimate the factors associated with inadequate BP control in hypertensive patients adherent to anti-hypertensive drug treatment assisted by a Brazilian Family Doctor Program (FDP). Methods A cross-sectional study of men and women aged 20 years and over collected data on sociodemographic characteristics, co-morbidities, lifestyle and food frequency, the latter using a questionnaire validated for the investigation of dietary habits. Blood and urine samples were obtained and anthropometric and nutritional studies performed. Results Independent of time of treatment and systolic BP at admission to FDP, individuals with inadequate BP control had a higher body mass index (BMI) (Prevalence Ratio, PR 1.027 (95% CI 1.009 to 1.045)), consumed more meat (PR 1.091 (1.022 to 1.165)), had higher levels of serum creatinine (PR 1.894 (1.241 to 2.892)) and more often had white skin colour (PR 1.363 (1.006 to 1.847)). Following adjustment for the sodium excretion index, an indirect measure of salt intake, there association with meat was no longer significant. Conclusion Inadequate control of BP in patients who were being treated with anti-hypertensive drugs, even in a community assisted by a primary care program, was independently associated with modifiable factors including salt consumption and BMI. An association with skin colour and serum creatinine was also observed.

The human brain is a system consisting of various interconnected neural networks, with functional specialization coexisting with functional integration occurring both; temporally and spatially at many levels. The current study ranked and compared fast and slow participants in processing information by assessing latency and amplitude of early and late Event-Related Potential (ERP) components, including P200, N200, Premotor Potential (PMP) and P300. In addition, the Reaction Time (RT) of participants was compared and related to the respective ERP components. For this purpose, twenty right-handed and healthy individuals were subjected to a classical ERP "Oddball" paradigm. Principal Component Analysis (PCA) and Discriminant Function analyses (DFA) used PRE components and the Reaction Time (RT) to classify individuals. Our results indicate that latencies of P200 (O2 electrode), N200 (O2), PMP (C3) and P300 (Pz) components are significantly reduced in the group of fast responding participants. In addition, the P200 amplitude is significantly increased in the group of fast responding participants. Based on these findings, we suggest that the ERP is able to detect even minimal impairments, in the processing of somatosensory information and cognitive and motor stages. Hence, the study of ERP might also be capable of assessing sensorimotor dysfunctions in healthy old-aged people and in neuropsychiatric patients (suffering from dementia, Parkinson's disease, and other neurological disorders).

Different treatments for stroke patients have been proposed; among them the mirror therapy and motion imagery lead to functional recovery by providing a cortical reorganization. Up today the basic concepts of the current literature on mirror neurons and the major findings regarding the use of mirror therapy and motor imagery as potential tools to promote reorganization and functional recovery in post-stroke patients. Bibliographic research was conducted based on publications over the past thirteen years written in English in the databases Scielo, Pubmed/MEDLINE, ISI Web of Knowledge. The studies showed how the interaction among vision, proprioception and motor commands promotes the recruitment of mirror neurons, thus providing cortical reorganization and functional recovery of post-stroke patients. We conclude that the experimental advances on Mirror Neurons will bring new rational therapeutic approaches to post-stroke rehabilitation.

Background The isolated atrophy of the infraspinatus muscle is an uncommon clinical alteration, generally secondary to the selective lesion of the suprascapular nerve related to sport activities, especially in professional volleyball players. The lesion of the suprascapular nerve can cause kinesthetic deficits. The assessment of kinesthesia is determined by the ability to detect joint movement and has been traditionally conducted by measuring the Threshold of Perception of Passive Motion (TPPM). Objective The goal of the present study was to compare the TPPM among a group of healthy individuals (control group), a group of World League volleyball players with atrophy of the infraspinatus muscle on the dominant side, and group of athletes with no shoulder pathologies. Design, setting and participants Observational study at a controlled research laboratory at the Brazilian Volleyball Training Center (CDV – Saquarema). 12 healthy non-athlete controls, 12 athletes with atrophy of the infraspinatus muscle, and 12 athletes without the atrophy. Interventions A proprioception-testing device passively moved the shoulder and participants were instructed to respond as soon as movement was detected (TPPM) by pressing a button-switch. EEG and electromyographic (EMG) activities were recorded simultaneously. Response latency was established as the delay between the stimulus (movement) and the response (button press). The time-frequency dynamics of the EEG was analyzed. Results An analysis of variance indicated a significant latency reduction (p Conclusions The results suggest that systematically trained motor abilities, as well as the atrophy of the infraspinatus muscle, change the cortical representation of the different stages of proprioceptive information processing and, ultimately, the cortical representation of the TPPM.

Introduccion. La estimulacion electrica funcional (EEF) es una tecnica utilizada para la rehabilitacion de la disfuncion motora y sensorial que consiste en aplicar una estimulacion electrica neuromuscular al tiempo que se lleva a cabo una actividad funcional. Estudios precedentes sugieren que el procesamiento sensoriomotor que tiene lugar durante la estimulacion de la mano con EEF es similar al generado con su movimiento voluntario. Objetivo. Examinar los cambios de la coherencia de la banda theta (4-8 Hz) en la union centroparietal y temporoparietal durante la ejecucion de una tarea con EEF. La hipotesis planteada es que diferentes condiciones de electroestimulacion pueden producir cambios en la coherencia de la banda theta durante la integracion sensoriomotora y multisensorial. Sujetos y metodos. La muestra se compuso de 24 estudiantes, 14 varones y 10 mujeres, de 25 a 40 anos de edad. Los participantes se distribuyeron al azar en tres grupos: grupo control (n = 8), grupo G24 (n = 8) y grupo G36 (n = 8). El grupo control simulo cuatro bloques sin recibir electroestimulacion. El grupo G24 se expuso a cuatro bloques de electroestimulacion, y el G36, a seis bloques. La electroestimulacion aplicada con el equipo de EEF consistio en estimular la extension del dedo indice derecho al tiempo que se registraba la senal electroencefalografica. Resultados. Se hallo un efecto principal de la condicion, el bloque y el electrodo en la union centroparietal, a diferencia de la union temporoparietal, en la que unicamente se constato un efecto principal de la condicion y del electrodo. Conclusion. Los resultados parecen indicar que el acoplamiento funcional entre las zonas central y parietal esta vinculado directamente con la funcion de la memoria de preparacion (priming), aunque el acoplamiento entre las zonas temporal y parietal se relacione con la memoria de trabajo.

Introduccion. La integracion sensitivomotora se define como la capacidad del sistema nervioso central para integrar diferentes fuentes de estimulos y, paralelamente, transformar dichas entradas en acciones motoras. Objetivos. Revisar los principios basicos de la integracion sensitivomotora, como sus bases neuronales y sus mecanismos elementales implicados en tareas orientadas hacia la consecucion de objetivos especificos realizadas por sujetos sanos, y las anomalias descritas en los trastornos del movimiento mas frecuentes, como la enfermedad de Parkinson, la distonia y el accidente cerebrovascular, ademas de los mecanismos relacionados con la reorganizacion cortical. Desarrollo y conclusiones. Todavia no esta claro si estos trastornos se asocian a una entrada sensitiva periferica anormal o a un procesamiento central defectuoso, pero la mayoria de datos respaldan un mecanismo central. Nuestros resultados muestran que el proceso de integracion sensitivomotora desempena un posible papel en los mecanismos elementales implicados en tareas orientadas hacia la consecucion de objetivos especificos realizadas por sujetos sanos y en la aparicion de anomalias en la mayoria de trastornos del movimiento mas frecuentes; asimismo, desempena un posible papel en la adquisicion de habilidades que tienen como factor critico el acoplamiento de diferentes datos sensitivos que constituiran la base de elaboracion de entradas motoras orientadas conscientemente hacia la consecucion de objetivos.

Introduccion. Entender el funcionamiento del control motor humano constituye una cuestion importante para la neurociencia. Un ejemplo es el modo en que la corteza motora controla la actividad muscular, control que puede observarse a traves de la coherencia corticomuscular (CCM). Objetivo. El presente estudio tiene por objeto comprobar la influencia sobre la CCM de diversos factores relacionados con el control motor fino de las tareas de fuerza. Nuestro interes estribaba en averiguar si seria posible medir la solidez del acoplamiento entre el sistema nervioso central (SNC) y el aparato locomotor a traves de los cambios de la actividad oscilatoria en las bandas beta y gamma influida por tales factores, tanto en personas sanas como enfermas. Desarrollo. La CCM en la banda beta resulto especialmente importante en la ejecucion sostenida de las tareas de control preciso, que demandan mas concentracion y esfuerzo, y constatamos que la CCM en dicha banda estaba influida por diversos factores. Por lo que respecta a la CCM en la banda gamma, su modulacion requeriria en principio una integracion dinamica compleja y continua de varios mecanismos, puesto que la magnitud de la fuerza no ejercio efecto modulador alguno. De lo dicho se desprende que tales mecanismos serian necesarios para un funcionamiento adecuado y eficaz de las redes neuronales cuando se necesita producir una fuerza dinamica. Conclusion. La CCM en las bandas beta y gamma podria ampliar nuestros conocimientos acerca de los cambios dinamicos del sistema motor, tanto en las personas sanas como en los pacientes neurologicos. Se podria utilizar como un indice sensible para cuantificar los cambios dinamicos en el control motor fino de la fuerza, y tiene posibilidades de convertirse en una herramienta util para caracterizar los patrones de cambio en las actividades del SNC en el campo de la investigacion basica, especialmente en la restauracion de la funcion motora.

Objetivos. Investigar los efectos del uso del bromacepam en la potencia relativa en alfa durante la realizacion de una tarea de mecanografia. Teniendo en cuenta las particularidades de cada hemisferio cerebral, nuestra hipotesis era que a traves de la medida de la potencia relativa seria posible investigar el efecto del bromacepam sobre areas corticales especificas. Concretamente, se esperaba observar diferentes patrones de potencias en los procesos de atencion, activacion e integracion sensoriomotora. Sujetos y metodos. La muestra estaba formada por 39 sujetos (15 hombres y 24 mujeres) con una media de edad de 30 ± 10 anos. Los grupos control (placebo) y experimental (bromacepam de 3 mg y 6 mg) fueron entrenados en la tarea de mecanografia con un modelo doble ciego aleatorizado. Resultados. Mediante el ANOVA de tres vias y el test de Scheffe se comprobaron interacciones entre los factores condicion y momento y entre condicion y sector. Conclusion. Las dosis empleadas en este estudio facilitaron el desarrollo motor de la tarea de mecanografia. En este estudio, el uso del farmaco no impidio el aprendizaje de la tarea, pero parece ser que concentro el esfuerzo mental sobre aspectos mas restringidos y especificos de la mecanografia. Tuvo lugar una influencia sobre el ritmo y la eficacia de las operaciones ejecutadas durante mecanismos de codificacion y almacenamiento de nuevas informaciones. Asimismo, se comprobo un predominio de actividad en el area frontal izquierda (dominante) en el grupo bromacepam 3 mg, lo cual indica que esta dosis del farmaco permite al sujeto un mayor direccionamiento de la actividad cortical para la planificacion y la ejecucion de la tarea.

Introduccion. La planificacion de acciones futuras tiene como aspecto fundamental la realizacion y el control de la tarea motora. Este comportamiento se da a traves de la integracion sensoriomotora. Objetivo. Explicar los mecanismos electrofisiologicos corticales (modificaciones en banda alfa) que intervienen en las acciones anticipatorias cuando los individuos tienen que coger un objeto en caida libre. Sujetos y metodos. La muestra estaba compuesta por 20 sujetos sanos de ambos sexos (11 hombres y 9 mujeres), con edades que oscilaban entre los 25 y 40 anos (32,5 ± 7,5), sin enfermedades mentales ni fisicas (anamnesis previa), diestros (inventario de Edimburgo) y que no tomaban ninguna sustancia psicoactiva o psicotropica en el momento del estudio. El experimento consistio en una tarea de coger objetos en caida libre. Constaba de seis bloques con 15 pruebas, con una duracion de 2 minutos y 30 segundos cada una de ellas, y con un minuto de intervalo entre los bloques. La captacion de los datos a traves de la electroencefalografia cuantitativa se produjo dos segundos antes y dos segundos despues de la caida de la bola. Resultados. Se verifico una interaccion de los factores momento y posicion solamente para la corteza parietooccipital derecha, en la combinacion de electrodos P4-O2. Conclusion. Estos hallazgos indican una importante participacion de la corteza parietooccipital derecha en el aumento de la expectativa y la celeridad en los procesos preparatorios de una tarea motora.

Introduccion. El aprendizaje y la memoria son procesos complejos que hace mas de un siglo que desafian a los investigadores en su intento de esclarecer cuales son los mecanismos basicos implicados. Objetivos. Revisar los mecanismos celulares y moleculares basicos implicados en el proceso de retencion de procedimientos, proporcionar una vision global de los mecanismos basicos implicados en el almacenamiento de informacion mediante teorias y modelos de la memoria, y discutir los diferentes tipos de memoria y el papel del cerebelo como modulador de la memoria de procedimientos. Desarrollo. Los resultados experimentales de las ultimas decadas establecieron nuevas direcciones en la participacion de los procesos bioquimicos y celulares relacionados con la consolidacion de la informacion en el sistema nervioso. Conclusiones. Los circuitos neuronales implicados en la adquisicion y consolidacion de la memoria aun no se conocen del todo, ni tampoco la localizacion de la memoria en el sistema nervioso. Numerosos factores intrinsecos y extrinsecos interfieren en estos procesos, como los mecanismos moleculares (potenciacion y depresion a largo plazo) y celulares, que responden a la comunicacion y transmision entre las celulas nerviosas, y los factores que proceden del medio externo, capaces de propiciar, a traves de las asociaciones de sucesos, la formacion de nuevas memorias o de desviar al sujeto de su foco principal. La memoria no es un hecho unico; se subdivide en declarativa y no declarativa, o, cuando se refiere al tiempo de duracion, en memoria de corta y larga duracion. Ademas, no se puede afirmar que la memoria constituya un proceso aislado, dada su relacion con los mecanismos neuronales del aprendizaje.

Introduccion. El bromacepam es el segundo benzodiacepinico mas utilizado en Brasil. La investigacion psicofisiologica sobre esta sustancia es aun incipiente. Objetivo. Contrastar la neurotoxicidad del bromacepam a traves de los tiempos de reaccion (TR) y de las variaciones negativas contingentes (VNC). Sujetos y metodos. Utilizando un videojuego elaborado en nuestro laboratorio para la investigacion psicofisiologica (Car Acquisition), 14 voluntarios sanos ?9 hombres?, entre 23 y 42 anos, conducian un vehiculo por una carretera llena de curvas (distractor) mientras tenian que responder a los estimulos imperativos (comandos para apretar el boton del joystick) precedidos por estimulos de alerta (paradigma S1-S2-RM con distractor). Comparamos los TR, las amplitudes y las latencias de las VNC, en cada uno de los tres electrodos de la linea media (Fz, Cz y Pz), una hora despues del placebo (P), de 3 mg de bromacepam (B3) o 6 mg de bromacepam (B6) ?aleatorio, doble ciego, cruzado y en dias diferentes?. Estadistica: ANOVA one-way y Post Hoc Scheffe. Resultados. Los TR no diferiran de manera significativa. En Pz, las amplitudes de las VNC diferiran significativamente para P, B3 y B6 (p = 0,006), y tambien para B3 y B6 (p = 0,018), con B6 > B3 = P. En Fz, una tendencia no significativa (p = 0,074) sugeria una diferencia entre las latencias, menor en B6 que en B3 (p = 0,098), ambas equivalentes al placebo. Las amplitudes oscilaban de media entre 2,4 y 5,9 mV. Conclusiones. La neurotoxicidad, comportamental y neurofisiologica, fue insignificante una hora despues de la administracion de una dosis unica de 3 o 6 mg de bromacepam en adultos jovenes y sanos. Las amplitudes menores eran compatibles con la interferencia de los distractores, y no se observaron como efecto aislado.