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Drug influence on the decision making process has been scarcely studied. Researchers have driven the hypothesis that drugs might cause interference on cortical circuits. The aim of the present study is to evaluate the electrophysiological and behavioral changes occurring in the P300 after ingestion of modafinil (200mg), bromazepam (6mg) and placebo in healthy subjects exposed to a sensorimotor task based on the oddball paradigm. The sample for this study consisted of 10 subjects of both sexes, with ages ranging between 20 and 45, who were submitted to a quantitative electroencephalography. The experimental procedure was carried out in three visits, before and after drug ingestion. The results demonstrated a significant increase in the P300 latency and amplitude for the target condition, when compared to the non-target condition, for all analyzed electrodes. No significant difference was found for group or moment. A statistically significant difference was found for the group variable in the behavioral analysis. Such results suggest that the P300 is a measure, which is not sensitive to drug ingestion. On the other hand, the measure presented certain level of sensitivity when the subjects faced two different conditions in the decision making process orientation.

The dynamic visual stimulation (DS) protocol was employed for inducing vection during stabilometric test (orthostatic position in a force platform). The center of pressure (COP) displacement signals of 29 healthy volunteers were acquired with subject observing a virtual scene (1.72 × 1.16 m) projected 1 m ahead of the force platform and centered at the vision line (visual angle: θl = 81.4° and θv = 60.2°). This scene consists of a room containing a floor with chessboard pattern, walls and ceiling with distinct texture and furniture. To induce vection, the virtual scenario (floor, walls and ceiling) moved in a forward direction (or backward), during 250 ms (constant velocity: Vi = 2 m/s), so that the furniture was expanded (or reduced). For each DS scene, the luminance changed 2 cd/m2 with optic flow stimulation as a tunnel pattern. A set of 100 DS distracter stimuli was applied in a random order, interspersed by 10 s of Static Scene and synchronized by the start of exhibiting scene. The percentage of DS inducing vection differs among volunteers, varying from 63% to 80%, hence indicating the potential applications of this DS protocol in postural control study.

Objective Response Detection (ORD) Techniques applied to Evoked Potentials depend on the effective Number of Degrees of Freedom (NDOF) of spontaneous EEG. Previous works proposed a method for estimating the NDOF of the Evoked Potential Detector (EPD) probability distribution under the null hypothesis of no response, based on the autocorrelation function (ACF) of the EEG, modeled as wide- or narrow-band colored noise. Considering narrow-band EEG, the use of Beta distribution based on NDOF estimates via ACF is able to reflect EPD distribution provided that the stimulation rate is non-uniform. The present work assesses an approach for randomizing the inter-stimulus interval using Maximum-Length Sequences (MLS) based on Monte Carlo simulation for several combinations of EEG bandwidths, central frequencies, numbers of epochs and number of samples per epoch. The results suggest such approach as a valid algorithm to be implemented in the development of specific devices to produce random inter-stimuli intervals.

The dynamic virtual stimulation (DS) was employed to investigate postural control response using the motion- related visual evoked potential (M-VEP) and vection. The multi-channel electroencephalogram (EEG) and the center-ofpressure (COP) displacement signals were acquired simultaneously during stabilometric test with DS scenes interspersed by 10 s of static scene (SS). The trials from 29 healthy volunteers were performed in orthostatic position on a force platform observing a virtual scene (1.72 × 1.16 m) projected 1 m ahead and centered at the vision line (visual angle: θl= 81.4° and θv = 60.2°). The scenario was moved randomly in forward (DSF) or backward direction (DSB), during 250 ms (velocity: 2 m/s). For each DS, the luminance varied 2 cd/m2. Such dynamic effect was employed to generate an optical flow as a tunnel pattern. For each subject, the M-VEP was estimated by coherent averaging up to 50 artifact-free EEG epochs, synchronized by the onset of DS. Similar procedure was applied for the COP signal. The running t-test (α = 0.05) suggested that there is difference between DSF and DSB M-VEPs 600 ms after DS onset, with an increasing time delay from occipital to central derivations. Moreover, the DS induced COP displacements in the same direction of the exhibiting scene (p < 0.001). Therefore, vection is dependent on the DS direction, mainly during DSF, for which the linear vection varies from 72% to 90%. These findings suggest that the cognitive, planning and motor processing to control balance depends on the DS direction and hence indicate the potential applications of this dynamic virtual protocol in postural control studies.

To investigate the effects of bromazepam on motor performance and electroencephalographic activity (qEEG) in healthy subjects, during the process of learning a typewriting task, with a focused attention demand. A randomized double-blind model was used to allocate subjects in one of the following conditions: placebo (n=13), bromazepam 3 mg (n=13) or bromazepam 6 mg (n=13). Forty minutes after treatment administration, subjects were submitted to the motor task. EEG activity was recorded simultaneously. The analyzed variables were: number of errors and execution time, which were extracted from each block of the typewriting task, and mean relative power values in the beta band (13-35 Hz), extracted from the qEEG. A significantly lower number of typing errors was observed in both bromazepam conditions (Br 3 mg and Br 6 mg) when compared to the placebo. There was no difference between the two bromazepam conditions. For the execution time variable, a better performance was observed in the Br 3 mg condition, but with no statistical significance. The highest degree of cortical activation during the task was observed in Br 3 mg and Br 6 mg when compared to placebo. The medication's anxiolytic effect intensifies the attentional focus over predictable events occurring in reduced perceptual fields. The qEEG's accentuated response in pre-motor and primary motor areas suggests a greater effort directed to the most relevant aspects of the task. In short, the doses employed (3 and 6 mg) seem to enhance the learning of motor tasks that involve focused attention, such as typewriting.

Total or partial sleep deprivation (SD) causes degrading effects on different cognitive and psychomotor functions that might be related to electrophysiological changes frequently observed. In the present study, we investigated the effects of one night of sleep deprivation on waking EEG. Experimental protocol consisted of recording electroencephalographic data from eleven healthy young subjects before (baseline) and after (time 2) one night of sleep deprivation. A natural log transformation was carried out and showed a significant increase in theta T6 (p=0.041), O2 (p=0.018) and OZ (p=0.028); and delta T6 (p=0.043) relative power; and a decrease in alpha Fp1 (p=0.040), F3 (p=0.013), Fp2 (p=0.033), T4 (p=0.050), T6 (p=0.018), O2 (p=0.011) and Oz (p=0.025) and beta (p=0.022) absolute power. These outcomes show that the EEG power spectra, after sleep deprivation, exhibit site-specific differences in particular frequency bands and corroborate for the premise of local aspects of brain adaptation after sleep deprivation, rather than global. Privação total ou parcial de sono causa efeitos deletérios em diferentes funções cognitivas e psicomotoras, que podem estar relacionados às mudanças eletrofísiológicas frequentemente observadas. No presente estudo, investigou-se os efeitos de uma noite de privação de sono nas respostas eletrencefalográficas de repouso. O protocolo experimental consistiu na coleta e gravação dos dados do qEEG de onze sujeitos jovens e saudáveis antes (momento baseline) e após (momento 2) uma noite de privação de sono. Todos os dados sofreram transformação logarítmica, que evidenciou um aumento significativo nas potências relativas de teta T6 (p=0,041), O2 (p=0,018) e OZ (p=0,028); e delta T6 (p=0,043). As bandas de freqüência mais rápidas alfa Fp1 (p=0,040), F3 (p=0,013), Fp2 (p=0,033), T4 (p=0,050), T6 (p=0,018), O2 (p=0,011), Oz (p=0,025) e beta (p=0,022) apresentaram reduções significativas na potência absoluta. Os resultados demonstram que o espectro de potência exibe diferenças específicas em freqüências de bandas diferentes, e corroboram para a premissa de que o cérebro, após privação ou perda de sono, promove ajustes e adaptações locais, ao invés de globais.

Several studies have investigated the relationship between asymmetrical EEG activity over the frontal cortex and mood. This study aimed at investigating the association between state fluctuations in frontal alpha EEG asymmetry and state changes followed by 24 h of sleep deprivation (SD). Our results show that sleep deprivation caused a significant alteration in the asymmetry values. Activation shifted from the left hemisphere, before SD, to the right hemisphere, after SD, in all frontal electrode pairs. In addition, according to the self-rating scale of SD-related mood effects, subjects became significantly less alerted and active, and sleepier. According to these results, increased right prefrontal activation might be potentially associated with the negative mood states typically seen after sleep deprivation, although the causal relationship is still uncertain. However, more studies will be necessary to establish the viability of EEG asymmetry and the cerebral lateralization hypothesis to explain the SD-related affective changes. Diversos estudos têm investigado a relação entre a atividade assimétrica do EEG no córtex frontal e mudanças no humor. Adotando tal abordagem, o presente estudo teve como objetivo investigar a associação entre os estados de oscilação na assimetria frontal de alfa e mudanças no estado emocional ou motivacional após 24h de privação de sono. Os resultados mostram que 24h de privação de sono ocasionaram alterações significativas nos valores de assimetria. Ativação cerebral mudou do hemisfério esquerdo, antes da privação de sono, para o hemisfério direito, após a privação de sono, em todos os pares de eletrodos frontais. Além disso, de acordo com a escala relacionada aos efeitos subjetivos do humor após privação de sono, os sujeitos mostraram-se significativamente menos alerta e ativos e mais sonolentos. É possível que as duas variáveis estejam associadas, embora a relação causal seja ainda incerta. Estudos serão ainda necessários para que se possa estabelecer a viabilidade da assimetria pré-frontal e da hipótese de lateralização cerebral na elucidação de mudanças emocionais relacionadas à privação ou falta de sono.

O objetivo do presente estudo foi avaliar parâmetros atencionais, motores e eletrencefalográficos durante uma tarefa de procedimentos em sujeitos que ingeriram 6mg de bromazepam. A amostra consistiu de 26 sujeitos saudáveis, ambos os sexos, entre 19 e 36 anos. Os grupos controle e experimental foram submetidos à tarefa datilográfica em desenho duplo-cego randomizado. Os achados não revelaram diferenças nas medidas atencionais e motoras entre os grupos. Foram avaliadas medidas de coerência (EEGq) entre regiões do escalpo nas bandas teta, alfa e beta. Análise inicial revelou um efeito principal para condição (Anova 2- critérios de variação - condição versus blocos). Uma segunda Anova, também com 2 critérios de variação (condição versus região do escalpo), demonstrou um efeito principal para ambos os fatores. Em conclusão, a medida de coerência parece não ser uma ferramenta sensível para demonstrar diferenças entre áreas corticais em função de uma tarefa de procedimentos.

Os efeitos sedativos do bromazepam no desempenho cognitivo têm sido amplamente investigados. Várias abordagens têm sido implementadas no intuito de avaliar a influência do bromazepam em sujeitos submetidos à tarefa motora. Neste contexto, o presente estudo objetiva avaliar as alterações eletrofisiológicas em sujeitos expostos à tarefa de datilografia e tratados com bromazepam (6 mg). Os dados do EEGq foram gravados simultaneamente à tarefa. Em particular, a potência relativa na banda delta (0,5-3,5 Hz) foi analizada. O tempo de execução e erros durante a tarefa foram considerados variáveis comportamentais. O grupo experimental (bromazepam 6 mg) demonstrou melhor desempenho e valores de potência relativa mais elevados que o grupo controle (placebo). Estes resultados sugerem que menor nível de ansiedade favorece o desempenho motor. The sedative effects of bromazepam on cognitive and performance have been widely investigated. A number of different approaches have assessed the influence of bromazepam when individuals are engaged to a motor task. In this context, the present study aimed to investigate electrophysiological changes when individuals were exposed to a typewriting task after taking 6 mg of bromazepam. qEEG data were simultaneously recorded during the task. In particular, relative power in delta band (0.5-3.5 Hz) was analyzed. Time of execution and errors during the task were registered as behavioral variables. The experimental group, bromazepam 6mg, showed a better motor performance and higher relative power than control individuals (placebo). These results suggest that the use of bromazepam reduces anxiety levels as expected and thus, produces an increment in motor performance.

Caffeine is the most consumed psychoactive substance in the world. The effects of caffeine have been studied using cognitive and motor measures, quantitative electroencephalography (qEEG) and event-related potentials. However, these methods are not usually employed in combination, a fact that impairs the interpretation of the results. The objective of the present study was to analyze changes in electrophysiological, cognitive and motor variables with the ingestion of caffeine, and to relate central to peripheral responses. For this purpose we recorded event-related potentials and eyes-closed, resting EEG, applied the Stroop test, and measured reaction time. Fifteen volunteers took caffeine (400 mg) or placebo in a randomized, crossover, double-blind design. A significant reduction of alpha absolute power over the entire scalp and of P300 latency at the Fz electrode were observed after caffeine ingestion. These results are consistent with a stimulatory effect of caffeine, although there was no change in the attention (Stroop) test or in reaction time. The qEEG seems to be the most sensitive index of the changes produced by caffeine in the central nervous system since it proved to be capable of detecting changes that were not evident in the tests of cognitive or motor performance.

A eficiência com que uma informação é transmitida dentro da circuitaria neural pode ser alterada por neuromoduladores. O uso do Bromazepam nos transtornos de ansiedade se deve a sua propriedade ansiolítica. Porém, os efeitos deste benzodiazepínico na aprendizagem motora não são plenamente conhecidos. O objetivo deste estudo foi analisar alterações neuropsicológicas, comportamentais e eletrofisiológicas decorrentes da administração de Bromazepam (6 mg) durante o aprendizado de uma tarefa motora. A amostra consistiu de 26 sujeitos saudáveis, de ambos os sexos, entre 19 e 36 anos. Os grupos controle (placebo) e experimental (Bromazepam 6 mg) foram submetidos ao aprendizado de datilografia, em desenho duplo-cego randomizado. Os resultados não revelaram diferenças nas variáveis neuropsicológicas e comportamentais entre os grupos. Testes estatísticos demonstraram interação entre condição e momento e um efeito principal para setor, ou seja, uma diminuição da potência relativa no hemisfério direito. Esta diminuição de potência sugere uma especialização da circuitaria neural no hemisfério contralateral ao dedo utilizado no pressionamento da tecla. Tal diminuição é independente do uso da droga. The efficiency with which an information is processed by the brain's neural circuitry can be altered by neuromodulators. The use of Bromazepam in the pharmacological treatment of anxiety disorders is due to its anxiolytic property. However, the effects of this benzodiazepine in motor learning tasks are not entirely understood. In this context, the goal of this study was to assess the effects of Bromazepam (6mg) on psychophysiological, behavioral, and electrophysiological variables, during the process of learning a motor task. The sample consisted of 26 healthy individuals, of both sexes, between 19 and 36 years of age. The control (placebo) and experimental (Bromazepam 6 mg) groups were submitted to a typewriting task, in a randomized, doble-blind design. The results did not reveal differences for phychophysiological and behavioral variables between the groups. Statistical tests pointed out to an interaction between condition and moment, and a hemisphere main effect, i.e. a reduction of relative power in the right hemisphere. This reduction suggests a specialization of the neural circuitry in the hemisphere contralateral to the finger used in the task. Such reduction is independent from the drug administration.

Neuromoduladores alteram constantemente as relações neurais pré-existentes no sistema nervoso. O bromazepam é utilizado com freqüência na prática clínica para diminuir padrões de ansiedade. Poucos são os experimentos correlacionando este ansiolítico às tarefas motoras. Neste contexto, o presente experimento visa analisar as alterações motoras e eletrocorticais decorrentes da administração de diferentes doses de bromazepam mediante a prática motora, e relacionar o efeito da droga a performance motora mão-dominante versus não dominante. Sujeitos saudáveis (39), de ambos os sexos, entre 20 a 30 anos compuseram a amostra. Os grupos controle (placebo) e experimental (bromazepam de 3mg e 6mg) foram treinados na tarefa de datilografia num modelo duplo-cego randomizado. Resultados do teste Stroop (atenção) não demonstraram diferenças no escore bruto e no tempo de execução do mesmo. Em contrapartida, nos resultados comportamentais foram observados um efeito principal entre blocos nas variáveis tempo de execução e erros cometidos durante a pratica motora. Os dados eletrofisiológicos evidenciaram interações significantes para: lateralidade/condição/momento; lateralidade/condição; lateralidade/momento; condição/momento; condição/setor.

Taking into consideration differences in syntactic configurations underlying the verb-complement merge operation, this experiment investigates three series of sentences containing incongruous and congruous merges. The aim is to relate syntactic specificities to the resulting ERP morphologies. Conditions tested required three types of computations: local merge, local merge depending on inheritance of semantic properties from an antecedent and merge performed at distance (WH-displacement). A total of 240 experimental sentences (80 for each condition) and 240 distractor sentences were generated in Brazilian Portuguese. Using a kinetic presentation protocol, sentences were displayed to each of 25 subjects, while the raw EEG was acquired at 20 derivations. Signal processing techniques were used to estimate the individual ERP for each anatomic region. Series 1 involving strictly local computations resulted in classic parietal N400s, whereas the inheritance stimuli elicited two peaks in the parietal and central region ERPs. Series 3—WH-displacement—presented earlier and more salient cortical responses. The different ERP morphologies resulting from each condition are consistent with a model in which language processing results from task-specific computations involving different neurological subsystems.

The P300 component of the Event-Related Potential (ERP) is a general measurement of "cognitive efficiency". It is an index of the ability of an individual's Central Nervous System (CNS) to process incoming information. OBJECTIVE: To develop a normative database for the visual P300. METHODOLOGY: 30 right-handed individuals (same number of each sex), between 20 and 30 years of age, healthy, free of any cognitive impairment and not making use of psychoactive substances. Participants were submitted to a visual discrimination task, which employed the "oddball" paradigm. RESULTS: The expected scalp distribution trend was seen for latency but not for amplitude values. CONCLUSION: A high variability of latency and amplitude values was observed across the age span. Mean reaction time for the entire sample of the study was 391.56 ± 37.03 ms.

Objective.The mid-latency auditory evoked potential (MLAEP) has been used to indicate depth of anaesthesia, and is usually analysed in time-domain. This work compares three techniques: Wave Deformation Parameters (PDO), Auditory Evoked Potential Index (AEPidx) and an automatic Nb-wave latency estimator (N~b), in the assessment of unconsciousness onset based on EEG under auditory stimulation. Methods.Ten normal adult volunteers, under no pre-anaesthetic drug administration, received propofolduring two successive periods of 45 min each one (3 mg/Kg/h and 9 mg/Kg/h), being the EEG collected from 10 min previous to infusion beginning until the subjects woke up. From the time-evolution of MLAEP (averaging of successive sets of 1000 epochs) all the parameters were compared to thresholds (unconsciousness onset indication time) and the results were compared to the instant of pressing interruption of a soft-touch switch, when one assumed the volunteer became unconscious. Results.The Wilcoxon Signed-Ranktest points equivalence between each of the parameters and the switch for, say, α = 5%. Bland–Altman diagrams revealed that the Attenuation-PDO has better agreement to the switch than N~b and AEPidx. Conclusion.The results suggest that, at least to indicate unconsciousness, the most reliable effect of the anaesthetic drug on MLAEP would be the amplitude attenuation. Despite the high dependence on noise due to its time-domain basis, the Attenuation-PDO seems to be adequate to assess depth of anaesthesia.

OBJECTIVE The present study sought to analyze the influence of Levetiracetam (LEV) in cognitive performance by identifying the changes produced by LEV in reaction time, in neuropsychological assessment of attention and memory and in absolute theta power in frontal activity. METHODS Twelve healthy subjects (5 men and 7 women; mean age, 30.08 years, standard deviation, 4.71) were recruited for this study. The neuropsychological tests: Trail Making Test (A and B), Digit Span (direct and indirect numerical orders/working memory); Stroop test (inhibitory control of attention); Tower of London (planning and decision-making) and a quantitative electroencephalography were applied in 2 different days after and before the participants ingested the capsule of placebo or 500 mg LEV. RESULTS A two-way-ANOVA was implemented to observe the interaction between conditions (placebo or LEV 500 mg) and moments (pre- and post-ingestion of LEV or placebo). The data were analyzed by the SPSS statistical package (p

Many different factors can temporarily or permanently impair movement and impairs cortical organization, e.g. hand immobilization. Such changes have been widely studied using electroencephalography. Within this context, we have investigated the immobilization effects through the theta band coherence analysis, in order to find out whether the immobilization period causes any changes in the inter and intra-hemispheric coherence within the cerebral cortex, as well as to observe whether the theta band provides any information about the neural mechanisms involved during the motor act. We analyzed the cortical changes that occurred after 48 hours of hand immobilization. The theta band coherence was study through electroencephalography in 30 healthy subjects, divided into two groups (control and experimental). Within both groups, the subjects executed a task involving flexion and extension of the index finger, before and after 48 hours. The experimental group, however, was actually submitted to hand immobilization. We were able to observe an increase in the coupling within the experimental group in the frontal, parietal and temporal regions, and a decrease in the motor area. In order to execute manual tasks after some time of movement restriction, greater coherence is present in areas related to attention, movement preparation and sensorimotor integration processes. These results may contribute to a detailed assessment of involved neurophysiological mechanism in motor act execution.

Bromazepam is a benzodiazepine, which has been widely employed in the treatment of anxiety. We investigated the electrophysiological changes in absolute theta power within the frontal cortex when individuals performed a visuomotor task under bromazepam. The sample of 17 healthy individuals was randomized into 2 experimental conditions, under which bromazepam 6 mg and placebo were administered on different days. All subjects were right -handed, with no mental or physical illness and were not using any psychoactive or psychotropic substance during the entire period of the study. We found an increase in reaction time under bromazepam compared with placebo . With regard to the electrophysiological variable, we found a lower theta power value in the prefrontal cortex prior to task execution, compared with after. We therefore suggested that this could be an increase of neural activity in this region, because of the subjects’ readiness to perform the task, that is, because of their higher alertness. The right lateral frontal region showed lower theta power under bromazepam for pre- and post-finger movement. This could have occurred because of more effort to execute the task. In the left frontal region: premovement did not demonstrate any difference between conditions, possibly because the proposed task was simple to execute. In conclusion, theta power plays an important role in the analysis of visuomotor performance, assuming that bromazepam causes impairment on sustained attention and sensory perception.

The coherent average was used for investigating the motion-related VEP (M-VEP). The electroencephalogram (EEG) signals of 29 healthy subjects were acquired during stabilometric protocol with distinct virtual scenes: static (SS) and dynamic (forward, DS F , or backward motion, DS B ). The grand-averaged M-VEP for these visual conditions presented N2 peak dominance with higher values for parietal EEG derivation. The DS increased the N2 peak and latency, as well as the N2 ( P3 amplitude, in comparison with SS. These components are not sensitive to motion orientation (t-test α = 0.05). However, the running t-test (α = 0.05) showed difference in the DS F ( DS B waveforms 600 ms after the DS onset, with an increasing time delay from the occipital to central derivations. These findings suggest that the cognitive, planning and motor processing to maintain balance depends on the virtual scene direction.

Ramachandran et al. foram os primeiros a introduzirem o uso do espelho para induzir a sensação cinestésica em membros amputados. Os mecanismos neurofisiológicos envolvidos para explicar a terapia–espelho ainda não são claros, mas estão relacionados com o efeito causado pelo feedback visual em áreas corticais sensóriomotoras. Essa entrada visual pode ser o suficiente para evocar a percepção cinestésica em certas circunstâncias. Neste contexto, a terapia-espelho é uma possibilidade segura e útil que vem demonstrando resultados positivos na recuperação funcional de pacientes com hemiparesia pós-acidente vascular cerebral.

A estimulação magnética transcraniana (EMT) foi introduzida há quase 20 anos e desde então tem sido desenvolvido como uma ferramenta sofisticada para a pesquisa em neurociência. É uma excelente técnica que complementa outros métodos não-invasivos para estudar a fisiologia do cérebro humano. O objetivo do presente estudo foi rever os conceitos básicos da técnica EMT repetitiva (EMTr) demonstrando suas reais aplicações na recuperação funcional de pacientes pós-AVC. Vários estudos clínicos têm relatado que as sessões de EMT podem melhorar os déficits motores associados ao AVC. No entanto, uma vez que estas alterações são transitórias, é prematuro propor estas aplicações como opções terapêuticas realista, embora a técnica de EMT mostrou-se, potencialmente um modulador da integração sensório-motora e da reorganização cortical. Trabalhos futuros prometem fornecer valiosos avanços para o estudo da recuperação funcional, e talvez, estabelecer a neuromodulação como opção terapêutica viável à recuperação de funções.

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.

Objective The study presented here analyzed the patterns of relationship between oculomotor performance and psychopathology, focusing on depression, bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and anxiety disorder. Methods Scientific articles published from 1967 to 2013 in the PubMed/Medline, ISI Web of Knowledge, Cochrane, and SciELO databases were reviewed. Results Saccadic eye movement appears to be heavily involved in psychiatric diseases covered in this review via a direct mechanism. The changes seen in the execution of eye movement tasks in patients with psychopathologies of various studies confirm that eye movement is associated with the cognitive and motor system. Conclusion Saccadic eye movement changes appear to be heavily involved in the psychiatric disorders covered in this review and may be considered a possible marker of some disorders. The few existing studies that approach the topic demonstrate a need to improve the experimental paradigms, as well as the methods of analysis. Most of them report behavioral variables (latency/reaction time), though electrophysiological measures are absent.

It is well known that perception and estimation of time are fundamental for the relationship between humans and their environment. However, this temporal information processing is inefficient in patients with Parkinson’ disease (PD), resulting in temporal judgment deficits. In general, the pathophysiology of PD has been described as a dysfunction in the basal ganglia, which is a multisensory integration station. Thus, a deficit in the sensorimotor integration process could explain many of the Parkinson symptoms, such as changes in time perception. This physiological distortion may be better understood if we analyze the neurobiological model of interval timing, expressed within the conceptual framework of a traditional information-processing model called “Scalar Expectancy Theory”. Therefore, in this review we discuss the pathophysiology and sensorimotor integration process in PD, the theories and neural basic mechanisms involved in temporal processing, and the main clinical findings about the impact of time perception in PD.

Selective attention is fundamental for the information processing. The perceptive system receives different external and internal stimuli at all times and our organism needs to be capable to perceive environmental stimuli, in order to discriminate the difference among these stimuli and, thus, archive relevant information in the brain. In such manner, the attention process becomes a determinant mechanism in the sensorimotor integration.

For many decades the parietal cortex (PC) has been considered the key area in tasks which involve the integration of different stimuli. PC is fundamental to determine spatial sense, information navigation and integration, and is involved in several aspects of the complex motor repertoire and in neurological and psychiatric disorders. In this review, we focus on seven different aspects of PC: (i) neuroanatomy of the parietal cortex; (ii) sensory motor integration processes; iii) hand movement control: reaching, grasping, and pointing; (iv) saccadic eye movements; (v) movement observation; (vi) neurological aspects: ataxia, autism and Parkinson's disease; and (vii) psychiatric aspects: schizophrenia, bipolar disorder and depression. Among these, we related the perspectives which involve the functions of the parietal cortex and mirror neurons and that seem to play a fundamental role in action prediction, planning, observation and execution. Furthermore, we focused on the relationship between posterior parietal cortex (PPC) and hand-guided movements. For this review, we conducted an academic paper search which fulfilled the objective of the study. We conclude that the PC has great participation in different motor functions and neurological/psychiatric disorders.

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. Alguns estudos relataram a importância da eletroencefalografia (EEG) como método de investigação de parâmetros anormais em transtornos psiquiátricos. Achados diferentes na análise do domínio do tempo e da frequência em relação à excitabilidade do sistema nervoso central durante estados agudos de pânico já foram obtidos. O objetivo deste estudo foi revisar sistematicamente os achados de EEG no transtorno do pânico (TP), discuti-los com base em uma hipótese neuroanatômica atualmente aceita para essa patologia e identificar limitações nos estudos selecionados. A pesquisa bibliográfica foi realizada nas bases de dados PubMed e ISI Web of Knowledge, utilizando as palavras-chave eletroencefalografia e transtorno do pânico; 16 artigos foram selecionados. Apesar da inconsistência dos achados de EEG no TP, as principais conclusões sobre a potência absoluta das bandas alfa e beta apontam para uma diminuição da potência em alfa, enquanto em beta a potência tende a aumentar. Diferentes padrões de assimetria foram encontrados entre estudos. Os estudos de coerência apontaram para um menor grau de conectividade funcional inter-hemisférica na região frontal e intra-hemisférica na região temporal bilateral. Estudos de potenciais eventos relacionados demonstraram mudanças no processamento da memória em pacientes com TP quando expostos a estímulos aversivos. Notou-se que a maioria dos resultados reflete a atual hipótese neurobiológica do TP, nos quais déficits inibitórios do córtex pré-frontal em relação à modulação da atividade da amígdala, e a subsequente ativação de regiões subcorticais, podem ser responsáveis por desencadear respostas de ansiedade. Foram abordadas algumas questões importantes que precisam ser consideradas em futuras pesquisas, especialmente o uso de diferentes métodos de análise de sinais de EEG. Descritores: Eletroencefalografia, transtorno do pânico, neurobiologia, mapeamento encefálico.

The goal of the present study is to compare the electrophysiological correlates of the threshold to detection of passive motion (TTDPM) among three groups: healthy individuals (control group), professional volleyball athletes with atrophy of the infraspinatus muscle on the dominant side, and athletes with no shoulder pathologies. More specifically, the study aims at assessing the effects of infraspinatus muscle atrophy on the cortical representation of the TTDPM. A proprioception testing device (PTD) was used to measure the TTDPM. The device passively moved the shoulder and participants were instructed to respond as soon as movement was detected (TTDPM) by pressing a button switch. Response latency was established as the delay between the stimulus (movement) and the response (button press). Electroencephalographic (EEG) and electromyographic (EMG) activities were recorded simultaneously. An analysis of variance (ANOVA) and subsequent post hoc tests indicated a significant difference in latency between the group of athletes without the atrophy when compared both to the group of athletes with the atrophy and to the control group. Furthermore, distinct patterns of cortical activity were observed in the three experimental groups. 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 TTDPM.

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).

Background There is increasing evidence that neurocognitive dysfunction is associated with the different states in Bipolar Disorder. Gamma coherence is strongly related to cognitive processes and cortico-cortical communication. This paper aims at shedding light on the relationship between cortical gamma coherence within bipolar patients and a control group during a prosaccadic attention task. We hypothesized that gamma coherence oscillations act as a main neural mechanism underlying information processing which changes in bipolar patients. Method Thirty-two (12 healthy controls and 20 bipolar patients) subjects were enrolled in this study. The subjects performed a prosaccadic attention task while their brain activity pattern was recorded using quantitative electroencephalography (20 channels). Results We observed that the maniac group presented lower saccade latency when compared to depression and control groups. The main finding was a greater gamma coherence for control group in the right hemisphere of both frontal and motor cortices caused by the execution of a prosaccadic attention task. Limitations The findings need to be confirmed in larger samples and in bipolar patients before start the pharmacological treatment. Conclusions Our findings suggest a disrupted connection of the brain's entire functioning of maniac patients and represent a deregulation in cortical inhibitory mechanism. Thus, our results reinforce our hypothesis that greater gamma coherence in the right and left frontal cortices for the maniac group produces a “noise” during information processing and highlights that gamma coherence might be a biomarker for cognitive dysfunction during the manic state.

Background Catching an object is a complex movement that involves not only programming but also effective motor coordination. Such behavior is related to the activation and recruitment of cortical regions that participates in the sensorimotor integration process. This study aimed to elucidate the cortical mechanisms involved in anticipatory actions when performing a task of catching an object in free fall. Methods Quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 20 healthy right-handed participants performed the catching ball task. We used the EEG coherence analysis to investigate subdivisions of alpha (8-12 Hz) and beta (12-30 Hz) bands, which are related to cognitive processing and sensory-motor integration. Results Notwithstanding, we found the main effects for the factor block; for alpha-1, coherence decreased from the first to sixth block, and the opposite effect occurred for alpha-2 and beta-2, with coherence increasing along the blocks. Conclusion It was concluded that to perform successfully our task, which involved anticipatory processes (i.e. feedback mechanisms), subjects exhibited a great involvement of sensory-motor and associative areas, possibly due to organization of information to process visuospatial parameters and further catch the falling object.

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. O movimento sacádico é uma importante medida de comportamento usada para investigar vários processos cognitivos, incluindo atenção e integração sensório-motora. O presente estudo teve como objetivo investigar as mudanças na coerência em beta nos córtices frontal, motor, parietal e occipital durante a realização de duas condições diferentes de um paradigma do movimento sacádico. As condições envolveram um padrão diferente de apresentação do estímulo: a apresentação do estímulo fixo e do aleatório. Doze voluntários saudáveis (três do sexo masculino, com idade média de 26,25; DP=4,13) realizaram a tarefa, enquanto o seu padrão de atividade cerebral era monitorado, usando eletroencefalografia quantitativa. Os resultados mostraram uma interação entre condição dos fatores e momento para o par de eletrodos C3/C4. Observou-se um efeito principal ao momento para CZ/C4, FZ/F3 e P3/PZ. Encontrou-se também um efeito principal à condição para FZ/F4, P3/P4 e O1/O2. Os resultados demonstram um importante papel da ligação interconexão entre os dois hemisférios, em busca visual e preparação do movimento. O estudo demonstra uma automatização da ação e uma redução do foco de atenção durante a tarefa. Identificou-se também que a coerência em beta entre regiões inter-hemisféricas desempenha um papel importante na diferenciação entre as duas condições. Ainda, beta no córtex frontal direito é capaz de diferenciar as condições, demonstrando-se um maior envolvimento da memória de procedimento em condição fixa. Sendo assim, os presentes resultados sugerem especialização neuronal na execução do paradigma prossacádico envolvendo sequência de tarefa motora.

This study aimed to investigate the acute modulatory effect of bromazepam, a benzodiazepine derivative drug, on alpha and beta bands (8-35Hz) in primary motor areas (M1) through event-related spectral perturbation (ERSP). Ten healthy subjects were submitted to a cross-over double-blind design. Subjects performed a visuomotor task where they had to identify rapidly the ball launched horizontally and catch it quickly, while electroencephalographic activity was acquired. We found a statistically significant difference on the time windows of 2920 ms for 13Hz in the electrodes C3 and Cz, and on the time window of 2000 ms for 18Hz in the electrodes C3, when compared the bromazepam and placebo conditions. We concluded that the acute effects of bromazepam provoked changes in information process in the left M1 represented by electrode C3 in both 13 Hz and 18 Hz. Our paradigm is relevant for a better understanding of the brain dynamics due to the information related to bromazepam effects on sensorimotor processes. We consider this report an invitation to conduct more studies in order to associate electro-cortical activity and psychometric tests.

ObjectiveTo estimate dietary habits and other factors associated with inadequate blood pressure (BP) control in hypertensive patients adherent to antihypertensive drug treatment assisted by a Brazilian Family Doctor Program (FDP).DesignA cross-sectional study.SettingFDP units, Niterói, Rio de Janeiro, Brazil.SubjectsWe included data from both male and female participants aged ≥20 years. Participants completed a standardized questionnaire containing questions related to demographics, socio-economic factors, comorbidities and lifestyle, as well as a validated FFQ and eleven additional qualitative questions to investigate dietary habits. Food items were divided into sixteen groups. Medical consultations were performed, BP measurements were taken, blood and urine samples were assessed and anthropometric and nutritional status was evaluated.ResultsIndividuals with inadequate BP control presented higher BMI values (prevalence ratio (PR) = 1·027, 95 % CI 1·009, 1·045) and also consumed more meat (PR = 1·091, 95 % CI 1·022, 1·165), which are potentially modifiable variables. Higher levels of serum creatinine (PR = 1·894, 95 % CI 1·241, 2·892) were also associated with inadequate BP control, as were skin colour (white). After inclusion of the Na excretion index, which is an indirect measure of salt intake, a slight decrease was observed in the PR for meat, which resulted in loss of statistical significance.ConclusionsThe results indicate that salt consumption, skin colour, BMI and serum creatinine are associated with inadequate BP control.

Functional electrical stimulation (FES) is a technique used for rehabilitation of motor and sensory dysfunction and consisted in the application of neuromuscular electrical stimulation concurrently with a functional activity. Previous studies suggest that sensory motor processing during FES stimulation of hand is similar to that of voluntary hand movement.To examine the changes in theta band (4-8 Hz) coherence in the centro-parietal and temporo-parietal junction during a FES task. Our hypothesis is that different conditions of electro-stimulation can produce changes in the theta band coherence in the sensory-motor and multisensory integration.The sample was composed of 24 students, male (n =14) and female (n =10), between 25 and 40 years old. Subjects were randomly distributed in three groups: control group (n = 8), G24 (n = 8) and G36 (n = 8). The control group simulated four blocks without electrostimulation been applied. The G24 group was exposed to four blocks of electrostimulation. The G36 group was exposed to six blocks of electrostimulation. We employed FES equipment to stimulate the extension of the right index finger and the electroencephalographic signal was simultaneously recorded.A main effect was found for the condition, block and electrode in the centro-parietal junction, although we only found a main effect for condition and electrode in the temporo-parietal junction. CONCLUSION. Our results suggest that the functional coupling between the central and parietal areas is directly connected to the priming memory function, although the coupling between temporal and parietal areas is related to the working memory.

This study aimed at analyzing the relationship between slow- and fast-alpha asymmetry within frontal cortex and the planning, execution and voluntary control of saccadic eye movements (SEM), and quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 12 healthy participants performing a fixed (i.e.,memory-driven) and a random SEM (i.e., stimulus-driven) condition. We find main effects for SEM condition in slow- and fast-alpha asymmetry at electrodes F3-F4,which are located over premotor cortex, specifically a negative asymmetry between conditions. When analyzing electrodes F7-F8,which are located over prefrontal cortex, we found a main effect for condition in slow-alpha asymmetry, particularly a positive asymmetry between conditions. In conclusion, the present approach supports the association of slow- and fast-alpha bands with the planning and preparation of SEM, and the specific role of these sub-bands for both, the attention network and the coordination and integration of sensory information with a (oculo)-motor response. (PsycINFO Database Record (c) 2012 APA, all rights reserved) (journal abstract)

Recent evidence is reviewed to examine relationships among sensorimotor and cognitive aspects in some important psychiatry disorders. This study reviews the theoretical models in the context of sensorimotor integration and the abnormalities reported in the most common psychiatric disorders, such as Alzheimer's disease, autism spectrum disorder and squizophrenia.The bibliographical search used Pubmed/Medline, ISI Web of Knowledge, Cochrane data base and Scielo databases. The terms chosen for the search were: Alzheimer's disease, AD, autism spectrum disorder, and Squizophrenia in combination with sensorimotor integration. Fifty articles published in English and were selected conducted from 1989 up to 2010.We found that the sensorimotor integration process plays a relevant role in elementary mechanisms involved in occurrence of abnormalities in most common psychiatric disorders, participating in the acquisition of abilities that have as critical factor the coupling of different sensory data which will constitute the basis of elaboration of consciously goal-directed motor outputs. Whether these disorders are associated with an abnormal peripheral sensory input or defective central processing is still unclear, but some studies support a central mechanism.Sensorimotor integration seems to play a significant role in the disturbances of motor control, like deficits in the feedforward mechanism, typically seen in AD, autistic and squizophrenic patients.

This work aims at analyzing event-related potentials (ERPs) of posterior and central areas of the cortex during motor imagery of spike volleyball task along the time of imagination. Multi-channel EEG was acquired following 10–20 international system over occipital, parietal and central areas during kinesthetic motor imagery (KMI) of volleyball spike and reference (REF) period (mental countdown), from athletes and non-athletes. The Event Related desynchronization / synchronization (ERD/ERS) was calculated to assess changes in alpha peak frequency in two moments: between 0.5 and 1.5 s (E1), and between 1.5 and 2.5 s (E2) after trigger sound of imagery start. The athletes showed more number of subjects with desynchronization in central areas, while in non-athletes in parietal areas ones. Moreover, the KMI along time analysis indicated more desynchronism in E2 than E1 in athletes, except for P3. According to the results, we conclude that kinesthetic motor imagery of complex task as volleyball spike demands more cognitive effort in central areas of athletes than non-athletes, reflected in desynchronism of alpha peak frequency. Moreover, the behavior of alpha peak frequency along time of imagination suggests an interaction effect related with the knowledge of task imagined. Nevertheless, more studies are needed to support these findings.

This study investigated the effects of bromazepam on qEEG when 14 healthy subjects were asked to perform a visuomotor task (i.e., motor vehicle driving task). The subjects were exposed to two experimental conditions: the placebo (PL) and 6 mg of bromazepam (Br 6 mg), following a randomized, double-blind design on different days. Specifically, we observe absolute power extracted from qEEG data for theta band. We expected to see a decrease in absolute theta power in the temporal and parietal areas due to the influence of bromazepam for the experimental group when compared with the placebo group. We found a main effect for the condition factor for electrodes T3, T4, P3 and P4. We also observed a main effect for the period factor for electrodes P3 and P4. We observed that the ingestion of 6 mg of bromazepam induces different patterns in theta power at the temporal and parietal sites. We concluded that 6 mg of bromazepam was an important factor in the fluctuation of the activities in the temporal and parietal areas. We then hypothesize about the specific role of this drug during the execution of a visuomotor task and within the sensorimotor integration process.

Background The present study examined absolute alpha power using quantitative electroencephalogram (qEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions. Methods Twenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired. Results We found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM. Conclusion Although we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor system. In other words, MPH seems to provoke a period of initial instability due to a possible modulation in neural activity, which can be explained by lower levels of alpha power (i.e., higher cortical activity). However, after the end of the PB1 a new stabilization was established in neural circuits, due to repetition of the task, resulting higher cortical activity during the task. In conclusion, MPH group performance was not initially superior to that of the control group, but eventually exceeded it, albeit without achieving statistical significance.

This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 healthy right-handed subjects had to catch a free falling object through quantitative electroencephalogram (qEEG). For this reason, we used coherence that represents a measurement of linear covariation between two signals in the frequency domain. In addition, we investigated gamma-band (30-100 Hz) activity that is related to cognitive and somatosensory processes. We hypothesized that gamma coherence will be increase in both parietal and occipital areas during moment after ball drop, due to their involvement in manipulation of objects, visuospatial processing, visual perception, stimuli identification and attention processes. We confirmed our hypothesis, an increase in gamma coherence on P3-P4 (t= -2.15; p=0.033) and PZ-OZ (t= -2.16; p=0.034) electrode pairs was verified for a paired t-test. We conclude that to execute tasks involving anticipatory movements (feedforward mechanisms), like our own task, probably, there is no need of a strong participation of visual areas in the process of information organization to manipulate objects and to process visuospatial information regarding the contact hand-object. Este estudo teve como objetivo elucidar os mecanismos corticais envolvidos em ações antecipatórias quando 23 indivíduos saudáveis destros tinham que apreender um objeto em queda livre, através da eletroencefalografia quantitativa (EEGq). Por esta razão, usamos a coerência que representa a covariação linear entre dois sinais no domínio da frequência. Além disso, investigamos a atividade da banda gama (30-100 Hz), que está relacionada à processos cognitivos e somato-sensoriais. Nossa hipótese é que a coerência de gama estará aumentada em ambas as áreas parietais e occipitais durante o momento pós-queda da bola, devido ao seu envolvimento na manipulação de objetos, processamento visuo-espacial, percepção visual, identificação de estímulos e processos de atenção. Confirmamos nossa hipótese. Um aumento de coerência em gama nos pares de eletrodos P3-P4 (t= -2,15; p=0,033) e PZ-OZ (t= -2,16; p=0,034) foi verificado por teste-t pareado. Conclui-se que, para executar tarefas que envolvem movimentos de antecipação (mecanismos de retro-alimentação) como a nossa própria tarefa, provavelmente, não há necessidade de forte participação de áreas visuais no processo de organização da informação como para manipular objetos e processar a informação visuo-espacial no contato mão-objeto.

Sensorimotor integration is defined as the capability of the central nervous system to integrate different sources of stimuli, and parallelly, to transform such inputs in motor actions.To review the basic principles of sensorimotor integration, such as, its neural bases and its elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects, and the abnormalities reported in the most common movement disorders, such as, Parkinson' disease, dystonia and stroke, like the cortical reorganization-related mechanisms.Whether these disorders are associated with an abnormal peripheral sensory input or defective central processing is still unclear, but most of the data support a central mechanism. We found that the sensorimotor integration process plays a potential role in elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects and in occurrence of abnormalities in most common movement disorders and, moreover, play a potential role on the acquisition of abilities that have as critical factor the coupling of different sensory data which will constitute the basis of elaboration of motor outputs consciously goal-directed.

The effects of physical exercise on mental health have been extensively investigated, mainly in older people. Recent studies have looked into the acute effect of exercise on the brain using standardized low-resolution brain electromagnetic tomography (sLORETA). We assessed EEG power and mood changes after 20 min of aerobic exercise in elderly (N = 10) and young (N = 19) healthy individuals. Both groups showed improvement in total mood disturbance (TMD) post exercise (young: P = 0.03; elderly: P = 0.02). Only the young group showed significant improvement in anger (P = 0.05) and vigor (P = 0.006). Comparison pre versus post-exercise for each group separately revealed significant changes in the young group (an increase in alpha, beta-1 and beta-2 activity in Brodmann areas 24, 33 and 23, respectively). However, the elderly group did not show significant changes. An inverse correlation was found between alpha asymmetry and STAI (rs = −0.50; P = 0.029) in the young group. On the other hand, a significant correlation between beta-1 activity and TMD was observed in the elderly group (rs = 0.67; P = 0.045). We conclude that acute exercise can have distinct effects on brain activity and mood variables in young individuals when compared with elderly adults. However, additional studies are necessary to further investigate the role of exercise intensity in these results.

Summary Objectives To estimate familial aggregation and the heritability of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in families assisted by the Family Doctor Program in a Brazilian city, and to evaluate associations between some environmental factors and familial aggregation of these lipids. Study design Cross-sectional familial study. Methods The association of lipids with sociodemographic factors, lifestyle factors and comorbidities (e.g. physical activity, alcohol consumption, smoking, hypertension, impaired glucose tolerance, body mass index) was estimated using linear models and generalized estimating equations. Correlation of TC, LDL-C and HDL-C between pairs of relatives was estimated with the familial correlation procedure, and heritability was estimated with the ASSOC procedure. Results All associations were statistically significant. There was familial aggregation of TC (parent/offspring, r = 0.33; sibling/sibling, r = 0.37), LDL-C (parent/offspring, r = 0.29; sibling/sibling, r = 0.37) and HDL-C (parent/offspring, r = 0.25; sibling/sibling, r = 0.48), but less than 3%, 6% and 14%, respectively, which was explained by lifestyle factors. Correlation between pairs with genetic sharing (parent/offspring and sibling/sibling) was higher than that observed between father and mother. Heritability estimates ranged between 0.32 (HDL-C) and 0.50 (TC). Similar results were found for the two approaches used to estimate the contribution of genetic and environmental factors in the correlation of TC, LDL-C and HDL-C between the family pairs. Conclusion The results showed that there is familial aggregation of TC, LDL-C and HDL-C, and point to the predominance of genetic factors because little influence of environmental variables was found.

Some patients are no longer able to communicate effectively or even interact with the outside world in ways that most of us take for granted. In the most severe cases, tetraplegic or post-stroke patients are literally 'locked in' their bodies, unable to exert any motor control after, for example, a spinal cord injury or a brainstem stroke, requiring alternative methods of communication and control. But we suggest that, in the near future, their brains may offer them a way out. Non-invasive electroencephalogram (EEG)-based brain-computer interfaces (BCI) can be characterized by the technique used to measure brain activity and by the way that different brain signals are translated into commands that control an effector (e.g., controlling a computer cursor for word processing and accessing the internet). This review focuses on the basic concepts of EEG-based BCI, the main advances in communication, motor control restoration and the downregulation of cortical activity, and the mirror neuron system (MNS) in the context of BCI. The latter appears to be relevant for clinical applications in the coming years, particularly for severely limited patients. Hypothetically, MNS could provide a robust way to map neural activity to behavior, representing the high-level information about goals and intentions of these patients. Non-invasive EEG-based BCIs allow brain-derived communication in patients with amyotrophic lateral sclerosis and motor control restoration in patients after spinal cord injury and stroke. Epilepsy and attention deficit and hyperactive disorder patients were able to downregulate their cortical activity. Given the rapid progression of EEG-based BCI research over the last few years and the swift ascent of computer processing speeds and signal analysis techniques, we suggest that emerging ideas (e.g., MNS in the context of BCI) related to clinical neurorehabilitation of severely limited patients will generate viable clinical applications in the near future.

Literature has shown that failures in the ability to down-regulate negative emotions are the core substrate of anxiety disorders. Previous studies have investigated this issue by encouraging individuals to voluntarily change how they think about a situation in order to decrease its emotional impact. The majority of studies has demonstrated that explicit instructions to reduce negative affect in anxious individuals are usually ineffective. Thus, the goal of the present study was to investigate whether an implicit regulation strategy would modulate electrophysiological activity (Late Positive Potential) associated to affective picture viewing. The Late Positive Potential (LPP) is a sustained positive deflection in the event-related potential that is larger following the presentation of emotional compared to neutral visual stimuli. Participants (low trait anxious - LTA and high trait anxious - HTA individuals) performed an attention task (bar orientation discrimination) while emotional distractive pictures were presented. The task was performed in two different contexts: in the Real context, participants were informed that the distractive pictures had been obtained from real life situations, whereas in the Fictitious context they were told that the pictures had been obtained from movie scenes. In this vein, we encouraged participants to change how they appraised the pictures. Results showed that HTA individuals exhibited larger Late Positive Potential (LPPs) when mutilation pictures were presented in the Real context. Importantly, during the Fictitious one (regulation strategy) the LPP was reduced even in HTA individuals, emphasizing its importance to psychotherapeutic interventions. The present results indicate that HTA individuals are susceptible to modifications in affective contexts.

Our study aims to investigate changes in electrocortical activity by observing the variations in absolute theta power in the primary somatomotor and parietal regions of the brain under three different electrical stimulation conditions: control group (without stimulation), group 24 (24 trials of stimulation) and group 36 (36 trials of stimulation). Thus, our hypothesis is that the application of different patterns of electrical stimulation will promote different states of habituation in these regions. The sample was composed of 24 healthy (absence of mental and physical impairments) students (14 male and 10 female), with ages varying from 25 to 40 years old (32.5+/-7.5), who are right-handed (Edinburgh Inventory). The subjects were randomly distributed into three groups: control (n=8), G24 (n=8) and G36 (n=8). We use the Functional electrical stimulation (FES) equipment (NeuroCompact-2462) to stimulate the right index finger extensor muscle, while the electroencephalographic signal was simultaneously recorded. We found an interaction between condition and block factors for the C3 and P3 electrode, a condition and block main effects for the C4 electrode, and a condition main effect for the P4 electrode. Our results support the hypothesis that electrical stimulation promotes neurophysiological changes. It appears that stimulus adaptation (accommodation) of specific circuits can strengthen the brain's ability to distinguish between and respond to such stimuli over time.

This study aimed to elucidate cortical mechanisms and to identify the areas where occur such mechanisms due to interaction between bromazepam and motor learning. The sample was composed of 45 healthy subjects randomly distributed in 3 groups: placebo (n=15), bromazepam 3 mg (n=15) or bromazepam 6 mg (n=15). To perform the experimental task, subjects sat comfortably at a distance of approximately 20 cm from the typewriter. The typewriter keyboard was covered with a wooden box to avoid visual information about the hands' position. The typewriting task was performed concomitantly with EEG recording. ANOVA two-way results indicated a decreased asymmetry in sensorimotor areas in the experimental groups. Our interpretation is that moderate doses of bromazepam may improve performance on tasks with predictable elements to promote stability of psychomotor functions, but may also impair performance on tasks executed in unpredictable environments. O objetivo do estudo foi elucidar mecanismos corticais e identificar as áreas onde estas ocorrem tais mecanismos devido à interação entre bromazepam e aprendizagem motora. A amostra compreendeu 45 sujeitos hígidos distribuídos randomicamente em 3 grupos: placebo (n=15), bromazepam 3 mg (n=15) ou bromazepam 6 mg (n=15). Para a realização da tarefa experimental, sujeitos sentaram-se confortavelmente a uma distância de aproximadamente 20 cm da máquina de escrever. O teclado da máquina foi coberto com uma caixa de madeira para evitar informações visuais sobre a posição das mãos. O registro do EEGq ocorreu simultaneamente à tarefa de datilografia. Os resultados da ANOVA two-way indicaram menor assimetria em áreas sensório-motoras nos grupos experimentais. Nossa interpretação é que doses moderadas de bromazepam podem melhorar o desempenho em tarefas previsíveis por promover estabilidade das funções psicomotoras, mas pode prejudicar o desempenho em tarefas realizadas em ambientes imprevisíveis.

Transcranial magnetic stimulation (TMS) was introduced nearly 20 years ago and has since been developed as a sophisticated tool for neuroscience research. It is an excellent technique that complements other non-invasive methods for studying human brain physiology. The aim of the present study was to review the basic concepts and principles of the repetitive TMS (rTMS) technique, gathering evidence of its applications in neurorehabilitation. Several clinical studies have reported that sessions of rTMS can improve some or all of the motor symptoms associated with Parkinson's disease, dystonia and stroke. However, since these changes are transient, it is premature to propose these applications as realistic therapeutic options, even though the rTMS technique has shown itself to be, potentially, a modulator of sensorimotor integration and neurogenesis. Future work in this area promises to advance our understanding of the pathophysiology of a wide range of neurological conditions, generate widely applicable diagnostic tools for clinical neurophysiology, and perhaps establish neuromodulation as a viable therapeutic option in neurorehabilitation.

Statistical Objective Response Detection (ORD) Techniques applied to Evoked Potentials usually depend on the effective Number of Degrees of Freedom (NDOF) of spontaneous EEG. This work proposes a method for estimating the NDOF of the EPD (Evoked Potential Detector) probability distribution under the null hypothesis of no response, based on the EEG autocorrelation function (ACF). Its performance was assessed by both simulation and by applying it to mid-latency auditory evoked potentials (MLAEP) of ten adult volunteers at different stimulus intensities. NDOF estimates based on the autocorrelation function were close to the theoretical values. Moreover, ORD based on the proposed method achieved better specificity in detecting MLAEP in comparison with alternative approaches using white-noise EEG model and estimation of NDOF via cumulative distribution fitting, though all methods achieved similar sensitivity. This result supports the use of EPD as a robust ORD method.