The relationship between physical activity and mental health has been widely investigated, and several hypotheses have been formulated about it. Specifically, during the aging process, physical exercise might represent a potential adjunctive treatment for neuropsychiatric disorders and cognitive impairment, helping delay the onset of neurodegenerative processes. Even though exercise itself might act as a stressor, it has been demonstrated that it reduces the harmful effects of other stressors when performed at moderate intensities. Neurotransmitter release, neurotrophic factor and neurogenesis, and cerebral blood flow alteration are some of the concepts involved. In this review, the potential effects of exercise on the aging process and on mental health are discussed, concerning some of the recent findings on animal and human research. The overwhelming evidence present in the literature today suggests that exercise ensures successful brain functioning.

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.

-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.KEY WORDS: brain mapping, EEG, LORETA (low resolution electromagnetic tomography), schizophrenia.Atividade elétrica neurocortical em esquizofrênicos crônicos Atividade elétrica neurocortical em esquizofrênicos crônicos Atividade elétrica neurocortical em esquizofrênicos crônicos Atividade elétrica neurocortical em esquizofrênicos crônicos Atividade elétrica neurocortical em esquizofrênicos crônicos RESUMO -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. PALAVRAS-CHAVE: mapeamento cerebral, eletroencefalografia quantitativa (EEGq), LORETA (tomografia de baixa resolução), esquizofrenia.

-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).KEY WORDS: qEEG, neurometrics, Alzheimer´s disease, depression. Eletroencefalografia quantitativa (EEGq) na discriminação entre demência degenerativa primária e transtorno depressivo maior (depressão)RESUMO -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...

The ED are possibly associated with a certain degree of neuropsychological dysfunction, even though there is no consensus with regard to which function is particularly impaired. The fact that some cognitive dysfunction tend to disappear after treatment argues in favor of the hypothesis that these are functional deficits. Other deficits, however, tend to persist, suggesting that they may precede the development of eating disorders or even contribute to their development or to a worse prognosis. The study of the neuropsychological aspects of ED may help tailoring more selective therapeutic approaches to patients suffering from these disorders.