Efeito de um programa de treinamento da memória de trabalho em adultos idosos / Effect of a working memory training program in older adults

Este estudo objetivou examinar os efeitos de um Treinamento da Memória de Trabalho (TMT) em idosos saudáveis. Vinte participantes compuseram a amostra final, onze do grupo experimental (TMT) e nove do controle (socialização). Todos foram submetidos a uma avaliação neuropsicológica pré e pós-intervenção. Os encontros foram realizados uma vez por semana, durante três meses. Houve melhora significativa, no grupo experimental, em atenção concentrada, aprendizagem, memória de curto prazo e episódica, e no grupo controle, em um menor número de variáveis, na atenção concentrada e memória episódica. O TMT parece ter promovido efeito de transferência, principalmente na memória episódica, que é relacionada diretamente aos subsistemas da memória de trabalho (MT), sugerindo que o TMT pode ser útil no contexto da neuropsicologia do envelhecimento.

The present study examined the effects of a Working Memory Training (WMT) in healthy elderly. Twenty participants comprised the final sample, eleven from the experimental group (WMT) and nine from the control group (socialization). Every subject underwent a neuropsychological evaluation pre and post-intervention. The meetings were held once a week, for three months. Results indicated that subjects in the experimental group improved cognitive functions related to concentrated attention, learning, short-term and episodic memory. Subjects in the control group also demonstrated, in a smaller number of variables, improvement in concentrated attention and episodic memory. WMT seems to have generated a transfer effect, especially to episodic memory, which is directly related to the subsystem of working memory (WM), suggesting that WMT may be useful in the context of the neuropsychology of aging.

Correlação entre espessura cortical frontal e desempenho de funções executivas em pacientes com infecção pelo vírus da imunodeficiência humana / Correlation between frontal cortical thickness and executive functions performance in patients with human immunodeficiency virus infection

OBJETIVO: Investigar a relação entre a espessura cortical medida pela ressonância magnética em regiões frontais e o desempenho em instrumentos que avaliam funções executivas em pacientes com HIV positivo. MATERIAIS E MÉTODOS: Participaram deste estudo 22 pacientes HIV-positivos, com déficits em funções executivas, sob terapia antirretroviral, idades entre 45 e 65 anos e escolaridade entre 3 e 20 anos. Foi realizada ressonância magnética com sequências convencionais, T1 3D, processado pelo Freesurfer para verificar espessura cortical. Instrumentos de avaliação das funções executivas: Teste de Trilhas, Wisconsin, Hayling, Dígitos (WAIS-III), fluência verbal ortográfica e Stroop. Para análise da relação espessura versus cognição, utilizou-se coeficiente de correlação de Pearson. RESULTADOS: Correlações significativas foram encontradas entre escores de: Wisconsin e espessura das regiões pré-central e orbitofrontal lateral à direita e pré-central esquerda; Teste de Trilhas e espessura da área pré-central direita e cíngulo anterior caudal esquerdo; e Teste Hayling e espessura da área lateral orbitofrontal esquerda. CONCLUSÃO: As correlações existentes entre medidas de espessura cortical pela ressonância magnética e desempenho cognitivo sugerem que os déficits executivos em pacientes HIV-positivos relacionam-se a uma redução da espessura cortical das regiões frontais.

OBJECTIVE: To investigate the correlation between frontal regions cortical thickness measured by magnetic resonance imaging of HIV-positive patients and their performance on instruments for assessing executive functions. MATERIALS AND METHODS: The present study included 22 HIV-positive patients in the age range from 45 to 65, schooling ranging between three and 20 years, with executive functions deficit and undergoing antiretroviral therapy. Magnetic resonance imaging was performed with conventional T1-weighted, 3D sequences and the images were processed with the Freesurfer software to measure cortical thickness. The following instruments were utilized to evaluate the patients' executive functions: Trail Making, Wisconsin, Hayling, working memory (WAIS-III), verbal fluency and Stroop tests. The Pearson's correlation coefficient was utilized in the data statistical analysis. RESULTS: Significant correlations were found between: Wisconsin scores and the thickness of the right pre-central, lateral and left pre-central orbitofrontal regions; Trail Making scores and thickness of right pre-central and left anterior caudal cingulate areas; and Hayling Test scores and thickness of the left lateral orbitofrontal area. CONCLUSION: Correlations between cortical thickness measurements by magnetic resonance imaging and cognitive performance suggest that the executive function deficit in HIV-positive patients are related to a reduction in the thickness of the frontal cortex.

Theoretical, behavioral and neuroimage evidence on discourse processing aging

A growing interest in cognition in aging has been observed because of both the epidemiologic factor of an increase in the lifespan of the world's population and the cognitive changes behaviorally and biologically detectable in this population. The most complex of language components and fundamental in social interaction, discourse production and comprehension are among the most scarcely explored cognitive functions in this context. This review presents and discusses discourse processing in healthy aging with regard to theoretical, behavioral, and neuroimaging evidence. Cognitive and neurobiological models are reviewed, such as the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) model and the Posterior-Anterior Shift in Aging (PASA) model. Among the neuropsycholinguistic research developed to characterize discourse processing in aging individuals, which has contributed to the prevention and treatment of language impairment and the maintenance of communicative competence in aging, studies on the relationship between discourse and working memory, attention, and some executive components are discussed. Regarding neuroimaging data, very few studies that have included cognitive tasks and discourse stimuli were found. Such studies suggest that discourse processing requires not only the participation of both brain hemispheres, but also a more prominent activation of frontal regions. Considering the great complexity and usefulness of discourse in elderly adults' daily communication and the emergence of cognitive deficits related to aging in complex information processing, the necessity of further behavioral and neuroimaging studies, including discourse processing tasks, comparing tasks involving executive, attentional, and mnemonic demands becomes evident.