Advisor(s)
Abstract(s)
O presente trabalho tem como objectivo principal esclarecer e explorar o
impacto da idade na memória de trabalho (MT). Para tal, estudou-se o desempenho de
jovens e idosos normais em diferentes tarefas de MT organizadas num contínuo de
armazenamento-manipulação. A amostra foi constituída por um grupo de 20 jovens
(média de idades: 26,75 anos ± 4,387) e por um grupo de 20 idosos (média de idades:
66,50 ± 5,492), ambos sem alterações neurológicas e/ou cognitivas. O protocolo
utilizado para avaliar a MT era composto por tarefas de digit, word e spatial span
directas, tarefas de digit, word e spacial span inversas, uma self-ordered task, tarefas
de n-back, o Wisconsin Card Sorting Test e uma tarefa de fluência verbal. Para se
analisar a relação entre a idade e o desempenho dos sujeitos nas tarefas explanadas foi
realizada uma comparação de médias. Para as variáveis de desempenho que não
seguiam uma distribuição normal foi utilizado o teste não-paramétrico de Mann-
Whitney U para amostras independentes e, para as variáveis de desempenho que
seguiam uma distribuição normal foi utilizado o teste paramétrico de t para amostras
independentes. Os resultados são discutidos com base em hipóteses levantadas ao
longo do trabalho e enquadrados à luz da revisão de literatura realizada. Verificou-se
que a idade afecta o desempenho de tarefas de MT. No entanto, quando entre os dois
grupos é comparada a diferença de desempenho entre uma tarefa que exige menos
manipulação e outra que exige uma manipulação superior, não se verificam grandes
diferenças significativas relacionadas com a idade, a não ser em tarefas espaciais.
The present work has as a main objective clarify and explore the impact of age on working memory (WM). To this end, we studied the performance of normal young and old subjects in different working memory tasks organized in a continuum of storage-manipulation. The sample consisted of a group of 20 young subjects (mean age: 26.75 years ± 4.387) and a group of 20 elderly subjects (mean age: 66.50 ± 5.492), both without neurological and/or cognitive impairments. The protocol used to evaluate the WM was composed by tasks of direct digit, word and spatial span, backward digit, word and spatial span, self-ordered task, n-back task, Wisconsin Card Sorting Test and a task of verbal fluency. To analyze the relationship between age and the subjects performance at the explained tasks, a comparison of means was made. For the performance variables that did not follow a normal distribution we used the nonparametric Mann-Whitney U test for independent samples and, for the performance variables that followed a normal distribution we used the parametric t test for independent samples. The results are discussed based on assumptions made throughout the paper and framed in light of the literature review. It was found that age affects the performance of WM tasks. However, when between the two groups are compared the difference in performance between a task that requires less manipulation and another that requires a superior manipulation, there are no major differences related to age, except in spatial tasks.
The present work has as a main objective clarify and explore the impact of age on working memory (WM). To this end, we studied the performance of normal young and old subjects in different working memory tasks organized in a continuum of storage-manipulation. The sample consisted of a group of 20 young subjects (mean age: 26.75 years ± 4.387) and a group of 20 elderly subjects (mean age: 66.50 ± 5.492), both without neurological and/or cognitive impairments. The protocol used to evaluate the WM was composed by tasks of direct digit, word and spatial span, backward digit, word and spatial span, self-ordered task, n-back task, Wisconsin Card Sorting Test and a task of verbal fluency. To analyze the relationship between age and the subjects performance at the explained tasks, a comparison of means was made. For the performance variables that did not follow a normal distribution we used the nonparametric Mann-Whitney U test for independent samples and, for the performance variables that followed a normal distribution we used the parametric t test for independent samples. The results are discussed based on assumptions made throughout the paper and framed in light of the literature review. It was found that age affects the performance of WM tasks. However, when between the two groups are compared the difference in performance between a task that requires less manipulation and another that requires a superior manipulation, there are no major differences related to age, except in spatial tasks.
Description
Keywords
Memória de trabalho Envelhecimento Desempenho cognitivo Working memory Aging Cognitive performance