A produção discursiva oral em idosos típicos e com Doença de Alzheimer

• Autor(a) principal: Malcorra, Bárbara Luzia Covatti
• Data de Publicação: 2022
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: https://tede2.pucrs.br/tede2/handle/tede/10154
• topic: Envelhecimento Típico; Doença de Alzheimer; Escolaridade; Hábitos de Leitura e Escrita; Produção Discursiva Oral; LINGUISTICA, LETRAS E ARTES::LETRAS

Oral discursive production is part of our daily lives, fulfilling several functions in social relationships. In the case of older adults, in which cognitive changes typical of aging can occur, the diagnosis of alterations in discursive skills presents itself as a tool for the early detection of disorders indicative of neurodegenerative diseases, such as Alzheimer’s Disease (AD). This thesis is composed of four studies. The first study aimed to verify, through a systematic review, which tasks are commonly used to elucidate the oral discursive production in older adults and their relation with education and reading and writing habits (RWH). It was found that most of the studies used tasks with visual stimuli (i.e., images), especially in a sequential format, while a small part of the studies used tasks based on autobiographical events, free conversations, or descriptions of procedures. Few studies investigated the effect of education, while no study addressed the effect of RWH. Such results point to gaps to be filled by future studies. The second study sought to investigate the effect of education and RWH on the oral discursive production of typical older adults. To this end, participants (n=117) produced a narrative based on a sequence of seven images. Macro and microstructural measures, as well as modalizations, were computed and entered as dependent variables in hierarchical regression analyses that included age, education, and RWH as regressors. We found an effect of education on the discursive macro and microstructure, and an effect of RWH on the production of modalizations. While formal education explained a better performance at the macro- and microstructure dimensions, the frequency of RWH explained the production of fewer modalizations. This highlights the positive effects of these socio-cultural factors on oral discursive production. The third study aimed to investigate the association of short- and long-range recurrences with age, education, and RWH in typical older adults. We represented, using Speech Graphs software, the transcripts of the narratives of 118 typical adults - aged between 51 and 82 years old and, on average, 10 years of formal education - as a word trajectory graph, in which each word is represented as a node and the temporal link between consecutive words is represented by an edge. This method makes it possible to measure the degree of connectivity of the words that compose a text from the total number of incoming and outcoming edges of the nodes. From this, three graph attributes were extracted: (1) the total number of repeated edges (RE - repeated edges), defined as the sum of all edges connecting the same pair of nodes; (2) the number of nodes in the largest connected component (LCC), defined as the largest set of nodes directly or indirectly connected by some path; (3) the number of nodes in the largest strongly connected component (LSC), defined as the largest set of nodes directly or indirectly connected by reciprocal paths, such that all nodes in the component that are mutually reachable. The increase in age led to an increase in repeated edges (i.e., short-range recurrences) and reduced connectivity (long-range recurrences). This made oral speech more repetitive and less connected. This relationship lost statistical significance when corrected for education and RWH, suggesting a protective effect of reading on cognition in a low-education population. Finally, the fourth study sought to verify whether graph attributes can differentiate the production of oral narratives of adults with AD (n=24) and typical adults (n=48). Three graph attributes were analyzed: (1) the number of edges (E - edges); (2) LCC; and (3) LSC. Participants with AD produced less connected narratives than the control group. Low connectivity was associated with poorer semantic memory performance in participants with AD. Such results indicate that connected speech and the analysis of graph attributes represent a practical tool to assess cognitive impairment in elderly people with AD. In turn, this might help AD early detection and diagnosis. In sum, the studies of this thesis stress the potential of linguistic analysis at the speech level to understand the relationship between language and cognitive and sociocultural factors and to detect cognitive impairment.