Cognitive performance in the elderly with and without MCI: effect of time of day and relationship with chronotype

• Autor(a) principal: Valente, João Pedro Braga
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/29049
• topic: Time of day; Cognition; Cognitive performance; Chronotype; Circadian rythm

The influence of different times of day and cognitive status, in the cognitive performance is still mostly not investigated. In the literature it has been described peaks of cognitive performance throughout the day, for older adults.Besides, there seems to exist a relationship between aging and time of day effects, in the cognitive performance of older adults. It is expected that this relationship would be evident in MCI groups. 34 Caucasian older adults (one MCI group and a normative group) forming a morning group and an afternoon group completed the Wisconsin card sorting test, the digit span task, the choice response time, the Halstead category test and the attentional network task. There was no time of day effect for the cognitive tasks. There were time of day and cognitive status interaction for choice response time and backwards digit span. It was found some interesting patterns of larger time of day effects for MCI group, with better performance in the morning period in tasks that required inhibitory control, learning from feedback and timed tasks. However, some of these patterns did not reach statistical significance. The present study suggests that there might be a larger time of day effect for MCI population, with better performance in the morning period. Is also suggests that there might be a larger time of day effect for normative population, on the backwards digit span, with better performance in the afternoon. Future research should investigate the relationship of cognitive decline and time of day effects, in some cognitive functions, such as inhibitory control, learning from feedback, abstract reasoning and processing speed, in older adults with MCI and more advanced cognitive decline states and young adults as well.