published_or_final_version / abstract / Clinical Psychology / Master / Master of Social Sciences

Physical activity is associated with greater independence in old age. While most research has focused on the frequency, intensity and time spent in activity, inconsistent findings have emerged, possibly due to differences across different types of physical activity. Physical activities differ in terms of their non-metabolic, mental, physical and social demands, however, to date, the effects of these demands on functional independence are unexplored. The present thesis aimed to investigate the effect of different types of physical activity on functional independence in old age. A systematic review of randomised controlled trials (RCTs) found a significant, beneficial effect of physical activity on functional performance, with the largest effects found for moderate physical activity levels, and activity types with high levels of mental (e.g. memory, attention), physical (e.g. coordination, balance) and social (e.g. social interaction) demands. These findings generated the hypothesis that physical activities high in mental, physical and social demands are associated with greater functional independence. Thus, a novel typology of physical activities was generated by systematically coding the mental (i.e. attention/concentration, memory, decision-making and strategy), physical (i.e. flexibility, balance, coordination, speeded reactions) and social (i.e. social interaction) demands of 59 physical activities. The typology was then used to recode data from the Understanding Society survey. Findings revealed that as the non-metabolic, physical activity demands increased, functional independence improved. Associations remained significant after controlling for demographics. Key findings included differences across gender, in that the mental and physical demands of activity predicted muscular strength in males, whereas social demands predicted muscular strength in females. In conclusion, physical activities with higher mental, physical and social demands (e.g. dancing) are associated with greater functional independence in old age, compared with simpler types (e.g. walking). Future research is required to test whether these novel findings are replicated elsewhere, ideally using longitudinal or RCT designs.

Thesis (M.Soc.Sc.)--University of Hong Kong, 2006. / Title from title page (viewed Apr. 23, 2007) Includes bibliographical references (p. 83-114).

Thesis (M.P.H.)--University of Adelaide, Dept. of Public Health, 1999? / Includes bibliographical references ((leaves 113-124)).

No description available.

published_or_final_version / Nursing Studies / Master / Master of Nursing

This thesis contains two studies which examined the cognitive functioning of the aging brain. Specifically, age-related changes in processing speed and its remediation via cognitive training were studied. In study 1, younger adults (n = 34) and older adults (n = 39) were recruited to investigate the age-related differences in the relationships between processing speed and general cognitive status (GCS). Their performance in GCS (as measured by The Montreal Cognitive Assessment, Hong Kong Version), cognitive processing speed (as measured by Processing Speed Index, Wechsler Adult Intelligence Scale), cognitive inhibition (as measured by Stroop Color-Word Test), and divided attention (as measured by Color Trails Test) was examined. Current findings indicated that processing speed predicted GCS in older but not younger adults. In older adults, processing speed as a predictor accounted for an additional 13% of variance in GCS. This study further verified the relationship between processing speed and prefrontal abilities, including verbal fluency, cognitive inhibition and divided attention in aging. Findings revealed that despite the abovementioned prefrontal abilities were significantly correlated with processing speed, verbal fluency had remained the strongest predictor, accounting for 21% of variance in processing speed in older adults. Based on findings in study 1, it was anticipated that training cognitive skills including processing speed and prefrontal abilities in older adults would improve cognitive functioning in general. Therefore, in study 2, elderly people at risk of progressive cognitive decline (n = 70) were recruited to investigate the training effect of computerized cognitive training programs that aimed to improve cognitive processing speed, cognitive inhibition and divided attention. Findings indicated that cognitive processing speed and divided attention improved post-training. Results obtained from the two studies implied potential intervention through training cognitive processing speed in elderly people at risk of progressive cognitive decline. Future studies should focus on training specific effect and examining the optimal effect by modification of the training paradigms, particularly the design of the contents and level of difficulty. / published_or_final_version / Clinical Psychology / Doctoral / Doctor of Psychology

No description available.

The present study expanded the story recognition and inference literature by investigating age differences within the older age range, differences as a result of mild cognitive impairment (MCI), and extending the focus of the investigation into the consistency of responding. 304 older adults completed a story recognition task across five different occasions. Old-old (00) adults and those with more severe MCI showed poorer ability to accurately recognize inferences, and less sensitivity to discriminate between statement types. Intraindividual variability was positively correlated with increasing age and cognitive impairment, and interactions revealed the greatest inconsistency involved the false, rather than inferred statements. The findings support our proposal that participants used two different recognition strategies, and their episodic memory ability defined the efficiency and frequency of use of the strategies. 00 and MCI adults may be less able to recognize that something plausible and consistent with an event may not have actually occurred.

Current classification systems for identifying individuals at the earliest stages of dementia, based primarily on cognitive measures, may be limited in scope. The present study examined physical functioning in a sample of 304 nondemented, older adults, classified based on presence and severity of mild cognitive impairment. In general, lower levels of physical functioning and greater inconsistency in physical functioning were found in older participants and in participants with increasing severity of cognitive impairment. Evaluation of the combined and unique contributions of level of and inconsistency in physical functioning to predicting cognitive status group membership revealed that, for some physical measures, inconsistency in physical functioning provided unique information beyond level of performance. These results are consistent with the notion that inconsistency in performance may be a behavioural marker of compromised neurological functioning and that information regarding physical functioning may prove useful for identifying individuals at the earliest stages of dementia.