Rachel Sarah Newson

Factors That Promote and Prevent Exercise Engagement in Older Adults

Objective: This study aimed to (a) identify factors that motivate or prevent older Australians from exercising; (b) determine how these factors differ as a function of age, gender, and exercise level; and (c) examine how they relate to intentions to exercise in the future. Method: In all, 217 older adults (aged 63 to 86) completed a questionnaire in their own home. Participants rated various motivators and barriers to exercise and indicated future intention to exercise. Results: Health concerns were the strongest motivators to exercise, whereas physical ailments were the most common barrier to exercise. Older Australians were fairly motivated to exercise and experienced few barriers to exercise. Age, gender, and exercise level differentiated between reported motivators and barriers, which in turn were associated with future intentions to exercise. Discussion: Reasons that promote and prevent exercise engagement are quite varied and depend on personal factors. Exercise intervention programs for older adults should incorporate these factors.

Comparison of adult age differences in verbal and visuo-spatial memory: the importance of 'pure', parallel and validated measures

The study compared age-related decrements in verbal and visuo-spatial memory across a broad elderly adult age range. Twenty-four young (18–25 years), 24 young-old (65–74 years), 24 middle-old (75–84 years) and 24 old-old (85–93 years) adults completed parallel recall and recognition measures of verbal and visuo-spatial memory from the Doors and People Test (Baddeley, Emslie & Nimmo-Smith, 1994). These constituted ‘pure’ and validated indices of either verbal or visuo-spatial memory. Verbal and visuo-spatial memory declined similarly with age, with a steeper decline in recall than recognition. Unlike recognition memory, recall performance also showed a heightened decline after the age of 85. Age-associated memory loss in both modalities was largely due to working memory and executive function. Processing speed and sensory functioning (vision, hearing) made minor contributions to memory performance and age differences in it. Together, these findings demonstrate common, rather than differential, age-related effects on verbal and visuo-spatial memory. They also emphasize the importance of using ‘pure’, parallel and validated measures of verbal and visuo-spatial memory in memory ageing research. This research was supported by a grant from the Australian Association of Gerontology RM Gibson Scientific Research Fund to Eva Kemps. We are grateful to Nathan Weber for developing the software for the computerized administration of the Corsi Blocks Backward Task, and to Judith Slater for assistance with data collection.

The Influence of Physical and Cognitive Activities on Simple and Complex Cognitive Tasks in Older Adults

This study examined the relative benefits of physical and cognitive activities on simple and complex cognitive task performance in older adults. Participants were 24 young (18–27 years), 24 young-old (65–74 years), 24 middle-old (75–84 years), and 24 old-old (85–92 years) adults. Participants recorded the amount of time engaged in physically and cognitively stimulating activities as well as the effort exerted during these activities. They also completed a simple and complex version of a visual imagery task. Age-related declines were evident in activity and imagery performance. Both physical and cognitive activities were related to better cognitive performance. Furthermore, cognitive activity was a stronger predictor than physical activity of the complex, but not the simple task. However, within each activity domain there were no significant differences between performance on the simple and complex task. These results suggest that physical and cognitive stimulation are useful in protecting against cognitive decline with age, but that they may exert their influence via different paths.

The nature of subjective cognitive complaints of older adults

The current study investigated the nature of subjective cognitive complaints of older adults in relation to a broad array of individual cognitive functions known to decline with age. A 60-item questionnaire was developed to examine: 1) whether older adults experience problems with these cognitive functions (problems with cognition); 2) the extent to which these problems have changed over time (changes in cognition); and 3) whether these cognitive decrements interfere with their daily functioning (difficulties with cognition). The cognitive functions examined were attention, processing speed, working memory, executive function, and memory. One hundred eight-two community-dwelling adults (aged 65–92 years) completed the questionnaire. While participants reported problems with, and changes in, each cognitive function, working memory was recorded as most problematic and demonstrated the most change. Yet, although older adults experience problems with cognition and report changes in cognitive functioning over time, these did not necessarily produce difficulties in daily life. This points to the existence of support mechanisms that may assist older adults in cognitively demanding situations.

Cardiorespiratory fitness as a predictor of successful cognitive ageing.

This study examined whether cardiorespiratory fitness influences cognitive ageing and whether this influence is domain specific. A cross-sectional design comprising 25 young (18–30 years), 25 young-old (65–74 years), 25 middle-old (75–84 years) and 25 old-old adults (85–92 years) compared the relationship between cardiorespiratory fitness (VO2max) and measures of processing resources (attention, working memory, speed) and higher-order cognitive functions (executive function, memory). Fitness was a strong predictor of cognition and accounted for more variance in processing resources than in higher-order functions. This suggests that cardiorespiratory fitness may have a selective protective effect against age-associated cognitive decline. We gratefully acknowledge the participation of all of the men and women who volunteered for this study. This research was funded by a RM Gibson Scientific Research Fund grant from the Australian Association of Gerontology.

Patterns and predictors of adult age differences in mental imagery

Abstract Adult age differences in, and predictors of, component imagery processes were examined across a broad elderly adult age range (65-86 years). Relative to younger adults, older adults were slower and less accurate on tasks of image generation, maintenance, scanning, and rotation. Ability to maintain mental images in particular was compromised by older age. Manipulations of stimulus complexity produced inconsistent differential age effects across tasks. Processing speed and sensorimotor functioning were prominent predictors of performance and age-related variance in all imagery components, with smaller contributions from working memory and executive function. These findings suggest that age-related decrements in individual imagery processes depend primarily on how quickly information can be processed and on the neurophysiological integrity of the ageing brain.

Cognitive Mechanisms Underlying Decrements in Mental Synthesis in Older Adults

The extent and nature of age-related differences in mental synthesis was examined in light of Baddeleys working memory model and resource theories. Mental synthesis performance of 30 young, young-old, middle-old and old-old adults was examined using a dual-task experiment and individual differences approach. Age-related differences in mental synthesis were shown, with an unprecedented heightened decrement evident after the age of 85. The central executive was not a mechanism of this decline. Executive function, speed of information processing, and working memory capacity were mechanisms underlying this decline, and together accounted for 86% of the age-related variance in mental synthesis. Environmental support enhanced mental synthesis.

Relationship between fitness and cognitive performance in younger and older adults

The present study investigated the association between cardiorespiratory fitness and cognitive ageing. An extreme groups comparison design compared the performance of 24 young low-fitness adults, 24 young high-fitness adults, 24 older low-fitness adults and 24 older high-fitness adults on a comprehensive neuropsychological battery. A series of ANCOVAs demonstrated that younger adults performed better than older adults on most cognitive tasks. Additionally, across both age groups high-fitness adults performed at a higher level than low-fitness adults on tasks of basic abilities, i.e., simple reaction time, attention, working memory and processing speed. However, there were no differences between the fitness groups in terms of performance on higher-order fluid abilities, i.e., executive function and memory. These findings suggest that the relationship between fitness and cognitive ageing is domain specific.