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Objective The extent to which increasing age is associated with impairment in cognitive function, termed cognitive aging, may have been overestimated in prior studies. The inclusion of individuals with severe or uncontrolled systemic medical illness or prodromal neurodegenerative disease in normal aging samples is likely to bias estimates toward lower cognitive performance and inflate estimates of variability. Method Unbiased estimates of cognitive aging in 658 adults aged 60–84, who underwent rigorous screening to ensure their general and cognitive health, were computed. The first study screened the psychometric properties of a battery of neuropsychological tests in order to identify those with optimal properties to evaluate cognitive aging. The second study used the selected tests to compare baseline performance within 5-year age bands from 60 to 84. Results The first study identified a battery of 12 tests that provided reliable measures of memory, psychomotor speed, attention, and executive function and were appropriate for investigating age-related cognitive changes. The second study observed moderate to large age-related impairment for performance on tests of complex psychomotor function, category fluency, verbal learning, and verbal and visual memory. No, or only small, age effects were observed for working memory, phonemic fluency, learning of visual information, and reaction time. Conclusions These data suggested that while increasing age is associated with impairment in cognitive function, this impairment is less severe and is evident only on more complex neuropsychological tests than estimated previously in samples selected using less rigorous criteria to ensure cognitive health.

Objective The extent to which increasing age is associated with impairment in cognitive function, termed cognitive aging, may have been overestimated in prior studies. The inclusion of individuals with severe or uncontrolled systemic medical illness or prodromal neurodegenerative disease in normal aging samples is likely to bias estimates toward lower cognitive performance and inflate estimates of variability. Method Unbiased estimates of cognitive aging in 658 adults aged 60–84, who underwent rigorous screening to ensure their general and cognitive health, were computed. The first study screened the psychometric properties of a battery of neuropsychological tests in order to identify those with optimal properties to evaluate cognitive aging. The second study used the selected tests to compare baseline performance within 5-year age bands from 60 to 84. Results The first study identified a battery of 12 tests that provided reliable measures of memory, psychomotor speed, attention, and executive function and were appropriate for investigating age-related cognitive changes. The second study observed moderate to large age-related impairment for performance on tests of complex psychomotor function, category fluency, verbal learning, and verbal and visual memory. No, or only small, age effects were observed for working memory, phonemic fluency, learning of visual information, and reaction time. Conclusions These data suggested that while increasing age is associated with impairment in cognitive function, this impairment is less severe and is evident only on more complex neuropsychological tests than estimated previously in samples selected using less rigorous criteria to ensure cognitive health.

Objectives: We investigated whether there were differences in associations between cognition with muscle strength, fitness and function in men with prostate cancer (PCa) treated with, and without androgen deprivation therapy (ADT) and non-PCa controls. A secondary aim was to compare differences in the prevalence of cognitive impairment. Design: This cross-sectional study compared 70 ADT-treated men with PCa aged 50-85 years to non-ADT-treated men (n=52) and non-PCa controls (n=70). Setting: University clinical exercise laboratory. Interventions: Nil. Primary and secondary outcome measures: Standardised assessments were conducted for cognition (learning, memory, attention, processing speed and executive function), muscle strength (grip strength and leg press), fitness (400 m walk), gait speed (4 m walk) and dual-tasking mobility (timed-up-and-go with a cognitive task). Results: ADT-treated men showed stronger associations between fitness and executive function and task switching relative to controls (both: p ≤ 0.03). For both PCa groups (independent of ADT use), poorer dual-task mobility was more strongly associated with decreased psychomotor attention (both: p ≤ 0.027) and global cognitive function (both: p ≤ 0.031) compared with non-PCa controls. The overall prevalence of cognitive impairment was low (4%-13%) and did not differ between the groups. Conclusions: The presence of PCa, with or without ADT treatment, did not increase the risk of cognitive impairment relative to non-PCa controls, yet did alter the associations between physical fitness and some measures of functional performance with certain cognitive domains. This highlights the importance of men with PCa maintaining fitness and functional capacity to optimise cognitive health. Trial registration number: This study was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12614000317695).

Objectives: We investigated whether there were differences in associations between cognition with muscle strength, fitness and function in men with prostate cancer (PCa) treated with, and without androgen deprivation therapy (ADT) and non-PCa controls. A secondary aim was to compare differences in the prevalence of cognitive impairment. Design: This cross-sectional study compared 70 ADT-treated men with PCa aged 50-85 years to non-ADT-treated men (n=52) and non-PCa controls (n=70). Setting: University clinical exercise laboratory. Interventions: Nil. Primary and secondary outcome measures: Standardised assessments were conducted for cognition (learning, memory, attention, processing speed and executive function), muscle strength (grip strength and leg press), fitness (400 m walk), gait speed (4 m walk) and dual-tasking mobility (timed-up-and-go with a cognitive task). Results: ADT-treated men showed stronger associations between fitness and executive function and task switching relative to controls (both: p ≤ 0.03). For both PCa groups (independent of ADT use), poorer dual-task mobility was more strongly associated with decreased psychomotor attention (both: p ≤ 0.027) and global cognitive function (both: p ≤ 0.031) compared with non-PCa controls. The overall prevalence of cognitive impairment was low (4%-13%) and did not differ between the groups. Conclusions: The presence of PCa, with or without ADT treatment, did not increase the risk of cognitive impairment relative to non-PCa controls, yet did alter the associations between physical fitness and some measures of functional performance with certain cognitive domains. This highlights the importance of men with PCa maintaining fitness and functional capacity to optimise cognitive health. Trial registration number: This study was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12614000317695).

Interest in measurement of children’s executive functions has shown a major increase over the past two decades. The present study evaluates two new apps (EYT and eFun) for measuring executive functions in children. The results of this study show that children (aged 5–8) enjoy executive function assessment in the form of games on an iPad. However, only one executive function, EYT working memory, showed significant positive correlations with several types of grades (e.g., English and maths) in primary school students. New, self-assessed, child-friendly executive function measurement tools have the potential to provide future possibilities for teachers to integrate information on cognitive ability into student learning plans.

Interest in measurement of children’s executive functions has shown a major increase over the past two decades. The present study evaluates two new apps (EYT and eFun) for measuring executive functions in children. The results of this study show that children (aged 5–8) enjoy executive function assessment in the form of games on an iPad. However, only one executive function, EYT working memory, showed significant positive correlations with several types of grades (e.g., English and maths) in primary school students. New, self-assessed, child-friendly executive function measurement tools have the potential to provide future possibilities for teachers to integrate information on cognitive ability into student learning plans.

Interest in measurement of children’s executive functions has shown a major increase over the past two decades. The present study evaluates two new apps (EYT and eFun) for measuring executive functions in children. The results of this study show that children (aged 5–8) enjoy executive function assessment in the form of games on an iPad. However, only one executive function, EYT working memory, showed significant positive correlations with several types of grades (e.g., English and maths) in primary school students. New, self-assessed, child-friendly executive function measurement tools have the potential to provide future possibilities for teachers to integrate information on cognitive ability into student learning plans.

Interest in measurement of children’s executive functions has shown a major increase over the past two decades. The present study evaluates two new apps (EYT and eFun) for measuring executive functions in children. The results of this study show that children (aged 5–8) enjoy executive function assessment in the form of games on an iPad. However, only one executive function, EYT working memory, showed significant positive correlations with several types of grades (e.g., English and maths) in primary school students. New, self-assessed, child-friendly executive function measurement tools have the potential to provide future possibilities for teachers to integrate information on cognitive ability into student learning plans.

Interest in measurement of children’s executive functions has shown a major increase over the past two decades. The present study evaluates two new apps (EYT and eFun) for measuring executive functions in children. The results of this study show that children (aged 5–8) enjoy executive function assessment in the form of games on an iPad. However, only one executive function, EYT working memory, showed significant positive correlations with several types of grades (e.g., English and maths) in primary school students. New, self-assessed, child-friendly executive function measurement tools have the potential to provide future possibilities for teachers to integrate information on cognitive ability into student learning plans.

Mobility and balance problems are common and often debilitating features of Huntington's disease (HD). In this exploratory study we aimed to investigate the influence of disease severity, severity of motor deficits, lower limb muscle strength, cognition, executive function, lean muscle mass and reactivity on mobility and balance.Twenty-two individuals with HD were recruited from the North Metropolitan Area Mental Health Service, Perth, Australia. Pertinent demographic, genetic and disease progression information was recorded prior to testing. Balance was assessed using dynamic and static balance tasks. Mobility was assessed using self-paced and fast-paced mobility measures. Cognitive and executive measures were used to assess verbal learning and memory, information processing speed, attention, response inhibition and cognitive flexibility. Lower limb muscle strength was evaluated by maximal isokinetic and isometric voluntary contractions. Lean tissue mass was quantified using Dual-energy X-ray absorptiometry. Reactivity was measured using Moyart equipment.Univariate and multivariate linear regression statistical models were used to examine the influence of these measures on mobility and balance. Univariate analyses showed that disease severity as well as measures of information processing speed, attention, cognitive flexibility, response inhibition and lower limb strength, were strongly related with mobility and balance. Additionally multivariate analyses showed that disease severity, cognitive flexibility and knee flexion strength together were better able to explain mobility and balance performance than any single measure (50-85%).In conclusion, our preliminary results suggest that as well as disease severity, cognitive and executive impairment and reduced lower limb strength contribute significantly to mobility and balance problems.

Mobility and balance problems are common and often debilitating features of Huntington's disease (HD). In this exploratory study we aimed to investigate the influence of disease severity, severity of motor deficits, lower limb muscle strength, cognition, executive function, lean muscle mass and reactivity on mobility and balance.Twenty-two individuals with HD were recruited from the North Metropolitan Area Mental Health Service, Perth, Australia. Pertinent demographic, genetic and disease progression information was recorded prior to testing. Balance was assessed using dynamic and static balance tasks. Mobility was assessed using self-paced and fast-paced mobility measures. Cognitive and executive measures were used to assess verbal learning and memory, information processing speed, attention, response inhibition and cognitive flexibility. Lower limb muscle strength was evaluated by maximal isokinetic and isometric voluntary contractions. Lean tissue mass was quantified using Dual-energy X-ray absorptiometry. Reactivity was measured using Moyart equipment.Univariate and multivariate linear regression statistical models were used to examine the influence of these measures on mobility and balance. Univariate analyses showed that disease severity as well as measures of information processing speed, attention, cognitive flexibility, response inhibition and lower limb strength, were strongly related with mobility and balance. Additionally multivariate analyses showed that disease severity, cognitive flexibility and knee flexion strength together were better able to explain mobility and balance performance than any single measure (50-85%).In conclusion, our preliminary results suggest that as well as disease severity, cognitive and executive impairment and reduced lower limb strength contribute significantly to mobility and balance problems.

Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.

Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.

Background: There is a wealth of evidence detailing gray matter degeneration and loss of cognitive function over time in individuals with Huntington's disease (HD). Efforts to attenuate disease-related brain and cognitive changes have been unsuccessful to date. Multidisciplinary rehabilitation, comprising motor and cognitive intervention, has been shown to positively impact on functional capacity, depression, quality of life and some aspects of cognition in individuals with HD. This exploratory study aimed to evaluate, for the first time, whether multidisciplinary rehabilitation can slow further deterioration of disease-related brain changes and related cognitive deficits in individuals with manifest HD. Methods: Fifteen participants who manifest HD undertook a multidisciplinary rehabilitation intervention spanning 9 months. The intervention consisted of once-weekly supervised clinical exercise, thrice-weekly self-directed home based exercise and fortnightly occupational therapy. Participants were assessed using MR imaging and validated cognitive measures at baseline and after 9 months. Results: Participants displayed significantly increased gray matter volume in the right caudate and bilaterally in the dorsolateral prefrontal cortex after 9 months of multidisciplinary rehabilitation. Volumetric increases in gray matter were accompanied by significant improvements in verbal learning and memory (Hopkins Verbal Learning-Test). A significant association was found between gray matter volume increases in the dorsolateral prefrontal cortex and performance on verbal learning and memory. Conclusions: This study provides preliminary evidence that multidisciplinary rehabilitation positively impacts on gray matter changes and cognitive functions relating to verbal learning and memory in individuals with manifest HD. Larger controlled trials are required to confirm these preliminary findings.

Background: There is a wealth of evidence detailing gray matter degeneration and loss of cognitive function over time in individuals with Huntington's disease (HD). Efforts to attenuate disease-related brain and cognitive changes have been unsuccessful to date. Multidisciplinary rehabilitation, comprising motor and cognitive intervention, has been shown to positively impact on functional capacity, depression, quality of life and some aspects of cognition in individuals with HD. This exploratory study aimed to evaluate, for the first time, whether multidisciplinary rehabilitation can slow further deterioration of disease-related brain changes and related cognitive deficits in individuals with manifest HD. Methods: Fifteen participants who manifest HD undertook a multidisciplinary rehabilitation intervention spanning 9 months. The intervention consisted of once-weekly supervised clinical exercise, thrice-weekly self-directed home based exercise and fortnightly occupational therapy. Participants were assessed using MR imaging and validated cognitive measures at baseline and after 9 months. Results: Participants displayed significantly increased gray matter volume in the right caudate and bilaterally in the dorsolateral prefrontal cortex after 9 months of multidisciplinary rehabilitation. Volumetric increases in gray matter were accompanied by significant improvements in verbal learning and memory (Hopkins Verbal Learning-Test). A significant association was found between gray matter volume increases in the dorsolateral prefrontal cortex and performance on verbal learning and memory. Conclusions: This study provides preliminary evidence that multidisciplinary rehabilitation positively impacts on gray matter changes and cognitive functions relating to verbal learning and memory in individuals with manifest HD. Larger controlled trials are required to confirm these preliminary findings.

Cognitive decline and dementia due to Alzheimer's disease (AD) have been associated with genetic, lifestyle, and environmental factors. A number of potentially modifiable risk factors should be taken into account when preventive or ameliorative interventions targeting dementia and its preclinical stages are investigated. Bone mineral density (BMD) and body composition are two such potentially modifiable risk factors, and their association with cognitive decline was investigated in this study. 164 participants, aged 34–87 years old (62.78 ± 9.27), were recruited for this longitudinal study and underwent cognitive and clinical examinations at baseline and after 3 years. Blood samples were collected for apolipoprotein E (APOE) genotyping and dual energy x-ray absorptiometry (DXA) was conducted at the same day as cognitive assessment. Using hierarchical regression analysis, we found that BMD and lean body mass, as measured using DXA were significant predictors of episodic memory. Age, gender, APOE status, and premorbid IQ were controlled for. Specifically, the List A learning from California Verbal Learning Test was significantly associated with BMD and lean mass both at baseline and at follow up assessment. Our findings indicate that there is a significant association between BMD and lean body mass and episodic verbal learning. While the involvement of modifiable lifestyle factors in human cognitive function has been examined in different studies, there is a need for further research to understand the potential underlying mechanisms.

Cognitive decline and dementia due to Alzheimer's disease (AD) have been associated with genetic, lifestyle, and environmental factors. A number of potentially modifiable risk factors should be taken into account when preventive or ameliorative interventions targeting dementia and its preclinical stages are investigated. Bone mineral density (BMD) and body composition are two such potentially modifiable risk factors, and their association with cognitive decline was investigated in this study. 164 participants, aged 34–87 years old (62.78 ± 9.27), were recruited for this longitudinal study and underwent cognitive and clinical examinations at baseline and after 3 years. Blood samples were collected for apolipoprotein E (APOE) genotyping and dual energy x-ray absorptiometry (DXA) was conducted at the same day as cognitive assessment. Using hierarchical regression analysis, we found that BMD and lean body mass, as measured using DXA were significant predictors of episodic memory. Age, gender, APOE status, and premorbid IQ were controlled for. Specifically, the List A learning from California Verbal Learning Test was significantly associated with BMD and lean mass both at baseline and at follow up assessment. Our findings indicate that there is a significant association between BMD and lean body mass and episodic verbal learning. While the involvement of modifiable lifestyle factors in human cognitive function has been examined in different studies, there is a need for further research to understand the potential underlying mechanisms.