Executive control functioning and functional ability in older adults

The relationship between executive function and activities of daily living in children with specific learning disorders

This study explores the relationship between executive functions (EF) and activities of daily living in children with specific learning disorder (SLD). Thirty SLD children (14 females and 16 males) and thirty typically developing (TD) children (13 females and 17 males) aged 8 to 11 years were selected from learning disabilities schools and centers as well as public schools in Tehran, Iran. The mean age for the TD group was 9.67 ± 0.82 and for the SLD group was 9.5 ± 0.5. Basic Activities of Daily Living (B-ADL) and Instrumental Activities of Daily Living (IADLs) were assessed using the Modified Barthel questionnaire and the Lawton scale, respectively. Executive function was evaluated using the Parent Form of Behavior Rating Inventory of Executive Function (BRIEF) questionnaire. Pearson correlations were utilized to determine the correlation between the average score of "executive function" and "daily life activities". Results indicated that children with SLD scored significantly lower in EFs compared to TD children. Although there was no significant difference in B-ADL between the two groups, children with SLD scored lower in IADL. This study sheds light on the impact of EF on the ability of children with SLD to complete daily living activities. Further research is needed to better understand and address these challenges.

Assessing the impact of age on everyday cognitive function with a virtual environment task: The EcoKitchen

More realistic assessment tools are imperative for a better understanding of the impact of age-related cognitive deficits on functional status. With this in mind, we probed the ability of the EcoKitchen, a non-immersive virtual environment task with increasing executively demanding kitchen chores, to detect the effects of aging on the simulated everyday functioning of healthy adults. Fifty-three adults (age between 23 and 77 years) were assessed with the EcoKitchen and a set of conventional paper-and-pencil neuropsychological tests. The associations between the baseline features of study participants and each of the two different assessment methods were examined. The associations between the EcoKitchen variables and an executive composite score were also explored. Our results showed that older individuals present deficits in the performance of both the EcoKitchen task and standard assessment methods. Notably, we found that, unlike conventional tests, accuracy in the EcoKitchen task was not related to the education level and IQ score of participants. Moreover, the EcoKitchen performance time was significantly correlated with executive tests. We have demonstrated that the EcoKitchen task, an ecologically relevant computerized neuropsychological assessment tool, might be more suitable than classic paper-and-pencil tests to capture the impact of aging on everyday cognitive function, as it proved to be less prone to the influence of confounding factors. Additionally, we have shown that executive function plays an important role in the timely performance of cognitively challenging virtual environment tasks.

Assessing functional ability of healthy adults with the Night Out Task

Objective: Given the negative health outcomes associated with functional loss, there is need to better understand the trajectory of functional change and compensation use with age. Many older adults successfully age in place, and there is not a one-to-one relationship between cognitive changes and ability to live independently. This study compared healthy age cohorts' performance and approach on a functional measure, particularly examining compensatory strategy use to support task performance. Methods: 57 young adults (YAs; ages 18-39), 42 young-old adults (YOAs; ages 60-69) and 47 old-old (OOAs; ages 70+) completed the Night Out Task (NOT); an open-ended functional assessment in which participants complete eight subtasks in preparation for a night out with a friend (e.g. prepare tea and gather items for a recipe). The NOT measures both primary outcome variables (e.g. time and accuracy), error types and 'compensation variables', which are process-approach variables intended to map on to the types of compensatory strategies individuals use in their everyday lives (e.g. planning and checking). Results: Results revealed that YAs performed better than the oldest group on the NOT in accuracy, execution time and number of both inefficient and inaccurate/incomplete errors. YAs additionally used fewer compensatory strategies than both older groups. Only one compensation variable had a positive relationship to outcome; double-checking was related to improved accuracy and fewer inaccurate/incomplete errors within the oldest cohort. Conclusion: Together these findings support a spectrum of functional change with age. While compensation use increased with age, the relationship between compensation use and outcome was unclear. Future work is needed to understand under what conditions older adults' self-initiate compensation use and to understand the relationship between compensation use and outcome.

How to prevent cognitive overload in the walking-arithmetic dual task among patients with Parkinson's disease

BACKGROUND

Participants with Parkinson's disease (PD) may experience difficulty during certain dual-task (DT) tests. Thus, it is necessary to keep the cognitive load within the limits of their ability.

OBJECTIVE

To identify cognitive overload and its influence on the walking and auditory addition and subtraction (AAS, all values within the range of 0-20) DT performance of patients with PD.

STUDY DESIGN

A cross-sectional observational study with convenience sampling.

SETTING

Outpatient clinic of the Department of Neurology.

SUBJECTS

Sixteen patients with PD and 15 sex- and age- matched people elderly healthy controls (HCs).

METHODS

Verbal calculation responses and gait parameters were collected from the two groups in the 2-min single arithmetic task (2-min SAT), 2-min single walking task (2-min SWT), and 2-min walking-arithmetic dual task (2-min WADT).

RESULTS

The group differences in the lower-limb gait parameters increased in the 2-min WADT (P < 0.01), and those in the arm, trunk, and waist parameters did not change (P > 0.05). In the 2-min SAT, the calculation speed of the PD group was significantly lower than that of the HC group (P < 0.01). In the 2-min WADT, both groups made more errors (P < 0.05), especially the PD group (P = 0.00). PD group miscalculations occurred in the first half of the 2-min SAT but were uniformly distributed in the 2-min WADT. The HC group and PD group had subtraction self-correction rates of 31.25% and 10.25%, respectively. The PD group tended to make subtraction errors when the value of the first operand was 20 or 13.46 ± 2.60 and when the value of the second and third operands were 7.75 ± 2.51 (P = 0.3657) and 8.50 ± 4.04 (P = 0.170), respectively.

CONCLUSIONS

Cognitive overload was observed in patients with PD. This was mainly reflected in the failure of gait control and accurate calculation, indicated by gait parameters of the lower limbs and accuracy of calculation. To impose a constant cognitive load, the amount added or subtracted, especially in subtraction with borrowing, should not be mixed during a sequential arithmetic problem in the DT, and equations with the value of the first operand equal to 20 or approximately 13, the value of the second operand approximately 7, or the value of the third operand of approximately 9 should be excluded in the AAS DT.

TRIAL REGISTRATION

Clinical trial registration number: ChiCTR1800020158.

The cognitive and behavioral correlates of functional status in patients with frontotemporal dementia: A pilot study

Objective: Frontotemporal dementia (FTD) impinges significantly on cognition, behavior, and everyday functioning. Goal of the present study is the detailed description of behavioral disturbances and functional limitations, as well as the investigation of associations between cognition, behavior, and functional impairment among FTD patients. Given the importance of maintaining a satisfying functional status as long as possible, this study also aims to identify the cognitive correlates of compensatory strategy use in this clinical group. Methods: A total of 13 patients diagnosed with FTD (behavioral variant FTD = 9, non-fluent variant primary progressive aphasia = 3, semantic dementia = 1) were administrated a broad range of neuropsychological tests for the assessment of different cognitive abilities. Behavioral symptomatology and performance on everyday activities were rated with informant-based measures. Descriptive statistics were used for the delineation of behavioral and functional patterns, whereas stepwise multiple regression analyses were performed to identify associations between cognition, behavior, and functional status. Results: Negative symptoms, especially apathy, were found to predominate in the behavior of FTD patients. Instrumental tasks, such as housework and leisure activities, appeared to be the most impaired functional domains. Working memory was the strongest cognitive correlate of performance across various domains of everyday functioning, whereas working memory along with short-term verbal memory accounted for a great proportion of variance in compensatory strategy use. Behavioral disturbances and especially negative symptoms were also found to contribute significantly to functional impairment in FTD. Conclusions: Executive dysfunction, as well as behavioral disturbances contribute significantly to functional disability in FTD. Early interventions tailored at these domains may have the potential to improve functional outcomes and delay the rate of functional decline among FTD patients.

Investigating the relationship between specific executive functions and functional decline among community-dwelling older adults: results from a prospective pilot study

BACKGROUND

As cognitive functions and, more specifically, executive functions (EF) seem to influence autonomy among the elderly, we investigated the role of each of the five EF sub-components (inhibition, spontaneous flexibility, reactive flexibility, planning, and updating in working memory) for the risk of functional decline.

METHOD

A total of 137 community-dwelling participants over 75 years of age were included in a prospective cohort study and assigned to three groups: individuals with neuro-degenerative cognitive disorders, those having cognitive disorders with non-degenerative aetiology, and a control group without any cognitive problems. We measured each EF sub-component and assessed functional decline by evaluating basic (b-ADL) and instrumental activities of daily living (i-ADL) at baseline and 6 months later. We conducted three separate multiple logistic regression models to examine the extent to which the five EF facets predicted overall functional decline at the end of the follow-up period.

RESULTS

We found that people who exhibited a decline in b-ADLs or/and i-ADLs over 6 months had worse performance on inhibition and two flexibility tasks than those who did not experience a decline. The results suggest that decliners have more difficulties in managing unforeseen events. Inhibition and updating in working memory predicted a decline in b-ADL while spontaneous and reactive flexibilities predicted a decline in i-ADL.

CONCLUSION

In our sample, specific executive dysfunctions were associated with a decline in functional status. With respect to the risk of decline in b-ADL, deficits in inhibition may represent a risk factor, as it regulates over-learned activities. Bothtypes of flexibility, which allow the shifting and generating of adaptive responses, predicted decline in i-ADL. In sum, paying more attention to particular EF profiles would help clinicians to anticipate some aspects of functional decline.

Pre-Morbid IQ Moderates the Relationship between Cognitive Performance and Performance-Based Functional Status in Older Adults

Objectives: The current study sought to evaluate the relationship between cognitive performance and Instrumental Activities of Daily Living (IADL) performance in a population of community dwelling older adults, and assess to what extent this relationship is moderated by cognitive reserve (Premorbid-IQ)Methods: 123 community-dwelling older adults completed a general cognitive assessment, a word-reading based premorbid-IQ estimate (PMIQE) measure, and the performance-based Direct Assessment of Functional Status, Revised (DAFS-R). Moderated regression analysis was used to assess the influence of PMIQE on the relationship between cognitive performance and IADLs.Results: There was a significant main effect of cognitive performance on IADLs, and no main effect of PMIQE on functional IADLs. There was a significant moderating effect of PMIQE on the relationship between cognitive performance and IADLs performance, such that at higher levels of PMIQE, cognitive performance scores became slightly less predictive of weaknesses in IADLs.Conclusions: Results suggest that for individuals with high reserve, assessment of cognitive performance alone may not be robust a predictor of IADLs functioning.Clinical implications: In estimating functional abilities as a consequence of cognitive performance, consideration should be given to premorbid-IQ/cognitive reserve.

Minority Women

Perceptions of illness, pain, and death are not static. They vary among populations according to their cultural and biological characteristics. Older black and Hispanic/Latinx women are unique in their approach to health care with respect to mentation, mobility, medication adherence, and what matters to them. It is the complexity of these components, which affect the ability of these women to age gracefully.

The executive control correlate of loneliness in healthy older people

Perceived loneliness has implications in both cognitive and affective domains. High loneliness is considered to be a major risk factor for major depressive disorder. Loneliness is also associated with impaired executive control functioning (ECF) including multiple cognitive subdomains, such as working memory, planning, response inhibition, and attention control. However, little knowledge exists as to whether perceived loneliness is associated with impaired functioning of specific ECF components. The relationship between perceived loneliness and the latent dimensions capturing multiple measures across different ECF paradigms has not been established. In this study, we first investigated the latent dimensions of ECF processes across a comprehensive range of paradigms using exploratory factor analysis. We then examined the association of perceived loneliness and the resulted ECF components in older adults while simultaneously controlling for other demographic and affective measures. Four components emerged from the factor analysis: social cognition and processing speed, planning and working memory, selective, divided attention and inhibition control, and sustained attention and motor inhibition. We observed that the second ECF component, planning and working memory, was a significant predictor of perceived loneliness even after controlling for depressive characteristics measured by the Geriatric Depression Scale. Our findings have potential clinical significance in the older population, by showing that planning and working memory functions may predict perceived loneliness, which is also associated with higher risk for major depression. Thus, older individuals who have lower planning and working memory functions may be specifically targeted for possible early prevention of chronic loneliness and depression.

Do morbidity measures predict the decline of activities of daily living and instrumental activities of daily living amongst older inpatients? A systematic review

OBJECTIVES

Older adults often suffer from multimorbidity, which results in hospitalisations. These are often associated with poor health outcomes such as functional dependence and mortality. The aim of this review was to summarise the current literature on the capacities of morbidity measures in predicting activities of daily living (ADL) and instrumental activities of daily living (IADL) amongst inpatients.

METHODS

A systematic literature search was performed using four databases: Medline, Cochrane, Embase, and Cinahl Central from inception to 6th March 2019. Keywords included comorbidity, multimorbidity, ADL, and iADL, along with specific morbidity measures. Articles reporting on morbidity measures predicting ADL and IADL decline amongst inpatients aged 65 years or above were included.

RESULTS

Out of 7334 unique articles, 12 articles were included reporting on 7826 inpatients (mean age 77.6 years, 52.7% females). Out of five morbidity measures, the Charlson Comorbidity Index was most often reported. Overall, morbidity measures were poorly associated with ADL and IADL decline amongst older inpatients.

CONCLUSION

Morbidity measures are poor predictors for ADL or IADL decline amongst older inpatients and follow-up duration does not alter the performance of morbidity measures.

Functional Ability in Everyday Life: Are Associations With an Engaged Lifestyle Mediated by Working Memory?

OBJECTIVES

An engaged lifestyle has been linked to measures of functional ability in everyday life. However, the underlying mechanism of this link is still understudied. We propose working memory as a potential mediator of this relation.

METHODS

Modeling data of 158 older adults with a latent-variables approach, we examined whether working memory mediated the relation between an engaged lifestyle, that is, intellectual, social, and physical activities, and functional ability, that is, self-reported everyday failures and test-based everyday performance.

RESULTS

Working memory was found to fully mediate the relation between gaming activities and test-based everyday performance. Furthermore, we found a negative association between sports activities and self-reported everyday failures not mediated through working memory, indicating that individuals who reported high levels of sports activities reported fewer everyday cognitive failures. All other lifestyle activities were, however, neither directly nor indirectly associated with functional ability.

DISCUSSION

Working memory is one pathway by which gaming activities are related to test-based measures of functional ability in everyday life. Given the overlapping cognitive demands of working memory, gaming activities, and the test-based measure of functional ability, the findings suggest that while an engaged lifestyle can benefit functional ability, those benefits may be limited to highly similar domains.

Development and Evaluation of Maze-Like Puzzle Games to Assess Cognitive and Motor Function in Aging and Neurodegenerative Diseases

There is currently a need for engaging, user-friendly, and repeatable tasks for assessment of cognitive and motor function in aging and neurodegenerative diseases. This study evaluated the feasibility of a maze-like Numberlink puzzle game in assessing differences in game-based measures of cognition and motor function due to age and neurodegenerative diseases. Fifty-five participants, including young (18-31 years, n = 18), older (64-79 years, n = 14), and oldest adults (86-98 years, n = 14), and patients with Parkinson's (59-76 years, n = 4) and Huntington's disease (HD; 35-66 years, n = 5) played different difficulty levels of the Numberlink puzzle game and completed usability questionnaires and tests for psychomotor, attentional, visuospatial, and constructional and executive function. Analyses of Numberlink game-based cognitive (solving time and errors) and motor [mean velocity and movement direction changes (MDC)] performance metrics revealed statistically significant differences between age groups and between patients with HD and older adults. However, patients with Parkinson's disease (PD) did not differ from older adults. Correlational analyses showed significant associations between game-based performance and movement metrics and performance on neuropsychological tests for psychomotor, attentional, visuospatial, and constructional and executive function. Furthermore, varying characteristics of the Numberlink puzzle game succeeded in creating graded difficulty levels. Findings from this study support recent suggestions that data from a maze-like puzzle game provide potential "digital biomarkers" to assess changes in psychomotor, visuoconstructional, and executive function related to aging and neurodegeneration. In particular, game-based movement measures from the maze-like puzzle Numberlink games are promising as a tool to monitor the progression of motor impairment in neurodegenerative diseases. Further studies are needed to more comprehensively establish the cognitive validity and test-retest reliability of using Numberlink puzzles as a valid cognitive assessment tool.

Predictors of instrumental activities of daily living in community-dwelling older adults

Psychiatric mental health clinicians often rely on proxy and self-report evaluations to determine the cognitive function of older adults however, performance measures have greater accuracy and predictive ability for everyday function. This study tested physical and cognitive predictors of functional abilities in fifty-one community residing older adults. We administered a computerized battery of executive function tasks, a performance-based measure of instrumental activities of daily living (IADL), and three physical function measures (grip strength, 30-second Chair Stand Test, and 8-foot Up and Go). Regression models assessed the associations of three components of executive function (updating, shifting, and inhibition) with IADLs and physical functions. Updating was a significant predictor of the Medications and Financial DAFS scores and of grip strength. Shifting also predicted grip strength. In conclusion, different executive functions predict different domains of IADL functioning. Working memory was a robust predictor of IADL functioning in older adults, especially medication management skills.

Neuropsychological predictors of health and safety abilities in dementia

The Independent Living Scales Health and Safety (ILS HS) scale is commonly used by neuropsychologists when evaluating older adults' instrumental activities of daily living (IADLs). However, there is a minimal amount of research on its use in dementia populations and, specifically, its relationship to other neuropsychological measures. The present study investigated relationships between the ILS HS scale and measures of cognition and depression. The study utilized archival data from a sample (N = 142) of older adults (mean age = 77.85) diagnosed with dementia, who were evaluated at Saint Louis University Medical Center and administered the ILS HS scale as part of a larger clinical neuropsychological evaluation. Multiple regression analyses demonstrated that up to 37% of the variance in ILS HS performance was accounted for by demographic variables, premorbid intelligence, and cognitive functioning (e.g., global cognition, delayed verbal recall, and executive functioning), and regression models demonstrated medium to large effect sizes. Depression and self- or informant-reported IADLs were unrelated to the ILS HS scale. Results suggest that older adults' ability to function in health and safety-related situations requires a range of cognitive abilities. Performance on these measures may help guide clinical decision making regarding independent living and treatment planning.

Cognitive Flexibility Training: A Large-Scale Multimodal Adaptive Active-Control Intervention Study in Healthy Older Adults

As aging is associated with cognitive decline, particularly in the executive functions, it is essential to effectively improve cognition in older adults. Online cognitive training is currently a popular, though controversial method. Although some changes seem possible in older adults through training, far transfer, and longitudinal maintenance are rarely seen. Based on previous literature we created a unique, state-of-the-art intervention study by incorporating frequent sessions and flexible, novel, adaptive training tasks, along with an active control group. We created a program called TAPASS (Training Project Amsterdam Seniors and Stroke), a randomized controlled trial. Healthy older adults (60–80 y.o.) were assigned to a frequent- (FS) or infrequent switching (IS) experimental condition or to the active control group and performed 58 half-hour sessions over the course of 12 weeks. Effects on executive functioning, processing- and psychomotor speed, planning, verbal long term memory, verbal fluency, and reasoning were measured on four time points before, during and after the training. Additionally, we examined the explorative question which individual aspects added to training benefit. Besides improvements on the training, we found significant time effects on multiple transfer tasks in all three groups that likely reflected retest effects. No training-specific improvements were detected, and we did not find evidence of additional benefits of individual characteristics. Judging from these results, the therapeutic value of using commercially available training games to train the aging brain is modest, though any apparent effects should be ascribed more to expectancy and motivation than to the elements in our training protocol. Our results emphasize the importance of using parallel tests as outcome measures for transfer and including both active and passive control conditions. Further investigation into different training methods is advised, including stimulating social interaction and the use of more variable, novel, group-based yet individual-adjusted exercises.

Characterising omission errors in everyday task completion and cognitive correlates in individuals with mild cognitive impairment and dementia

OBJECTIVE

Functional ability declines with age and cognitive impairment. This study investigated errors of omission made by community-dwelling older adults completing everyday tasks in a naturalistic setting.

METHOD

Sixty-five cognitively healthy older adults (HOA), 19 individuals with single domain mild cognitive impairment (sdMCI), 33 individuals with multi-domain MCI (mdMCI), and 13 individuals with dementia completed measures of memory, processing speed, working memory, and executive functioning, as well as eight different activities of daily living in a naturalistic environment. Task steps were divided into preparatory, action-oriented, and concluding steps.

RESULTS

For action-oriented steps, the number of omission errors increased with level of cognitive impairment beyond sdMCI (i.e., HOA = sdMCI < mdMCI < dementia). In contrast, for preparatory and concluding steps, the dementia group committed more omission errors than the HOA, sdMCI, and mdMCI groups, which did not differ.

CONCLUSIONS

The results suggest that the more complex and integrative action-oriented steps may be the first type of everyday task step to be affected in the process of cognitive decline, with preparatory and concluding steps being preserved longer and only showing decline in later stages of impairment (i.e., dementia). Individuals with sdMCI may use other intact abilities to compensate for task omission errors.

Enhancing Cognitive Functioning in Healthly Older Adults: a Systematic Review of the Clinical Significance of Commercially Available Computerized Cognitive Training in Preventing Cognitive Decline

Successfully assisting older adults to maintain or improve cognitive function, particularly when they are dealing with neurodegenerative disorders such as Alzheimer's disease (AD), remains a major challenge. Cognitive training may stimulate neuroplasticity thereby increasing cognitive and brain reserve. Commercial brain training programs are computerized, readily-available, easy-to-administer and adaptive but often lack supportive data and their clinical validation literature has not been previously reviewed. Therefore, in this review, we report the characteristics of commercially available brain training programs, critically assess the number and quality of studies evaluating the empirical evidence of these programs for promoting brain health in healthy older adults, and discuss underlying causal mechanisms. We searched PubMed, Google Scholar and each program's website for relevant studies reporting the effects of computerized cognitive training on cognitively healthy older adults. The evidence for each program was assessed via the number and quality (PEDro score) of studies, including Randomized Control Trials (RCTs). Programs with clinical studies were subsequently classified as possessing Level I, II or III evidence. Out of 18 identified programs, 7 programs were investigated in 26 studies including follow-ups. Two programs were identified as possessing Level I evidence, three programs demonstrated Level II evidence and an additional two programs demonstrated Level III evidence. Overall, studies showed generally high methodological quality (average PEDro score = 7.05). Although caution must be taken regarding any potential bias due to selective reporting, current evidence supports that at least some commercially available computerized brain training products can assist in promoting healthy brain aging.

Assessment of Activities of Daily Living, Self-Care, and Independence

Activities of daily living (ADL) comprise the basic actions that involve caring for one's self and body, including personal care, mobility, and eating. In this review article, we (1) review useful clinical tools including a discussion on ways to approach ADL assessment across settings, (2) highlight relevant literature evaluating the relationship between cognitive functioning and ADLs, (3) discuss other biopsychosocial factors affecting ADL performance, (4) provide clinical recommendations for enhancing ADL capacity with an emphasis on self-care tasks (eating, grooming, dressing, bathing and toileting), and (5) identify interventions that treatment providers can implement to reduce the burden of ADL care.

Executive function subcomponents and their relations to everyday functioning in healthy older adults

Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures than did young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted.

Examination of Variables That May Affect the Relationship Between Cognition and Functional Status in Individuals with Mild Cognitive Impairment: A Meta-Analysis

The objective of this meta-analysis was to improve understanding of the heterogeneity in the relationship between cognition and functional status in individuals with mild cognitive impairment (MCI). Demographic, clinical, and methodological moderators were examined. Cognition explained an average of 23% of the variance in functional outcomes. Executive function measures explained the largest amount of variance (37%), whereas global cognitive status and processing speed measures explained the least (20%). Short- and long-delayed memory measures accounted for more variance (35% and 31%) than immediate memory measures (18%), and the relationship between cognition and functional outcomes was stronger when assessed with informant-report (28%) compared with self-report (21%). Demographics, sample characteristics, and type of everyday functioning measures (i.e., questionnaire, performance-based) explained relatively little variance compared with cognition. Executive functioning, particularly measured by Trails B, was a strong predictor of everyday functioning in individuals with MCI. A large proportion of variance remained unexplained by cognition.

The relationship between cognitive reserve and functional ability is mediated by executive functioning in older adults

It has been noted in the literature that cognitive reserve (CR) predicts future functional ability (FA), but the association between CR and current FA is rather limited. This investigation aimed to explicate this relationship, and hypothesized it would be mediated by executive functioning (EF). To best understand the relationship between CR and FA, we recruited and tested independent community-dwelling older adults (OAs). Bivariate correlations and hierarchical regressions were completed to determine the association between CR and FA. Both individual CR measures and a composite CR score were used. Mediation analyses were completed to examine our hypothesis that EF would mediate the CR and FA relationship. All measures of CR were positively related to and predictive of FA. Although the highest zero-order correlation across the independent CR proxies was between income and FA (r = .417), education accounted for the greatest amount of variance in FA, 8.3% after controlling for age and Mini-Mental State Examination performance. Furthermore, the CR composite had a higher correlation (r = .447) and accounted for more variance than any of the independent proxies. Complete mediation was found between a CR composite and FA via an internally consistent D-KEFS composite score (Cronbach's α = .795). This suggests that as CR increases so does EF, which in turn improves FA. Thus, future investigations could determine the effect on FA in OAs by improving EF.

Development and psychometric properties of the instrumental activities of daily living: compensation scale

The Instrumental Activities of Daily Living - Compensation (IADL-C) scale was developed to capture early functional difficulties and to quantify compensatory strategy use that may mitigate functional decline in the aging population. The IADL-C was validated in a sample of cognitively healthy older adults (N=184) and individuals with mild cognitive impairment (MCI; N=92) and dementia (N=24). Factor analysis and Rasch item analysis led to the 27-item IADL-C informant questionnaire with four functional domain subscales (money and self-management, home daily living, travel and event memory, and social skills). The subscales demonstrated good internal consistency (Rasch reliability 0.80 to 0.93) and test-retest reliability (Spearman coefficients 0.70 to 0.91). The IADL-C total score and subscales showed convergent validity with other IADL measures, discriminant validity with psychosocial measures, and the ability to discriminate between diagnostic groups. The money and self management subscale showed notable difficulties for individuals with MCI, whereas difficulties with home daily living became more prominent for dementia participants. Compensatory strategy use increased in the MCI group and decreased in the dementia group.

"Executive functions" cannot be distinguished from general intelligence: two variations on a single theme within a symphony of latent variance

The empirical foundation of executive control function (ECF) remains controversial. We have employed structural equation models (SEM) to explicitly distinguish domain-specific variance in executive function (EF) performance from memory (MEM) and shared cognitive performance variance, i.e., Spearman's “g.” EF does not survive adjustment for both MEM and g in a well fitting model of data obtained from non-demented older persons (N = 193). Instead, the variance in putative EF measures is attributable only to g, and related to functional status only through a fraction of that construct (i.e., “d”). d is a homolog of the latent variable δ, which we have previously associated specifically with the Default Mode Network (DMN). These findings undermine the validity of EF and its putative association with the frontal lobe. ECF may have no existence independent of general intelligence, and no functionally salient association with the frontal lobe outside of that structure's contribution to the DMN.

Cognitive correlates of functional abilities in individuals with mild cognitive impairment: comparison of questionnaire, direct observation, and performance-based measures

The relationship between, and the cognitive correlates of, several proxy measures of functional status were studied in a population with mild cognitive impairment (MCI). Participants were 51 individuals diagnosed with MCI and 51 cognitively healthy older adults (OA). Participants completed performance-based functional status tests and standardized neuropsychological tests, and performed eight activities of daily living (e.g., watered plants, filled medication dispenser) while under direct observation in a campus apartment. An informant interview about everyday functioning was also conducted. Compared to the OA control group, the MCI group performed more poorly on all proxy measures of everyday functioning. The informant report of instrumental activities of daily living (IADL) did not correlate with the two performance-based measures; however, both the informant-report IADL and the performance-based everyday problem-solving test correlated with the direct observation measure. After controlling for age and education, cognitive predictors did not explain a significant amount of variance in the performance-based measures; however, performance on a delayed memory task was a unique predictor for the informant-report IADL, and processing speed predicted unique variance for the direct observation score. These findings indicate that differing methods for evaluating functional status are not assessing completely overlapping aspects of everyday functioning in the MCI population.

Cognitive reserve moderates relation between global cognition and functional status in older adults

The ability to perform instrumental activities of daily living (IADLs) is necessary for independent living. Research suggests that community-dwelling older adults are at risk for experiencing subtle decrements in the performance of IADLs. Neuropsychological tests have been used to account for differences in IADL status. Studies of the relationship between cognitive ability and functional status have produced variable results, however, and cognitive ability appears to be only a moderate predictor. Several studies of normal aging have revealed cognitive and functional benefits of higher cognitive reserve (CR) in healthy, nondemented older adults. The purposes of the present study were to: (a) examine the relationship between global cognitive ability and IADL performance among 53 community-dwelling older adults, and (b) determine whether formal education, as a proxy of CR, significantly moderates this relationship. Consistent with previous findings, global cognitive ability accounted for a considerable portion of variance in IADL performance [ΔR(2) = .54; ΔF(2, 53) = 67.96; p < .001]. Additionally, CR modestly but significantly attenuated this relationship [ΔR(2) = .044; ΔF(4, 53) = 5.98; p = .018; total R(2) = .65]. This finding suggests that community-dwelling older adults with lower levels of formal education may be at greater risk for functional decrements associated with age-related cognitive decline.

Minimal functional brain differences between older adults with and without mild cognitive impairment during the stroop

This investigation compared the neural correlates of inhibition in normal older adults (OAs) and OAs with mild cognitive impairment (MCI). It was hypothesized the MCI group would require a greater amount of resources for inhibition, and therefore display greater functional activation in specific regions of interest (ROIs). Twenty-six OAs without and 17 with MCI completed the Stroop task during functional neuroimaging, and completed additional out-of-scanner neuropsychological measures. During inhibition, there were minimal functional Magnetic Resonance Imaging (fMRI) differences found between groups in a priori specified ROIs and with post-hoc multiple regression analyses. However, these minimal differences did not survive corrected thresholds. Robust differences were found with several tasks of a neuropsychological screening battery. The results of this study suggest only very minimal group differences in fMRI activation during inhibition which may not reliably identify MCI, and this condition may be best detected by traditional neuropsychological techniques.

The Judgment Test of the Neuropsychological Assessment Battery (NAB): psychometric considerations in an assisted-living sample

A total of 82 older adults recruited from assisted-living facilities completed the Judgment subtest of the Neuropsychological Assessment Battery. The internal consistency reliability of Judgment scores in this sample, as estimated by Cronbach's α, was .83. Significant and strong Judgment score correlations with measures of general cognitive functioning and instrumental activities of daily living provided evidence of construct validity. Furthermore, participants who exhibited the capacity to consent to the evaluation performed significantly better on the Judgment subtest than did participants who did not exhibit consent capacity. Finally, Judgment scores predicted a significant proportion of variance in both instrumental and basic activities of daily living over and above the variance accounted for by scores on measures of general cognitive functioning and executive functioning. This study presents promising preliminary evidence of the incremental validity of Judgment subtest scores for predicting both basic and instrumental activities of daily living in an assisted-living sample.

Depressive symptoms predict longitudinal change in executive control but not memory

OBJECTIVE

Depression in non-demented persons has been identified as a possible risk factor for incident Alzheimer's disease (AD).

METHODS

Latent Growth Curve models were developed of baseline depressive symptoms as a predictor of longitudinal changes in cognition. Depressive symptoms were assessed using the 15-item Geriatric Depression Scale (GDS). Memory was assessed by the California Verbal Learning Task (CVLT). Executive control function (ECF) was assessed by the Executive Interview (EXIT25) and Trail-Making Test Part B (Trails-B). Five hundred forty-seven non-institutionalized older retirees living in a single comprehensive care retirement community participated.

RESULTS

Depressive symptoms were significantly associated only with the 3-year rate of decline in psychomotor speed, as measured by Trails A, and ECF, as measured by the EXIT25. Both associations withstood adjustment for age, gender, education, and baseline level of care.

CONCLUSIONS

Depressive symptoms are associated with longitudinal decline in cognition. However, this association selectively involves executive control, not memory, and possibly only a subset of 'executive' functions. Although depressive symptoms may hasten conversion from mild cognitive impairment (MCI) to dementia, depression-related conversion is not likely to be mediated by evolution of the AD pathological process.

Memory for intentions is uniquely associated with instrumental activities of daily living in healthy older adults

Moderate declines in prospective memory (PM) are common among older adults, but whether such decrements are associated with everyday functioning problems is not well established. To examine this issue, we administered the Memory for Intentions Screening Test (MIST), Prospective and Retrospective Memory Questionnaire (PRMQ), and Activities of Daily Living Questionnaire (ADLQ) to 50 healthy older Australian adults as part of a broader neuropsychological battery. In a series of hierarchical regressions controlling for demographics, medical/psychiatric factors, and other neurocognitive functions, the MIST event-based PM score and PRMQ PM scale were significantly associated with the total number of instrumental ADL (IADL) domains in which participants reported needing assistance. Extending prior findings in clinical populations, results indicate that lower PM functioning is uniquely associated with mild, concurrent IADL problems in healthy older adults. Future investigation of the potentially moderating effects of cognitive and behavioral compensatory strategies may be beneficial.

Cognitive correlates of functional performance in older adults: comparison of self-report, direct observation, and performance-based measures

Neuropsychologists are often asked to answer questions about the effects of cognitive deficits on everyday functioning. This study examined the relationship between and the cognitive correlates of self-report, performance-based, and direct observation measures commonly used as proxy measures for everyday functioning. Participants were 88 community-dwelling, cognitively healthy older adults (age 50-86 years). Participants completed standardized neuropsychological tests and questionnaires, and performed eight activities of daily living (e.g., water plants, fill a medication dispenser) while under direct observation in a campus apartment. All proxy measures of everyday function were sensitive to the effects of healthy cognitive aging. After controlling for age, cognitive predictors explained a unique amount of the variance for only the performance-based behavioral simulation measure (i.e., Revised Observed Tasks of Daily Living). The self-report instrumental activities of daily living (IADL) and the performance-based everyday problem-solving test (i.e., EPT) did not correlate with each other; however, both were unique predictors of the direct observation measure. These findings suggest that neuropsychologists must be cautious in making predictions about the quality of everyday activity completion in cognitively healthy older adults from specific cognitive functions. The findings further suggest that a self-report of IADLs and the performance-based EPT may be useful measures for assessing everyday functional status in cognitively healthy older adults.

Detecting subtle changes in visuospatial executive function and learning in the amnestic variant of mild cognitive impairment

BACKGROUND AND PURPOSE

Amnestic mild cognitive impairment (aMCI) is a putative prodromal stage of Alzheimer's disease (AD) characterized by deficits in episodic verbal memory. Our goal in the present study was to determine whether executive dysfunction may also be detectable in individuals diagnosed with aMCI.

METHODS

This study used a hidden maze learning test to characterize component processes of visuospatial executive function and learning in a sample of 62 individuals with aMCI compared with 94 healthy controls.

RESULTS

Relative to controls, individuals with aMCI made more exploratory/learning errors (Cohen's d = .41). Comparison of learning curves revealed that the slope between the first two of five learning trials was four times as steep for controls than for individuals with aMCI (Cohen's d = .64). Individuals with aMCI also made a significantly greater number of rule-break/error monitoring errors across learning trials (Cohen's d = .21).

CONCLUSIONS

These results suggest that performance on a task of complex visuospatial executive function is compromised in individuals with aMCI, and likely explained by reductions in initial strategy formulation during early visual learning and "on-line" maintenance of task rules.

Activities of Daily Living Are Associated With Older Adult Cognitive Status

We compared the extent to which subjective report of activities of daily living (ADLs) by caregivers and older adults were associated with objective measures of older adults’ cognition. In independent studies (Study 1 N = 238; Study 2 N = 295), bivariate correlations and multiple regression analyses examined the association of caregiver and self-rated reports of older adult basic, instrumental, and total ADLs and older adult cognition. We examined the magnitude of the caregiver/self-report discrepancy and older adult cognition. In both studies, caregiver reports more accurately accounted for older adult cognitive differences. Older adult visuospatial/constructional deficits were uniquely related to caregiver basic ADL reports. Results indicate that caregiver reports of older adult ADLs are more reliable indicators of older adult cognition than self-reports, and this difference grows as older adult cognition decreases. Thus, older adult ADL assessment may be useful in providing information on potential cognitive decline.

The fate of the 0.5s: predictors of 2-year outcome in mild cognitive impairment

Impairments in executive cognition (EC) may be predictive of incident dementia in patients with mild cognitive impairment (MCI). The present study examined whether specific EC tests could predict which MCI individuals progress from a Clinical Dementia Rating (CDR) score of 0.5 to a score ≥1 over a 2-year period. Eighteen clinical and experimental EC measures were administered at baseline to 104 MCI patients (amnestic and non-amnestic, single- and multiple-domain) recruited from clinical and research settings. Demographic characteristics, screening cognitive measures and measures of everyday functioning at baseline were also considered as potential predictors. Over the 2-year period, 18% of the MCI individuals progressed to CDR ≥ 1, 73.1% remained stable (CDR = 0.5), and 4.5% reverted to normal (CDR = 0). Multiple-domain MCI participants had higher rates of progression to dementia than single-domain, but amnestic and non-amnestic MCIs had similar rates of conversion. Only three EC measures were predictive of subsequent cognitive and functional decline at the univariate level, but they failed to independently predict progression to dementia after adjusting for demographic, other cognitive characteristics, and measures of everyday functioning. Decline over 2 years was best predicted by informant ratings of subtle functional impairments and lower baseline scores on memory, category fluency, and constructional praxis.

Physical performance is associated with executive functioning in older african american women

An older adult's ability to perform physical tasks is predictive of disability onset and is associated with declines in cognition. Risk factors for physical performance declines among African Americans, a group with the highest rates of disability, remain understudied. This study sought to identify demographic, health, and cognitive factors associated with lower-extremity physical performance in a sample of 106 African American women ages 56 to 91. After controlling for global cognitive functioning (Mini Mental State Exam), physical performance was associated with executive functioning (Stroop Color/Word), but not visuospatial construction (WASI Block Design) or processing speed (Trail Making Test, Part A). Executive functioning remained associated with physical performance after entry of demographic variables, exercise, depression, disease burden, and body mass index (BMI). Age, and BMI were also significant in this model. Executive functioning, age and BMI are associated with lower-extremity physical performance among older African American women.

Regression-based estimates of observed functional status in centenarians

PURPOSE OF THE STUDY

There is lack of consensus on the best method of functional assessment, and there is a paucity of studies on daily functioning in centenarians. We sought to compare associations between performance-based, self-report, and proxy report of functional status in centenarians. We expected the strongest relationships between proxy reports and observed performance of basic activities of daily living (BADLs) and instrumental activities of daily living (IADLs). We hypothesized that the discrepancy between self-report and observed daily functioning would be modified by cognitive status. We additionally sought to provide clinicians with estimates of centenarians' observed daily functioning based on their mental status in combination with subjective measures of activities of daily living (ADLs).

DESIGN AND METHODS

Two hundred and forty-four centenarians from the Georgia Centenarian Study were included in this cross-sectional population-based study. Measures included the Direct Assessment of Functional Status, self-report and proxy report of functional status, and the Mini-Mental State Examination (MMSE).

RESULTS

Associations between observed and proxy reports were stronger than between observed and self-report across BADL and IADL measures. A significant MMSE by type of report interaction was found, indicating that lower MMSE performance is associated with a greater discrepancy between subjective and objective ADL measures.

IMPLICATIONS

Results demonstrate associations between 3 methods of assessing functional status and suggest proxy reports are generally more accurate than self-report measures. Cognitive status accounted for some of the discrepancy between observed and self-reports, and we provide clinicians with tables to estimate centenarians' performance on observed functional measures based on MMSE and subjective report of functional status.

Peculiarities of geriatric psychiatry: a focus on aging and depression

There is a debate on whether Geriatric Psychiatry stands for itself as a discrete specialty or whether it is an extension of clinical Geriatrics, Neurology, and Psychiatry. This review aims to outline some recent data and possible approaches to define peculiarities of Geriatric Psychiatry, focusing on certain characteristics that define the aging brain. Geriatric depression is discussed taking into consideration some data from translational research. The brain aging process is not uniform. Frontal areas show marked impairment in inhibiting irrelevant information in working memory as they age, and the recruitment of these areas occur differently than in young subjects. Executive functions also change in normal elderly. Geriatric depression is a general definition of a multidimensional disorder with multiple risk factors. Dysexecutive syndrome is considered as a key to the neuropsychology of geriatric depression, correlated with functional impairment in late life. Late-onset depression has a higher load of comordibity, of cerebrovascular disease, and of some genetic factors that may be different from early onset depression. Also, there are at least four clusters of treatment outcomes that are common in geriatric depression, which mirror the neuropsychological and clinical profiles. Research and practice in Geriatric Psychiatry should focus on the interaction of various dimensions and risk factors rather than on attempting to find a single cause to the disorders. Some answers may be found in comorbidity issues, in white matter lesions, which are more common in the elderly, and in genetic factors that impact on the aging process.

Measuring perceived difficulty in post-acute brain injury rehabilitation: The Sister Kenny Symptom Management Scale

PRIMARY OBJECTIVE

Patients' perceptions of difficulty managing symptoms contribute to disability after brain injury. This study introduces the Sister Kenny Symptom Management Scale (KSMS) and reports on its factor structure, reliability, validity and clinical value.

METHOD

Archived data from (overlapping) samples of patients with brain injuries of mixed aetiologies, seen at an outpatient clinic over 16 years were used in development and validation studies of the KSMS. Comparison measures included the Profile of Mood States (POMS), neuropsychological test scores and employment.

RESULTS

Factor analysis of 34 items (n = 328) identified five sub-scales with satisfactory internal consistency and test-re-test stability representing difficulty with executive functions, language, recent memory, aggressive behaviour and physical symptoms. A pattern of correlations (n = 336) with Profile of Mood States (POMS) sub-scales of similar and different content supported the concurrent validity of KSMS sub-scales. Only the Memory sub-scale correlated with its test index. The Language score and test index approached significance. The Executive sub-scale did not. Hierarchical regression analysis (n = 102) that included ratings of mood and symptom management showed that employment after discharge was only predicted by post-treatment ratings of difficulty with cognitive functions.

CONCLUSION

Self-assessments of difficulty managing symptoms can be reliably assessed and may contribute to understanding patients' disability, treatment response and future prospects.

Everyday functioning in mild cognitive impairment and its relationship with executive cognition

OBJECTIVE

Elderly persons with mild cognitive impairment (MCI) are at increased risk of dementia and functional impairments. The present study investigated the contribution of three domains of executive cognition to everyday functioning among persons with MCI.

METHODS

124 MCI patients and 68 cognitively normal elderly participants were administered a cognitive screening battery. These tests were used to divide patients into four subgroups (amnestic single domain, amnestic multiple domain, non-amnestic single domain, and non-amnestic multiple domain). Subjects were then administered 18 executive function tests that assess planning/problem-solving, working memory, and judgment. Performance of everyday activities and everyday cognition was rated with two informant-reported measures.

RESULTS

All MCI subtypes had more difficulties in everyday activities than cognitively normal elderly participants. Multiple domain MCI patients had more functional impairments than single domain MCI patients. Contrary to our expectations, only one executive function component, working memory, contributed significantly to functional status after controlling for demographic, health-related and other cognitive factors.

CONCLUSIONS

Functional abilities are compromised in all MCI subtypes. Working memory may be associated with functional impairments, but general cognitive measures account for more unique variance.

Can structural MRI indices of cerebral integrity track cognitive trends in executive control function during normal maturation and adulthood?

We explored the relationship between structural neuroimaging-based indices of cerebral integrity and executive control function (ECF) in two groups of healthy subjects: A maturing group (33 subjects; 19-29 years) and a senescing group (38 adults; 30-90 years). ECF was assessed using the Executive Interview (EXIT) battery. Cortical indices of cerebral integrity included GM thickness, intergyral span, and sulcal span, each measured for five cortical regions per hemisphere. Subcortical indices included fractional anisotropy (FA), measured using track-based-spatial-statistics (TBSS), and the volume of T2-hyperintense WM (HWM). In the maturing group, no significant relationships between neuroanatomical changes and ECF were found; however, there were hints that late-term maturation of cerebral WM influenced variability in ECF. In the senescing group, the decline in ECF corresponded to atrophic changes in cerebral WM (sulcal and intergyral span) primarily in the superior frontal and anterior cingulate regions. A large fraction of the variability in ECF (62%) can be explained by variability in the structural indices from these two regions.

Selectivity of executive function deficits in mild cognitive impairment

Impairment in executive cognition (EC) is now recognized as relatively common among older persons with mild cognitive impairment (MCI) and may be predictive of the development of dementia. However, both MCI and executive functioning are broad and heterogeneous constructs. The present study sought to determine whether impairments in specific domains of EC are associated with specific subtypes of MCI. MCI patients (n = 124) were divided into 4 subgroups (amnestic vs. nonamnestic, and single- vs. multiple-domain) on the basis of their performance of widely used neuropsychological screening tests. These patients and 68 normal older persons were administered 18 clinical and experimental tests of executive function. Principal components analysis suggested 2 highly reliable EC components, planning/problem solving and working memory, and a less reliable 3rd component, judgment. Planning/problem solving and working memory, but not judgment, were impaired among the MCI patients. This was true even among those with "pure amnestic" MCI, the least impaired group overall. Multiple-domain MCI patients had more severe impairments in planning/problem solving and working memory than single-domain patients, leading to the supposition that they, not pure amnestic MCIs, are at highest risk of imminent dementia.