The goal-control model: An integrated neuropsychological framework to explain impaired performance of everyday activities

Knowing "what for," but not "where": Dissociation between functional and contextual tool knowledge in healthy individuals and patients with dementia

OBJECTIVE

Semantic tool knowledge underlies the ability to perform activities of daily living. Models of apraxia have emphasized the role of functional knowledge about the action performed with tools (e.g., a hammer and a mallet allow a "hammering" action), and contextual knowledge informing individuals about where to find tools in the social space (e.g., a hammer and a mallet can be found in a workshop). The goal of this study was to test whether contextual or functional knowledge, would be central in the organization of tool knowledge. It was assumed that contextual knowledge would be more salient than functional knowledge for healthy controls and that patients with dementia would show impaired contextual knowledge.

METHODS

We created an original, open-ended categorization task with ambiguity, in which the same familiar tools could be matched on either contextual or functional criteria.

RESULTS

In our findings, healthy controls prioritized a contextual, over a functional criterion. Patients with dementia had normal visual categorization skills (as demonstrated by an original picture categorization task), yet they made less contextual, but more functional associations than healthy controls.

CONCLUSION

The findings support a dissociation between functional knowledge ("what for") on the one hand, and contextual knowledge ("where") on the other hand. While functional knowledge may be distributed across semantic and action-related factors, contextual knowledge may actually be the name of higher-order social norms applied to tool knowledge. These findings may encourage researchers to test both functional and contextual knowledge to diagnose semantic deficits and to use open-ended categorization tests.

Preliminary validation of the Virtual Kitchen Challenge as an objective and sensitive measure of everyday function associated with cerebrovascular disease

Preliminary validity of a computer-based test of everyday function (Virtual Kitchen Challenge [VKC]) was examined against brain-imaging markers of cerebrovascular disease and in contrast to conventional neuropsychological and self-report measures. Twenty community-dwelling older adults (n = 6 mild cognitive impairment) performed simulated breakfast and lunch tasks using a computer touchscreen (VKC). Automated measures (completion time, proportion time off screen, etc.) were computed during training and test conditions. White matter hyperintensity (WMH) volumes from brain magnetic resonance imaging and conventional measures of cognition and function also were obtained. VKC completion time and proportion time off screen improved significantly from training to test and were significantly associated with WMH volume (r > 0.573). VKC measures and WMH were not significantly correlated with conventional cognitive or self-report measures. The VKC holds promise as a valid measure of subtle functional difficulties in older adults that is sensitive to change and cerebrovascular pathology, highlighting its potential for clinical trials.

Highlights

Virtual Kitchen Challenge (VKC) scores showed significant improvement from training to test conditions.VKC scores (completion time and proportion of time off screen) were associated with a neuroimaging biomarker of brain health (white matter hyperintensities).

A Multidimensional, Person-Centered Framework for Functional Assessment in Dementia: Insights from the 'What', 'How', 'To Whom', and 'How Much' Questions

Dementia is a syndrome characterized by cognitive and neuropsychiatric symptoms associated with progressive functional decline (FD). FD is a core diagnostic criterion for dementia, setting the threshold between its prodromal stages and the full-blown disease. The operationalization of FD continues to generate a great deal of controversy. For instance, the threshold of FD for the diagnosis of dementia varies across diagnostic criteria, supporting the need for standardization of this construct. Moreover, there is a need to reconsider how we are measuring FD to set boundaries between normal aging, mild cognitive impairment, and dementia. In this paper, we propose a multidimensional framework that addresses outstanding issues in the assessment of FD: i) What activities of daily living (ADLs) are necessary to sustain an independent living in aging? ii) How to assess FD in individuals with suspected neurocognitive disorders? iii) To whom is the assessment directed? and iv) How much does FD differentiate healthy aging from mild and major neurocognitive disorders? Importantly, the To Whom Question introduces a person-centered approach that regards patients and caregivers as active agents in the assessment process of FD. Thus, once impaired ADLs have been identified, patients can indicate how significant such impairments are for them in daily life. We envisage that this new framework will guide future strategies to enhance functional assessment and treatment of patients with dementia and their caregivers.

Original research: longitudinal evaluation of cognitively demanding daily function using performance-based functional assessment highlights heterogeneous trajectories in cognitive and functional abilities in people with Parkinson's disease

Background

Longitudinal assessment of functional abilities in Parkinson's disease (PD) is needed to determine the efficacy of cognitive interventions in providing meaningful improvements in daily life. Additionally, subtle changes in instrumental activities of daily living may precede a clinical diagnosis of dementia and could aid earlier detection of and intervention for cognitive decline.

Objective

The primary goal was to validate the longitudinal application of the University of California San Diego Performance-Based Skills Assessment (UPSA). An exploratory secondary goal was to determine whether UPSA may identify individuals at higher risk of cognitive decline in PD.

Methods

Seventy participants with PD completed the UPSA with at least one follow-up visit. Linear mixed effects modeling was used to identify associations between baseline UPSA score and cognitive composite score (CCS) over time. Descriptive analysis of four heterogeneous cognitive and functional trajectory groups and individual case examples was performed.

Results

Baseline UPSA score predicted CCS at each timepoint for functionally impaired and unimpaired groups (p < 0.01) but did not predict the rate change in CCS over time (p = 0.83). Participants displayed heterogenous trajectories in both UPSA and CCS during the follow-up period. Most participants maintained both cognitive and functional performance (n = 54), though some displayed cognitive and functional decline (n = 4), cognitive decline with functional maintenance (n = 4), and functional decline with cognitive maintenance (n = 8).

Conclusion

The UPSA is a valid measure of cognitive functional abilities over time in PD. Given the heterogeneity of functional and cognitive trajectories, this performance-based assessment did not predict cognitive decline with this relatively short follow-up. Further work is needed to understand longitudinal functional assessments in PD-associated cognitive impairment.

Influencing factors on instrumental activities of daily living functioning in people with mild cognitive disorder - a secondary investigation of cross-sectional data

BACKGROUND

Finding a strategy to reduce the impact of cognitive decline on everyday functioning in persons suffering from cognitive impairment is a public health priority. Instrumental activities of daily living (IADL) are key to everyday functioning. Hence, it is essential to understand the influencing factors on IADL to develop specific interventions to improve everyday functioning in persons with mild cognitive disorder. Therefore, this study aimed to 1) explore different influencing factors on IADL functioning considering all domains of the International Classification of Functioning, disability, and health and 2) rank these factors.

METHODS

We performed a secondary analysis of a cohort including participants with amnestic mild cognitive impairment (a-MCI) or mild Alzheimer's Dementia (mild AD). The IADL functioning model was used as a starting point to estimate the effects of cognitive and physical function factors and personal and environmental factors on IADL functioning using multiple linear regression analysis, including subgroup analysis in persons with a-MCI. We used standardized coefficient estimates to relate the size of the predictor effects in the final model.

RESULTS

We included 105 participants (64 a-MCI, 41 mild AD); the mean age was 81.9 years (SD 4.9), with 70% females. Based on a multi-step approach and model fit, the final model included IADL functioning as the response variable and memory, attention, executive function, vision and hearing, mobility, balance, education, and social support as predictors. The final model explained 75% of the variability. The significant predictors in the model were mobility, balance, attention, and education, and were the predictors with the most considerable effects based on standardized coefficient estimates. The subgroup analysis, including only a-MCI participants, revealed a similar pattern.

CONCLUSION

Our results confirm that IADL functioning in people with mild cognitive disorder is influenced by cognitive and physical function and personal factors. The study provides further insight into understanding IADL functioning impairments in persons with mild impaired cognition and may be used to develop specific non-pharmacological interventions.

Daily Assessment of Executive Functioning and Expressive Suppression Predict Daily Functioning among Community-Dwelling Older Adults

OBJECTIVE

Executive functioning (EF) is known to be associated with performance of instrumental activities of daily living (IADLs). However, prior research has found that the degree to which EF fluctuates was more predictive of self-reported cognitive and IADL lapses than was average EF performance. One source of such EF fluctuations is engagement in an emotion regulation strategy known as expressive suppression (ES). Importantly, ES has also been shown to relate to IADL performance, presumably due to its impact on EF. However, past research is limited due to assessing IADLs only in the laboratory or via self-report. The present study examined (a) the association of daily EF and ES fluctuations with performance of actual IADL tasks in participants' homes, and (b) whether any significant association between ES fluctuations and daily IADLs would be mediated by daily EF variability.

METHOD

Participants were 52 older adults aged 60 to 95. Over the course of 18 days while at home, participants completed daily IADL tasks as well as daily measures of EF and ES via ecological momentary assessment.

RESULTS

Contrary to our hypothesis, average EF across days predicted at-home IADLs above and beyond daily EF variability, which itself was also predictive. ES variability also predicted daily IADLs, and this association was fully mediated by average daily EF.

CONCLUSIONS

Daily fluctuations in ES appear to have a deleterious impact on performance of IADLs at home, likely due to the impact of such fluctuations on EF, although the average level of EF capacity is also important.

Capturing Cognitive Aging in Vivo: Application of a Neuropsychological Framework for Emerging Digital Tools

As the global burden of dementia continues to plague our healthcare systems, efficient, objective, and sensitive tools to detect neurodegenerative disease and capture meaningful changes in everyday cognition are increasingly needed. Emerging digital tools present a promising option to address many drawbacks of current approaches, with contexts of use that include early detection, risk stratification, prognosis, and outcome measurement. However, conceptual models to guide hypotheses and interpretation of results from digital tools are lacking and are needed to sort and organize the large amount of continuous data from a variety of sensors. In this viewpoint, we propose a neuropsychological framework for use alongside a key emerging approach—digital phenotyping. The Variability in Everyday Behavior (VIBE) model is rooted in established trends from the neuropsychology, neurology, rehabilitation psychology, cognitive neuroscience, and computer science literature and links patterns of intraindividual variability, cognitive abilities, and everyday functioning across clinical stages from healthy to dementia. Based on the VIBE model, we present testable hypotheses to guide the design and interpretation of digital phenotyping studies that capture everyday cognition in vivo. We conclude with methodological considerations and future directions regarding the application of the digital phenotyping approach to improve the efficiency, accessibility, accuracy, and ecological validity of cognitive assessment in older adults.

Remind Me To Remember: A pilot study of a novel smartphone reminder application for older adults with dementia and mild cognitive impairment

The SmartPrompt is a smartphone-based reminder application informed by a neuropsychological model of functional disability. This laboratory-based pilot study examined the SmartPrompt feasibility, efficacy, and subjective usability using a within-participant, counterbalanced, cross-over design. Ten participants (M age = 80.3 + 8.2; M education = 15.7 + 2.5; 60% female) with mild cognitive impairment or mild dementia completed the Remember to Drink Test, which required preparing a glass of water at four predetermined times, in a SmartPrompt (SP) and Unprompted condition (UP). Written cues and a clock were available in both conditions; however, in the SP, the smartphone presented auditory alarms and visual reminders to obtain the water at specified times and required photo logging. In a separate session, caregivers were trained and tested on configuring the SmartPrompt. Overall, caregivers and participants learned to effectively use the SmartPrompt. Caregivers achieved near-perfect scores on the configuration quiz and responded well to training. Participants completed significantly more Remember to Drink tasks in the SP (93%) than UP (56%); checking the cues/clock decreased by 87% in the SP. Usability ratings were excellent among caregivers and fair among participants. Results indicate that the SmartPrompt holds promise for reducing functional disability in older adults with cognitive difficulties in at-home contexts.

100 years after Liepmann-Lesion correlates of diminished selection and application of familiar versus novel tools

100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of apraxia. Many studies thereafter attributed to an extended left fronto-temporo-parietal network. Yet, to date there are only few studies that looked at apraxic performance in the selection and application of familiar versus novel tools. In the current study we applied modern voxel-based lesion-symptom mapping (VLSM) to analyze neural correlates of impaired selection and application of familiar versus novel tools. 58 left (LBD) and 51 right brain damaged (RBD) stroke patients participated in the Novel Tools Test (NTT) and the Familiar Tools Test (FTT) of the Diagnostic Instrument for Limb Apraxia (DILA-S). We further assessed performance in control tasks, namely semantic knowledge (BOSU), visuo-spatial working memory (Corsi Block Tapping) and meaningless imitation of gestures (IML). Impaired tool use was most pronounced after LBD. Our VLSM results in the LBD group suggested that selection- versus application-related aspects of praxis and semantics of familiar versus novel tool use can be behaviorally and neuro-anatomically differentiated. For impairments in familiar tool tasks, the major focus of lesion maps was rather ventral while deficiencies in novel tool tasks went along with rather dorsal lesions. Affected selection processes were linked to rather anterior lesions, while impacted application processes went along with rather posterior lesion maps. In our study, particular tool selection processes were rather specific for familiar versus novel tools. Foci for lesion overlaps of experimental and control tasks were noticed ventrally for semantic knowledge and FTT, in fronto-parietal regions for working memory and NTT, and ventro-dorsally for imitation of meaningless gestures and the application of NTT and FTT. We visualized our current interpretation within a neuroanatomical model for apraxia of tool use.

Similarities between Cognitive Models of Language Production and Everyday Functioning: Implications for Development of Interventions for Functional Difficulties

The loss of the ability to independently complete activities of daily living, such as meal preparation and household chores, is a defining characteristic of clinical dementia; however, minor difficulties in completing everyday activities emerge in the mild cognitive impairment stage, and even healthy older adults exhibit subtle functional difficulties compared to younger adults. These functional difficulties are associated with an array of negative outcomes, including decreased quality of life, higher costs of care, and increased frustration, depression, caregiver burden, and institutionalization. While cognitive models have been proposed to explain the functional deficits seen in dementia and subtler forms of cognitive decline, in contrast to other cognitive disorders such as aphasia, there are essentially no theoretically motivated interventions to address difficulties in everyday functioning. Proposed models of functional impairment share features with cognitive processing models of language, including hierarchical organization of representations and interactive, spreading activation; thus, an examination of aphasia interventions has the potential to inform the development of theoretically motivated interventions for everyday activities. This review first addresses the shared characteristics of cognitive models of everyday function and language, with a focus on linguistic production. Next, we will present aphasia interventions that target single-word production, sentence production, short-term memory, and semantics, and discuss their implications for everyday functioning interventions. We conclude with a discussion of limitations of the language-everyday functioning comparison as well as areas of future research.