Artificial intelligence for dementia-Applied models and digital health.

INTRODUCTION: The use of applied modeling in dementia risk prediction, diagnosis, and prognostics will have substantial public health benefits, particularly as "deep phenotyping" cohorts with multi-omics health data become available. METHODS: This narrative review synthesizes understanding of applied models and digital health technologies, in terms of dementia risk prediction, diagnostic discrimination, prognosis, and progression. Machine learning approaches show evidence of improved predictive power compared to standard clinical risk scores in predicting dementia, and the potential to decompose large numbers of variables into relatively few critical predictors. RESULTS: This review focuses on key areas of emerging promise including: emphasis on easier, more transparent data sharing and cohort access; integration of high-throughput biomarker and electronic health record data into modeling; and progressing beyond the primary prediction of dementia to secondary outcomes, for example, treatment response and physical health. DISCUSSION: Such approaches will benefit also from improvements in remote data measurement, whether cognitive (e.g., online), or naturalistic (e.g., watch-based accelerometry).

An interlaboratory capillary zone electrophoresis-UV study of various monoclonal antibodies, instruments, and ε-aminocaproic acid lots.

Capillary zone electrophoresis ultraviolet (CZE-UV) has become increasingly popular for the charge heterogeneity determination of mAbs and vaccines. The ε-aminocaproic acid (eACA) CZE-UV method has been used as a rapid platform method. However, in the last years, several issues have been observed, for example, loss in electrophoretic resolution or baseline drifts. Evaluating the role of eACA on the reported issues, various laboratories were requested to provide their routinely used eACA CZE-UV methods, and background electrolyte compositions. Although every laboratory claimed to use the He et al. eACA CZE-UV method, most methods actually deviate from He's. Subsequently, a detailed interlaboratory study was designed wherein two commercially available mAbs (Waters' Mass Check Standard mAb [pI 7] and NISTmAb [pI 9]) were provided to each laboratory, along with two detailed eACA CZE-UV protocols for a short-end, high-speed, and a long-end, high-resolution method. Ten laboratories participated each using their own instruments, and commodities, showing excellence method performance (relative standard deviations [RSDs] of percent time-corrected main peak areas from 0.2% to 1.9%, and RSDs of migration times from 0.7% to 1.8% [n = 50 per laboratory], analysis times in some cases as short as 2.5 min). This study clarified that eACA is not the main reason for the abovementioned variations.

Remote monitoring technologies in Alzheimer's disease: design of the RADAR-AD study.

BACKGROUND: Functional decline in Alzheimer's disease (AD) is typically measured using single-time point subjective rating scales, which rely on direct observation or (caregiver) recall. Remote monitoring technologies (RMTs), such as smartphone applications, wearables, and home-based sensors, can change these periodic subjective assessments to more frequent, or even continuous, objective monitoring. The aim of the RADAR-AD study is to assess the accuracy and validity of RMTs in measuring functional decline in a real-world environment across preclinical-to-moderate stages of AD compared to standard clinical rating scales. METHODS: This study includes three tiers. For the main study, we will include participants (n = 220) with preclinical AD, prodromal AD, mild-to-moderate AD, and healthy controls, classified by MMSE and CDR score, from clinical sites equally distributed over 13 European countries. Participants will undergo extensive neuropsychological testing and physical examination. The RMT assessments, performed over an 8-week period, include walk tests, financial management tasks, an augmented reality game, two activity trackers, and two smartphone applications installed on the participants' phone. In the first sub-study, fixed sensors will be installed in the homes of a representative sub-sample of 40 participants. In the second sub-study, 10 participants will stay in a smart home for 1 week. The primary outcome of this study is the difference in functional domain profiles assessed using RMTs between the four study groups. The four participant groups will be compared for each RMT outcome measure separately. Each RMT outcome will be compared to a standard clinical test which measures the same functional or cognitive domain. Finally, multivariate prediction models will be developed. Data collection and privacy are important aspects of the project, which will be managed using the RADAR-base data platform running on specifically designed biomedical research computing infrastructure. RESULTS: First results are expected to be disseminated in 2022. CONCLUSION: Our study is well placed to evaluate the clinical utility of RMT assessments. Leveraging modern-day technology may deliver new and improved methods for accurately monitoring functional decline in all stages of AD. It is greatly anticipated that these methods could lead to objective and real-life functional endpoints with increased sensitivity to pharmacological agent signal detection.

Evaluating the Feasibility of Frequent Cognitive Assessment Using the Mezurio Smartphone App: Observational and Interview Study in Adults With Elevated Dementia Risk.

BACKGROUND: By enabling frequent, sensitive, and economic remote assessment, smartphones will facilitate the detection of early cognitive decline at scale. Previous studies have sustained participant engagement with remote cognitive assessment over a week; extending this to a period of 1 month clearly provides a greater opportunity for measurement. However, as study durations are increased, the need to understand how participant burden and scientific value might be optimally balanced also increases. OBJECTIVE: This study explored the little but often approach to assessment employed by the Mezurio app when prompting participants to interact every day for over a month. Specifically, this study aimed to understand whether this extended duration of remote study is feasible, and which factors promote sustained participant engagement over such periods. METHODS: A total of 35 adults (aged 40-59 years) with no diagnosis of cognitive impairment were prompted to interact with the Mezurio smartphone app platform for up to 36 days, completing short, daily episodic memory tasks in addition to optional executive function and language tests. A subset (n=20) of participants completed semistructured interviews focused on their experience of using the app. RESULTS: Participants complied with 80% of the daily learning tasks scheduled for subsequent tests of episodic memory, with 88% of participants still actively engaged by the final task. A thematic analysis of the participants' experiences highlighted schedule flexibility, a clear user interface, and performance feedback as important considerations for engagement with remote digital assessment. CONCLUSIONS: Despite the extended study duration, participants demonstrated high compliance with the schedule of daily learning tasks and were extremely positive about their experiences. Long durations of remote digital interaction are therefore definitely feasible but only when careful attention is paid to the design of the users' experience.

Gallery Game: Smartphone-based assessment of long-term memory in adults at risk of Alzheimer's disease.

Introduction: Gallery Game, deployed within the Mezurio smartphone app, targets the processes of episodic memory hypothesized to be first vulnerable to neurofibrillary tau-related degeneration in Alzheimer's Disease, prioritizing both perirhinal and entorhinal cortex/hippocampal demands.Methods: Thirty-five healthy adults (aged 40-59 years), biased toward those at elevated familial risk of dementia, completed daily Gallery Game tasks for a month. Assessments consisted of cross-modal paired-associate learning, with subsequent tests of recognition and free recall following delays ranging from one to 13 days.Results: Retention intervals of at least three days were needed to evidence significant forgetting at both recognition and paired-associate recall test. The association between Gallery Game outcomes and established in-clinic memory assessments were small but numerically in the anticipated direction. In addition, there was preliminary support for utilizing the perirhinal-dependent pattern of semantic false alarms during object recognition as a marker of early impairment.Conclusions: These results support the need for tests of longer-term memory to sensitively record behavioral differences in adults with no diagnosis of cognitive impairment. Aggregate behavioral outcomes promote Gallery Game's utility as a digital assessment of episodic memory, aligning with established theoretical models of object memory and showing small yet uniform associations with existing in-clinic tests. Initial support for the discriminatory value of perirhinal-targeted outcomes justifies ongoing large-sample validation against traditional biomarkers of Alzheimer's disease.

Prospective Memory: Age related change is influenced by APOE genotype.

Non-focal prospective memory (PM) is sensitive to age-related decline; an additional impairment in focal PM is characteristic of mild stage Alzheimer's disease. This research explored whether, by mid-adulthood, the distinct demands of focal and non-focal PM expose differences in carriers of an APOE ε4 allele, a genetic risk factor for Alzheimer's disease. Thirty-three young and 55 mid-age adults, differentiated by APOE genotype, completed a category-decision task with a concurrent focal or non-focal PM demand. Only mid-age ε4 carriers showed a cost of carrying a focal PM intention. In addition, mid-age ε4 carriers showed a significantly greater cost of carrying a non-focal PM intention than young ε4 carriers, supporting a profile of accelerated aging. Consistency in the profile of cost differences observed in mid-age ε4 carriers and pathological aging may indicate premature vulnerability. Future research correlating a shift in PM performance with early genotype differences in brain-based markers of decline is important.

Impairment in Theory of Mind in Parkinson's Disease Is Explained by Deficits in Inhibition.

OBJECTIVE: Several studies have reported that people with Parkinson's disease (PD) perform poorly on tests of 'Theory of Mind' (ToM), suggesting impairment in the ability to understand and infer other people's thoughts and feelings. However, few studies have sought to separate the processes involved in social reasoning from those involved in managing the inhibitory demands on these tests. In this study, we investigated the contribution of inhibition to ToM performance in PD. METHODS: 18 PD patients and 22 age-matched healthy controls performed a ToM test that separates the ability to infer someone else's perspective from the ability to inhibit one's own. Participants also completed a battery of standard measures of social and executive functioning, including measures of inhibition. RESULTS: The PD patients performed worse on the ToM test only when the inhibitory demands were high. When the level of inhibition required was reduced, there were no significant group differences. Furthermore, executive impairments in PD patients were limited to measures of inhibition, with disadvantages associated with poorer ToM performance in this group. CONCLUSIONS: This study provides convincing evidence that the apparent impairment observed on ToM tests in PD is explained by deficits in inhibition.

Digital technologies for the assessment of cognition: a clinical review.

Dementia is the most widespread form of neurodegenerative disorder and is associated with an immense societal and personal cost. Prevalence of this disorder is projected to triple worldwide by 2050 leading to an urgent need to make advances in the efficiency of both its care and therapy research. Digital technologies are a rapidly advancing field that provide a previously unavailable opportunity to alleviate challenges faced by clinicians and researchers working in this area. This clinical review aimed to summarise currently available evidence on digital technologies that can be used to monitor cognition. We identified a range of pervasive digital systems, such as smartphones, smartwatches and smart homes, to assess and assist elderly demented, prodromal and preclinical populations. Generally, the studies reported good level of agreement between the digital measures and the constructs they aimed to measure. However, most of the systems are still only in the initial stages of development with limited data on acceptability in patients. Although it is clear that the use of digital technology to monitor and support the cognitive domains affected by dementia is a promising area of development, additional research validating the efficacy, utility and cost-effectiveness of these systems in patient populations is needed.

Putting attention in the spotlight: The influence of APOE genotype on visual search in mid adulthood.

The Apolipoprotein E e4 allele is associated with greater cognitive decline with age, yet effects of this gene are also observed earlier in the lifespan. This research explores genotype differences (e2, e3, e4) in the allocation of visuospatial attention in mid-adulthood. Sixty-six volunteers, aged 45-55 years, completed two paradigms probing the active selection of information at the focus of attention (a dynamic scaling task) and perceptual capacity differences. Two methods of statistical comparison (parametric statistics, Bayesian inference) found no significant difference between e4 carriers and the homozygous e3 group on either the dynamic scaling or perceptual load task. E2 carriers, however, demonstrated less efficient visual search performance on the dynamic scaling task. The lack of an e4 difference in visuospatial attention, despite previous suggestion in the literature of genotype effects, indicates that select attentional processes are intact in e4 carriers in mid-adulthood. The association of e2 genotype with slower visual search performance complicates the premised protective effects of this allele in cognitive ageing.

The Elusive Nature of APOE ε4 in Mid-adulthood: Understanding the Cognitive Profile.

OBJECTIVES: The apolipoprotein E (APOE) ε4 allele is an established risk factor for dementia, yet this genetic variant is associated with a mixed cognitive profile across the lifespan. This study undertakes both a systematic and meta-analytic review of research investigating APOE-related differences in cognition in mid-adulthood, when detrimental effects of the allele may first be detectable. METHODS: Thirty-six papers investigating the behavioral effects of APOE ε4 in mid-adulthood (defined as a mean sample age between 35 and 60 years) were reviewed. In addition, the effect of carrying an ε4 allele on individual cognitive domains was assessed in separate meta-analyses. RESULTS: The average effect size of APOE ε4 status was non-significant across cognitive domains. Further consideration of genotype effects indicates preclinical effects of APOE ε4 may be observable in memory and executive functioning. CONCLUSIONS: The cognitive profile of APOE ε4 carriers at mid-age remains elusive. Although there is support for comparable performance by ε4 and non-e4 carriers in the 5th decade, studies administering sensitive cognitive paradigms indicate a more nuanced profile of cognitive differences. Methodological issues in this field preclude strong conclusions, which future research must address, as well as considering the influence of further vulnerability factors on genotype effects. (JINS, 2016, 23, 239-253).

The APOE paradox: do attentional control differences in mid-adulthood reflect risk of late-life cognitive decline.

Possession of an Apolipoprotein E (APOE) e4 allele is an established risk factor for Alzheimer's disease, whereas the less commonly studied e2 variant is premised to offer some protection. This research explores the purported deleterious-protective dichotomy of APOE variants on attentional control in mid-adulthood. Sixty-six volunteers, aged 45-55 years, completed 3 tasks that provided complementary measures of attentional control: prospective memory, sustained attention, and inhibition. Performance was compared between e2 carriers, e4 carriers, and e3 homozygotes (the population norm). Carriers of the e4 allele showed subtle disadvantages, compared with the e3 group, in accuracy of Stroop task and prospective memory performance. Contrary to expectations, e2 carriers showed performance disadvantages in sustained attention. The finding of detrimental effects in attentional control for both e4 and e2 complicates the current model that proposes opposing effects of these variants on later-life cognition. Future research is needed to understand how cognitive differences develop with increasing age, and the physiological mechanisms that underpin these changes.

Effects of priming thoughts about control on anxiety and food intake as moderated by dietary restraint.

The study was designed to examine: (a) if activating thoughts about control affects anxiety and food intake and (b) if those effects are moderated by dietary restraint. Eighty female undergraduates were administered the Dietary Restraint questionnaire and were primed for cognitions of control or of lack of control. The participants' perceptions of control over food consumption, their state anxiety, and their food intake as part of an alleged taste-test, were assessed. As evidence for the effectiveness of priming, participants reported less control over food consumption after being primed for lack of control than for control cognitions. As expected, Restraint score was negatively correlated with perceived control over food consumption. Consistent with hypothesis, participants high in dietary restraint experienced greater anxiety after being primed for control than after priming for lack of control, whereas participants low in dietary restraint displayed the opposite pattern. These findings were consistent with the cognitive dissonance principle that individuals experience greater anxiety when cognitions are inconsistent with personal beliefs than when they are consistent. As expected, priming thoughts of lack of control resulted in greater food intake than did priming thoughts of control, supporting the hypothesis of a nonconscious, automatic link between cognitions and food intake.