Early classification and prediction of Alzheimer disease (AD) and amnestic mild cognitive impairment (aMCI) with noninvasive approaches is a long-standing challenge. This challenge is further ...exacerbated by the sparsity of data needed for modeling. Deep learning methods offer a novel method to help address these challenging multiclass classification and prediction problems.
We analyzed 3 target feature-sets from the National Alzheimer Coordinating Center (NACC) dataset: (1) neuropsychological (cognitive) data; (2) patient health history data; and (3) the combination of both sets. We used a masked Transformer-encoder without further feature selection to classify the samples on cognitive status (no cognitive impairment, aMCI, AD)-dynamically ignoring unavailable features. We then fine-tuned the model to predict the participants' future diagnosis in 1 to 3 years. We analyzed the sensitivity of the model to input features via Feature Permutation Importance.
We demonstrated (1) the masked Transformer-encoder was able to perform prediction with sparse input data; (2) high multiclass current cognitive status classification accuracy (87% control, 79% aMCI, 89% AD); (3) acceptable results for 1- to 3-year multiclass future cognitive status prediction (83% control, 77% aMCI, 91% AD).
The flexibility of our methods in handling inconsistent data provides a new venue for the analysis of cognitive status data.
As members of an increasingly aging society, one of our major priorities is to develop tools to detect the earliest stage of age-related disorders such as Alzheimer's Disease (AD). The goal of this ...paper is to evaluate the possibility of using unobtrusively collected activity-aware smart home behavior data to detect the multimodal symptoms that are often found to be impaired in AD. After gathering longitudinal smart home data for 29 older adults over an average duration of >2 years, we automatically labeled the data with corresponding activity classes and extracted time-series statistics containing ten behavioral features. Mobility, cognition, and mood were evaluated every six months. Using these data, we created regression models to predict symptoms as measured by the tests and a feature selection analysis was performed. Classification models were built to detect reliable absolute changes in the scores predicting symptoms and SmoteBOOST and wRACOG algorithms were used to overcome class imbalance where needed. Results show that all mobility, cognition, and depression symptoms can be predicted from activity-aware smart home data. Similarly, these data can be effectively used to predict reliable changes in mobility and memory skills. Results also suggest that not all behavioral features contribute equally to the prediction of every symptom. Future work therefore can improve model sensitivity by including additional longitudinal data and by further improving strategies to extract relevant features and address class imbalance. The results presented herein contribute toward the development of an early change detection system based on smart home technology.
Objective: Interruptions are ubiquitous in everyday life, and recovering from interruptions requires several cognitive processes working in tandem. In this study, we assessed the effects of an ...interruption on the performance of older individuals with and without mild cognitive impairment (MCI) completing everyday tasks in a naturalistic apartment setting. Method: Thirty-two persons with MCI and 64 cognitively healthy older adults (HOA) completed two different sets of everyday activities, of which one received an interruption. Participants also completed tests assessing cognitive constructs thought to be important in interruption recovery including retrospective memory, prospective memory, planning, working memory, and executive function. Results: As a consequence of an interruption, participants with MCI took longer to complete primary task demands and made more substitution errors, but did not make more omission errors. In contrast, an interruption led HOAs to make more omission errors, but their time on task was not affected. Results from a hierarchical linear regression suggest that the ecologically valid interruption task time was more predictive of everyday functional status than the traditional neuropsychological measures. Conclusions: Results suggest that a brief task interruption taxed cognitive resources of both MCI and HOA groups, but was more detrimental to MCI in terms of time on task and total errors committed. Participant groups appeared to use a speed-accuracy trade-off to mitigate negative effects, where HOAs emphasized speed and MCI participants focused on accuracy. Amount of cognitive engagement/disengagement was also theorized to have played a role, where MCI may have maintained information online throughout the interruption, and HOAs disengaged and reengaged resulting in worse reactivation of goals. Although MCI held onto task goals, their execution of details was imperfect over the interruption delay resulting in substitution errors likely due to further taxed executive abilities.
General Scientific Summary
Interruptions, such as a telephone ringing while preparing a meal, occur regularly in everyday life; yet, little is known about how they may impact community residing older adults. This study utilized a natural apartment setting to assess how a brief interruption impacts older adults with and without cognitive impairment completing everyday tasks. This study is important because it provides evidence for the negative effects of an interruption and spontaneous cognitive strategies used in an attempt to reduce these effects.
Objective: The day-out task (DOT), a naturalistic task that requires multitasking in a real-world setting, was used to examine everyday functioning in individuals with mild cognitive impairment ...(MCI). Method: Thirty-eight participants with MCI and 38 cognitively healthy older adult controls prioritized, organized, initiated, and completed a number of subtasks in a campus apartment to prepare for a day out (e.g., determine and gather change for bus, bring a magazine). Participants also completed tests assessing cognitive constructs important in multitasking (i.e., retrospective memory, prospective memory, planning). Results: As compared with controls, the MCI group required more time to complete the DOT and demonstrated poorer task accuracy, performing more subtasks incompletely and inaccurately. Despite poorer DOT task accuracy, the MCI and control groups approached completion of the DOT in a similar manner. For the MCI group, retrospective memory was a unique predictor of the number of subtasks left incomplete and inaccurate, while prospective memory was a unique predictor of DOT sequencing. The DOT measures, but not the cognitive tests, were predictive of knowledgeable informant report of everyday functioning. Conclusions: These findings suggest that difficulty remembering and keeping track of multiple goals and subgoals may contribute to the poorer performance of individuals with MCI in complex everyday situations.
Objective: Compensatory strategies such as assistive technology, external reminders, and environmental cues may help support instrumental activities of daily living (IADLs) and independence. However, ...functional ability is most often evaluated in clinical settings where everyday compensation cannot be readily observed. The present study used a novel, real-world evaluation of everyday activities (prospective memory, household chores, complex IADLs, and planning tasks) to examine the impact of compensation. Method: Fifty community dwelling older adults were recruited with cognitive status ranging from healthy to mildly impaired. Participants completed a battery of validated performance-based and cognitive tasks, an IADL questionnaire (also completed by an informant), and real-world activities carried out in their own homes. Results: The real-world evaluation demonstrated adequate interrater reliability (intraclass coefficient = 0.92) and construct validity (r = 0.55). Compensation improved real-world task outcome on prospective memory and household chores tasks. Further, cognition emerged as a moderator between compensation and prospective memory task outcome. Participants' ratings on an IADL questionnaire were related to real-world and performance-based functioning whereas informants' ratings were related to performance-based tasks and cognition. Conclusions: Our results suggest that proxy measures of functional ability (i.e., performance-based, cognitive, and IADL questionnaire measures) do not fully capture the complexity of real-world performance for nondemented community dwelling older adults. Compensation appeared to improve prospective memory performance, particularly for individuals with average to low average cognitive abilities. A difference in IADL questionnaire ratings suggest that participants may be better able to judge their real-world performance than informants.
General Scientific Summary
Neuropsychologists are often asked to determine whether a person can safely complete everyday tasks such as cooking, bill payment, and medication management independently. However, it is not well understood how sufficient clinic-based tools for assessing everyday tasks are at accurately estimating a person's functioning in the real-world. Results from the current study suggest that current clinic-based tools are limited because they do not account for a person's ability to compensate for cognitive weaknesses in the real-world. For example, a person may use an alarm to remind them to do something in the future. Targeted interventions to improve and maintain compensation at the earliest stages of cognitive change may enhance independence.
The purpose of this study is to investigate if type II diabetes can be prevented in African Americans by consuming a plant-based diet. This study aspires to answer the following research question: ...Can type II diabetes be prevented in African Americans by consuming a plant-based diet? A plant-based diet is free from all animal products such as meat and dairy and is substituted with plants such as fruits and vegetables. This is a systematic review aimed at answering the previously mentioned research question. Many black people assume that because their parents and great-grandparents were diagnosed with chronic illnesses such as diabetes, hypertension, or cancer, it is set in stone that they too will have the same health disadvantages and hardships. This study aims to break that stigma by examining the relationship a plant-based diet can have on the prevention of illness.
Heat stress is associated with workplace injuries, likely through a combination of fatigue, reduced cognitive function, and thermal discomfort. The purpose of this study was to evaluate four ...cognitive tasks for sensitivity to heat stress. Eight participants performed treadmill exercise followed by assessments of serial reaction time (RT), Stroop effect, verbal delayed memory, and continuous performance working memory in an environmental chamber. A control (21.1 °C) trial, and “Hot 1” and “Hot 2” (both 37.8 °C) trials were run sequentially on two separate days to evaluate the four cognitive tasks. Heat strain (comparing Hot 1 and Hot 2 with the control trial) resulted in impairments in the serial RT test response and Stroop accuracy. Delayed memory was impacted only in the Hot 2 trial compared with the control trial. Given the demonstrated impact of heat on cognitive processes relevant to workers’ real-world functioning in the workplace, understanding how to assess and monitor vigilant attention in the workplace is essential.
•We evaluated four cognitive tasks for sensitivity to heat stress and feasibility of field-based measurement.•Heat stress impacted vigilant attention, inhibition of automatic responses, and verbal memory, but not working memory.•The serial reaction time task measuring vigilant attention was sensitive to heat stress and feasible for field-based use.•Heat stress had a greater effect on serial reaction time than Stroop, Hopkins Verbal Learning Test-Revised, and N-back tests.•Delayed stimulus responses during the second of two trials in a hot chamber suggest a cumulative effect of heat on vigilance.
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