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Attentional control of executive function declines during the early stages of Alzheimer's disease. Controversy exists as to whether this decline results from a single global deficit or whether attentional control can be fractionated, with some aspects being more vulnerable than others. We investigated three proposed domains of attention, namely (i)...
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Simultaneously presented signals may be processed in serial or in parallel. One potentially valuable indicator of a system's characteristics may be the appearance of multimodality in the response time (RT) distributions. It is known that standard serial models can predict multimodal RT distributions, but it is unknown whether multimodality is diagn...
Some investigators have argued that aging affects the slowing of processes in nonlexical tasks more than it does the slowing of processes in lexical tasks, but that within task domains, the slowing is identical. Other investigators have argued that even within nonlexical tasks there is differential slowing such that aging affects processing speed m...
The present experiment was conducted to investigate the effects of varying degrees of task consistency on the performance and maintenance of skill in a semantic-category visual search task. Four groups of participants first received 6000 trials of consistent mapping (CM) training on two different categories. The participants then performed 4000 tri...
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... AD is a fatal disease [3] and is classified as the fourth most common cause of death in developed countries [4]. AD is not limited to memory impairment and has other effects, such as loss of attention, and behavioral and linguistic abilities [5], resulting in the patient no longer being able to perform activities of daily living. People aged 65 years or older are at the greatest risk of developing AD [6], and the number of patients will increase as the population ages [7]. ...
Acetylcholinesterase (AChE) is one of the main drug targets for treating Alzheimer's disease. This current study relies on multiple molecular modeling approaches to develop new potent inhibitors of AChE. We explored a 2D QSAR study using the statistical method of multiple linear regression based on a set of substituted 5-phenyl-1,3,4-oxadiazole and N-benzylpiperidine analogs, which were recently synthesized and proved their inhibitory activities against acetylcholinesterase (AChE). The molecular descriptors, polar surface area, dipole moment, and molecular weight are the key structural properties governing AChE inhibition activity. The MLR model was selected based on its statistical parameters: R 2 = 0.701, R 2 test = 0.76, Q 2 CV = 0.638, and RMSE = 0.336, demonstrating its predictive reliability. Randomization tests, VIF tests, and applicability domain tests were adopted to verify the model's robustness. As a result, 11 new molecules were designed with higher anti-Alzheimer's activities than the model molecule. We demonstrated their improved pharmaco-kinetic properties through an in silico ADMET study. A molecular docking study was conducted to explore their AChE inhibition mechanisms and binding affinities in the active site. The binding scores of compounds M1, M2, and M6 were (−12.6 kcal/mol), (−13 kcal/mol), and (−12.4 kcal/mol), respectively, which are higher than the standard inhibitor Donepezil with a binding score of (−10.8 kcal/mol). Molecular dynamics simulations over 100 ns were used to validate the molecular docking results, indicating that compounds M1 and M2 remain stable in the active site, confirming their potential as promising anti-AChE inhibitors.
... 41 Increased misbinding in patients with both sporadic, late-onset AD and familial AD has now been reported using both change-detection and delayed reproduction tasks, 12,35,42,43,44 and specifically linked to hippocampal dysfunction. 45,46,47 An increased vulnerability to distractors is also detectable from the earliest phases of AD, 48,49,50,51,52 particularly if task instructions need to be maintained over time, pointing towards a deficit of goal-maintenance processes. 53,54 Crucially, comparative data on distractor filtering presented at encoding or maintenance within the same study are lacking. ...
The differential impact on working memory (WM) performance of distractors presented either at encoding or during maintenance was investigated in Alzheimer's (AD), Parkinson's Disease (PD) and healthy ageing. Across three studies, 28 AD and 28 PD patients, 28 elderly (EHC) and 28 young healthy controls (YHC) were enrolled. All participants performed a delayed reproduction task, where they reported the orientation of an arrow from a study set of either two or three items, with a distractor present either at encoding or at maintenance. Mean absolute error (the difference between probed and reported orientation) was calculated as an analogue measure of WM. Additionally, mixture model metrics i.e., memory precision, target detection, misbinding (swapping the features of an object with another probed item) and guessing were computed. MRI data was also acquired in AD, PD and EHC participants, and whole hippocampal volumes were extracted to test whether WM filtering and overall performance were related to hippocampal integrity. EHC and PD patients showed good filtering abilities both at encoding and during maintenance. However, AD patients exhibited significant filtering deficits specifically when the distractor appeared during maintenance. Healthy ageing and AD were associated with higher rates of both misbinding and guessing, as well as lower target detection, and memory precision. However, in healthy ageing there was a prominent decline in WM memory precision, whilst in AD lower target detection and higher guessing were the main sources of error. Conversely, PD was associated only with higher guessing rates. Hippocampal volume was significantly correlated with filtering during maintenance - but not at encoding - as well as with overall mean absolute error, target detection, guessing and misbinding. These findings demonstrate how healthy ageing and neurodegenerative diseases exhibit distinct patterns of WM impairment, including differential effects on filtering irrelevant material presented at encoding and maintenance.
... One of the difficulties most commonly observed in the those with memory-led Alzheimer's disease during everyday activities was disorientation to task, and this is also fitting with existing literature, which suggests this is underpinned by attentional, executive function or memory deficits (Baddeley, Baddeley, Bucks, & Wilcock, 2001;Chiu et al., 2004). Respondents with posterior cortical atrophy, while often motivated and oriented to tasks, were often unable to initiate or execute them. ...
... egenerativo de manera temprana, previniendo el posible deterioro físico y planificando, acorde a dicho estado, los posibles tratamientos terapéuticos; se sabe que la detección precoz y la intervención temprana es más eficaz para prevenir efectos nocivos derivados de procesos inflamatorios, oxidativos, de excitotoxicidad y apoptosis (muerte celular)(Baddeley y col. 2001).Se pone de manifiesto, por tanto, la importancia de la existencia de metodologías de valoración funcional que puedan hacer, mediante el estudio y valoración de diferentes funciones, como la marcha, una identificación de los enfermos dentro de una categoría o estadío y poder predecir el curso de la enfermedad y mejorar los tratamientos ...
Functional assessment is fundamental in the evaluation and monitoring of musculoskeletal and neurological pathologies, as it allows understanding a person's gait, balance, and muscular strength. This facilitates the prescription of rehabilitative treatments or surgical interventions. In the case of older adults, this assessment becomes even more important, as the World Health Organization (WHO) considers that health in older individuals is measured in terms of function, which is a fundamental part of a comprehensive geriatric assessment and allows evaluating frailty in older adults based on their ability to perform daily activities. Through early and continuous functional assessment, healthy aging can be promoted, and possible declines in function can be prevented and diagnosed early, thus improving quality of life and maintaining independence in older adults for as long as possible.
This doctoral thesis presents the development of an instrumented methodology for functional assessment in older adults, which is an agile and portable tool that, far from being a diagnostic methodology, can support clinical decision-making regarding multiple pathologies of the musculoskeletal system. It enables classification and prediction of the degree of impairment based on the functionality of the musculoskeletal system.
A series of studies have been conducted involving different groups of older adults: those with Alzheimer's disease, Parkinson's disease, and frail older adults at risk of falling. The main objective of these studies was to objectively determine the ability to perform functional activities such as balance, gait, turning to sit and stand from a chair, in comparison with healthy individuals of the same age. The secondary objective was to study the reliability of the procedure in these populations and to generate a series of mathematical models based on both traditional statistical methods and neural networks, combining different types of data.
The most notable aspects of this methodology are, firstly, the inclusion of assessment of activities of daily living within a shortened testing duration of less than 2 minutes, making it more practical and feasible in a clinical setting. Secondly, it involves a simple instrumentation consisting of a single sensor embedded in a smartphone, capable of managing the entire registration process and performing the necessary calculations to analyze the obtained measurements. All of this highlights the usefulness of the procedure and the feasibility of the developed models for functional assessment of older adults in a clinical environment.
... Deficits in memory and executive functioning, which are involved in PM (Laera et al., 2021;McFarland & Glisky, 2009;Schnitzspahn et al., 2013), are characteristic features of mild cognitive impairment (MCI) and dementia (e.g. Alzheimer's disease, AD; Arnáiz & Almkvist, 2003;Bäckman et al., 2005;Baddeley et al., 2001;Petersen, 2004). Mild cognitive impairment (MCI) is an intermediate clinical state between normal cognitive decline due to ageing and dementia (Albert et al., 2011;Díaz-Mardomingo et al., 2017). ...
Prospective memory (PM) is the ability to remember to perform planned actions in a future moment and it is of fundamental importance for an independent and autonomous lifestyle from development to late adulthood. Deficits in episodic memory and executive functions, which are involved in PM are characteristic features of mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Considering that the number of older adults is drastically increasing over the next decades, it is of great interest to understand how PM decline in healthy older adults and patients with different degree of cognitive decline. The present meta-analysis included 46 studies investigating PM performance in AD patients (17 studies) and people with MCI (24 studies); 5 studies included both clinical conditions in the same article. The 46 studies contributed a total of 63 independent samples and 129 effect sizes from 4668 participants (2115 patients and 2553 controls). Unlike previous reviews of the literature, our results with a larger and updated sample of studies confirmed lower PM abilities in AD compared to MCI and controls, although we did not observe conclusive differences between event-based and time-based PM in patients. Surprisingly, PM deficits shown by MCI and AD patients have decreased across years, in parallel to a reduction of the evidence of publication bias and an increase in the number of observations per task. We propose the use of more reliable research designs as one plausible explanation for the reduction of PM impairments.
... Patients with stroke are more likely to have conscious control over their movements [10,19], and those with more conscious control have better cognitive resources such as attention and working memory [19]. In particular, patients with suspected attention or working memory deficits are less likely to succeed in dividing and allocating their resources [43][44][45]. Implicit learning strategies may therefore be useful in enhancing the learning of motor sequences in patients with stroke who rely on attention and working memory to control their movements. In addition, it is necessary to consider that we encounter various dual-task situations in our daily lives. ...
Background and Objectives: In stroke rehabilitation, the use of either implicit or explicit learning as a motor learning approach during dual tasks is common, but it is unclear which strategy is more beneficial. This study aims to determine the benefits of implicit versus explicit motor learning approaches in patients with stroke. Materials and Methods: Seventeen patients with stroke and 21 control participants were included. Motor learning was evaluated using the Serial Reaction Time Task (SRTT) in the context of dual-task conditions. The SRTT was conducted on two separate days: one day for implicit learning conditions and the other day for explicit learning conditions. Under the explicit learning conditions, a task rule was given to the participants before they started the task, but not under the implicit learning conditions. Learning scores were calculated for both implicit and explicit learning, and these scores were then compared within groups for patients with stroke and controls. We calculated the difference in learning scores between implicit and explicit learning and conducted a correlation analysis with the Trail Making Test (TMT) Parts A and B. Results: Learning scores on the SRTT were not different between implicit and explicit learning in controls but were significantly greater in patients with stroke for implicit learning than for explicit learning. The difference in learning scores between implicit and explicit learning in patients with stroke was correlated with TMT-A and showed a correlation trend with TMT-B. Conclusions: Implicit learning approaches may be effective in the acquisition of motor skills with dual-task demands in post-stroke patients with deficits in attention and working memory.
... The concept is simple, and core brain damage associated with AD does not have to be directly evaluated through extensive physical assessments involving visualizations of the human eye or brain. Significant physiological changes, such as the accumulation of the pathological hallmarks of AD (intracellular neurofibrillary tangles, senile plaques), and the subsequent disruptions in synaptic transmission result in profound cognitive impairments (Baddeley, 2001;Forlenza et al., 2010;Kumar et al., 2015;Readman et al., 2021). Current evidence suggests that attention is the initial non-memory domain to be affected in AD, with visual information processing impairments occurring in the MCI phase (Ramzaoui et al., 2018; Frontiers in Psychology 07 frontiersin.org ...
Mild cognitive impairment (MCI), representing the ‘transitional zone’ between normal cognition and dementia, has become a novel topic in clinical research. Although early detection is crucial, it remains logistically challenging at the same time. While traditional pen-and-paper tests require in-depth training to ensure standardized administration and accurate interpretation of findings, significant technological advancements are leading to the development of procedures for the early detection of Alzheimer’s disease (AD) and facilitating the diagnostic process. Some of the diagnostic protocols, however, show significant limitations that hamper their widespread adoption. Concerns about the social and economic implications of the increasing incidence of AD underline the need for reliable, non-invasive, cost-effective, and timely cognitive scoring methodologies. For instance, modern clinical studies report significant oculomotor impairments among patients with MCI, who perform poorly in visual paired-comparison tasks by ascribing less attentional resources to novel stimuli. To accelerate the Global Action Plan on the Public Health Response to Dementia 2017–2025, this work provides an overview of research on saccadic and exploratory eye-movement deficits among older adults with MCI. The review protocol was drafted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases were systematically searched to identify peer-reviewed articles published between 2017 and 2022 that examined visual processing in older adults with MCI and reported gaze parameters as potential biomarkers. Moreover, following the contemporary trend for remote healthcare technologies, we reviewed studies that implemented non-commercial eye-tracking instrumentation in order to detect information processing impairments among the MCI population. Based on the gathered literature, eye-tracking-based paradigms may ameliorate the screening limitations of traditional cognitive assessments and contribute to early AD detection. However, in order to translate the findings pertaining to abnormal gaze behavior into clinical applications, it is imperative to conduct longitudinal investigations in both laboratory-based and ecologically valid settings.
... Attentional control is the ability to maintain goaloriented behavior by sustaining informationprocessing activity over time in terms of distraction, temporarily stopping the activity to respond to other information, and coordinating the course of concurrent activities [131]. ...
Cognitive decline is one of the most distinct signs of aging, and age-related cognitive decline is a heterogeneous issue varying in different cognitive domains and has significant differences among older adults. Identifying characteristics of cognitive aging is the basis of cognitive disease for early-detection and healthy aging promotion. In the current chapter, age-related decline of main cognitive domains, including sensory perception, memory, attention, executive function, language, reasoning, and space navigation ability are introduced respectively. From these aspects of cognition, we focus on the age-related effects, age-related cognitive diseases, and possible mechanisms of cognitive aging.
... While dual-tasking or concurrent multitasking (Burgess, 2014;Koechlin et al., 1999;MacPherson, 2018), and rapid switching (e.g., Koch et al., 2010;Monsell, 2003) do not focus on the broader demands of everyday multitasking, there is likely some overlap between these task paradigms and serial multitasking. In terms of aging, dual-task or concurrent multitasking provide conflicting findings where some studies report poorer performance in healthy older adults compared to younger adults, especially when the demands of the simultaneous tasks are high (Craik, 1977;McDowd & Craik, 1988;Salthouse et al., 1984), while others report no age-related differences (Baddeley et al., 2001;Anderson et al., 2011;Argiris et al., 2020;Kilb & Naveh Benjamin, 2014). Importantly, these latter studies are inclined to equate single-task performance across the age groups by adjusting the difficulty of each task for individual ability. ...
Cognitive aging research has studied the influence of healthy aging on the ability to multitask. Yet, little is known about the factors that might improve or impair serial multitasking performance in older adults. Three experiments involving younger and older adults assessed the impact of interruptions and planning on a prop-based test of multitasking. In Experiment 1, 26 younger adults and 25 older adults' multitasking abilities were assessed; older adults performed significantly more poorly than younger adults. In Experiment 2, 19 younger and 22 older adults were randomly allocated to a group who experienced a one minute unexpected interruption while multitasking or a group with no interruption. The results showed that, when there was an interruption, the age difference disappeared. In Experiment 3, 32 younger and 30 older adults were randomly allocated to a group who were given 3 minutes to write an outline describing how they intended to approach the multitasking task, and another group who were given 3 minutes to label pictures of everyday objects prior to multitasking. Again, when participants were encouraged to plan, no age difference was found. These results highlight the advantage that interruptions and planning might have on serial everyday multitasking performance in older adults.
... The antisaccade task requires a participant to inhibit shifting their gaze towards the displayed target and instead look towards the opposite side [14,15]. Due to a reduction in inhibitory control, disengagement of attention, and a decline in working memory and executive functioning [16], people with AD are significantly Vision 2023, 7, 38 2 of 12 slower at performing pro and antisaccadic eye movements resulting in an increase in mean latencies [17][18][19]. In an addition to cognitive slowing, Crawford et al. [15] demonstrated higher error rates and uncorrected errors in AD on the antisaccade task that correlated with dementia severity. ...
Studies demonstrated impairment in the control of saccadic eye movements in Alzheimer’s disease (AD) and people with mild cognitive impairment (MCI) when conducting the pro-saccade and antisaccade tasks. Research showed that changes in the pro and antisaccade latencies may be particularly sensitive to dementia and general executive functioning. These tasks show potential for diagnostic use, as they provide a rich set of potential eye tracking markers. One such marker, the coefficient of variation (CV), is so far overlooked. For biological markers to be reliable, they must be able to detect abnormalities in preclinical stages. MCI is often viewed as a predecessor to AD, with certain classifications of MCI more likely than others to progress to AD. The current study examined the potential of CV scores on pro and antisaccade tasks to distinguish participants with AD, amnestic MCI (aMCI), non-amnesiac MCI (naMCI), and older controls. The analyses revealed no significant differences in CV scores across the groups using the pro or antisaccade task. Antisaccade mean latencies were able to distinguish participants with AD and the MCI subgroups. Future research is needed on CV measures and attentional fluctuations in AD and MCI individuals to fully assess this measure’s potential to robustly distinguish clinical groups with high sensitivity and specificity.
