Neuropsychology最新文献

Objective: Short-term memory (STM) binding tests assess the ability to temporarily hold conjunctions between surface features, such as objects and their colors (i.e., feature binding condition), relative to the ability to hold the individual features (i.e., single feature condition). Impairments in performance of these tests have been considered cognitive markers of Alzheimer's disease (AD). The objective of the present study was to conduct a meta-analysis of results from STM binding tests used in the assessment of samples mapped along the AD clinical continuum.

Method: We searched PubMed, Scopus, and Web of Science for articles that assessed patients with AD (from preclinical to dementia) using the STM binding tests and compared their results with those of controls. From each relevant article, we extracted the number of participants, the mean and standard deviations from single feature and of feature binding conditions. Results across studies were combined using standardized mean differences (effect sizes) to produce overall estimates of effect.

Results: The feature binding condition of the STM binding showed large effects in all stages of AD. However, small sample sizes across studies, the presence of moderate to high heterogeneity and cross-sectional, case-controls designs decreased our confidence in the current evidence.

Conclusions: To be considered as a cognitive marker for AD, properly powered longitudinal designs and studies that clearly relate conjunctive memory tests with biomarkers (amyloid and tau) are still needed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: Prior to evidence of episodic memory decline, a lengthy preclinical phase of Alzheimer's disease (AD) exists characterized by the build-up of tau pathology within extrahippocampal structures. Semantic memory, also impaired in AD, has been linked to degradation within these earliest affected areas. This study aimed to assess the utility of performance discrepancies between letter and category verbal fluency tasks to detect neuronal loss in brain regions affected very early by AD.

Method: Whole-brain voxel-based morphometry was used to assess the neural correlates of semantic processing in three patient groups: two groups of mild cognitive impairment (MCI) patients split into mildly (n = 58) and moderately (n = 53) affected and a mild AD dementia group (n = 71). Discrepancies between the level of impairment on the semantic category fluency test and nonsemantic letter fluency test were calculated for each participant and included in regression models measuring the relationship between semantic memory and whole-brain gray matter volume.

Results: Patients at all disease stages demonstrated a loss of the normal semantic advantage in fluency tests, showing significantly greater impairments in category relative to letter fluency. Discrepancy scores in mild MCI correlated strongly with the structural integrity of the anterior medial temporal lobes. Correlations in more severely affected groups were weaker and more widespread.

Conclusions: Semantic memory appears a useful indicator of even the earliest stages of medial temporal damage in AD. With advancing disease severity, the discrepancy index loses its focal anatomical association, reinforcing its value as an early marker of incipient decline. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: We aimed to develop a measure to specifically assess the functioning of the perirhinal cortex (PRC), a brain structure affected very early in Alzheimer's disease (AD) pathology. In this novel task, participants were shown arrays of six complex figures and had to identify the "odd-one."

Method: The pilot study included 50 normal controls (NCs) and 50 patients in very early stages of AD. Participants completed the task and received MRI scanning. Best differentiating items were determined and applied in a validation study including 25 NCs, 27 early-stage AD patients, and 26 patients with major depression. Logistic regression models investigated if task performance predicted group membership. Task performance was then related to whole-brain gray matter integrity. As proof of concept, cortical thickness values of four regions of interest (ROIs; e.g., medial PRC and entorhinal cortex [ERC]) were compared between the groups. The associations of task performance and cortical thickness of the ROIs were investigated using linear models.

Results: Task performance showed good discriminative ability between early-stage AD patients and NCs. Whole-brain analyses revealed four significant clusters (p < .001) with peak voxels in parahippocampal regions including PRC and ERC. ROI analyses showed distinctly reduced cortical thickness in the AD group compared to both other groups in the medial PRC and ERC (p ≤ .001). Task performance modeled by ROI cortical thickness did not achieve significant results.

Conclusion: Although further validation is needed, especially with age-matched participant groups, these findings indicate that the task detects early cognitive impairment related to AD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Dementia is one of the most challenging health and social emergencies today. It affects more than 55 million people worldwide with epidemiological projections of reaching 140 million people in 2050. Diagnosis of Alzheimer's disease (AD), the clinical-pathological entity responsible for 60%-70% of all dementia cases, rests currently on the demonstration of cerebrospinal fluid or neuroimaging biomarkers, as a proxy of AD cortical neuropathology. In this context, the role of neuropsychological assessment, as a rapid and noninvasive tool able to accurately detect the early cognitive alterations and eventually promote the search for specific biological markers of AD, has become a matter of intense investigation and theoretical debate. This special issue includes original studies as well as literature reviews of the most current and promising approaches aimed at addressing the critical question of distinguishing cognitive decline due to preclinical or prodromal AD from decline associated with physiological aging. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objectives: There is currently a lack of consensus among neuropsychologists about which cognitive assessment paradigms hold the most promise in identifying subtle cognitive deficits in preclinical Alzheimer's Disease (AD) and which are most useful for monitoring risk of cognitive deterioration. Many widely used instruments are older versions of tests originally developed for the assessment of dementia or traumatic brain injury. Current efforts to digitize these measures provides more uniform and remote assessment, which is an advancement, but does not reflect significant changes in paradigmatic underpinnings or recent advances in cognitive neuroscience.

Method: This work provides an overview of novel Cognitive Challenge Tests (CCTs) that employ semantic interference paradigms that uniquely measure the failure to recover from proactive semantic interference (frPSI). Other salient methods to measure meaningful cognitive change in early stage AD are also presented, as well as how they compare with traditional neuropsychological assessments. Finally, future directions for the development of more effective assessment paradigms are discussed.

Results: frPSI is a cognitive marker which measures the persistent inability to learn new semantically competing stimuli despite multiple opportunities to do so. frPSI and deficits in semantic inhibitory control have repeatedly shown utility for the early detection of AD during its preclinical stages. These novel cognitive markers have been related to various biomarkers of AD and neurodegeneration among culturally diverse older adults.

Conclusions: To meet the critical needs of a rapidly evolving field, cognitive assessment instruments must show sufficient scientific rigor including robust sensitivity, specificity, and predictive utility among culturally and linguistically diverse populations and importantly, be correlated to AD biomarkers. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: Advances in our understanding of the Alzheimer's disease (AD) continuum through in vivo biomarkers have highlighted the need to develop neuropsychological tests that are more sensitive to subtle cognitive changes in the preclinical stages of the disease. Recent data suggest that the assessment of memory retention over extended delays, to detect so-called accelerated long-term forgetting (ALF), may be a reliable way to discriminate between presymptomatic AD and healthy aging. This review aims to present the scientific evidence published to date on this particular aspect of memory.

Method: A comprehensive review of all published articles on ALF in AD to the present day.

Results: We present findings relating to ALF in neurological disease, discuss theoretical aspects related to the integration of the concept of ALF in the framework of memory models, explain mechanisms that may be involved in its genesis and present supportive work from research in animal models. We focus particularly on aspects relevant to the assessment of ALF in clinical practice.

Conclusions: Despite many advances, further research will be needed to define more precisely what ALF is, what neural structures and mechanisms are involved in its occurrence, whether there are distinct patterns of forgetting according to etiology, and when and how to detect ALF most reliably. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: The cognitive characterization of Alzheimer's disease risk states, such as amnestic mild cognitive impairment (aMCI) and subjective cognitive decline (SCD), is fundamental for timely diagnosis and interventions. The Face Name Associative Memory Exam (FNAME) is sensitive to early Alzheimer's disease brain changes, and an extended version captures a fuller range of associative memory abilities. We aimed to assess group effects in the extended FNAME in older adults with SCD, aMCI, and older adult controls (CON).

Method: Two concurrently created versions of the extended FNAME were used to test three groups of older adults (CON = 35, SCD = 37, aMCI = 31) at two sites (Mexico = 59, Netherlands = 44). Extended FNAME memory abilities were analyzed in five analyses of variance. Group and site were considered as independent variables. For the recall ability, subtest levels were entered as a within-subject variable. The remaining abilities (Face Recognition, Name Recognition, Spontaneous Name Recall, and Face-Name Matching) were analyzed in independent models.

Results: In all models, the main effect for group was significant with large effect sizes, driven by a worse performance of aMCI participants. No significant differences were found between SCD and CON. The main effect for site was only significant in Face Recognition.

Conclusions: The worse performance of aMCI in the extended FNAME implies an impairment in associative memory abilities beyond recall. The similar performance of CON and SCD might be explained by the recruitment of SCD participants that did not spontaneously seek help for memory decline. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: The preeminent in vivo cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are amyloid β 1-42 (Aβ42), phosphorylated Tau (p-tau), and total Tau (t-tau). The goal of this study was to examine how well traditional (total and delayed recall) and process-based (recency ratio [Rr]) measures derived from Rey's Auditory Verbal Learning test (AVLT) were associated with these biomarkers.

Method: Data from 235 participants (M_age = 65.5, SD = 6.9), who ranged from cognitively unimpaired to mild cognitive impairment, and for whom CSF values were available, were extracted from the Wisconsin Registry for Alzheimer's Prevention. Bayesian regression analyses were carried out using CSF scores as outcomes, AVLT scores as predictors, and controlling for demographic data and diagnosis.

Results: We found moderate evidence that Rr was associated with both CSF p-tau (Bayesian factor [BF_M] = 5.55) and t-tau (BF_M = 7.28), above and beyond the control variables, while it did not correlate with CSF Aβ42 levels. In contrast, total and delayed recall scores were not linked with any of the AD biomarkers, in separate analyses. When comparing all memory predictors in a single regression, Rr remained the strongest predictor of CSF t-tau levels (BF_M = 3.57).

Conclusions: Our findings suggest that Rr may be a better cognitive measure than commonly used AVLT scores to assess CSF levels of p-tau and t-tau in nondemented individuals. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: Subjective cognitive decline (SCD) was recently proposed as an early risk factor for future mild cognitive impairment and Alzheimer's disease (AD). In this study, we investigated the sensitivity of novel neuropsychological testing paradigms (which have been proposed as potentially challenging tools for the identification of preclinical AD) in capturing the subtle cognitive changes leading to SCD but not objectively detected by traditional tests.

Method: The performances of 18 patients with SCD and 15 healthy individuals with no worries of cognitive decline (healthy controls [HC]) was compared on demanding tasks that investigated, respectively, associative memory, memory binding, spatial pattern separation processes and semantic memory. The diagnostic utility of these tests in capturing the subtle cognitive changes associated with SCD and possible relationships with SCD-related worries were investigated.

Results: No significance between-group difference was found on the standard neuropsychological tests. Conversely, the performance of patients with SCD and HC differed significantly on specific indexes derived from experimental tasks assessing face-name associative memory and spatial pattern separation. Moreover, these measures correctly classified group membership with good overall accuracy (between 79% and 82%) and were significantly associated with self-perceived memory functioning.

Conclusions: Our preliminary findings suggest that specific measures derived from demanding cognitive paradigms could be sensitive neuropsychological indexes for detecting the subtle cognitive impairment associated with SCD. These observations could be useful for further refining cognitive assessment aimed at early detection of AD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objective: Growing evidence supports the importance of learning as a central deficit in preclinical/prodromal Alzheimer's disease. The aims of this study were to conduct a series of neural network simulations to develop a functional understanding of a distributed, nonmodular memory system that can learn efficiently without interference. This understanding is applied to the development of a novel digital memory test.

Method: Simulations using traditional feed forward neural network architectures to learn simple logic problems are presented. The simulations demonstrate three limitations: (a) inefficiency, (b) an inability to learn problems consistently, and (c) catastrophic interference when given multiple problems. A new mirrored cascaded architecture is introduced to address these limitations, with support provided by a series of simulations.

Results: The mirrored cascaded architecture demonstrates efficient and consistent learning relative to feed forward networks but also suffers from catastrophic interference. Addition of context values to add the capability of distinguishing features as part of learning eliminates the problem of interference in the mirrored cascaded, but not the feed forward, architectures.

Conclusions: A mirrored cascaded architecture addresses the limitations of traditional feed forward neural networks, provides support for a distributed memory system, and emphasizes the importance of context to avoid interference. These process models contributed to the design of a digital computer-adaptive word list learning test that places maximum stress on the capability to distinguish specific episodes of learning. Process simulations provide a useful method of testing models of brain function and contribute to new approaches to neuropsychological assessment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).