Forgetting Rate on the Recency Portion of a Word List Differentiates Mild to Moderate Alzheimer’s Disease from Other Forms of Dementi

A comparison of story-recall metrics to predict hippocampal volume in older adults with and without cognitive impairment

Objective: Process-based scores of episodic memory tests, such as the recency ratio (Rr), have been found to compare favourably to, or to be better than, most conventional or "traditional" scores employed to estimate memory ability in older individuals (Bock et al., 2021; Bruno et al., 2019). We explored the relationship between process-based scores and hippocampal volume in older adults, while comparing process-based to traditional story recall-derived scores, to examine potential differences in their predictive abilities. Methods: We analysed data from 355 participants extracted from the WRAP and WADRC databases, who were classified as cognitively unimpaired, or exhibited mild cognitive impairment (MCI) or dementia. Story Recall was measured with the Logical Memory Test (LMT) from the Weschler Memory Scale Revised, collected within twelve months of the magnetic resonance imaging scan. Linear regression analyses were conducted with left or right hippocampal volume (HV) as outcomes separately, and with Rr, Total ratio, Immediate LMT, or Delayed LMT scores as predictors, along with covariates. Results: Higher Rr and Tr scores significantly predicted lower left and right HV, while Tr showed the best model fit of all, as indicated by AIC. Traditional scores, Immediate LMT and Delayed LMT, were significantly associated with left and right HV, but were outperformed by both process-based scores for left HV, and by Tr for right HV. Conclusions: Current findings show the direct relationship between hippocampal volume and all the LMT scores examined here, and that process-based scores outperform traditional scores as markers of hippocampal volume.

A comparison of diagnostic performance of word-list and story recall tests for biomarker-determined Alzheimer's disease

BACKGROUND

Wordlist and story recall tests are routinely employed in clinical practice for dementia diagnosis. In this study, our aim was to establish how well-standard clinical metrics compared to process scores derived from wordlist and story recall tests in predicting biomarker determined Alzheimer's disease, as defined by CSF ptau/Aβ42 ratio.

METHODS

Data from 295 participants (mean age = 65 ± 9.) were drawn from the University of Wisconsin - Madison Alzheimer's Disease Research Center (ADRC) and Wisconsin Registry for Alzheimer's Prevention (WRAP). Rey's Auditory Verbal Learning Test (AVLT; wordlist) and Logical Memory Test (LMT; story) data were used. Bayesian linear regression analyses were carried out with CSF ptau/Aβ42 ratio as outcome. Sensitivity analyses were carried out with logistic regressions to assess diagnosticity.

RESULTS

LMT generally outperformed AVLT. Notably, the best predictors were primacy ratio, a process score indexing loss of information learned early during test administration, and recency ratio, which tracks loss of recently learned information. Sensitivity analyses confirmed this conclusion.

CONCLUSIONS

Our study shows that story recall tests may be better than wordlist tests for detection of dementia, especially when employing process scores alongside conventional clinical scores.

The recency ratio assessed by story recall is associated with cerebrospinal fluid levels of neurodegeneration biomarkers

Recency refers to the information learned at the end of a study list or task. Recency forgetting, as tracked by the ratio between recency recall in immediate and delayed conditions, i.e., the recency ratio (Rr), has been applied to list-learning tasks, demonstrating its efficacy in predicting cognitive decline, conversion to mild cognitive impairment (MCI), and cerebrospinal fluid (CSF) biomarkers of neurodegeneration. However, little is known as to whether Rr can be effectively applied to story recall tasks. To address this question, data were extracted from the database of the Alzheimer's Disease Research Center at the University of Wisconsin - Madison. A total of 212 participants were included in the study. CSF biomarkers were amyloid-beta (Aβ) 40 and 42, phosphorylated (p) and total (t) tau, neurofilament light (NFL), neurogranin (Ng), and α-synuclein (a-syn). Story Recall was measured with the Logical Memory Test (LMT). We carried out Bayesian regression analyses with Rr, and other LMT scores as predictors; and CSF biomarkers (including the Aβ42/40 and p-tau/Aβ42 ratios) as outcomes. Results showed that models including Rr consistently provided best fits with the data, with few exceptions. These findings demonstrate the applicability of Rr to story recall and its sensitivity to CSF biomarkers of neurodegeneration, and encourage its inclusion when evaluating risk of neurodegeneration with story recall.

Forgetting rate for the familiarity and recollection components of recognition in amnestic mild cognitive impairment: A longitudinal study

Here we aimed to investigate the rate of forgetting of the familiarity and recollection components of recognition in patients at the onset of medial temporal lobe (MTL) pathology and destined to convert to Alzheimer's disease (AD). For this purpose, we conducted a longitudinal study of 13 patients who were diagnosed with amnestic mild cognitive impairment (a-MCI) at the first assessment and followed-up for 3 years. During this time, five patients converted to AD and eight remained in a stable condition of cognitive impairment. A group of 15 healthy subjects were enrolled as the control group (HC). In order to separately quantify the contribution of recollection and familiarity to recognition memory performance, the experimental sample was submitted to a modified version of Huppert and Piercy's procedure that included a Remember/Know paradigm. Data demonstrated that both stable and converter a-MCI patients forgot memory traces relative to the familiarity components of recognition at the same rate as HC. Conversely, converter a-MCI patients showed accelerated long-term forgetting specifically for the recollection component of recognition compared to stable a-MCI and HC. This is the first empirical demonstration that familiarity and recollection components of declarative memory are subject to different rates of forgetting in a-MCI patients as a function of their longitudinal clinical outcome. Our finding of accelerated long-term forgetting of the recollection component of recognition disclosed by converter a-MCI patients suggests that atrophy in the MTL not only interferes with the storage aspects but also disrupts the consolidation of memory traces.

Cross-sectional associations of CSF tau levels with Rey's AVLT: A recency ratio study

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) 2022 APA, all rights reserved).

Using the ATN system as a guide for the neuropsychological assessment of Alzheimer's disease

INTRODUCTION

Many studies have attempted to determine whether Alzheimer's disease (AD) in-vivo biomarkers can predict neuropsychological performance since pathophysiological changes precede cognitive changes by several years. Nonetheless, neuropsychological measures can also detect cognitive deterioration in cognitively normal individuals with AD-positive biomarkers. Recent studies have investigated whether cognitive measures can be used as a proxy for biomarkers. This is a crucial issue since biomarker analysis is expensive, invasive, and not yet widespread in clinical practice. However, these studies have so far considered only one or two classes of AD biomarkers. Here, we aim at preliminarily evaluating whether and which neuropsychological measures can discriminate individuals that have been classified according to the full scheme of biomarkers known as ATN system. This scheme groups biomarkers as a function of the three main AD-related pathologic processes they measure (i.e., β-amyloidosis, tauopathy, and neurodegeneration) to provide an unbiased and descriptive definition of the Alzheimer's continuum.

METHOD

Biomarkers and neuropsychological data from 78 patients (70.01 ± 9.15 years; 38 females) with suspected cognitive decline were extracted from a medical database. Participants' biomarker profiles were classified into the following ATN categories: normal AD biomarkers; Alzheimer's continuum; non-AD pathologic change. Data were analyzed using a Bayesian approach, to guarantee reliable result interpretation of data stemming from small samples.

RESULTS

The discrimination ability of each neuropsychological measure varied depending on the pairs of ATN categories compared. The best-discriminating predictor in the Alzheimer's continuum vs. normal biomarkers comparison was the figure naming ability. In contrast, in the Alzheimer's continuum vs. non-AD pathologic change comparison the best predictor was the wordlist forgetting rate.

CONCLUSIONS

Although the study was exploratory in nature, the proposed methodological approach may have the potential to identify the best neuropsychological measures for estimating AD neuropathological changes, leading to a more biologically informed use of neuropsychological assessment.

Serial position effects in the Logical Memory Test: Loss of primacy predicts amyloid positivity

BACKGROUND

Story recall is a frequently used neuropsychological test of episodic memory with clinical populations and for screening participants in drug trials for Alzheimer's disease. However, it is unclear at this stage which underlying mechanisms confer the test its sensitivity. In this paper, we examined serial position effects, that is, better recall for items learned early and late on a list, in story recall, and their usefulness to predict early changes associated with neurodegenerative markers.

METHODS

We analysed data from the Wisconsin Registry for Alzheimer's Prevention. First, we tested whether serial position effects were present in story recall (measured with the Wechsler Memory Scale Logical Memory Task; LMT) across individuals who were classified as cognitively unimpaired - stable, cognitively unimpaired - declining, or as having mild cognitive impairment (MCI).

RESULTS

Our results showed clear serial position effects for all groups, except for delayed recall among individuals with MCI, where no primacy effect was observed. Second, we tested whether loss of primacy from immediate to delayed recall was associated with amyloid burden (as measured with PiB PET) in individuals who were cognitively unimpaired at baseline. We found that more primacy loss predicted amyloid positivity, above and beyond the LMT total score.

CONCLUSIONS

This report is the first to show that loss of primacy between immediate and delayed story recall is associated with amyloid burden.

Reliability and Validity of a Home-Based Self-Administered Computerized Test of Learning and Memory Using Speech Recognition

INTRODUCTION

The objective of this study is to evaluate the reliability and validity of the ReVeRe^TM word list recall test (RWLRT), which uses speech recognition, when administered remotely and unsupervised.

METHODS

Prospective cohort study. Participants included 249 cognitively intact community dwelling older adults. Measures included clinician administered neuropsychological assessments at baseline and unsupervised remotely administered tests of cognition from six time-points over six months.

RESULTS

The RWLRT showed acceptable validity. Reliability coefficients varied across time points, with poor reliability between times 1 and 2 and fair-to-good reliability across the remaining five testing sessions. Practice effects were observed with repeated administration as expected.

DISCUSSION

Unsupervised computerized tests of cognition, particularly word list learning and memory tests that use speech recognition, have significant potential for large scale early detection and long-term tracking of cognitive decline due to AD.

Forgetting Rates on the Recency Portion of a Word List Predict Conversion from Mild Cognitive Impairment to Alzheimer's Disease

Amnestic mild cognitive impairment has a greater risk of progressing to Alzheimer's disease (AD). Consistent with AD patients' distinctive deficit in consolidating new memory traces, in a recent study we demonstrated that the forgetting rate on the recency portion of a word list differentiates AD from other forms of dementia. In line with this finding, the aim of this study was to investigate whether increased recency forgetting could be a reliable index for predicting amnestic mild cognitive impairment (MCI) patients' conversion to AD. For this purpose, we compared accuracy in immediate and delayed recall from different portions of a word list in a group of patients with amnestic MCI who converted (C-MCI) or did not convert (S-MCI) to AD during a three-year follow-up period and in a group of normal controls. The results of the present study show that the forgetting from the recency portion of the list (operationalized as a ratio between immediate and delayed recall) was significantly larger in C-MCI than in S-MCI patients. Consistently, the hierarchical logistic regression analyses demonstrated that the recency ratio is a strong predictor of group membership. Similar to what occurs in full-blown AD patients, the results of our study suggest that the increased forgetting rate from the recency portion of the list in C-MCI patients is due to severely reduced efficiency in converting transitory short-term memory representations into stable long-term memory traces. This is consistent with prominent involvement of neuropathological changes in the cortical areas of the medial-temporal lobes and suggests that the recency ratio is a cognitive marker able to identify MCI patients who have a greater likelihood of progressing to AD.

Following H.N. over 21 years: recency change and reduced retention predict later impairment in memory, and recency ratio may combine both effects

The study follows an intellectually superior patient from initial subjective memory complaints to MCI and dementia over 21 years. Primary memory measures, process- and reliable change-measures from 12 assessments with the California Verbal Learning Test (CVLT) were analyzed as well as experimental measures of retrieval and Recency-Ratio (Rr) combining traditional recency measures with selective retrieval impairments of recency items.Recency change preceded normatively impaired memory by four years, and retention percentage by two years. Rr indicated risk for MCI conversion 13 years prior to receiving that diagnosis, and is an interesting measure for early detection of dementia in CVLT.