Distinct serial position profiles and neuropsychological measures differentiate late life depression from normal aging and Alzheimer's disease

Application of the Japanese Verbal Learning Test to Patients With Alzheimer's Disease in the Early Stage

INTRODUCTION

This study aimed to investigate the mechanism of memory function in the context of explicit memory in early-stage Alzheimer's disease (AD) using the short-form Japanese Verbal Learning Test (JVLT-9).

METHODS

Participants were 20 patients with early-stage AD and a control group of 23 healthy older adults (normal controls: NC), each of whom was administered the JVLT-9, which is a verbal list learning task used to assess explicit memory comprehensively. Between-group differences for each score were investigated using the Mann-Whitney U test. A two-way analysis of variance (ANOVA) was performed for the number of correct recalls by group (AD/NC) × JVLT-9 task. In addition, the AD group was divided into a CDR 0.5 group and a CDR 1.0 group, and it was performed as a group (CDR 0.5/1.0) × JVLT-9 task two-way ANOVA.

RESULTS

The results demonstrated that the AD group had lower immediate recall, learning rate, semantic clustering, and recognition discrimination and significantly higher intrusion errors compared to the NC group. Further, JVLT-9 recall and recognition rates were found to be lower with higher CDR (an index of dementia severity).

CONCLUSION

These results are largely consistent with the features of explicit memory in AD reported in the English version, confirming the clinical utility of the JVLT-9 as a test of explicit memory function.

Disruption of the serial position effect as an early marker of Alzheimer's disease in Spanish-English bilinguals

OBJECTIVES

The present study examined if disruption of serial position effects in list recall could serve as an early marker of Alzheimer's disease (AD) in Spanish-English bilinguals.

METHODS

We tested 20 participants initially diagnosed as cognitively normal or with mild cognitive impairment who declined and eventually received a diagnosis of AD (decliners), and 37 who remained cognitively stable (controls) over at least 2 years. Participants were tested on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test in English or Spanish as part of an annual neuropsychological evaluation.

RESULTS

Compared to controls, decliners exhibited significantly reduced recall including reduced primacy scores (i.e., items recalled from the first three list items on Trial 1), whereas recency scores (i.e., items recalled from the last 3 list items on Trial 1) were equivalent in decliners and controls. Further analyses suggested that the sensitivity of the primacy effect to preclinical AD was initially stronger in participants tested in Spanish, a surprising finding given that the CERAD was developed for English speakers. However, in the subsequent year of testing, primacy scores declined to the same level regardless of language of testing.

CONCLUSIONS

Several list learning measures may facilitate early diagnosis of AD in Spanish-English bilinguals, possibly including the relatively understudied primacy effect. Additional studies are needed to investigate the possibility that linguistic or demographic variables might modulate sensitivity of list learning tests to preclinical AD, which could lead to broader improvements in their utility for early diagnosis of AD in all populations.

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.

Using serial position effects to investigate memory dysfunction in homeless and precariously housed persons

Background: Homeless and precariously housed persons exhibit significant memory impairment, but the component processes underlying memory dysfunction have not been explored. We examined the serial position profile (i.e., primacy and recency effects) of verbal memory and its neuroanatomical correlates to identify the nature of memory difficulties in a large cohort of homeless and precariously housed adults. Method: The sample included 227 community-dwelling homeless and precariously housed adults. Serial position scores (primacy, middle, recency) were computed using the Hopkins Verbal Learning Test-Revised. Paired sample t-tests were used to compare percent recall from each word list region. Age-adjusted correlations assessed associations between serial position scores and other cognitive domains (attention, processing speed, executive functioning). Regression analyses were conducted to examine regional brain volumes of interest (hippocampus, entorhinal cortex, dorsolateral prefrontal cortex [DLPFC]) and their differential associations with serial position scores. Results: The serial position profile was characterized by a diminished recency effect in relation to the primacy effect. Serial position scores positively correlated with sustained attention and cognitive control. Larger hippocampal volume was associated with better primacy item recall. DLPFC volume was not associated with serial position recall after adjustment for false discovery rate. There were no associations between regional brain volumes and recency item recall. Conclusion: Our results suggest that commonly reported memory difficulties in homeless and precariously housed adults are likely secondary to a core deficit in executive control due to compromised frontal lobe functioning. These findings have implications for cognitive rehabilitation in this complex and vulnerable group.

Neuropsychological Performance in Alzheimer's Disease versus Late-Life Depression: A Systematic Review and Meta-Analysis

OBJECTIVE

Despite decades of research, neuropsychological tests (NPTs) that clearly differentiate between Alzheimer's disease (AD) and late-life depression (LLD) have yet to be agreed upon. Given this gap in knowledge and the rapid deployment of disease-modifying drugs for the two disorders, accurate clinical diagnosis using evidence-based assessment is essential. This study aims to systematically examine the literature to identify NPTs that would be able to differentiate AD and LLD.

METHOD

Databases and bibliographies were searched to identify articles for analysis. Two major inclusion criteria were that the studies compared neuropsychological functioning of AD versus LLD using normed NPTs and provided data for effect size calculation. Risk of bias was minimized by having independent coders for all steps in the review.

RESULTS

Forty-one studies met inclusion criteria (N = 2,797) and provided effect sizes for tests that were classified as belonging to 15 domains of functioning. The two groups were well differentiated by tasks of delayed contextual verbal memory as compared to immediate or non-contextual memory, recognition cueing, confrontation naming, visuospatial construction, and conceptualization. Specific NPTs that appear to be useful for differential diagnosis include the Rey Auditory Verbal Learning Test-Delayed Recognition; Boston Naming Test; the Dementia Rating Scale's memory, conceptualization, and construction subscales; and the CERAD Constructional Praxis.

CONCLUSIONS

The NPTs highlighted in this systematic review could be used as a relatively simple and cost-effective method to differentiate between patients with cognitive dysfunction due to AD versus LLD.

Primacy and recency effects in verbal memory are differentially associated with post-mortem frontal cortex p-tau 217 and 202 levels in a mixed sample of community-dwelling older adults

INTRODUCTION

Serial position effects in verbal memory are associated with in vivo fluid biomarkers and neuropathological outcomes in Alzheimer's disease (AD). To extend the biomarker literature, associations between serial position scores and postmortem levels of brain phosphorylated tau (p-tau) were examined, in the context of Braak stage of neurofibrillary tangle progression.

METHOD

Participants were 1091 community-dwelling adults (Mage = 80.2, 68.9% female) from the Rush University Religious Orders Study and Memory and Aging Project who were non-demented at enrollment and followed for a mean of 9.2 years until death. The CERAD Word List Memory test administered at baseline and within 1 year of death was used to calculate serial position (primacy, recency) and total recall scores. Proteomic analyses quantified p-tau 217 and 202 from dorsolateral prefrontal cortex samples. Linear regressions assessed associations between cognitive scores and p-tau with Braak stage as a moderator.

RESULTS

Cognitive status proximal to death indicated 34.7% were unimpaired, 26.2% met criteria for MCI, and 39.0% for dementia. Better baseline primacy recall, but not recency recall, was associated with lower p-tau 217 levels across Braak stages. Delayed recall showed a similar pattern as primacy. There was no main effect of immediate recall, but an interaction with Braak stages indicated a negative association with p-tau 217 level only in Braak V-VI. Within 1 year of death, there were no main effects for cognitive scores; however, recency, immediate and delayed recall scores interacted with Braak stage showing better recall was associated with lower p-tau 217 only in Braak V-VI. No associations were observed with p-tau 202.

CONCLUSIONS

Primacy recall measured in non-demented adults may be sensitive to emergent tau phosphorylation that occurs in the earliest stages of AD. Serial position scores may complement the routinely used delayed recall score and p-tau biomarkers to detect preclinical AD.

Serial position effects and mild cognitive impairment: a comparison of measures and scoring approaches

INTRODUCTION

Serial position effects (SPEs) have shown promise as predictors of future cognitive decline and conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD), even when accounting for total learning and memory scores. However, conflicting results have been found in the literature, which may be at least partially related to the many ways in which SPEs are calculated. The current study aimed to address the discrepancies in the literature by examining whether one method of analyzing SPEs is more sensitive at distinguishing those with and without psychometrically defined MCI.

METHOD

86 older adult participants (57 healthy comparison, 29 MCI) completed the California Verbal Learning Test, Third Edition (CVLT3) and the Rey Auditory Verbal Learning Test (RAVLT), along with measures assessing multiple cognitive domains. Each participant completed two visits, between 3 and 9 days apart, with a different memory measure administered on each day. The standard scoring approach and the regional scoring approach to calculating SPEs were compared.

RESULTS

Results showed that, when significant differences were found, SPEs were always reduced in the MCI group compared to the healthy comparison group when using regional scoring; however, results were not as consistent when using standard scoring. Further, lower primacy than recency scores were only consistently seen in the MCI group when using the RAVLT but not the CVLT3. ROC analyses showed that only regional scoring of SPEs from delayed recall of the RAVLT and the CVLT3 accurately discriminated between those with and without MCI.

CONCLUSION

Regional scoring of SPEs may be more sensitive at identifying subtle cognitive decline compared to standard scoring. However, the specific measure that is used to analyze SPEs can impact the interpretation of findings.

Neural evidence for advantaged representation of first items in memory

Visual areas activated during perception can retain specific information held in memory without the presence of physical stimuli via distributed activity patterns. Neuroimaging studies have shown that the delay-period representation of information in visual areas is modulated by factors such as memory load and task demands, raising the possibility of serial position as another potential modulator. Specifically, enhanced representation of first items during the post-encoding delay period may serve as a mechanism underlying the well-established but not well-understood primacy effect - the mnemonic advantage of first items. To test this hypothesis, 13 males and 16 females performed a human fMRI task, wherein each trial consisted of the sequential encoding of two stimuli (a famous face and landscape, order counterbalanced), followed by a distracting task, a delay period, and then a cued recall of one of the items. Participants exhibited the expected behavioral primacy effect, manifested as faster recall of the first items. In order to elucidate the still debated neural underpinnings of this effect, using multivariate decoding, a classifier was trained on data collected during encoding to differentiate stimulus categories (i.e., faces vs. landscapes) and tested on data collected during the post-encoding period. Greater reactivation of first versus second items was observed in the ventral occipito-temporal cortex during the entire post-encoding period but not during encoding. Moreover, trial-level analyses revealed that the degree of first-item neural advantage during the post-encoding delay predicted the behavioral primacy effect. These findings highlight the role of item reinstatement in ventral occipito-temporal cortex in the primacy effect and are discussed in the context of the uniqueness of the very first item and event boundaries, illuminating putative neural mechanisms underlying the effect.

Gender differences in the serial position among older adults

INTRODUCTION

There are gender disparities in age of diagnosis with Mild Cognitive Impairment (MCI) or dementia, which may be related to general female advantages in verbal memory across aging. Further examination of the serial position effect (SPE) may provide an avenue for earlier diagnosis of MCI/dementia among women.

METHOD

338 cognitively healthy adults aged 50⁺ (110 men; 228 women) were administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) List Learning task as part of dementia screening. We examined whether the SPE could be demonstrated on Trial 1 and delayed recall, and whether SPE patterns were consistent across genders, using mixed measure ANOVAs. Using regression, we also examined whether gender, SPE components, or their interactions predicted RBANS Delayed Memory Index (DMI) performance. Using cluster analyses, we identified a group with reduced primacy relative to recency on Trial 1 and a group without. We used ANOVA to examine whether clusters differed in DMI scores and whether this was moderated by gender.

RESULTS

We demonstrated the prototypical SPE on Trial 1. On delayed recall, we found reduced recency compared to primacy and middle performance. As expected, men exhibited worse performance on the DMI. However, gender did not interact with SPE. Primacy and middle, but not recency, performance on Trial 1 predicted DMI scores, as did the recency ratio. These relationships were not moderated by gender. Finally, participants with better primacy than recency on Trial 1 (N = 187) exhibited higher performance on DMI than participants with better recency than primacy (N = 151). Gender did not interact with cluster membership.

CONCLUSION

Our results have important clinical implications in assessment, where focusing on Trial 1 primacy performance and loss of recency between Trial 1 and delayed recall may help to address gender-related delays in age of diagnosis of MCI or dementia.

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.

Formal Neuropsychological Testing: Test Batteries, Interpretation, and Added Value in Practice

Neuropsychologists evaluate patients for cognitive decline and dementia, using validated psychometric tests, along with behavioral observation, record review, clinical interview, and information about psychological functioning, to evaluate brain-behavior relationships and aid in differential diagnosis and treatment planning. Also considered are premorbid functioning, education, sex, socioeconomic status, primary language, culture, and race-related health disparities when selecting tests, interpreting performance, and providing a diagnostic impression. Neuropsychologists provide diagnostic clarity, explain symptoms and likely disease course to patients and family members, and assist the family with future planning, behavioral management strategies, and ways to mitigate caregiver burden.

The Role of Entropy in Construct Specification Equations (CSE) to Improve the Validity of Memory Tests: Extension to Word Lists

Metrological methods for word learning list tests can be developed with an information theoretical approach extending earlier simple syntax studies. A classic Brillouin entropy expression is applied to the analysis of the Rey’s Auditory Verbal Learning Test RAVLT (immediate recall), where more ordered tasks—with less entropy—are easier to perform. The findings from three case studies are described, including 225 assessments of the NeuroMET2 cohort of persons spanning a cognitive spectrum from healthy older adults to patients with dementia. In the first study, ordinality in the raw scores is compensated for, and item and person attributes are separated with the Rasch model. In the second, the RAVLT IR task difficulty, including serial position effects (SPE), particularly Primacy and Recency, is adequately explained (Pearson’s correlation R=0.80) with construct specification equations (CSE). The third study suggests multidimensionality is introduced by SPE, as revealed through goodness-of-fit statistics of the Rasch analyses. Loading factors common to two kinds of principal component analyses (PCA) for CSE formulation and goodness-of-fit logistic regressions are identified. More consistent ways of defining and analysing memory task difficulties, including SPE, can maintain the unique metrological properties of the Rasch model and improve the estimates and understanding of a person’s memory abilities on the path towards better-targeted and more fit-for-purpose diagnostics.

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).

Cognitive Impairment in Late-Life Depression: A Comparative Study of Healthy Older People, Late-Life Depression, and Mild Alzheimer's Disease Using Multivariate Base Rates of Low Scores

Late-Life Depression (LLD) is often associated with cognitive impairment. However, distinction between cognitive impairment due to LLD and those due to normal aging or mild Alzheimer's Disease (AD) remain difficult. The aim of this study was to present and compare the multivariate base rates of low scores in LLD, mild AD, and healthy control groups on a battery of neuropsychological tests. Participants (ages 60-89) were 352 older healthy adults, 390 patients with LLD, and 234 patients with mild AD (i.e., MMSE ≥ 20). Multivariate base rates of low scores (i.e., ≤ 5th percentile) were calculated for each participant group within different cognitive domains (verbal episodic memory, executive skills, mental processing speed, constructional praxis, and language/semantic memory). Obtaining at least one low score was relatively common in healthy older people controls (from 9.4 to 17.6%), and may thus result in a large number of false positives. By contrast, having at least two low scores was unusual (from 0.3 to 4.6%) and seems to be a more reliable criterion for identifying cognitive impairment in LLD. Having at least three low memory scores was poorly associated with LLD (5.9%) compared to mild AD (76.1%) and may provide a useful way to differentiate between these two conditions [χ ( 1 ) 2 = 329.8, p < 0.001; Odds Ratio = 50.7, 95% CI = 38.2-77.5]. The multivariate base rate information about low scores in healthy older people and mild AD may help clinicians to identify cognitive impairments in LLD patients, improve the clinical decision-making, and target those who require regular cognitive and clinical follow-up.

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.

A Comparison of Serial Position Effects in Patients with Mild Cognitive Impairment due to Parkinson's Disease or to Alzheimer's Disease

OBJECTIVE

The first (primacy region) and last (recency region) items of a word list are generally better memorized than items from the middle region. The recency effect depends on short-term memory (STM) and the primacy effect on long-term memory (LTM), where verbal information is transferred from STM into LTM by maintenance rehearsal. We compared the serial position effects (SPE) between patients with mild cognitive impairment (MCI) due to Parkinson's disease (PD), i.e., PD-MCI, and patients with MCI due to Alzheimer's disease (AD-MCI), and evaluated the influence of SPE and frontostriatal deficits on verbal memory recall.

METHODS

Four similar groups of subjects participated in the study: 26 PD-MCI patients, 26 cognitively normal patients with PD (PD-CN), 26 AD-MCI patients, and 26 normal controls (NC). Verbal episodic memory, verbal span, attentional capacity, executive functions, and verbal working memory performance were assessed. Measures for primacy and recency regions were defined at the first trial of a 16-items word list. Hierarchical regression models were used to investigate the contribution of frontostriatal deficits beyond SPE on verbal memory recall performance ("long-delay free recall") in PD and AD patients.

RESULTS

Primacy effects were significantly diminished in both PD-MCI and AD-MCI patients relative to NC and PD-CN (all p < 0.01). Compared to PD-MCI patients, AD-MCI patients exhibited significantly worse "delayed-recall 'savings'." Reduced primacy effect was predictive for decreased recall performance in PD and AD. The conducted hierarchical regression model revealed that in PD, but not in AD patients, performance of attention and executive function significantly increased the prediction of free recalled words.

CONCLUSIONS

Reduced recall performance is likely due to impaired transition of newly learned material from STM into LTM in AD and in PD. Whereas AD-MCI patients suffer from a storage deficit, the similarly reduced recall performance found in patients with PD-MCI may additionally be related to deficient attentional and executive capacity.

The First Word Recalled Measure - A Potential Addition to Clinical Exams

Characterizing episodic memory abilities is highly important in the diagnosis of Alzheimer's disease (AD) and mild cognitive impairment (MCI), and usually includes wordlist learning and recall tasks. Clinical evaluations typically focus on the number of words recalled, ignoring additional information, like serial position. Here, we tested the potential value of two serial positioning measures for clinical diagnosis – how retrieval is initiated, as measured by the first word recalled, and how it proceeds – using data from patients with AD and MCI that completed a wordlist learning and recall task. Our results show that during the early stages of learning, patients with AD are less prone to retrieve the first word from the wordlist, manifested as lower primacy effect in the first word recalled, compared with MCI patients. The first word recalled measure adds to the differentiation between the groups over and above the total number of words learned. Thus, the first word recalled during word list learning and recall tasks may be used as a simple complementary measure to distinguish between MCI and AD during standard neuropsychological evaluations.

Predicting Early Mild Cognitive Impairment With Free Recall: The Primacy of Primacy

OBJECTIVES

Serial position effects have been found to discriminate between normal and pathological aging, and to predict conversion from Mild Cognitive Impairment (MCI) to Alzheimer's disease (AD). Different scoring methods have been used to estimate the accuracy of these predictions. In the current study, we investigated delayed primacy as predictor of progression to early MCI over established diagnostic memory methods. We also compared three serial position methods (regional, standard and delayed scores) to determine which measure is the most sensitive in differentiating between individuals who develop early MCI from a baseline of cognitively intact older adults.

METHOD

Data were analyzed with binary logistic regression and with receiver-operating characteristic (ROC). Baseline serial position scores were collected using the Rey's Auditory Verbal Learning Test and used to predict conversion to early MCI. The diagnosis of early MCI was obtained through statistical algorithm and consequent consensus conference. One hundred and ninety-one participants were included in the analyses. All participants were aged 60 or above and cognitively intact at baseline.

RESULTS

The binary logistic regression showed that delayed primacy was the only predictor of conversion to early MCI, when compared to total and delayed recall. ROC curves showed that delayed primacy was still the most sensitive predictor of progression to early MCI when compared to other serial position measures.

CONCLUSIONS

These findings are consistent with previous studies and support the hypothesis that delayed primacy may be a useful cognitive marker of early detection of neurodegeneration.

A Hot-Cold Cognitive Model of Depression: Integrating the Neuropsychological Approach Into the Cognitive Theory Framework

In the 50 years following Beck’s cognitive theory, empirical research has consistently supported the role of dysfunctional, ‘hot’ cognition in the onset and maintenance of major depressive disorder. Compromised ‘cold’ cognition in attention, memory, and executive control abilities, independent of the affective state, has attracted much clinical interest for its role throughout the course of illness and into remission. We propose integrating cold cognition into Beck’s cognitive theory framework to account for the complementary roles of both hot and cold cognition in depression onset and maintenance.

A critical review of cognitive research was conducted to inform an integrated hot-cold cognitive model of depression.

Cold cognitive deficits likely act as a gateway to facilitate the activation and expression of the hot cognitive biases through a weakened ability to attend, retrieve, and critically assess information. Cold deficits become exacerbated by the negative mood state, essentially ‘becoming hot’, lending to maladaptive emotion regulation through ruminative processes. Depleted cognitive resources contribute to the manifestation of further deficit in problem-solving ability in everyday life, which in itself, may act as a stressor for the onset of recurrent episodes, perpetuating the depressive cycle.

We discuss the interaction between hot and cold cognition within the cognitive theory framework and the potential of complementary hot-cold pathways to elucidate novel means of prevention and treatment for depression.

Dysfunction in hot (emotion-dependent) and cold (emotion-independent) cognition has been demonstrated in depression, but psychological treatment has largely focused on hot cognition only.

Hot and cold cognition are complementary processes throughout the activation and maintenance of depressive schemas and biases, necessitating the consideration of both hot and cold cognitive aspects to disrupt the depressive cycle.

The proposed hot-cold cognitive model shows promise to stimulate new research avenues for the prevention and treatment of depression.

Is there a specific memory signature associated with Aβ-PET positivity in patients with amnestic mild cognitive impairment?

Amnestic mild cognitive impairment (aMCI) is a clinical entity with various potential etiologies including but not limited to Alzheimer's disease. We examined whether a positive ([18F]Florbetapir) beta amyloid positron emission tomography scan, supporting underlying Alzheimer's disease pathophysiology, was associated with specific memory deficits in 48 patients with aMCI (33 beta amyloid positive, 15 beta amyloid negative). Memory was evaluated using an autobiographical fluency task and a word-list learning task with 2 different encoding types (shallow/incidental versus deep/intentional). Compared with 40 beta amyloid-negative controls, both aMCI subgroups demonstrated severe deficits in the global memory score and in most subscores of both tasks. Finer-grained analyses of memory tests showed subtle association with beta amyloid status, revealing a stronger impairment of the primacy effect in beta amyloid-positive patients. Structural magnetic resonance imaging showed that both aMCI subgroups exhibited comparable atrophy patterns, with similar degrees of medial temporal volume loss compared with controls. Specifically assessing the primacy effect might complement global memory scores in identifying beta amyloid-positive patients with aMCI.

Serial position effects differ between Alzheimer's and vascular features in mild cognitive impairment

Individuals with mild cognitive impairment (MCI) exhibit varying serial position effect (SPE) performances. The relationship between SPE performance in word list recall and clinical, genetic, and neuroimaging features of MCI requires elucidation. 119 MCI and 68 cognitively normal (CN) participants underwent cognitive assessment, apolipoprotein E (ApoE) genotyping, and volumetric MRI brain scans processed via voxel-based morphometry. A 10-word recall task was used to assess SPE performance in relation to recency and primacy recall. MCI participants were classified as having Good SPE performance (high primacy and recency, Good SPE) or Poor SPE performance (low primacy only, LP-SPE; low recency only, LR-SPE; or both low, Low SPE). Poor SPE participants had reduced grey matter (GM) volumes and increased white matter hyperintensities (WMH) volumes. Participants with LP-SPE demonstrated reduced hippocampal GM volumes and were more likely to be ApoE ε4 carriers. LR-SPE was associated with higher WMH volumes. Presence of both greater WMH volumes and ApoE ε4 resulted in Low SPE. LP-SPE MCI participants had features typical of Alzheimer's disease. LR-SPE MCI was associated with increased WMH volumes, likely representing vascular pathology. SPE profiles are associated with distinct clinical patterns of MCI pathophysiology and could have potential as a clinical marker.

The recency ratio as predictor of early MCI

ABSTRACTObjectives:Individuals with Alzheimer's disease (AD) present poor immediate primacy recall accompanied by intact or exaggerated recency, which then tends to decline after a delay. Bruno et al. (Journal of Clinical and Experimental Neuropsychology, Vol. 38, 2016, pp. 967-973) have shown that higher ratio scores between immediate and delayed recency (i.e. the recency ratio; Rr) are associated with cognitive decline in high-functioning older individuals. We tested whether Rr predicted conversion to early mild cognitive impairment (early MCI) from a cognitively healthy baseline.

DESIGN

Data were analyzed longitudinally with binomial regression. Baseline scores were used to predict conversion to early MCI after approximately nine years.

SETTING

Data were collected at the Wisconsin Registry of Alzheimer's Prevention, in Madison, Wisconsin.

PARTICIPANTS

For the study, 427 individuals were included in the analysis; all participants were 50 years of age or older and cognitively intact at baseline, and were native English speakers.

MEASUREMENTS

Memory data were collected using the Rey's Auditory Verbal Learning Test, and the early MCI diagnosis was obtained via consensus conference.

RESULTS

Our results showed that higher Rr scores are correlated with greater risk of later early MCI diagnosis, and this association is independent of total recall performance.

CONCLUSIONS

Rr is an emerging cognitive marker of cognitive decline.

The Hopkins Verbal Learning Test: an in-depth analysis of recall patterns

One of the earliest signs of dementia is memory issues and verbal word lists, such as the Hopkins Verbal Learning Test (HVLT), are successfully used for screening. To gain insight in how memory is affected in dementia, and to further improve the efficacy of the HVLT, in-depth analysis of the recall patterns of dementia cases and controls was conducted. Dementia cases and controls were matched for factors that can affect performance, such as age, gender and education level. Word frequency, syllable length, and orthographic neighbourhood size did not differ in the Indonesian version of the HVLT, nor did these characteristics affect recall. However dementia cases showed consistent and poor recall across the three trials; with the worst recall for the "human shelter" category and best recall for the "animals" category. Dementia cases also showed impaired accessibility of all categories with reduced subsequent recall from accessed categories and reduced primacy and recency levels. Finally, dementia cases exhibited lower levels of re-remembering and recalling new words, and higher levels of immediate forgetting and never recalling words. It was concluded that utilising the extra information provided by the in-depth analyses of the recall patterns could be beneficial to improve dementia screening.

The recency ratio is associated with reduced CSF glutamate in late-life depression

Glutamate is the principal excitatory neurotransmitter in the central nervous system, and is thought to be involved in the process of memory encoding and storage. Glutamate disturbances have also been reported in psychiatric disorders, such as schizophrenia and major depressive disorder (MDD), and in Alzheimer's disease. In this paper, we set out to study the relationship between cerebrospinal fluid (CSF) glutamate levels and memory performance, which we believe has not been reported previously. In particular, we focused on recall performance broken down by serial position. Our prediction was that the recency ratio (Rr), a novel cognitive marker of intellectual impairment, would be linked with CSF glutamate levels. We studied data from a group of cognitively intact elderly individuals, 28 of whom had MDD, while 19 were controls. Study results indicated that Rr levels, but no other memory score, were inversely correlated with CSF glutamate levels, although this was found only in individuals with late-life MDD. For comparison, glutamine or GABA were not correlated with any memory performance measure.

The effects of age on the learning and forgetting of primacy, middle, and recency components of a multi-trial word list

The serial position effect reveals that recall of a supraspan list of words follows a predictable pattern, whereby words at the beginning (primacy) and end (recency) of a list are recalled more easily than words in the middle. This effect has typically been studied using single list-learning trials, but in neuropsychology, multi-trial list-learning tests are more commonly used. The current study examined trends in learning for primacy, middle, and recency effects across multiple trials in younger and older age cohorts. Participants were 158 volunteers, including 79 adults aged 17-36 ("younger" group) and 79 adults aged 54-89 years ("older" group). Each participant completed four learning trials and one delayed (5-10 min) recall trial from the Memory Assessment Scales. Scores were divided into primacy (first four words), middle (middle four words), and recency (final four words) scores for all trials. For list acquisition, mixed effects modeling examined the main effects of and interactions between learning slope (logarithmic), age group, and serial position. Rate of learning increased logarithmically over four trials and varied by serial position, with growth of middle and recency word acquisition increasing more rapidly than recall of primacy words; this interaction did not differ by age group. Delayed retention differed according to age group and serial position; both older and younger adults demonstrated similar retention for primacy words, but older adults showed reduced retention for middle and recency words. Although older adults acquired less information across learning trials, the reason for this reduced acquisition was related to initial learning, not to rate of learning over time. Older compared to younger adults were less efficient at transferring middle and recency words from short-term to long-term memory.

The Bay Area Verbal Learning Test (BAVLT): Normative Data and the Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury

Verbal learning tests (VLTs) are widely used to evaluate memory deficits in neuropsychiatric and developmental disorders. However, their validity has been called into question by studies showing significant differences in VLT scores obtained by different examiners. Here we describe the computerized Bay Area Verbal Learning Test (BAVLT), which minimizes inter-examiner differences by incorporating digital list presentation and automated scoring. In the 10-min BAVLT, a 12-word list is presented on three acquisition trials, followed by a distractor list, immediate recall of the first list, and, after a 30-min delay, delayed recall and recognition. In Experiment 1, we analyzed the performance of 195 participants ranging in age from 18 to 82 years. Acquisition trials showed strong primacy and recency effects, with scores improving over repetitions, particularly for mid-list words. Inter-word intervals (IWIs) increased with successive words recalled. Omnibus scores (summed over all trials except recognition) were influenced by age, education, and sex (women outperformed men). In Experiment 2, we examined BAVLT test-retest reliability in 29 participants tested with different word lists at weekly intervals. High intraclass correlation coefficients were seen for omnibus and acquisition scores, IWIs, and a categorization index reflecting semantic reorganization. Experiment 3 examined the performance of Experiment 2 participants when feigning symptoms of traumatic brain injury. Although 37% of simulated malingerers showed abnormal (p < 0.05) omnibus z-scores, z-score cutoffs were ineffective in discriminating abnormal malingerers from control participants with abnormal scores. In contrast, four malingering indices (recognition scores, primacy/recency effects, learning rate across acquisition trials, and IWIs) discriminated the two groups with 80% sensitivity and 80% specificity. Experiment 4 examined the performance of a small group of patients with mild or severe TBI. Overall, both patient groups performed within the normal range, although significant performance deficits were seen in some patients. The BAVLT improves the speed and replicability of verbal learning assessments while providing comprehensive measures of retrieval timing, semantic organization, and primacy/recency effects that clarify the nature of performance.

Now you make false memories; now you do not: the order of presentation of words in DRM lists influences the production of the critical lure in Alzheimer's disease

Why do some Alzheimer's patients produce fewer false memories than healthy older participants in the Deese-Roediger-McDermott paradigm, which was especially designed for the study of false memories in a laboratory setting? Using a very simple methodology, this study examines a new explanatory factor inherent in the paradigm itself: the order of presentation of the words in the lists. A sample comprising 149 participants (36 younger, 40 middle-aged, 37 healthy older adults, and 36 Alzheimer's patients) performed a DRM task with either a classic descending forward associative strength (FAS) presentation order of the words or an ascending FAS presentation order. The results showed that this simple manipulation influenced the production of false memories in Alzheimer's patients only. Contrary to the other participants, Alzheimer's patients produced significantly more critical lures in the ascending FAS condition than in the descending FAS condition. These new data, interpreted in the light of serial position effects, invite a reconsideration of the relevance of the DRM paradigm for comparing the production of false memories in Alzheimer's patients and healthy older participants.

Verbal list learning and memory profiles in HIV-infected adults, Alzheimer's disease, and Parkinson's disease: An evaluation of the "cortical hypothesis" of NeuroAIDS

HIV+ population is getting older because of progress in treatments. Yet, there are concerns that Older HIV+ individuals (OHIV+) may be more vulnerable for developing a "cortical" dementia such as Alzheimer Disease (AD). Our aim was to explore the hypothesis that the cognitive deficit extends to ''cortical'' functions in OHIV+ by comparing serial position effects (SPE) in different groups of participants affected by "cortical" or "subcortical" damage. We enrolled a total of 122 subjects: 22 OHIV+ (≥60 years of age), 31 Younger HIV+ (YHIV+) (<60 years of age), 18 participants with AD, 23 subjects with Parkinson Disease (PD), and 28 healthy subjects. All subjects performed verbal learning tasks (VLT) to explore SPE. Factorial analysis of covariance showed a significant effect of "group" (p < 0.001) and "task" (Primacy vs Recency) (p < 0.001), but no significant group*task (p = 0.257) interaction. Compared with healthy subjects (p = 0.003), AD had the most severe reduction of Primacy, confirming a primary "encoding deficit," while PD confirmed a "frontal pattern." OHIV+ showed a memory profile similar to that of PD with a worsening of the cognitive performance in comparison with YHIV+. In conclusion, we did not confirm the "cortical" hypothesis in OHIV+, at least in terms of learning and memory functions.

The recency ratio as an index of cognitive performance and decline in elderly individuals

Individuals with Alzheimer's disease have been found to present a typical serial position curve in immediate recall tests, showing poor primacy performance and exaggerated recency recall. However, the recency advantage is usually lost after a delay. On this basis, we examined whether the recency ratio (Rr), calculated by dividing recency performance in an immediate memory task by recency performance in a delayed task, was a useful risk marker of cognitive decline. We tested whether change in Mini-Mental State Examination (MMSE) performance between baseline and follow-up was predicted by baseline Rr and found this to be the case (N = 245). From these analyses, we conclude that participants with high Rr scores, who show disproportionate recency recall in the immediate test compared to the delayed test, present signs of being at risk for cognitive decline or dysfunction.

Serial position effects in patients with mild cognitive impairment and early and moderate Alzheimer's disease compared with healthy comparison subjects

BACKGROUND/AIMS

This study aimed to investigate whether the serial position effects in memory can differentiate patients with different subtypes of mild cognitive impairment (MCI) from healthy controls and patients with different stages of Alzheimer's disease (AD).

METHODS

The serial position effects was tested with the CERAD word list task in 184 persons (39 healthy control subjects, 15 amnestic MCI single domain subjects, 23 amnestic MCI multiple domain subjects, 31 nonamnestic MCI subjects, 45 early or mild AD patients, and 31 moderate AD patients).

RESULTS

With progression of dementia, memory deficits increased and the impairment in the primacy effect during the learning trials advanced, whereas the recall of recent items was less impaired. The serial position profile of nonamnestic MCI patients resembled that of healthy control subjects, whereas amnestic MCI patients showed poorer performance in all 3 positions but no significant difference as a function of serial word position.

CONCLUSION

Analyses of the serial position effect may be a useful complement to clinical neuropsychological measures for distinguishing amnestic MCI patients from normal aging and patients with different stages of dementia.

Memory factors in Rey AVLT: Implications for early staging of cognitive decline

Supraspan verbal list learning is widely used to assess dementia and related cognitive disorders where declarative memory deficits are a major clinical sign. While the overall learning rate is important for diagnosis, serial position patterns may give insight into more specific memory processes in patients with cognitive impairment. This study explored these patterns in a memory clinic clientele. One hundred eighty three participants took the Rey Auditory-Verbal Learning Test (RAVLT). The major groups were patients with Alzheimer's disease (AD), Vascular Dementia (VD), Mild Cognitive Impairment (MCI), and Subjective Cognitive Impairment (SCI) as well as healthy controls (HC). Raw scores for the five trials and five serial partitions were factor analysed. Three memory factors were found and interpreted as Primacy, Recency, and Resistance to Interference. AD and MCI patients had impaired scores in all factors. SCI patients were significantly impaired in the Resistance to Interference factor, and in the Recency factor at the first trial. The main conclusion is that serial position data from word list testing reflect specific memory capacities which vary with levels of cognitive impairment.

Distinct neural systems underlying reduced emotional enhancement for positive and negative stimuli in early Alzheimer's disease

Emotional information is typically better remembered than neutral content, and previous studies suggest that this effect is subserved particularly by the amygdala together with its interactions with the hippocampus. However, it is not known whether amygdala damage affects emotional memory performance at immediate and delayed recall, and whether its involvement is modulated by stimulus valence. Moreover, it is unclear to what extent more distributed neocortical regions involved in e.g., autobiographical memory, also contribute to emotional processing. We investigated these questions in a group of patients with Alzheimer's disease (AD), which affects the amygdala, hippocampus and neocortical regions. Healthy controls (n = 14), patients with AD (n = 15) and its putative prodrome amnestic mild cognitive impairment (n = 11) completed a memory task consisting of immediate and delayed free recall of a list of positive, negative and neutral words. Memory performance was related to brain integrity in region of interest and whole-brain voxel-based morphometry analyses. In the brain-behavioral analyses, the left amygdala volume predicted the immediate recall of both positive and negative material, whereas at delay, left and right amygdala volumes were associated with performance with positive and negative words, respectively. Whole-brain analyses revealed additional associations between left angular gyrus integrity and the immediate recall of positive words as well as between the orbitofrontal cortex and the delayed recall of negative words. These results indicate that emotional memory impairments in AD may be underpinned by damage to regions implicated in emotional processing as well as frontoparietal regions, which may exert their influence via autobiographical memories and organizational strategies.

Serial position effects are sensitive predictors of conversion from MCI to Alzheimer's disease dementia

BACKGROUND

It is unclear whether the predictive strength of established cognitive variables for progression to Alzheimer's disease (AD) dementia from mild cognitive impairment (MCI) varies depending on time to conversion. We investigated which cognitive variables were best predictors, and which of these variables remained predictive for patients with longer times to conversion.

METHODS

Seventy-five participants with MCI were assessed on measures of learning, memory, language, and executive function. Relative predictive strengths of these measures were analyzed using Cox regression models.

RESULTS

Measures of word-list position-namely, serial position scores-together with Short Delay Free Recall of word-list learning best predicted conversion to AD dementia. However, only serial position scores predicted those participants with longer time to conversion.

CONCLUSIONS

Results emphasize that the predictive strength of cognitive variables varies depending on time to conversion to dementia. Moreover, finer measures of learning captured by serial position scores were the most sensitive predictors of AD dementia.

Discrimination of the cognitive profiles of MCI and depression using the KBNA

OBJECTIVE

The current study sought to determine if the Kaplan-Baycrest Neurocognitive Assessment (KBNA) was capable of discriminating individuals with subjective memory complaints associated with depression from individuals with mild cognitive impairment (MCI).

METHODS

Scores on 12 subtests of the KBNA were compared for 27 participants with MCI and 28 participants being treated for depression using Bonferroni correct between-group comparisons for each subtest. KBNA subtest scores were corrected for age and education.

RESULTS

Significant between-group differences were obtained on six subtests with large effect sizes (Cohen's d) ranging from 1.19 - 1.58. The six subtests involved encoding and delayed episodic memory for verbal and visual information. Using logistic regression analysis, five subtests of the KBNA were able to correctly classify 96.4% of study participants.

CONCLUSION

The results from this preliminary investigation indicate that the KBNA has the potential to serve as a brief and reliable assessment tool capable of distinguishing individuals with subjective memory complaints associated with depression from individuals with MCI in a clinical setting. Limitations of the current study and future research are discussed.

Déficits na memória de trabalho em idosos com depressão maior: uma revisão sistemática

A depressão em idosos é associada com prejuízos cognitivos, entretanto a extensão destes à Memória de Trabalho (MT) ainda não é consensual. Portanto, o objetivo deste estudo é revisar sistematicamente as associações encontradas entre MT e depressão em idosos. Para tanto conduzimos uma revisão sistemática dos artigos publicados entre 2000 e 2011 nas principais bases de dados internacionais. Posteriormente a aplicação dos critérios de exclusão, 17 artigos foram revisados integralmente. Os resultados apresentam evidências da associação entre depressão geriátrica e prejuízos da MT, que em alguns trabalhos ainda foram mantidos mesmo após a remissão da sintomatologia de humor.

Decreased recall of primacy words predicts cognitive decline

One of the cognitive changes associated with Alzheimer's disease is a diminution of the primacy effect, i.e., the tendency toward better recall of items studied early on a list compared with the rest. We examined whether learning and recall of primacy words predicted subsequent cognitive decline in 204 elderly subjects who were non-demented and cognitively intact when first examined. Our results show that poorer primacy performance in the Rey Auditory Verbal Learning Test delayed recall trials, but not in immediate recall trials, is an effective predictor of subsequent decline in general cognitive function. This pattern of performance can be interpreted as evidence that failure to consolidate primacy items is a marker of cognitive decline.

Serial position effects in Alzheimer's disease, mild cognitive impairment, and normal aging: predictive value for conversion to dementia

Serial position effects in word list learning have been used to differentiate normal aging and dementia. Prominent recency and diminished primacy have consistently been observed in Alzheimer's disease (AD). We examined serial position effects in patients with mild cognitive impairment (MCI), in patients with AD, and in normal healthy controls. Additionally, we classified MCI patients into those who progressed to AD (MCI-p) and those who did not (MCI-np). We compared two serial position measures: regional and standard scores. Regional scores, mainly the primacy effect, improved discrimination between MCI and controls and between MCI-np and MCI-p, proving to be more sensitive and specific than the recency effect.

Screening for cognitive impairment in late onset depression in a Brazilian sample using the BBRC-Edu

Depression and dementia are the most prevalent neuropsychiatric disorders in the elderly population. Alzheimer's disease is the leading cause of dementia in most countries, being responsible for more than half of all dementia cases. Late-onset depression is a frequent cause of cognitive decline in the elderly. Differentiating between cognitive impairment secondary to depression and incipient dementia poses a challenge in the clinical setting.

Objective

To evaluate the performance of elderly depressed patients using the BBRC-Edu.

Methods

We studied 25 patients with late onset depression (mean age: 73.6 y (6.6); schooling: 9.1 y (5.7)) and 30 patients with mild AD (mean age 76.6 y (5.4); schooling: 7.5 y (7.1)), who were compared to a control group of 30 healthy elderly (mean age 73.8 y (5.8); schooling: 9.1 y (5.4)) using the CERAD and BBRC-Edu batteries.

Results

For the CERAD battery, depressed patients performed better than AD patients on all tasks (p<0.0001) except for Constructional Praxis (p>0.05), and performed poorer than controls on verbal fluency (animals) and Word List Recall tasks (p<0.0001). For the BBRC-Edu, depressed patients performed better than AD patients on all tasks (p<0.0001) except for Digit Span (direct order) (p=0.076) and Incidental Memory (p>0.05), and performed worse than controls on Learning (second presentation) and verbal fluency (fruits) tasks (p<0.0001).

Conclusion

Overall performance on the BBRC-Edu allowed differentiation of controls and depressed patients from AD patients.

Machine learning amplifies the effect of parental family history of Alzheimer's disease on list learning strategy

Identification of preclinical Alzheimer's disease (AD) is an essential first step in developing interventions to prevent or delay disease onset. In this study, we examine the hypothesis that deeper analyses of traditional cognitive tests may be useful in identifying subtle but potentially important learning and memory differences in asymptomatic populations that differ in risk for developing Alzheimer's disease. Subjects included 879 asymptomatic higher-risk persons (middle-aged children of parents with AD) and 355 asymptotic lower-risk persons (middle-aged children of parents without AD). All were administered the Rey Auditory Verbal Learning Test at baseline. Using machine learning approaches, we constructed a new measure that exploited finer differences in memory strategy than previous work focused on serial position and subjective organization. The new measure, based on stochastic gradient descent, provides a greater degree of statistical separation (p = 1.44 × 10-5) than previously observed for asymptomatic family history and non-family history groups, while controlling for apolipoprotein epsilon 4, age, gender, and education level. The results of our machine learning approach support analyzing memory strategy in detail to probe potential disease onset. Such distinct differences may be exploited in asymptomatic middle-aged persons as a potential risk factor for AD.

Comparison of language impairment in late-onset depression and Alzheimer's disease

OBJECTIVES

Depression and dementia are highly prevalent in the elderly. Language impairment is an inherent component of Alzheimer's disease (AD), which can also be encountered in depressed patients. The aim of this study wasto compare the profiles of language abilities in late-onset depression and mild AD groups.

METHODS

We studied 25 patients with late-onset depression (mean age 73.6 ± 6.6 years; schooling 9.1 ± 5.7 years) and 30 patients with mild AD (77.6 ± 5.4 years; 7.5 ± 7.1 years) using the Arizona Battery for Communication Disorders of Dementia (ABCD), compared to a group of 30 controls (73.8 ± 5.8 years; 9.1 ± 5.4 years). Cut-off scores to discriminate between Controls × Depression and Depression × AD were determined.

RESULTS

Depressed patients' scores were similar to AD in confrontation naming, concept definition, following commands, repetition and reading comprehension (sentence). Episodic memory and mental status subtests were useful in differentiating depressed patients from AD, a result that was reproduced when using analysis of covariance to control for the effect of age in the same subtests (p = 0.01 and 0.04, respectively).

CONCLUSION

Language impairment resembling AD was found in the aforementioned language subtests of the ABCD in elderly depressed patients; the mental status and episodic memory subtests were useful to discriminate between AD and depression. The ABCD has proven to be a suitable tool for language evaluation in this population and should aid in the differentiation of AD and pseudodementia (as that of depression).

Getting the hang of it: preferential gist over verbatim story recall and the roles of attentional capacity and the episodic buffer in Alzheimer disease

Story recall in Alzheimer disease (AD) is typically used as a measure of episodic memory, but the degree to which recall is dependent on available attentional resources is not fully understood. The current study investigated how measures of attention were associated to verbatim recall (exact reproduction) or gist recall (relevant semantic meaning). Sixteen participants with AD and 16 age-matched healthy older adults recalled a story on immediate free recall and recognition. Controls recalled more units overall than AD. A group X response interaction revealed more gist than verbatim recall in AD, but those with mild disease generated approximately the same number gist responses as controls. For each group, qualitatively different attentional resources were associated with recall units. In controls, verbatim units correlated positively with primacy serial position items of the California Verbal Learning Test II (CVLTII), suggesting that episodic buffer resources may be associated with story recall. In AD, gist units were positively correlated with digits forward, but inversely related to the CVLTII primacy region items, suggesting reliance on low-level capacity resources. Possible explanations of the impaired performance in AD may be a bias in favor of gist processing, poor verbatim encoding, and/or processing failure at the level of the episodic buffer.

Serial position effects in mild cognitive impairment

Mild cognitive impairment (MCI) is often associated with the preclinical phase of Alzheimer's disease (AD). Special scoring of word-list recall data for serial position has been suggested to improve discrimination of normal aging from dementia. We examined serial position effects in word-list recall for MCI participants compared to Alzheimer patients and controls. Individuals with MCI, like Alzheimer patients, had a diminished primacy effect in recalling words from a list. No alternative scoring system was better than standard scoring of word-list recall in distinguishing MCI patients from controls. Retention weighted scoring improved the discrimination of MCI and AD groups.