Does tip-of-the-tongue for proper names discriminate amnestic mild cognitive impairment?

Associations between recall of proper names in story recall and CSF amyloid and tau in adults without cognitive impairment

Neuropsychological measures sensitive to decline in the preclinical phase of Alzheimer's disease are needed. We previously demonstrated that higher amyloid-beta (Aβ) assessed by positron emission tomography in adults without cognitive impairment was associated with recall of fewer proper names in Logical Memory story recall. The current study investigated the association between proper names and cerebrospinal fluid biomarkers (Aβ42/40, phosphorylated tau181 [pTau181], neurofilament light) in 223 participants from the Wisconsin Registry for Alzheimer's Prevention. We assessed associations between biomarkers and delayed Logical Memory total score and proper names using binary logistic regressions. Sensitivity analyses used multinomial logistic regression and stratified biomarker groups. Lower Logical Memory total score and proper names scores from the most recent visit were associated with biomarker positivity. Relatedly, there was a 27% decreased risk of being classified Aβ42/40+/pTau181+ for each additional proper name recalled. A linear mixed effects model found that longitudinal change in proper names recall was predicted by biomarker status. These results demonstrate a novel relationship between proper names and Alzheimer's disease-cerebrospinal fluid pathology.

Resilience, Psychological Well-Being and Daily Functioning Following Hospitalization for Respiratory Distress Due to SARS-CoV-2 Infection

The ongoing COVID-19 pandemic has affected people's psychological well-being, and hospitalized patients could face an even greater risk of psychological distress. We aimed to study resilience in recovered COVID-19 patients after hospital discharge. We recruited 50 patients (38 males, aged 28-77) who were hospitalized for COVID-19 between March and April 2020. Participants underwent a psychological assessment 5 months after hospital discharge. We administered the Connor-Davidson Resilience Scale (CD-RISC-25), Beck's Depression inventory-II (BDI-II), and the State-Trait Anxiety Inventory Y-form (STAI). We also evaluated the impact of persisting physical, behavioral, and cognitive symptoms on resilience. Patients reported low resilience in the months following hospital discharge (CD-RISC-25 score [mean ± SD] = 55.82 ± 20.76), compared to data from studies on the general population. Lower resilience was associated with mood disturbances in the months following clinical recovery (p = 0.005), persisting fatigue (p = 0.015), sleep changes (p = 0.046), and subjective cognitive complaints (p < 0.05). Recovered COVID-19 patients exhibit low resilience following hospital discharge, which affects psychological well-being. The presence of persisting symptoms following hospital discharge affects psychological resilience. Interventions tailored to increase resilience should be considered to improve quality of life for recovered COVID-19 patients.

Event-related brain potential indexes provide evidence for some decline in healthy people with subjective memory complaints during target evaluation and response inhibition processing

In the preclinical stage of the Alzheimer's disease (AD) continuum, subjects report subjective memory complaints (SMCs), although with the absence of any objective decline, and have a higher risk of progressing to dementia than the general population. Early identification of this stage therefore constitutes a major focus of current AD research, to enable early intervention. In this study, healthy adult participants with high and low SMCs (HSMCs and LSMCs) performed a Go/NoGo task during electroencephalogram (EEG) recording. Relative to LSMC participants, HSMC participants performed the task slower (longer reaction times) and showed changes in the event-related potential (ERP) components associated with response preparation (lower readiness potential -RP- amplitude in the Go condition), and also related to response inhibition processes (lower N2-P3 amplitude in the NoGo condition). In addition, HSMC participants showed lower Go-N2 and NoGo-N2 peak-to-baseline amplitudes, however these results seem to be influenced by a negative tendency overlapping stimulus-related waveforms. The declines observed in this study are mostly consistent with those observed in aMCI participants, supporting the notion of the AD continuum regarding SMC state.

Proper names from story recall are associated with beta-amyloid in cognitively unimpaired adults at risk for Alzheimer's disease

Due to advances in the early detection of Alzheimer's disease (AD) biomarkers including beta-amyloid (Aβ), neuropsychological measures that are sensitive to concurrent, subtle changes in cognition are critically needed. Story recall tasks have shown sensitivity to early memory declines in persons with mild cognitive impairment (MCI) and early stage dementia, as well as in persons with autosomal dominantly inherited AD up to 10 years prior to a dementia diagnosis. However, the evidence is inconclusive regarding relationships between evidence of Aβ and story recall measures. Because story recall tasks require the encoding and delayed retrieval of several lexical-semantic categories, such as proper names, verbs, and numerical expressions, and because lexical categories have been shown to be differentially impaired in persons with MCI, we focused on item-level analyses of lexical-semantic retrieval from a quintessential story recall task, Logical Memory from the Wechsler Memory Scale-Revised. Our objective was to investigate whether delayed recall of lexical categories (proper names, verbs and/or numerical expressions), as well as the traditional total score measure, was associated with "preclinical AD," or cognitively unimpaired adults with positive Aβ deposition on positron emission tomography (PET) neuroimaging using Pittsburgh Compound B (PiB). We developed an item-level scoring system, in which we parsed items into lexical categories and examined the immediate and delayed recall of these lexical categories from 217 cognitively unimpaired participants from the Wisconsin Registry for Alzheimer's Prevention (WRAP). We performed binary logistic regression models with story recall score as predictor and Aβ status (positive/negative) as the outcome. Using baseline Logical Memory data, proper names from delayed story recall were significantly associated with Aβ status, such that participants who recalled more proper names were less likely to be classified as PiB(+) (odds ratio = .58, p = .01). None of the other story recall variables, including total score, were associated with PiB status. Secondary analyses determined that immediate recall of proper names was not significantly associated with Aβ, suggesting a retrieval deficit rather than that of encoding. The present findings suggest that lexical semantic retrieval measures from existing story recall tasks may be sensitive to Aβ deposition, and may provide added utility to a widely-used, long-standing neuropsychological test for early detection of cognitive decline on the AD continuum.

Longitudinal Patterns of the Tip-of-the-Tongue Phenomenon in People With Subjective Cognitive Complaints and Mild Cognitive Impairment

Background

The Tip-of-the-Tongue (ToTs) state is considered a universal phenomenon and is a frequent cognitive complaint in old age. Previous cross-sectional studies have found that ToT measures successfully discriminate between cognitively unimpaired adults and adults with Mild Cognitive Impairment (MCI). The aim of this study was to identify longitudinal patterns of ToTs in individuals with subjective complaints and with MCI regarding progress of their cognitive status.

Method

The study included 193 participants with subjective cognitive complaints (SCC) and 56 participants with MCI who completed a baseline and two follow-up assessments, with an interval of about 18 months between each assessment. Participants were classified into three groups by considering cognitive stability or deterioration from the baseline diagnosis: SCC-stable, MCI-stable and MCI-worsened. Participants performed a ToT task involving recognition and naming of famous people depicted in 50 photographs. Generalized Linear Mixed Models (GLMM) were used to model longitudinal changes in familiarity, feeling of knowing, semantic access, phonological access and verbal fluency.

Results

Phonological access differentiated MCI patients, stable and worsened, from adults with SCCs at all evaluation times. Phonological access declined over time in the three groups, without significant interactions between groups and time.

Discussion

This study provides the first longitudinal evidence of differences in ToT measures for adults with MCI. The findings indicate that phonological access measures successfully differentiated between the diagnostic groups. However, slopes remain irrespective of the diagnostic group and progression toward more advance stages of cognitive impairment.

Autobiographical recall of personally familiar names and temporal information in e-mails: An automatic analytic approach using e-mail communications

An important question that arises from autobiographical memory research is whether the variables that influence memory in the laboratory also drive memory for autobiographical episodes in real life. We explored this question within the context of e-mail communications and investigated the variables that influence recall for personally familiar names and temporal information in e-mails. We designed a Web-based program that analyzed each participant's year-old sent e-mail archive and applied textual analysis algorithms to identify a set of sentences likely to be memorable. These sentences were then used as the stimuli in a cued recall task. Participants saw two sentences from their sent e-mail as a cue and attempted to recall the name of the e-mail recipient. Participants also rated the vividness of recall for the e-mail conversation and estimated the month in which they had written the e-mail. Linear mixed-effect analyses revealed that recipient name recall accuracy decreased with longer retention intervals and increased with greater frequency of contact with the recipient. Also, with longer retention intervals, participants dated e-mails as being more recent than their actual month. This telescoping error was moderately larger for e-mails with greater sentiment. These findings suggest that memory for personally familiar names and temporal information in e-mails closely follows the patterns for autobiographical memory and proper-name recall found in laboratory settings. This study introduces an innovative, Web-based experimental method for studying the cognitive processes related to autobiographical memories using ecologically valid, naturalistic communications.

The importance of age in the search for ERP biomarkers of aMCI

Alzheimer's Disease (AD) has become a major health issue in recent decades, and there is now growing interest in amnestic mild cognitive impairment (aMCI), an intermediate stage between healthy aging and dementia, usually AD. Event-related brain potential (ERP) studies have sometimes failed to detect differences between aMCI and control participants in the Go-P3 (or P3b, related to target classification processes in a variety of tasks) and NoGo-P3 (related to response inhibition processes, mainly in Go/NoGo tasks) ERP components. The aim of the present study was to evaluate whether the age factor, which is not usually taken into account in ERP studies, modulates group differences in these components. With this aim, we divided two groups of volunteer participants, 34 subjects with aMCI (51-87 years) and 31 controls (52-86 years), into two age subgroups: 69 years or less and 70 years or more. We recorded brain activity while the participants performed a distraction-attention auditory-visual (AV) task. Task performance was poorer in the older than in the younger group, and aMCI participants produced fewer correct responses than the matched controls; but no interactions of the age and group factors on performance were found. On the other hand, Go-P3 and NoGo-N2 latencies were longer in aMCI participants than in controls only in the younger subgroup. Thus, the younger aMCI participants categorized the Go stimuli in working memory and processed the NoGo stimuli (which required response inhibition) slower than the corresponding controls. Finally, the combination of the number of hits, Go-P3 latency and NoGo-N2 latency yielded acceptable sensitivity and specificity scores (0.70 and 0.92, respectively) as regards distinguishing aMCI participants aged 69 years or less from the age-matched controls. The findings indicate age should be taken into account in the search for aMCI biomarkers.

Neurocognitive and Behavioral Indexes for Identifying the Amnestic Subtypes of Mild Cognitive Impairment

Early identification of amnestic mild cognitive impairment (aMCI) subtypes is important for early diagnosis and prognosis of Alzheimer’s disease. Healthy, single-domain (sdaMCI) and multiple-domain aMCI (mdaMCI) participants performed an auditory-visual distraction-attention task. Event-related brain potentials (ERPs) were recorded while the participants performed the task to evaluate Go/NoGo N2 and P3 ERP components. The results showed the expected behavioral and cognitive decline in mdaMCI participants relative to controls (fewer hits, longer reaction times [RTs], slightly smaller Go-N2 and NoGo-N2 amplitudes), while sdaMCI participants showed some decline (slightly longer RTs, smaller Go- and NoGo-N2 amplitudes) along with some unexpected results (a late positive slow wave, PSW) and good levels of execution. In addition, some of these parameters proved to be useful markers. Thus, the number of hits was the best marker for diagnosing mdaMCI participants (distinguishing them from controls, from sdaMCI participants, and from both groups together), while the PSW amplitude was the best marker for diagnosing sdaMCI participants (distinguishing them from controls, and from control & mdaMCI participants).

Increased Amplitude of the P3a ERP Component as a Neurocognitive Marker for Differentiating Amnestic Subtypes of Mild Cognitive Impairment

The event-related potential (ERP) technique has been shown to be useful for evaluating changes in brain electrical activity associated with different cognitive processes, particularly in Alzheimer's disease (AD). Longitudinal studies have shown that a high proportion of people with amnestic mild cognitive impairment (aMCI) go on to develop AD. aMCI is divided into two subtypes according to the presence of memory impairment only (single-domain aMCI: sdaMCI) or impairment of memory and other cognitive domains (multi-domain aMCI: mdaMCI). The main aim of this study was to examine the effects of sdaMCI and mdaMCI on the P3a ERP component associated with the involuntary orientation of attention toward unattended infrequent novel auditory stimuli. Participants performed an auditory-visual distraction-attention task, in which they were asked to ignore the auditory stimuli (standard, deviant, and novel) and to attend to the visual stimuli (responding to some of them: Go stimuli). P3a was identified in the Novel minus Standard difference waveforms, and reaction times (RTs) and hits (in response to Go stimuli) were also analyzed. Participants were classified into three groups: Control, 20 adults (mean age (M): 65.8 years); sdaMCI, 19 adults (M: 67 years); and mdaMCI, 11 adults (M: 71 years). In all groups, the RTs were significantly longer when Go stimuli were preceded by novel (relative to standard) auditory stimuli, suggesting a distraction effect triggered by novel stimuli; mdaMCI participants made significantly fewer hits than control and sdaMCI participants. P3a comprised two consecutive phases in all groups: early-P3a (e-P3a), which may reflect the orienting response toward the irrelevant stimuli, and late-P3a (l-P3a), which may be a correlate of subsequent evaluation of these stimuli. The e-P3a amplitude was significantly larger in mdaMCI than in sdaMCI participants, and the l-P3a amplitude was significantly larger in mdaMCI than in sdaMCI and Control participants, indicating greater involuntary capture of attention to unattended novel auditory stimuli and allocation of more attentional resources for the subsequent evaluation of these stimuli in mdaMCI participants. The e-P3a and l-P3a components showed moderate to high sensitivity and specificity for distinguishing between groups, suggesting that both may represent optimal neurocognitive markers for differentiating aMCI subtypes.

Standardization, Clinical Validation, and Typicality Norms of a New Test Assessing Semantic Verbal Fluency

OBJECTIVE

Semantic verbal fluency (SVF) tests are widely used in clinical neuropsychology. We propose the standardization and clinical validation of a new SVF test based on the production of names of birds and articles of furniture (Birds and Articles of Furniture test-BAF).

METHODS

A sample of 268 subjects aged 40 years or more underwent the test. The clinical validation was conducted on subjects affected by amnesic Mild Cognitive Impairment (aMCI; N = 106), mild (N = 178), and moderate (N = 114) Alzheimer's disease (AD).

RESULTS

The BAF total score was influenced by both age and education, whereas the single scores obtained on BAF were also influenced by gender. The percentage of subjects with pathological score on BAF increased from aMCI (19%) to mild (45.5%) and moderate (71.1%) AD, and receiver operating characteristic curves analysis showed that the BAF may be highly reliable in distinguishing aMCI and AD patients from healthy subjects. We also provide typicality norms for birds and articles of furniture that could be useful in the assessment of qualitative features of words produced in semantic fluency tests.

CONCLUSIONS

The BAF test could be a valid and reliable tool in both clinical practice and research on subjects affected by cognitive impairment.

Temporal changes in semantic and lexical access related to mild cognitive impairment

BACKGROUND

It has been hypothesized that the deterioration in the ability to name famous people in normal aging and cognitive impairment is a continuum in which meaning-based representations and form-based representations are differentially impaired, with early impairments in lexical access but not in semantic access.

AIMS

This hypothesis is tested in a follow-up study comparing the performance of fifty-six participants with amnestic mild cognitive impairment and forty-one control participants were assessed.

METHOD

A lexical task was conducted involving recognition and naming of famous people from photographs. Proportional semantic and phonological access measures were calculated.

RESULTS

Comparisons revealed significant differences between baseline and follow-up, with improvements in semantic access in the control group and decrements in phonological access in the group with amnestic mild cognitive impairment. Phonological access and reaction time measures were significantly and positively correlated, and semantic access and reaction time were significantly and negatively correlated.

CONCLUSIONS

These results add evidence to the hypothesis that the decrease of processing resources is related to the increase of difficulties in lexical access throughout aging. Patterns of change must be replicated over longer periods of time.

Prevalence of Cognitive Impairment in Recently Diagnosed Type 2 Diabetes Patients: Are Chronic Inflammatory Diseases Responsible for Cognitive Decline?

OBJECTIVE

To estimate the prevalence of cognitive impairment (CI) among patients recently diagnosed with type 2 diabetes (RDD) and to identify any relationships between CI and RDD comorbidities.

METHODS

One thousand seven hundred twelve patients with RDD participated in a cross-sectional study. The patients' sociodemographic and clinical data were registered.

RESULTS

The sample population had an average age of 51 ± 11 years, and 63.26% of the patients were female. CI was diagnosed in 38 patients (2.2%) and was more common among both females (2.8% vs. 1.3%, p = 0.063) and the elderly (0% at an age ≤ 30 years vs. 10.4% at an age > 70 years, p = 0.0001). Rheumatoid arthritis (present in 15.8% vs. absent in 2.1%) and asthma (13% vs. 2.1%) correlated significantly with CI based on the results of our logistic regression analysis.

CONCLUSION

Age, female gender, rheumatoid arthritis and asthma are risk factors for CI in the setting of RDD.

Inhibition deficit in the spatial tendency of the response in multiple-domain amnestic mild cognitive impairment. An event-related potential study

Longitudinal studies have shown that a high percentage of people with amnestic mild cognitive impairment (MCI) develop Alzheimer’s disease (AD). Prodromal AD is known to involve deficits in executive control processes. In the present study, we examined such deficits by recording EEG in 13 single-domain amnestic MCI (sdaMCI), 12 multiple-domain amnestic MCI (mdaMCI) and 18 healthy elderly (control group, CG) participants while they performed a Simon task. The Simon task demands deployment of executive processes because participants have to respond to non-spatial features of a lateralized stimulus and inhibit the more automatic spatial tendency of the response. We specifically focused on the negativity central contralateral (N2cc), an event-related potential (ERP) component related to brain activity that prevents the cross-talk between direction of spatial attention and manual response preparation. The reaction time (RT) was not significantly different among the three groups of participants. The percentage of errors (PE) was higher in mdaMCI than in CG and sdaMCI participants. In addition, N2cc latency was delayed in mdaMCI (i.e., delayed implementation of mechanisms for controlling the spatial tendency of the response). The N2cc latency clearly distinguished among mdaMCI and CG/sdaMCI participants (area under curve: 0.91). Longer N2cc was therefore associated with executive control deficits, which suggests that N2cc latency is a correlate of mdaMCI.

Electro-cortical manifestations of common vs. proper name processing during reading

The main purpose of the present study was to investigate how proper and common nouns are represented in the brain independent of memory retrieval processes. Participants were instructed to perform a lexical decision task while dense-array EEG was continuously recorded. Both ERP components (namely N400 and P300) and swLORETA suggested that proper name processing engaged a more widespread neural network and required more cognitive resources than common noun processing. Overall, our results come down in favor of the hypothesis that specific effects of proper vs. common noun processing exist, and they suggest a possible neuro-functional segregation of proper vs. common noun processing. The difference in proper and common noun processing seems to emerge at the level of storage or representation of lexical knowledge, and it may crucially depend on their semantic characteristics.

Electrophysiological correlates of amnestic mild cognitive impairment in a simon task

Amnestic mild cognitive impairment (aMCI) represents a prodromal stage of Alzheimer`s disease (AD), especially when additional cognitive domains are affected (Petersen et al., 2009). Thus, single-domain amnestic MCI (sdaMCI) and multiple-domain-amnestic MCI (mdaMCI) biomarkers are important for enabling early interventions to help slow down progression of the disease. Recording event-related potentials (ERPs) is a non-invasive and inexpensive measure of brain activity associated with cognitive processes, and it is of interest from a clinical point of view. The ERP technique may also be useful for obtaining early sdaMCI and mdaMCI biomarkers because ERPs are sensitive to impairment in processes that are not manifested at behavioral or clinical levels. In the present study, EEG activity was recorded in 25 healthy participants and 30 amnestic MCI patients (17 sdaMCI and 13 mdaMCI) while they performed a Simon task. The ERPs associated with visuospatial (N2 posterior-contralateral - N2pc -) and motor (lateralized readiness potential - LRP -) processes were examined. The N2pc amplitude was smaller in participants with mdaMCI than in healthy participants, which indicated a decline in the correlates of allocation of attentional resources to the target stimulus. In addition, N2pc amplitude proved to be a moderately good biomarker of mdaMCI subtype (0.77 sensitivity, 0.76 specificity). However, the LRP amplitude was smaller in the two MCI groups (sdaMCI and mdaMCI) than in healthy participants, revealing a reduction in the motor resources available to execute the response in sdaMCI and mdaMCI patients. Furthermore, the LRP amplitude proved to be a valid biomarker (0.80 sensitivity, 0.92 specificity) of both amnestic MCI subtypes.

Mismatch negativity (MMN) amplitude as a biomarker of sensory memory deficit in amnestic mild cognitive impairment

It has been suggested that changes in some event-related potential (ERP) parameters associated with controlled processing of stimuli could be used as biomarkers of amnestic mild cognitive impairment (aMCI). However, data regarding the suitability of ERP components associated with automatic and involuntary processing of stimuli for this purpose are not conclusive. In the present study, we studied the Mismatch Negativity (MMN) component, a correlate of the automatic detection of changes in the acoustic environment, in healthy adults and adults with aMCI (age range: 50-87 years). An auditory-visual attention-distraction task, in two evaluations separated by an interval of between 18 and 24 months, was used. In both evaluations, the MMN amplitude was significantly smaller in the aMCI adults than in the control adults. In the first evaluation, such differences were observed for the subgroup of adults between 50 and 64 years of age, but not for the subgroup of 65 years and over. In the aMCI adults, the MMN amplitude was significantly smaller in the second evaluation than in the first evaluation, but no significant changes were observed in the control adult group. The MMN amplitude was found to be a sensitive and specific biomarker of aMCI, in both the first and second evaluation.