The Quebec Semantic Memory Battery: Development, Standardization, and Psychometric Assessment of a Semantic Memory Battery in French.

OBJECTIVE: People with aphasia often experience semantic memory (SM) impairment. To improve diagnostic outcomes, SM tasks should recruit various sensory input channels (oral, written, and pictographic), permitting accessible, complete evaluation. There is a need for SM batteries for French-speaking Quebecers that use multiple input channels. The present study, therefore, describes the development of a novel French-language semantic battery: la Batterie québécoise de la mémoire sémantique (BQMS), the assessment of the BQMS's psychometric properties, and the establishment of normative data for the BQMS. METHOD: We first developed eight SM tasks. Following a pilot validation study, we determined the BQMS's reliability and validity, to ensure consistent, accurate detection of SM impairment. Among French-speaking Quebecers with cerebrovascular aphasia (n = 10), people with the semantic variant of Primary Progressive Aphasia (n = 4), and healthy controls (n = 14), we examined its convergent validity, concurrent validity, test-retest reliability, and internal consistency. Finally, we established normative data for the BQMS by calculating cut-off scores per task that indicate SM impairment (in 93 cognitively healthy French-speaking Quebecers), stratified by sociodemographic variables associated with performance. RESULTS: The BQMS shows high concurrent, discriminant, and convergent validity, as well as good test-retest reliability and internal consistency. The cut-off score indicating SM impairment ranged from the 2nd to 25th percentiles (stratified by task, age, and sex). CONCLUSIONS: The BQMS's psychometric properties indicate that it could be a valuable clinical tool for detecting SM impairment. Our normative data will help clinicians detect such impairments.

An event-related potential investigation of the influence of bilingualism on disambiguating homonyms in older adults.

Ambiguity is ubiquitous in language; lexical ambiguity refers to instances where a single word has multiple meanings. The current investigation examined homonyms, words that have the same orthography and pronunciation in English but multiple meanings (e.g., BANK, meaning "financial institution" or "river's edge"). The processing of homonyms requires the engagement of executive control processes, for example, to select the appropriate meaning of the homonym while reducing interference from other meanings. Executive function processes are known to change over the lifespan and may be impacted by experiential factors such as bilingualism. The present study uses event-related brain potentials as an index of lexical access to examine whether bilingualism influences homonym processing in older adults. The results indicate that patterns of lexical access differ as a function of bilingual status in older adults and compared to young adults, suggesting that language experience may moderate language processing in both young and older adults, at least in situations where language processing is demanding on executive function, such as in the processing of homonyms. Importantly, we show that older bilinguals show a somewhat similar pattern of ambiguity processing as their younger counterparts, while age differences were observed in monolinguals when comparing across studies. This suggests that bilingual language experience may have a mitigating impact on age-related changes in ambiguity processing. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Potentially Modifiable Risk Factors for Dementia and Mild Cognitive Impairment: An Umbrella Review and Meta-Analysis.

INTRODUCTION: The prevalence of mild and major neurocognitive disorders (NCDs), also referred to as mild cognitive impairment and dementia, is rising globally. The prevention of NCDs is a major global public health interest. We sought to synthesize the literature on potentially modifiable risk factors for NCDs. METHODS: We conducted an umbrella review using a systematic search across multiple databases to identify relevant systematic reviews and meta-analyses. Eligible reviews examined potentially modifiable risk factors for mild or major NCDs. We used a random-effects multi-level meta-analytic approach to synthesize risk ratios for each risk factor while accounting for overlap in the reviews. We further examined risk factors for major NCD due to two common etiologies: Alzheimer's disease and vascular dementia. RESULTS: A total of 45 reviews with 212 meta-analyses were synthesized. We identified fourteen broadly defined modifiable risk factors that were significantly associated with these disorders: alcohol consumption, body weight, depression, diabetes mellitus, diet, hypertension, less education, physical inactivity, sensory loss, sleep disturbance, smoking, social isolation, traumatic brain injury, and vitamin D deficiency. All 14 factors were associated with the risk of major NCD, and five were associated with mild NCD. We found considerably less research for vascular dementia and mild NCD. CONCLUSION: Our review quantifies the risk associated with 14 potentially modifiable risk factors for mild and major NCDs, including several factors infrequently included in dementia action plans. Prevention strategies should consider approaches that reduce the incidence and severity of these risk factors through health promotion, identification, and early management.

Protocol for validating an algorithm to identify neurocognitive disorders in Canadian Longitudinal Study on Aging participants: an observational study.

INTRODUCTION: In population-based research, disease ascertainment algorithms can be as accurate as, and less costly than, performing supplementary clinical examinations on selected participants to confirm a diagnosis of a neurocognitive disorder (NCD), but they require cohort-specific validation. To optimise the use of the Canadian Longitudinal Study on Aging (CLSA) to understand the epidemiology and burden of NCDs, the CLSA Memory Study will validate an NCD ascertainment algorithm to identify CLSA participants with these disorders using routinely acquired study data. METHODS AND ANALYSIS: Up to 600 CLSA participants with equal numbers of those likely to have no NCD, mild NCD or major NCD based on prior self-reported physician diagnosis of a memory problem or dementia, medication consumption (ie, cholinesterase inhibitors, memantine) and/or self-reported function will be recruited during the follow-up 3 CLSA evaluations (started August 2021). Participants will undergo an assessment by a study clinician who will also review an informant interview and make a preliminary determination of the presence or absence of an NCD. The clinical assessment and available CLSA data will be reviewed by a Central Review Panel who will make a final categorisation of participants as having (1) no NCD, (2) mild NCD or, (3) major NCD (according to fifth version of the Diagnostic and Statistical Manual of Mental Disorders criteria). These will be used as our gold standard diagnosis to determine if the NCD ascertainment algorithm accurately identifies CLSA participants with an NCD. Weighted Kappa statistics will be the primary measure of agreement. Sensitivity, specificity, the C-statistic and the phi coefficient will also be estimated. ETHICS AND DISSEMINATION: Ethics approval has been received from the institutional research ethics boards for each CLSA Data Collection Site (Université de Sherbrooke, Hamilton Integrated Research Ethics Board, Dalhousie University, Nova Scotia Health Research Ethics Board, University of Manitoba, McGill University, McGill University Health Centre Research Institute, Memorial University of Newfoundland, University of Victoria, Élisabeth Bruyère Research Institute of Ottawa, University of British Columbia, Island Health (Formerly the Vancouver Island Health Authority, Simon Fraser University, Calgary Conjoint Health Research Ethics Board).The results of this work will be disseminated to public health professionals, researchers, health professionals, administrators and policy-makers through journal publications, conference presentations, publicly available reports and presentations to stakeholder groups.

Cognitive impairment indicator for the neuropsychological test batteries in the Canadian Longitudinal Study on Aging: definition and evidence for validity.

BACKGROUND: Prevalence of overall cognitive impairment based on each participant's performance across a neuropsychological battery is challenging; consequently, we define and validate a dichotomous cognitive impairment/no cognitive indicator (CII) using a neuropsychological battery administered in a population-based study. This CII approximates the clinical practice of interpretation across a neuropsychological battery and can be applied to any neuropsychological dataset. METHODS: Using data from participants aged 45-85 in the Canadian Longitudinal Study on Aging receiving a telephone-administered neuropsychological battery (Tracking, N = 21,241) or a longer in-person battery (Comprehensive, N = 30,097), impairment was determined for each neuropsychological test based on comparison with normative data. We adjusted for the joint probability of abnormally low scores on multiple neuropsychological tests using baserates of low scores demonstrated in the normative samples and created a dichotomous CII (i.e., cognitive impairment vs no cognitive impairment). Convergent and discriminant validity of the CII were assessed with logistic regression analyses. RESULTS: Using the CII, the prevalence of cognitive impairment was 4.3% in the Tracking and 5.0% in the Comprehensive cohorts. The CII demonstrated strong convergent and discriminant validity. CONCLUSIONS: The approach for the CII is a feasible method to identify participants who demonstrate cognitive impairment on a battery of tests. These methods can be applied in other epidemiological studies that use neuropsychological batteries.

Linking self-perceived cognitive functioning questionnaires using item response theory: The subjective cognitive decline initiative.

OBJECTIVE: Self-perceived cognitive functioning, considered highly relevant in the context of aging and dementia, is assessed in numerous ways-hindering the comparison of findings across studies and settings. Therefore, the present study aimed to link item-level self-report questionnaire data from international aging studies. METHOD: We harmonized secondary data from 24 studies and 40 different questionnaires with item response theory (IRT) techniques using a graded response model with a Bayesian estimator. We compared item information curves to identify items with high measurement precision at different levels of the self-perceived cognitive functioning latent trait. Data from 53,030 neuropsychologically intact older adults were included, from 13 English language and 11 non-English (or mixed) language studies. RESULTS: We successfully linked all questionnaires and demonstrated that a single-factor structure was reasonable for the latent trait. Items that made the greatest contribution to measurement precision (i.e., "top items") assessed general and specific memory problems and aspects of executive functioning, attention, language, calculation, and visuospatial skills. These top items originated from distinct questionnaires and varied in format, range, time frames, response options, and whether they captured ability and/or change. CONCLUSIONS: This was the first study to calibrate self-perceived cognitive functioning data of geographically diverse older adults. The resulting item scores are on the same metric, facilitating joint or pooled analyses across international studies. Results may lead to the development of new self-perceived cognitive functioning questionnaires guided by psychometric properties, content, and other important features of items in our item bank. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Contextual dynamics in lexical encoding across the ageing spectrum: A simulation study.

The field of psycholinguistics has recently questioned the primacy of word frequency (WF) in influencing word recognition and production, instead focusing on the importance of a word's contextual diversity (CD). WF is operationalised by counting the number of occurrences of a word in a corpus, while a word's CD is a count of the number of contexts that a word occurs in, with repetitions within a context being ignored. Numerous studies have converged on the conclusion that CD is a better predictor of word recognition latency and accuracy than frequency. These findings support a cognitive mechanism based on the principle of likely need over the principle of repetition in lexical organisation. In the current study, we trained the semantic distinctiveness model on communication patterns in social media platforms consisting of over 55-billion-word tokens and examined the ability of theoretically distinct models to explain word recognition latency and accuracy data from over 1 million participants from the Mandera et al. English Crowdsourding Project norms, consisting of approximately 59,000 words across six age bands ranging from ages 10 to 60 years. There was a clear quantitative trend across the age bands, where there is a shift from a social environment-based attention mechanism in the "younger" models, to a clear dominance for a discourse-based attention mechanism as models "aged." This pattern suggests that there is a dynamical interaction between the cognitive mechanisms of lexical organisation and environmental information that emerges across ageing.

Biopsychosocial Correlates of Subjective Cognitive Decline and Related Worry in the Canadian Longitudinal Study on Aging.

INTRODUCTION: Subjective cognitive decline (SCD), a self-reported decline in cognition in otherwise cognitively healthy people, has been acknowledged as a risk factor for Alzheimer's disease. Using data from the Canadian Longitudinal Study on Aging (CLSA), a large national study with participants' ages of 45-85 years at baseline, we sought to identify correlates of SCD and SCD-related worry. METHODS: In our primary analysis using a Poisson regression model, associations between biopsychosocial variables and SCD were identified (analytic sample: n = 21,920). In a second analysis using an ordinal regression model, associations between biopsychosocial variables and SCD-related worry were identified (analytic sample: n = 12,694). RESULTS: Multiple risk and protective factors of cognitive decline were not associated with SCD within our sample (i.e., physical activity, hypertension, vision problems), as well as minority stress variables such as sexual orientation and race. Rather, psychosocial variables (i.e., depression, perceived social status, and personality traits) showed a more consistent association with SCD within the sample. Greater SCD-related worry, which is believed to increase the risk of future dementia, was associated with specific personality traits, depression, age, gender, and sexuality. CONCLUSION: The results from this study confirm the association between multiple health variables and SCD but also emphasize the importance of considering psychological and social factors when conceptualizing SCD and its risk factors.

Using big data to understand bilingual performance in semantic fluency: Findings from the Canadian Longitudinal Study on Aging.

OBJECTIVES: This study aimed to characterize verbal fluency performance in monolinguals and bilinguals using data from the Canadian Longitudinal Study on Aging (CLSA). METHODS: A large sample of adults aged 45-85 (n = 12,875) completed a one-minute animal fluency task in English. Participants were English-speaking monolinguals (n = 9,759), bilinguals who spoke English as their first language (L1 bilinguals, n = 1,836), and bilinguals who spoke English as their second language (L2 bilinguals, n = 1,280). Using a distributional modeling approach to quantify the semantic similarity of words, we examined the impact of word frequency and pairwise semantic similarity on performance on this task. RESULTS: Overall, L1 bilinguals outperformed monolinguals on the verbal fluency task: they produced more items, and these items were of lower average frequency and semantic similarity. Monolinguals in turn outperformed L2 bilinguals on these measures. The results held across different age groups, educational, and income levels. DISCUSSION: These results demonstrate an advantage for bilinguals compared to monolinguals on a category fluency task, when performed in the first language, indicating that, at least in the CLSA sample, bilinguals have superior semantic search capabilities in their first language compared to monolingual speakers of that language.

Assessment of semantic memory in mild cognitive impairment: The psychometric properties of a novel semantic battery.

Semantic memory is stable in healthy older adults but shows decline in mild cognitive impairment (MCI). Current measures of semantic function do not assess multiple aspects of semantic function and/or are time-consuming to administer. Here we report the psychometric properties of a battery to detect semantic impairment that we recently developed and published. Study 1 determined the face validity of the battery; interviews were conducted with five professionals with expertise in MCI and language. Face validity interviews suggested the battery appropriately assesses semantic impairments. Study 2 assessed convergent validity and reliability (inter-rater reliability, test-retest reliability, and internal consistency). Participants included 102 healthy older adults and 60 people with MCI who completed a four-task semantic battery. Results demonstrate that performance on the semantic battery correlates with traditional measures of semantic function, inter-rater reliability and internal consistency was high, and there was no significant change in mean scores between participants' first and second testing sessions. The present findings suggest that the semantic battery is a reliable and valid assessment of semantic function. It is currently recommended for research use only.

Methodological considerations when establishing reliable and valid normative data: Canadian Longitudinal Study on Aging (CLSA) neuropsychological battery.

Objective: Creation of normative data with regression corrections for demographic covariates reduces risk of small cell sizes compared with traditional normative approaches. We explored whether methods of correcting for demographic covariates (e.g., full regression models versus hybrid models with stratification and regression) and choice of covariates (i.e., correcting for age with or without sex and/or education correction) impacted reliability and validity of normative data. Method: Measurement invariance for sex and education was explored in a brief telephone-administered cognitive battery from the Canadian Longitudinal Study on Aging (CLSA; after excluding persons with neurological conditions N = 12,350 responded in English and N = 1,760 in French). Results: Measurement invariance was supported in hybrid normative models where different age-based regression models were created for groups based on sex and education level. Measurement invariance was not supported in full regression models where age, sex, and education were simultaneous predictors. Evidence for reliability was demonstrated by precision defined as the 95% inter-percentile range of the 5th percentile. Precision was higher for full regression models than for hybrid models but with negligible differences in precision for the larger English sample. Conclusions: We present normative data for a remotely administered brief neuropsychological battery that best mitigates measurement bias and are precise. In the smaller French speaking sample, only one model reduced measurement bias, but its estimates were less precise, underscoring the need for large sample sizes when creating normative data. The resulting normative data are appended in a syntax file.

Effects of the Duration of a Resting-State EEG Recording in Healthy Aging and Mild Cognitive Impairment.

INTRODUCTION: The recording of resting-state EEG may provide a means to predict early cognitive decline associated with mild cognitive impairment (MCI). Previous studies have typically used very short recording times to avoid a confound with drowsiness that may occur in longer recordings. The effects of a longer recording have not however been systematically examined. METHODS: Eyes-closed resting-state EEG activity was recorded in 40 older adult participants (20 healthy older adults and 20 people with MCI). The recording period was a relatively long 6 minutes, divided into two equal 3-minute halves to determine if drowsiness will be more apparent as the recording progresses. The participants also completed standardized neuropsychological tasks that assessed global cognition (Montreal Cognitive Assessment) and memory (California Verbal Learning Test, Second Edition). A spectral analysis was performed on both short (2 seconds) and long (8 seconds) segments in both 3-minute halves. RESULTS: No differences in power density for any of the EEG frequency bands were found between the 2 halves of the study for either group. There was little evidence of increased drowsiness in the second half of the study even when frequency resolution was increased with the 8-second segmentation. Theta power density was overall larger for people with MCI compared to healthy older adults. A negative correlation was also observed between theta power and global cognition in healthy older adults. CONCLUSIONS: The present results indicate that longer resting-state EEG recording can be reliably employed without increased risk of drowsiness.

Event-Related Potential Measures of the Passive Processing of Rapidly and Slowly Presented Auditory Stimuli in MCI.

Much research effort is currently devoted to the development of a simple, low-cost method to determine early signs of Alzheimer's disease (AD) pathology. The present study employs a simple paradigm in which event-related potentials (ERPs) were recorded to a single auditory stimulus that was presented rapidly or very slowly while the participant was engaged in a visual task. A multi-channel EEG was recorded in 20 healthy older adults and 20 people with mild cognitive impairment (MCI). In two different conditions, a single 80 dB sound pressure level (SPL) auditory stimulus was presented every 1.5 s (fast condition) or every 12.0 s (slow condition). Participants were instructed to watch a silent video and ignore the auditory stimuli. Auditory processing thus occurred passively. When the auditory stimuli were presented rapidly (every 1.5 s), N1 and P2 amplitudes did not differ between the two groups. When the stimuli were presented very slowly, the amplitude of N1 and P2 increased in both groups and their latencies were prolonged. The amplitude of N1 did not significantly differ between the two groups. However, the subsequent positivity was reduced in people with MCI compared to healthy older adults. This late positivity in the slow condition may reflect a delayed P2 or a summation of a composite P2 + P3a. In people with MCI, the priority of processing may not be switched from the visual task to the potentially much more relevant auditory input. ERPs offer promise as a means to identify the pathology underlying cognitive impairment associated with MCI.

Event-related potential evidence that very slowly presented auditory stimuli are passively processed differently in younger and older adults.

The occurrence of a very infrequent and unattended auditory stimulus is highly salient and may result in an interruption of the frontoparietal network controlling processing priorities. Research has suggested that older adults may be unable to compute the level of salience of unattended stimulus inputs. A multi-channel EEG was recorded in 20 younger adults and 20 older adults. In different conditions, a single 80 dB SPL auditory stimulus was presented relatively rapidly, every 1.5 s or very slowly, every 12.0 s. Participants ignored the auditory stimuli while watching a silent video. When the stimuli were presented rapidly, group differences were not observed for the amplitudes of N1 and P2, which peaked at 100 and 180 ms respectively. When stimuli were presented very slowly, their amplitudes were much enhanced for younger adults, but did not increase for older adults. The failure to observe a large increase in the amplitude of N1 and P2 in older adults for very slowly presented auditory stimuli provides strong evidence of a dysfunction of the salience network in this group.

Social support, neurocognition, and posttraumatic stress disorder: Findings from the Canadian Longitudinal Study on Aging.

OBJECTIVE: Most research investigating neurocognitive changes in participants with PTSD has focused on young adults. Numerous studies have recognized the crucial role of social support in diminishing the likelihood of developing PTSD. The current study evaluates the cognitive performance of middle-aged and older adults with symptoms of PTSD, and examines if perceived social support can act as a cognitive reserve factor. METHOD: The study was conducted using data from the Canadian Longitudinal Study on Aging, a nationwide study on health and aging. The current study included 1,096 participants in the PTSD group and 22,158 participants in the comparison group, all between the ages of 45 and 85. Participants completed the MOS (Medical Outcomes Study) Social Support Survey as well as neuropsychological tests in the domains of executive functioning, declarative memory, and prospective memory. RESULTS: The PTSD group had worse performance in the domains of executive functioning and prospective memory than the comparison group. Furthermore, when examining global cognitive impairments (impairment was defined as scoring 1.5 or more standard deviations below age and education adjusted comparison group), the PTSD group demonstrated greater impairment rates than the comparison group on two or more tests. Moderation analyses revealed that greater social support was associated with better executive functioning for the comparison group, although this was not found to be true for the PTSD group. CONCLUSION: The PTSD group experienced greater cognitive deficits compared to the comparison group. Higher levels of perceived social support were associated with better performance on neurocognitive measures for the comparison group. However, social support did not appear to moderate this relationship for the PTSD group.

A discourse-theoretic approach to story recall in aging and mild cognitive impairment.

Recall of story materials is a primary way to assess episodic memory. However, the standard scoring method may not be maximally sensitive to cognitive decline. We developed a set of 24 stories, and younger and older adults heard these stories and recalled them immediately and after a delay (Study 1). Twelve of these stories were then selected, and older adults and people with MCI completed immediate and delayed recall of these stories (Study 2). Responses were classified as veridical, gist, or distorted, and were scored by number of units and number of propositions recalled. Younger adults had higher veridical recall than older adults, and proposition-based scoring revealed higher gist recall in older than younger adults. Gist and distortion recall increased over time in older adults, but decreased in MCI. Using proposition-based scoring and distinguishing between veridical and gist responses may discriminate better between healthy older adults and people with MCI.

Social Support Buffers Against Cognitive Decline in Single Mild Traumatic Brain Injury With Loss of Consciousness: Results From the Canadian Longitudinal Study on Aging.

OBJECTIVES: We investigated rates of cognitive decline at 3-year follow-up from initial examination in people reporting mild traumatic brain injury (mTBI) with loss of consciousness (LOC) more than a year prior to initial examination. We examined the role of social support as predictor of preserved cognitive function in this sample. METHOD: Analyses were conducted on 440 participants who had self-reported LOC of <1 min, 350 with LOC of 1-20 min, and 10,712 healthy controls, taken from the Canadian Longitudinal Study on Aging (CLSA), a nationwide study on health and aging. RESULTS: People who reported at baseline that they had experienced mTBI with LOC of 1-20 min more than a year prior were 60% more likely to have experienced global cognitive decline than controls at three-year follow-up. Cognitive decline was most apparent on measures of executive functioning. Logistic regression identified increased social support as predictors of relatively preserved cognitive function. DISCUSSION: mTBI with longer time spent unconscious (i.e., LOC 1-20 min) is associated with greater cognitive decline years after the head injury. Perceived social support, particularly emotional support, may help buffer against this cognitive decline.

The influence of different types of auditory change on processes associated with the switching of attention in younger and older adults.

Potentially highly relevant but unattended auditory stimuli may result in attention capture. The detection of stimulus change is associated with two event-related potentials: the deviant-related negativity (DRN), whose amplitude varies with the extent of change, and the P3a, which is elicited only by stimuli deemed to be highly relevant. In the present study, younger adults (aged 18-30 years) and older adults (aged 65-73 years) were presented with to-be-ignored auditory stimuli while engaged in a visual task. The auditory stimuli consisted of frequently presented standards and six different rarely presented deviants. In older adults, the amplitude of the DRN varied with the extent of deviance: it was significantly larger to the white noise and environmental sound deviants. A large P3a was elicited by these in younger adults but was much reduced in older adults. The DRN results suggest that older adults are able to compute saliency level of unattended stimulus input at an early stage of processing. However, the attenuated P3a results in older adults suggest that a potentially highly salient stimulus is not given sufficient priority to result in a switch of attention from current cognitive demands.

Ageism and COVID-19: what does our society's response say about us?

The goal of this commentary is to highlight the ageism that has emerged during the COVID-19 pandemic. Over 20 international researchers in the field of ageing have contributed to this document. This commentary discusses how older people are misrepresented and undervalued in the current public discourse surrounding the pandemic. It points to issues in documenting the deaths of older adults, the lack of preparation for such a crisis in long-term care homes, how some 'protective' policies can be considered patronising and how the initial perception of the public was that the virus was really an older adult problem. This commentary also calls attention to important intergenerational solidarity that has occurred during this crisis to ensure support and social-inclusion of older adults, even at a distance. Our hope is that with this commentary we can contribute to the discourse on older adults during this pandemic and diminish the ageist attitudes that have circulated.