Does bilingualism influence neuropsychological test performance in older adults? A systematic review

Geographic variability in limited English proficiency: A cross-cultural study of cognitive profiles

OBJECTIVE

This study was designed to evaluate the effect of limited English proficiency (LEP) on neurocognitive profiles.

METHOD

Romanian (LEP-RO; n = 59) and Arabic (LEP-AR; n = 30) native speakers were compared to Canadian native speakers of English (NSE; n = 24) on a strategically selected battery of neuropsychological tests.

RESULTS

As predicted, participants with LEP demonstrated significantly lower performance on tests with high verbal mediation relative to US norms and the NSE sample (large effects). In contrast, several tests with low verbal mediation were robust to LEP. However, clinically relevant deviations from this general pattern were observed. The level of English proficiency varied significantly within the LEP-RO and was associated with a predictable performance pattern on tests with high verbal mediation.

CONCLUSIONS

The heterogeneity in cognitive profiles among individuals with LEP challenges the notion that LEP status is a unitary construct. The level of verbal mediation is an imperfect predictor of the performance of LEP examinees during neuropsychological testing. Several commonly used measures were identified that are robust to the deleterious effects of LEP. Administering tests in the examinee's native language may not be the optimal solution to contain the confounding effect of LEP in cognitive evaluations.

Do executive functions differentiate Iranian children with attention-deficit/hyperactivity disorder with and without comorbid obesity?

OBJECTIVE

To compare multiple dimensions of executive function between children with attention-deficit/hyperactivity disorder (ADHD) with and without comorbid obesity.

METHOD

Participants were 90 Iranian children (ages 8-13, 50% female) who were equally dispersed across three study groups: typically developing (TD), ADHD with obesity (ADHD+O), and ADHD without obesity (ADHD-O). Study participants were administered a comprehensive battery of Iranian-adapted "cool" executive function tasks including Digit Span from the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V), Victoria Stroop Test (VST), Wisconsin Card Sorting Test (WCST), Tower of London, and dot-probe task (i.e., a task of attentional bias). Parents completed the Children's Scale for Future Thinking Questionnaire, which assesses future-oriented cognition (e.g., saving, planning, episodic foresight, delay of gratification), aligning more with "hot" executive functions. Groups were compared using multivariate and post-hoc univariate general linear models.

RESULTS

Significant group effects were observed for all executive function variables, broadly with the gradient pattern of TD > ADHD-O > ADHD+O. ADHD+O had poorer performances than ADHD-O for WISC-V Digit Span (d = -0.84), WCST Categories Completed (d = -0.55) and Perseverative Responses (d = 1.15), VST Interference Errors (d = 0.83) and Interference Time (d = 1.38), and Dot-Probe Task (d = 0.84). Relative to the ADHD-O group, ADHD+O had also poorer parent-reported Prospective Memory (d = -0.62), Episodic Foresight (d = -0.63), and Delay of Gratification (d = -0.54).

CONCLUSIONS

Children with ADHD-O have poorer executive functioning than those without obesity. We observed stronger effects for "cool" rather than "hot" domains of executive function, though this could be due to the former being performance-based and the latter parent-reported.

Bilingual neurocognitive resiliency, vulnerability, and Alzheimer's disease biomarker correlates in Latino older adults enrolled in the Health and Aging Brain Study - Health Disparities (HABS-HD)

INTRODUCTION

The effects of bilingualism on neuropsychological test performance in bilinguals with and without cognitive impairment are not well-understood and are relatively limited by small sample sizes of Latinos.

METHODS

Using analysis of covariance (ANCOVA), we explored patterns of cognitive performance and impairment across a large sample of community-dwelling bilingual and monolingual Latino older adults with (n = 180) and without (n = 643) mild cognitive impairment (MCI) enrolled in HABS-HD.

RESULTS

Bilinguals demonstrated cognitive resiliency in the form of significantly better performance on the Trail Making Test and Digit Symbol Substitution Test, observed across the cognitively unimpaired and MCI groups. In contrast, bilinguals demonstrated cognitive vulnerability in the form of significantly poorer performance and higher impairment rates on phonemic fluency in the MCI phase, only. Follow-up analyses revealed less balanced bilinguals demonstrated poorer performance and higher impairment rates on this measure, supported by lower levels of plasma Aβ 42/40.

DISCUSSION

Patterns of cognitive performance and impairment differ as a function of bilingualism. Bilingualism must be considered when evaluating cognitive and biomarker outcomes in Latino older adults.

Highlights

Latino bilinguals perform better on measures of processing speed and coding.Latino bilinguals with MCI demonstrate cognitive vulnerability in verbal fluency.Less balanced bilinguals demonstrate greatest vulnerability anchored by Aβ 42/40.

Clinical Neuropsychology of Bilingual Mexican American Adults: Effect of Language Proficiency and Dominance

OBJECTIVE

To assess the association between language proficiency and absolute dominance on language versus visual-perceptual formatted and executive versus delayed memory neuropsychological measures in bilingual adults.

METHODS

Data from 55 bilingual, conversationally fluent, neurologically intact, Mexican American, consecutive, adults tested in separate sessions in Spanish and English in a counterbalanced order were analyzed. Age, years of education, self-reported language proficiency, Woodcock-Muñoz Language Survey-Revised (WMLS-R) picture vocabulary measures of language proficiency, and dominance (absolute Spanish-English WMLS-R difference scores) were correlated with 11 measures from La Batería Neuropsicólogica en Español and its original English language tests.

RESULTS

Self-reported and WMLS-R measures of language proficiency were significantly correlated in each language. Absolute language dominance was not significantly associated with any Spanish or English neuropsychological raw score. The WMLS-R language proficiency, but not age or years of education, was significantly correlated with language-formatted neuropsychological measures of California Verbal Learning Test delayed free recall number of words (both languages), letter fluency (both languages), delayed story memory (in English), and Stroop interference (Spanish). Linear regression models using age, years of education, and WMLS-R picture vocabulary scores as predictors were significant for all these measures excepting the last. The WMLS-R language proficiency was not significantly associated with raw scores on any visual-perceptual formatted measure.

CONCLUSIONS

Monolingual neuropsychological test norms for language-formatted tests likely overestimate bilingual Mexican Americans' performance.

Does Language Distance Modulate the Contribution of Bilingualism to Cognitive Reserve in Seniors? A Systematic Review

We report a systematic review and exploratory meta-regression investigating the hypothesis that the effects of bilingualism on cognitive reserve are modulated by the distance between the pair of languages a bilingual uses. An inclusive multiple database search was performed in order to identify all relevant published research conducted in bilingual seniors. A combination of qualitative and quantitative synthesis methods were used in order to investigate our research questions. Results suggest that healthy bilingual seniors speaking more distant language pairs show improved monitoring performance on cognitive tasks. Evidence regarding a modulatory influence of language distance (LD) on the age of dementia diagnosis was inconclusive due to the small number of published studies meeting our inclusion criteria. We recommend more detailed reporting of individual differences in bilingual experience to assess the impact of LD and other variables on typical cognitive aging and the development of dementia. Linguistic differences in samples should also be considered as a constraint on bilingual advantages in future studies. Preregistration: PROSPERO CRD42021238705; OSF DOI 10.17605/OSF.IO/VPRBU.

Can Speaking More Than One Language Help Prevent Alzheimer's Disease?

Alzheimer's disease (AD) is an age-related neurocognitive disorder that is epidemic in the elderly population. Currently, there are limited pharmacological interventions, and this has heightened the urgency to identify potential preventable or modifiable risk factors that promote resilience to the neuropathological effects of AD. The regular use of two or more languages is one such factor that may increases cognitive reserve through the long-standing executive control involved in managing multiple languages in the brain. There is also evidence that bilingualism is associated with increased brain reserve or maintenance, particularly in frontal-executive structures and networks. This review examines the current, sometimes conflicting literature on bi/multilingualism and AD. These studies have confounding variations in the assessment of age of second language onset, language proficiency, language usage, and whether determining incidence of AD or age of symptom onset. Despite these limitations, most publications support the presence of increased frontal-executive reserve that compensates for the development of AD neuropathology and, thereby, delays the emergence of clinical symptoms of dementia by about 4-5 years. Although regularly speaking more than one language does not protect against AD neuropathology, the delay in its clinical expression has a potentially significant impact on the lifelong morbidity from this age-related disease. Learning other languages may be an important modifiable factor for delaying the clinical expression of AD in later life.

Effects of Sociodemographic Variables and Depressive Symptoms on MoCA Test Performance in Native Germans and Turkish Migrants in Germany

The validity of the Montreal Cognitive Assessment (MoCA) in migrants is questionable, as sociodemographic factors and the migration process may influence performance. Our aim was to evaluate possible predictors (age, education, sex, depression, and migration) of MoCA results in Turkish migrants and Germans living in Germany. Linear regression models were conducted with a German (n = 419), a Turkish (n = 133), and an overall sample. All predictor analyses reached statistical significance. For the German sample, age, sex, education, and depression were significant predictors, whereas education was the only predictor for Turkish migrants. For the overall sample, having no migration background and higher education were significant predictors. Migration background and education had an impact on MoCA performance in a sample of German and Turkish individuals living in Germany. Thus, culture-specific normative data for the MoCA are needed, and the development of culture-sensitive cognitive screening tools is encouraged.

Bilingualism, assessment language, and the Montreal Cognitive Assessment in Mexican Americans

BACKGROUND/OBJECTIVES

Assessment of cognition in linguistically diverse aging populations is a growing need. Bilingualism may complicate cognitive measurement precision, and bilingualism may vary across Hispanic/Latinx sub-populations. We examined the association among bilingualism, assessment language, and cognitive screening performance in a primarily non-immigrant Mexican American community.

DESIGN

Prospective, community-based cohort study: The Brain Attack Surveillance in Corpus Christi (BASIC)-Cognitive study.

SETTING

Nueces County, Texas.

PARTICIPANTS

Community-dwelling Mexican Americans age 65+, recruited door-to-door using a two-stage area probability sampling procedure.

MEASUREMENTS

Montreal Cognitive Assessment (MoCA); self-reported bilingualism scale. Participants were classified as monolingual, Spanish dominant bilingual, English dominant bilingual, or balanced bilingual based upon bilingualism scale responses. Linear regressions examined relationships among bilingualism, demographics, cognitive assessment language, and MoCA scores.

RESULTS

The analytic sample included 547 Mexican American participants (60% female). Fifty-eight percent were classified as balanced bilingual, the majority (88.6%) of whom selected assessment in English. Balanced bilinguals that completed the MoCA in English performed better than balanced bilinguals that completed the MoCA in Spanish (b = -4.0, p < 0.05). Among balanced bilinguals that took the MoCA in Spanish, education outside of the United States was associated with better performance (b = 4.4, p < 0.001). Adjusting for demographics and education, we found no association between the degree of bilingualism and MoCA performance (p's > 0.10).

CONCLUSION

Bilingualism is important to consider in cognitive aging studies in linguistically diverse communities. Future research should examine whether cognitive test language selection affects cognitive measurement precision in balanced bilinguals.

Lifelong Bilingualism Functions as an Alternative Intervention for Cognitive Reserve Against Alzheimer's Disease

Bilingualism has been reported to significantly delay the onset of dementia and plays an important role in the management of Alzheimer's disease (AD), a condition inducing impairment in the brain network and cognitive decline. Cognitive reserve is associated with the adaptive maintenance of neural functions by protecting against neuropathology. Bilingualism acts as a beneficial environmental factor contributing to cognitive reserve, although some potential confounding variables still need further elucidation. In this article, the relationship between bilingualism and cognitive reserve is discussed, interpreting the advantage of bilingualism in protecting against cognitive decline. In addition, the possible brain and biochemical mechanisms, supporting the advantageous effects of bilingualism in delaying the onset of dementia, involved in bilingualism are reviewed. Effectively, bilingualism can be considered as a pharmacological intervention with no side effects. However, the investigation of the pharmacological parameters of bilingualism is still at an early stage.