Does bilingualism influence cognitive aging?

Sex as a Determinant of Age-Related Changes in the Brain

The notion of notable anatomical, biochemical, and behavioral distinctions within male and female brains has been a contentious topic of interest within the scientific community over several decades. Advancements in neuroimaging and molecular biological techniques have increasingly elucidated common mechanisms characterizing brain aging while also revealing disparities between sexes in these processes. Variations in cognitive functions; susceptibility to and progression of neurodegenerative conditions, notably Alzheimer's and Parkinson's diseases; and notable disparities in life expectancy between sexes, underscore the significance of evaluating aging within the framework of gender differences. This comprehensive review surveys contemporary literature on the restructuring of brain structures and fundamental processes unfolding in the aging brain at cellular and molecular levels, with a focus on gender distinctions. Additionally, the review delves into age-related cognitive alterations, exploring factors influencing the acceleration or deceleration of aging, with particular attention to estrogen's hormonal support of the central nervous system.

The 2022 symposium on dementia and brain aging in low- and middle-income countries: Highlights on research, diagnosis, care, and impact

Two of every three persons living with dementia reside in low- and middle-income countries (LMICs). The projected increase in global dementia rates is expected to affect LMICs disproportionately. However, the majority of global dementia care costs occur in high-income countries (HICs), with dementia research predominantly focusing on HICs. This imbalance necessitates LMIC-focused research to ensure that characterization of dementia accurately reflects the involvement and specificities of diverse populations. Development of effective preventive, diagnostic, and therapeutic approaches for dementia in LMICs requires targeted, personalized, and harmonized efforts. Our article represents timely discussions at the 2022 Symposium on Dementia and Brain Aging in LMICs that identified the foremost opportunities to advance dementia research, differential diagnosis, use of neuropsychometric tools, awareness, and treatment options. We highlight key topics discussed at the meeting and provide future recommendations to foster a more equitable landscape for dementia prevention, diagnosis, care, policy, and management in LMICs. HIGHLIGHTS: Two-thirds of persons with dementia live in LMICs, yet research and costs are skewed toward HICs. LMICs expect dementia prevalence to more than double, accompanied by socioeconomic disparities. The 2022 Symposium on Dementia in LMICs addressed advances in research, diagnosis, prevention, and policy. The Nairobi Declaration urges global action to enhance dementia outcomes in LMICs.

The Beneficial, Formative Role of Lifetime Exposures across Cognitive Domains in Barbados Using Data from the SABE Study

This study tested the hypothesis that within older Barbadian adults, sex, education, and occupation type lessen age-related cognitive decline. The analyses used a cross-sectional data set from 1325 people collected in the 2006 SABE Study (Health, Well-being, and Aging). Cognition was assessed as scores in each subdomain of the Mini-Mental State Exam. The loss of a single point in each subdomain was predicted by sex, years of education, job type, and their interactions with age. Results demonstrated that age and protective factors affect each cognitive domain differently. High education combined with mentally complex employment helped maintain cognitive performance in later life. Beneficial lifetime exposures are additive, providing combined benefits. Findings provide insight into public policy aiming to minimize the number of adults with cognitive decline and dementia in Barbados and the Caribbean.

Protective effect of bilingualism on aging, MCI, and dementia: A community-based study

INTRODUCTION

Lifelong bilingualism is associated with a delayed age at onset of dementia, but evidence from community-based studies is limited. We investigated the relationship between bilingualism and the prevalence of cognitive impairment in a linguistically diverse community.

METHODS

A door-to-door community study was conducted from January to December 2021 in urban Bengaluru, India. 1234 individuals aged ≥60 years participated in the study. Participants were diagnosed with no cognitive impairment (NCI), mild cognitive impairment (MCI), or dementia using established diagnostic criteria.

RESULTS

Dementia prevalence was higher in monolinguals (4.9%) than bilinguals (0.4%) (P = .001). The prevalence of MCI was also higher in monolinguals (8.5%) than bilinguals (5.3%) (P = .001). The study also revealed better cognitive function in bilinguals than monolinguals with NCI, after controlling for confounding variables.

DISCUSSION

The current study provides significant support for the protective effect of bilingualism on cognitive impairment in an urban community with extensive bilingual interactional contexts in everyday life.

HIGHLIGHTS

Bilingualism has been demonstrated to protect against dementia and mild cognitive impairment in a linguistically diverse community with extensive code-switching contexts. Bilingual older individuals had superior baseline cognitive performance compared to monolingual older individuals. Bilingualism was found to have an independent effect on general cognition after adjusting for major social determinants of health in the group without cognitive impairment.

Language Learning for People Living with Dementia and Their Caregivers: Feasibility and the Quality of Experience

BACKGROUND

A body of research from around the world has reported positive effects of bilingualism on cognitive ageing and dementia. However, little is known about whether foreign language learning could be applied as an intervention for people already living with dementia. Yet, before it is possible to determine the efficacy of language courses as an intervention for people living with dementia (PLWD), it is necessary to establish whether such an intervention is feasible. Our study explored this possibility.

METHODS

We conducted an exploratory study to examine the feasibility and tolerability of 2-week Italian beginner courses for PLWD in early stages and their family carers in two Scottish Dementia Resource Centres (DRCs). The courses were delivered by trained tutors from Lingo Flamingo, a social enterprise specialising in language teaching for older learners and learners with dementia. Twelve PLWD and seven carers participated in the study. Focus groups preceded and followed the courses. Additional post-course open interviews with the DRC managers were conducted, with a follow-up via telephone approximately one year later.

RESULTS

Qualitative content analysis resulted in 12 themes, 5 reflected in the interview schedule and 7 arising from the focus groups and interviews. Overall, the courses were perceived positively by PLWD, carers, and DRC managers, although a few logistically and linguistically challenging aspects were also mentioned. The courses were found to positively impact both the individual by increasing self-esteem and producing a sense of accomplishment as well as the group by creating a sense of community. Notably, no adverse effects (in particular no confusion or frustration) were reported.

CONCLUSION

The positive outcomes of our study open a novel avenue for future research to explore foreign language training in dementia as an intervention and its implications.

Dual-Language Use and Cognitive Function Among Mexican Americans Aged 65 and Older

Background

Better English proficiency and higher frequency of using English among non-native speakers are associated with lower dementia risk.

Objective

We investigated if Mexican American older adults who use English and Spanish to a more similar degree demonstrate better cognitive function than those who use one language more than the other.

Methods

We used data from waves one (1992/93) to eight (2012/13) of the Hispanic Established Population for the Epidemiological Study of the Elderly. At baseline, participants were asked what language they usually use across communicative contexts. We based dual language on participants' use of Spanish and English within and across contexts. We categorized participants as low (n = 1,145), medium (n = 717), and high (n = 702) dual-language users. Linear mixed models were used to estimate the association between dual-language use, baseline Mini-Mental State Examination (MMSE) scores, and change in MMSE.

Results

Participants in the medium and high dual-language use categories scored 1.91 points and 3.03 points higher at wave one compared to the low dual-language use category. Adjusting for education reduced the association between dual-language use and baseline MMSE (medium B = 0.99 SE = 0.19 p < 0.01; high B = 1.41 SE = 0.21 p < 0.01). The association between dual-language use and decline in the MMSE was not statistically significant.

Conclusions

Greater dual-language use was associated with higher MMSE scores but not change in MMSE scores among Mexican Americans aged 65 and older. Future work should characterize bilingualism with greater nuance and use more rigorous cognitive measures to identify the components of the bilingual experience that may benefit the cognitive functioning of older adult bilinguals.

Age of Bilingual Onset Shapes the Dynamics of Functional Connectivity and Laterality in the Resting-State

Bilingualism is known to enhance cognitive function and flexibility of the brain. However, it is not clear how bilingual experience affects the time-varying functional network and whether these changes depend on the age of bilingual onset. This study intended to investigate the bilingual-related dynamic functional connectivity (dFC) based on the resting-state functional magnetic resonance images, including 23 early bilinguals (EBs), 30 late bilinguals (LBs), and 31 English monolinguals. The analysis identified two dFC states, and LBs showed more transitions between these states than monolinguals. Moreover, more frequent left-right switches were found in functional laterality in prefrontal, lateral temporal, lateral occipital, and inferior parietal cortices in EBs compared with LB and monolingual cohorts, and the laterality changes in the anterior superior temporal cortex were negatively correlated with L2 proficiency. These findings highlight how the age of L2 acquisition affects cortico-cortical dFC pattern and provide insight into the neural mechanisms of bilingualism.

Are Older Bilinguals' Better in Metaphor Generation?

Metaphor, as widely known, is a figure of speech where a word or phrase is used to describe an object, action, or event to which it cannot be applied exactly. Metaphors are often used figuratively to enable clarity or emphasize the similarities between the two things in a frame. In the current study, we aimed to investigate the relationship between cognitive functions and generating metaphor and their associations in older bilingual and monolingual participants. We conducted the experiment with fifty-six (Bilingual and Monolingual) participants in the age group ranging from 50 to 65 years. We administered the novel and conventional metaphor generation task based on vision words in perceptual domain in Telugu. Followed by a battery of cognitive function tests: Flanker task to study the attention, Semantic Fluency task, Corsi task to check working memory, LexTALE to measure the vocabulary, and a language questionnaire. These tasks are used to investigate the association and correlation between the old age bilingual and monolingual in generating vision metaphors. The current study's findings demonstrate that bilinguals have a considerable advantage in cognitive function and their ability to generate novel metaphors are better when compared to monolinguals.

The influence of bilingualism on gray matter volume in the course of aging: a longitudinal study

Background

Bilingualism is associated with higher gray matter volume (GMV) as a form of brain reserve in brain regions such as the inferior frontal gyrus (IFG) and the inferior parietal lobule (IPL). A recent cross-sectional study reported the age-related GMV decline in the left IFG and IPL to be steeper for bilinguals than for monolinguals. The present study aimed at supporting this finding for the first time with longitudinal data.

Methods

In the current study, 200 participants aged 19 to 79 years (87 monolinguals, 113 sequential bilinguals, mostly native German speakers with variable second language background) were included. Trajectories of GMV decline in the bilateral IFG and IPL were analyzed in mono- and bilinguals over two time points (mean time interval: 3.6 years). For four regions of interest (left/right IFG and left/right IPL), mixed Analyses of Covariance were conducted to assess (i) GMV changes over time, (ii) GMV differences for language groups (monolinguals/bilinguals), and (iii) the interaction between time point and language group. Corresponding analyses were conducted for the two factors of GMV, surface area (SA) and cortical thickness (CT).

Results

There was higher GMV in bilinguals compared to monolinguals in the IPL, but not IFG. While the left and right IFG and the right IPL displayed a similar GMV change in mono- and bilinguals, GMV decline within the left IPL was significantly steeper in bilinguals. There was greater SA in bilinguals in the bilateral IPL and a steeper CT decline in bilinguals within in the left IPL.

Conclusion

The cross-sectional observations of a steeper GMV decline in bilinguals could be confirmed for the left IPL. Additionally, the higher GMV in bilinguals in the bilateral IPL may indicate that bilingualism contributes to brain reserve especially in posterior brain regions. SA appeared to contribute to bilinguals' higher GMV in the bilateral IPL, while CT seemed to account for the steeper structural decline in bilinguals in the left IPL. The present findings demonstrate the importance of time as an additional factor when assessing the neuroprotective effects of bilingualism on structural features of the human brain.

Linking early-life bilingualism and cognitive advantage in older adulthood

Previous studies have identified bilingualism as a protective factor against dementia. Here we aimed to test whether being bilingual at different life stages impacts cognition and brain structure in older adulthood. We included 746 participants from the DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE). Assessment of bilingualism at 3 life stages (early: 13-30, middle: 30-65 and late: over 65 years old) was determined with the Lifetime of Experiences Questionnaire. Individuals reporting bilingualism (i.e., daily use of L2) in the early life stage outperformed monolinguals on learning & memory, working-memory, executive functions and language. Bilingualism in middle life stage showed a significant advantage on learning & memory, while no effect of bilingualism in old life stage was identified. Brain gray matter volume was not associated with L2 use and did not differ between groups. However, stronger correlations between brain gray matter volume in selected brain regions and cognitive performance were found in bilingual participants in the early and middle life stages. Our results indicate that bilingualism in early life might provide a long-lasting protective effect on cognition and shape the brain to sustain cognitive performance in older adulthood.

Improvement in executive function for older adults through smartphone apps: a randomized clinical trial comparing language learning and brain training

Bilingualism has been linked to improved executive function and delayed onset of dementia, but it is unknown whether similar benefits can be obtained later in life through deliberate intervention. Given the logistical hurdles of second language acquisition in a randomized trial for older adults, few interventional studies have been done thus far. However, recently developed smartphone apps offer a convenient means to acquire skills in a second language and can be compared with brain training apps specifically designed to improve executive function. In a randomized clinical trial, 76 adults aged 65-75 were assigned to either 16 weeks of Spanish learning using the app Duolingo 30 minutes a day, an equivalent amount of brain training using the app BrainHQ, or a waitlist control condition. Executive function was assessed before and after the intervention with preregistered (NCT03638882) tests previously linked to better performance in bilinguals. For two of the primary measures: incongruent Stroop color naming and 2-back accuracy, Duolingo provided equivalent benefits as BrainHQ compared to a control group. On reaction time for N-back and Simon tests, the BrainHQ group alone experienced strong gains over the other two groups. Duolingo was rated as more enjoyable. These results suggest that app-based language learning may provide some similar benefits as brain training in improving executive function in seniors but has less impact on processing speed. However, future advancements in app design may optimize not only the acquisition of the target language but also the side benefits of the language learning experience.

Gray Matter Volume as Evidence for Cognitive Reserve in Bilinguals With Mild Cognitive Impairment

BACKGROUND

Compared with monolinguals, bilinguals have a later onset of mild cognitive impairment (MCI) and Alzheimer disease symptoms and greater neuropathology at similar cognitive and clinical levels. The present study follows a previous report showing the faster conversion from MCI to Alzheimer disease for bilingual patients than comparable monolinguals, as predicted by a cognitive reserve (CR).

PURPOSE

Identify whether the increased CR found for bilinguals in the previous study was accompanied by greater gray matter (GM) atrophy than was present for the monolinguals.

METHODS

A novel deep-learning technique based on convolutional neural networks was used to enhance clinical scans into 1 mm MPRAGEs and analyze the GM volume at the time of MCI diagnosis in the earlier study.

PATIENTS

Twenty-four bilingual and 24 monolingual patients were diagnosed with MCI at a hospital memory clinic.

RESULTS

Bilingual patients had more GM loss than monolingual patients in areas related to language processing, attention, decision-making, motor function, and episodic memory retrieval. Bilingualism and age were the strongest predictors of atrophy after other variables such as immigration and education were included in a multivariate model.

DISCUSSION

CR from bilingualism is evident in the initial stages of neurodegeneration after MCI has been diagnosed.

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.

A Decade Later on How to "Use It" So We Don't "Lose It": An Update on the Unanswered Questions about the Influence of Activity Participation on Cognitive Performance in Older Age

Activity engagement is a modifiable factor that has been widely-cited as being good for the aging brain and cognition and represents a valuable target for reducing dementia risk. However, specific issues about activity engagement (mental, social, and physical) and cognition in older adulthood remain, and Bielak [Gerontology 2010;56: 507-519] reviewed seven major methodological and theoretical questions about this relationship. We present an updated reflection on these key questions, focusing on research published in the last 10 years. For some questions, a significant amount of work has been done and conclusions have become clearer; for others, there have been few additions to the literature and our knowledge remains much the same as it was a decade ago. We review the issues identified in the 2010 paper including the directionality and temporal nature of the relationship; whether specific activity domains offer different benefits to cognition and what domain(s) of cognition are affected; variation in the relation by age, gender, or education; potential mechanisms involved; and how activity engagement is assessed. For each, we present the most up-to-date research, discuss remaining challenges and possible future directions. This formal unifying of the information in the field is intended as a guide to support continued progress by spurring on studies addressing specific questions while reminding researchers of critical issues. We conclude with recommendations that future studies investigating the link between activity engagement and cognitive performance in adulthood should consider.

Demand Coupling Drives Neurodegeneration: A Model of Age-Related Cognitive Decline and Dementia

The societal burden of Alzheimer's Disease (AD) and other major forms of dementia continues to grow, and multiple pharmacological agents directed towards modifying the pathological "hallmarks" of AD have yielded disappointing results. Though efforts continue towards broadening and deepening our knowledge and understanding of the mechanistic and neuropathological underpinnings of AD, our previous failures motivate a re-examination of how we conceptualize AD pathology and progression. In addition to not yielding effective treatments, the phenotypically heterogeneous biological processes that have been the primary area of focus to date have not been adequately shown to be necessary or sufficient to explain the risk and progression of AD. On the other hand, a growing body of evidence indicates that lifestyle and environment represent the ultimate level of causation for AD and age-related cognitive decline. Specifically, the decline in cognitive demands over the lifespan plays a central role in driving the structural and functional deteriorations of the brain. In the absence of adequate cognitive stimulus, physiological demand-function coupling leads to downregulation of growth, repair, and homeostatic processes, resulting in deteriorating brain tissue health, function, and capacity. In this setting, the heterogeneity of associated neuropathological tissue hallmarks then occurs as a consequence of an individual's genetic and environmental background and are best considered downstream markers of the disease process rather than specific targets for direct intervention. In this manuscript we outline the evidence for a demand-driven model of age-related cognitive decline and dementia and why it mandates a holistic approach to dementia treatment and prevention that incorporates the primary upstream role of cognitive demand.

Multifactorial approaches to study bilingualism in the aging population: Past, present, future

A better understanding and more reliable classification of bilinguals has been progressively achieved through the fine-tuning methodology and simultaneously optimizing the measurement tools. However, the current understanding is far from generalization to a larger population varying in different measures of bilingualism-L2 Age of acquisition (L2 AOA), L2 usage and exposure, and L2 proficiency. More recent studies have highlighted the importance of modeling bilingualism as a continuous variable. An in-depth look at the role of bilingualism, comparing groups, may be considered a reductionist approach, i.e., grouping based on one measure of bilingualism (e.g., L2 AOA) may not account for variability in other measures of bilingualism (L2 exposure, L2 use or L2 proficiency, amongst others) within and between groups. Similarly, a multifactorial dimension is associated with cognitive performance, where not all domains of cognition and subcomponents are equally influenced by bilingualism. In addition, socio-cultural and demographical factors may add another dimension to the impact of bilingualism on cognitive performance, especially in older adults. Nevertheless, not many studies have controlled or used the multiple socio-cultural and demographical factors as a covariate to understand the role of different aspects of bilingualism that may influence cognitive performance differently. Such an approach would fail to generalize the research findings to a larger group of bilinguals. In the present review paper, we illustrate that considering a multifactorial approach to different dimensions of bilingual study may lead to a better understanding of the role of bilingualism on cognitive performance. With the evolution of various fine-tuned methodological approaches, there is a greater need to study variability in bilingual profiles that can help generalize the result universally.

The Nuance of Bilingualism as a Reserve Contributor: Conveying Research to the Broader Neuroscience Community

The neurological notion of “reserve” arises from an individually observable dissociation between brain health and cognitive status. According to the cognitive reserve hypothesis, high-reserve individuals experience functional compensation for neural atrophy and, thus, are able to maintain relatively stable cognitive functioning with no or smaller-than-expected impairment. Several lifestyle factors such as regular physical exercise, adequate and balanced nutrition, and educational attainment have been widely reported to contribute to reserve and, thus, lead to more successful trajectories of cognitive aging (CA). In recent years, it has become clear that bilingualism is also a potential reserve contributor. Yet, there is little communication between the neuroscience of bilingualism research community and researchers working in the field of CA more generally, despite compelling reasons for it. In fact, bilingualism tends to be overlooked as a contributory factor in the CA literature, or reduced to a dichotomous trait, despite it being a complex experience. Herein, we discuss issues that are preventing recognition of bilingualism as a reserve contributor across all literatures, highlight the benefits of including language experiences as a factor of interest across research disciplines, and suggest a roadmap to better integrate bilingualism and aging moving forward. We close with calls toward a model of aging that examines the contributions across lifestyle factors, including that of bilingual experience.

Bilingualism and Aging: Implications for (Delaying) Neurocognitive Decline

As a result of advances in healthcare, the worldwide average life expectancy is steadily increasing. However, this positive trend has societal and individual costs, not least because greater life expectancy is linked to higher incidence of age-related diseases, such as dementia. Over the past few decades, research has isolated various protective "healthy lifestyle" factors argued to contribute positively to cognitive aging, e.g., healthy diet, physical exercise and occupational attainment. The present article critically reviews neuroscientific evidence for another such factor, i.e., speaking multiple languages. Moreover, with multiple societal stakeholders in mind, we contextualize and stress the importance of the research program that seeks to uncover and understand potential connections between bilingual language experience and cognitive aging trajectories, inclusive of the socio-economic impact it can have. If on the right track, this is an important line of research because bilingualism has the potential to cross-over socio-economic divides to a degree other healthy lifestyle factors currently do not and likely cannot.

The neuroanatomical consequences and pathological implications of bilingualism

In recent years, there has been a rise in the number of people who are able to speak two or more languages. This has been paralleled by an increase in research related to bilingualism. Despite this, much of the neuroanatomical consequences and pathological implications of bilingualism are still subject to discussion. This review aims to evaluate the neuroanatomical structures related to language and to the acquisition of a second language as well as exploring how learning a second language can alter one's susceptibility to and the progression of certain cerebral pathologies. A literature search was conducted on the Medline, Embase, and Web of Science databases. A total of 137 articles regarding the neuroanatomical or pathological implications of bilingualism were included for review. Following analysis of the included papers, this review finds that bilingualism induces significant gray and white matter cerebral changes, particularly in the frontal lobes, anterior cingulate cortex, left inferior parietal lobule and subcortical areas, and that native language and acquired language largely recruit the same neuroanatomical structures with however, subtle functional and anatomical differences dependent on proficiency and age of language acquisition. There is adequate evidence to suggest that bilingualism offsets the symptoms and diagnosis of dementia, and that it is protective against both pathological and age-related cognitive decline. While many of the neuroanatomical changes are known, more remains to be elucidated and the relationship between bilingualism and other neurological pathologies remains unclear.

Add Bilingualism to the Mix: L2 Proficiency Modulates the Effect of Cognitive Reserve Proxies on Executive Performance in Healthy Aging

We investigated the contribution of bilingual experience to the development of cognitive reserve (CR) when compared with other, traditionally more researched, CR proxies, in a sample of cognitively healthy senior (60 +) bilingual speakers. Participants performed in an online study where, in addition to a wide inventory of factors known to promote CR, we assessed several factors related to their second language (L2) use. In addition, participants’ inhibitory executive control was measured via the Flanker Task. We used Structural Equation Modeling to derive a latent composite measure of CR informed by traditional CR proxies (i.e., occupational complexity, marital status, current and retrospective socio-economic status, physical exercise, perceived positive support, maximal educational attainment, frequency of leisure activities and extent of social network). We examined whether bilingualism may act as a mediator of the effects of such proxies on cognitive performance therefore assessing the unique contribution of dual language use to CR. First, our analyses revealed facilitatory effects of both L2 age of acquisition and L2 proficiency on the executive performance. Second, our analyses confirmed the moderating role of bilingual experience on the relationship between other factors known to promote CR and cognitive integrity, revealing a strong contribution by bilingualism to CR development. Our findings provide further support to the notion that bilingualism plays an important role in mitigating cognitive decline and promoting successful aging.

The influence of cognitive reserve in the protection of the cognitive status after an acquired brain injury: A systematic review

BACKGROUND

Cognitive Reserve (CR) hypothesis was introduced to account for the variability in cognitive performance of patients with similar degrees of brain injury or pathology. The individual variability of CR is modulated by the interaction of innate capacities and exposures throughout life, which can act as protectors against neuropathology's clinical effects. Individuals with higher CR appear to have better cognitive performance after a brain injury. The present review aimed to identify and map the scientific evidence available in literature regarding CR's influence in protecting the cognitive status after an Acquired Brain Injury (ABI).

METHOD

A systematic review was performed for published studies until October 2020 in PubMed, Scopus, and CINAHL electronic databases. Studies regarding CR's influence in protecting the cognitive status after an ABI were included in this review. The Newcastle-Ottawa Scale was used to assess risk of bias in the included studies. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021236594.

RESULTS

Twenty-one studies published between 2003 and 2020 were selected and analyzed. The literature analysis showed that CR has a positive effect on cognitive status after an ABI. Various proxies were used to estimate CR, including estimated premorbid IQ, education, occupation attainment, socioeconomic status, leisure activities, bilingualism, and social integration. CR proxies constitute a set of variables that may have a significant influence on cognitive status. Higher CR levels were associated with lower cognitive impairment after an ABI.

CONCLUSIONS

Although more research is necessary for a complete understanding of CR's impact on cognition, the synthesis of these studies confirmed that there is evidence on the beneficial impact of CR on cognitive status after an ABI. These findings support CR's cognitive status role following an ABI and may provide additional information for prognosis and rehabilitation plans.

Relationships between enriching early life experiences and cognitive function later in life are mediated by educational attainment

The study of how engagement in enriching cognitive, physical and social activities in childhood impacts cognitive function decades later will advance our understanding of how modifiable lifestyle activities promote cognition across the lifespan. 88 healthy older adults (aged 60-80 years) returned a retrospective questionnaire regarding their participation in seven lifestyle activities (musical instrument playing, language learning, sport participation, art/dance lessons, scouting, volunteering, family vacations) before age 13 years. After controlling for current age, educational attainment, socioeconomic status of the mother and current engagement in lifestyle activities, a greater number of activities were significantly associated with better vocabulary abilities, episodic memory and fluid intelligence. The relationships with vocabulary and fluid intelligence were mediated by educational attainment. We postulate that engagement in a higher number of enriching early life activities is a reflection of both one's sociocontextual environment and engagement with that environment. This engagement leads to attributes relevant for educational aspirations/attainment, ultimately contributing to factors that have a lifespan impact on cognitive function.

Bilingualism Effects on the Cognitive Flexibility of Autistic Children: Evidence From Verbal Dual-Task Paradigms

The deficit in cognitive flexibility (i.e., the ability to adapt cognitive behavior to changing contexts) is one of the most prominent characteristics of autistic individuals. Inflexibility may manifest in restricted interests and increased susceptibility to the effects of misinformation either through inefficient inhibition of non-target information or deficient recall of correct information. Bilingualism has been shown to enhance executive functions in both typically developing children and autistic children; yet, the effect of bilingualism on cognitive flexibility in autism remains underexplored. In this study, we used verbal dual-tasks to compare cognitive flexibility across 50 monolingual autistic and 50 bilingual autistic children, and 50 monolingual and 50 bilingual typically developing children. The children were also administered language ability tests and a nonverbal global-local cognitive flexibility task, in order to investigate whether performance in the dual-tasks would be modulated by the children's language and executive function skills. The bilingual autistic children outperformed their monolingual autistic peers in the dual-tasks. The strength of the bilingualism effect, however, was modulated by the type of language processing that interfered with the target information in each dual-task, which suggests that the bilingual autistic children calibrated their processing resources and efficiently adapted them to the changing demands of the dual-task only to the extent that the task did not exceed their language abilities. Bilingual autistic children relied on their executive functions rather than on their language abilities while performing in the dual-tasks. The overall results show that bilingualism compensates for the reduced cognitive flexibility in autism.

Music to My Ears: Developing Kanji Stroke Knowledge through an Educational Music Game

Millions of people worldwide are taking up foreign languages with logographic writing systems, such as Japanese or Chinese. Learning thousands of characters necessary for literacy in those languages is a unique challenge to those coming from alphabetic backgrounds, and sustaining motivation in the face of such a momentous task is a struggle for many students. Many games exist for this purpose, but few offer production memory practice such as writing, and the vast majority are thinly veiled flashcards. To address this gap, we created Radical Tunes—a musical kanji-writing game—which combines production practice with musical mnemonic by assigning a melody to each element of a character. We chose to utilize music as it is a powerful tool that can be employed to enhance learning and memory. In this article, we explore whether incorporating melodies into a kanji learning game can positively affect the memorization of the stroke order/direction and overall shape of several Japanese characters, similar to the mnemonic effect of adding music to text. Specifically, we conducted two experimental studies, finding that (1) music improved immersion—an important factor related to learning; and (2) there was a positive correlation between melody presence and character production, particularly for more complex characters.

Does Second Language Learning Promote Neuroplasticity in Aging? A Systematic Review of Cognitive and Neuroimaging Studies

As the population ages, understanding how to maintain older adults' cognitive abilities is essential. Bilingualism has been linked to higher cognitive reserve, better performance in executive control, changes in brain structure and function relative to monolinguals, and delay in dementia onset. Learning a second language thus seems a promising avenue for cognitive enhancement in older adults. Our review aims to determine whether learning a foreign language in later life improves cognition and promotes neuroplasticity. We screened articles from the Pubmed, Scopus, and Science Direct databases to identify interventional studies using second language training in senior participants, including either cognition or neuroimaging as outcome measures. A total of nine articles were found, with only one neuroimaging study. Results from these studies are inconsistent, but tend to suggest that second language learning is associated with improvement in attentional switching, inhibition, working memory, and increased functional connectivity. We discuss the implications of these results, and suggest new directions and methodological recommendations for future research.

Research on bilingualism as discovery science

An important aim of research on bilingualism is to understand how the brain adapts to the demands of using more than one language.In this paper, we argue that pursuing such an aim entails valuing our research as a discovery process that acts on variety.Prescriptions about sample size and methodology, rightly aimed at establishing a sound basis for generalization, should be understood as being in the service of science as a discovery process. We propose and illustrate by drawing from previous and contemporary examples within brain and cognitive sciences, that this necessitates exploring the neural bases of bilingual phenotypes:the adaptive variety induced through the interplay of biology and culture. We identify the conceptual and methodological prerequisites for such exploration and briefly allude to the publication practices that afford it as a community practice and to the risk of allowing methodological prescriptions, rather than discovery, to dominate the research endeavor.

Enriching activities during childhood are associated with variations in functional connectivity patterns later in life

Enriching early life experiences (e.g., sport, art, music, volunteering, language learning) during a critical period of brain development may promote structural and functional brain changes that are still present decades later (>60 years). We assessed whether a greater variety of enriching early life activities (EELA) before age 13 years were associated with individual differences in cortical and subcortical (hippocampus and amygdala) structure and function later in life (older adults aged 60-80 years). Results indicated no association between EELA and amygdala and hippocampus volumes, but higher functional connectivity between the amygdala and the insula was associated with more variety of EELA. EELA was not associated with cortical thickness controlling for sex, but sex-specific associations with the right pars opercularis were found. EELA was further associated with variations in functional connectivity patterns of the orbitofrontal cortex, driven by connecitivty to regions within the visual, somatosensory and limbic networks. Early life enriching activities appear to contribute to potential mechanisms of cognitive reserve (functional processes) more so than brain reserve (structure) later in life.

Bilingualism: A Global Public Health Strategy for Healthy Cognitive Aging

Dementia is a global public health priority which cost global societies $818 billion in 2015 and is disproportionately impacting low and middle-income countries (LMICs). With limited availability of disease modifying drugs to treat Alzheimer's disease (AD), researchers have increasingly focused on preventative strategies which may promote healthy cognitive aging and mitigate the risk of cognitive impairment in aging. Lifelong bilingualism has been presented as both a highly debated and promising cognitive reserve factor which has been associated with better cognitive outcomes in aging. A recent metanalysis has suggested that bilingual individuals present on average 4.05 years later with the clinical features of AD than monolinguals. Bilinguals are also diagnosed with AD ~2.0 years later than monolingual counterparts. In this perspective piece we critically evaluate the findings of this metanalysis and consider the specific implications of these findings to LMICs. Furthermore, we appraise the major epidemiological studies conducted globally on bilingualism and the onset of dementia. We consider how both impactful and robust studies of bilingualism and cognition in older age may be conducted in LMICs. Given the limited expenditure and resources available in LMICs and minimal successes of clinical trials of disease modifying drugs we propose that bilingualism should be positioned as an important and specific public health strategy for maintaining healthy cognitive aging in LMICs. Finally, we reflect upon the scope of implementing bilingualism within the education systems of LMICs and the promotion of bilingualism as a healthy cognitive aging initiative within government policy.

Music Modulates Cognitive Flexibility? An Investigation of the Benefits of Musical Training on Markers of Cognitive Flexibility

Cognitive flexibility enables the rapid change in goals humans want to attain in everyday life as well as in professional contexts, e.g., as musicians. In the laboratory, cognitive flexibility is usually assessed using the task-switching paradigm. In this paradigm participants are given at least two classification tasks and are asked to switch between them based on valid cues or memorized task sequences. The mechanisms enabling cognitive flexibility are investigated through two empirical markers, namely switch costs and n-2 repetition costs. In this study, we assessed both effects in a pre-instructed task-sequence paradigm. Our aim was to assess the transfer of musical training to non-musical stimuli and tasks. To this end, we collected the data of 49 participants that differed in musical training assessed using the Goldsmiths Musical Sophistication Index. We found switch costs that were not significantly influenced by the degree of musical training. N-2 repetition costs were small for all levels of musical training and not significant. Musical training did not influence performance to a remarkable degree and did not affect markers of mechanisms underlying cognitive flexibility, adding to the discrepancies of findings on the impact of musical training in non-music-specific tasks.

The Impact of Aging on Spatial Abilities in Deaf Users of a Sign Language

Research involving the general population of people who use a spoken language to communicate has demonstrated that older adults experience cognitive and physical changes associated with aging. Notwithstanding the differences in the cognitive processes involved in sign and spoken languages, it is possible that aging can also affect cognitive processing in deaf signers. This research aims to explore the impact of aging on spatial abilities among sign language users. Results showed that younger signers were more accurate than older signers on all spatial tasks. Therefore, the age-related impact on spatial abilities found in the older hearing population can be generalized to the population of signers. Potential implications for sign language production and comprehension are discussed.

Effects of foreign language learning on executive functions in healthy older adults: study protocol for a randomised controlled trial

Background

With age, most cognitive functions decline. As the number of people aged 60 years and older is expected to rise rapidly within the next decades, identifying interventions that promote healthy cognitive ageing is of utmost importance. Promising research on bilingualism has led to the notion that learning a foreign language could protect against cognitive decline. Foreign language learning likely promotes executive functions, which are higher-order cognitive abilities particularly affected by age-related cognitive decline. However, evidence is still sparse and has produced contradictory results. This study aims to investigate the effects of short and intensive foreign language learning on executive functions in healthy older adults.

Methods

In a randomised controlled trial, we will assign 60 native German-speaking monolingual healthy older adults, aged 65–80 years, to either a foreign language learning or a waiting list control group. Language learners will attend a face-to-face, group-based Spanish course for beginners for 1.5 h a day, 5 days a week, for a total of 3 weeks. Cognitive performance in executive functions will be assessed before and after the intervention or after a waiting period of 3 weeks (waiting list control group). Participants will be tested again after 3 months to evaluate longitudinal effects of foreign language learning. The waiting list control group will receive Spanish lessons only after the final assessment and will be invited to an additional voluntary evaluation after completion of the course.

Discussion

To the best of our knowledge, we are conducting the first randomised controlled trial on the effects of short and intensive foreign language learning in older adulthood on executive functions. Enhanced cognitive performance after foreign language learning would indicate that learning a foreign language could enlarge cognitive reserve and thus promote healthy cognitive ageing in older adults.

Trial registration

German Clinical Trials Register DRKS00016552. Registered on 11 February 2019.

Are There Any Cognitive Benefits of Computer-Based Foreign Language Training for Healthy Elderly People? - A Mini-Review

The purpose of this mini-review is to investigate if there are any cognitive benefits of computer-based foreign language training for healthy older individuals aged 55+ years. The author conducted a literature search of peer-reviewed English written research articles found in Pub Med, Web of Science and Scopus. The findings of this mini-review reveal that the research on the cognitive benefits of computer-based foreign language training for healthy older individuals is small-scale. The limited research findings of only three relevant studies indicate that these computer-based foreign language training programs may bring cognitive benefits for healthy elderly people, especially as far as the enhancement of their cognitive functions such as working memory are concerned. In addition, the authors of these studies suggest that foreign language learning is a useful activity for healthy older adults since it has the benefits of being meaningful (an advantage over other cognitive training approaches) and provides the chance for acquiring important skills that can benefit other aspects of life, such as travel or communication. In conclusion, the author of this mini-review also provides several implications for practice and future research.

Characterizing Bilingual Effects on Cognition: The Search for Meaningful Individual Differences

A debate over the past decade has focused on the so-called bilingual advantage-the idea that bilingual and multilingual individuals have enhanced domain-general executive functions, relative to monolinguals, due to competition-induced monitoring of both processing and representation from the task-irrelevant language(s). In this commentary, we consider a recent study by Pot, Keijzer, and de Bot (2018), which focused on the relationship between individual differences in language usage and performance on an executive function task among multilingual older adults. We discuss their approach and findings in light of a more general movement towards embracing complexity in this domain of research, including individuals' sociocultural context and position in the lifespan. The field increasingly considers interactions between bilingualism/multilingualism and cognition, employing measures of language use well beyond the early dichotomous perspectives on language background. Moreover, new measures of bilingualism and analytical approaches are helping researchers interrogate the complexities of specific processing issues. Indeed, our review of the bilingualism/multilingualism literature confirms the increased appreciation researchers have for the range of factors-beyond whether someone speaks one, two, or more languages-that impact specific cognitive processes. Here, we highlight some of the most salient of these, and incorporate suggestions for a way forward that likewise encompasses neural perspectives on the topic.

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.

Playing Analog Games Is Associated With Reduced Declines in Cognitive Function: A 68-Year Longitudinal Cohort Study

OBJECTIVES

Playing analog games may be associated with better cognitive function but, to date, these studies have not had extensive longitudinal follow-up. Our goal was to examine the association between playing games and change in cognitive function from age 11 to age 70, and from age 70 to 79.

METHOD

Participants were 1,091 nonclinical, independent, community-dwelling individuals all born in 1936 and residing in Scotland. General cognitive function was assessed at ages 11 and 70, and hierarchical domains were assessed at ages 70, 73, 76, and 79 using a comprehensive cognitive battery of 14 tests. Games playing behaviors were assessed at ages 70 and 76. All models controlled for early life cognitive function, education, social class, sex, activity levels, and health issues. All analyses were preregistered.

RESULTS

Higher frequency of playing games was associated with higher cognitive function at age 70, controlling for age 11 cognitive function, and the majority of this association could not be explained by control variables. Playing more games was also associated with less general cognitive decline from age 70 to age 79, and in particularly, less decline in memory ability. Increased games playing between 70 and 76 was associated with less decline in cognitive speed.

DISCUSSION

Playing games were associated with less relative cognitive decline from age 11 to age 70, and less cognitive decline from age 70 to 79. Controlling for age 11 cognitive function and other confounders, these findings suggest that playing more games is linked to reduced lifetime decline in cognitive function.

Moderation-Mediation Effects in Bilingualism and Cognitive Reserve

We first provide a critical review of the existing findings on bilingualism as a contributor to cognitive reserve from moderator-mediator warranting cause-effect research conclusions. We next address the question of direct or indirect effects between bilingualism and neurocognitive protective factors influencing the associated age-related mental deficits. The existing findings support bilingualism as a predictor and as a moderator. Third, we propose cognitive reserve models of bilingualism describing analytical approaches that allow testing of these models and hypotheses related to path strength and causal relationships between predictors, moderators, and mediators. Lastly and most importantly, we suggest using large datasets available via open repositories. This can aid in the testing of theoretical models, clarifying the roles of moderators and mediators, and assessing the research viability of multi-causal paths that can influence cognitive reserve. Creating collaborative datasets to test these models would greatly advance our field and identify critical variables in the study of the bilingual aging brain.

Enhancing Cognitive Performance of Healthy Czech Seniors through Non-Native Language Learning-A Mixed-Methods Pilot Study

The aim of this article is to discuss the effect of learning a non-native language on the enhancement of cognitive performance in healthy native Czech elderly. In addition, special emphasis is put on the qualitative assessment. To do this, 42 Czech cognitively unimpaired seniors were enrolled into the study. These were then divided into an experimental group (i.e., 20 healthy elderly studied English as a non-native language for three months) and a passive control group (22 healthy elderly, who did not undergo any non-native language intervention). The main outcome measures included the Montreal Cognitive Assessment, statistical processing of the data, and a qualitative content analysis. The results indicate that the cognitive performance of the intervention group did not differ from the control group. Therefore, no cognitive enhancement through non-native language learning was achieved. However, the findings of the qualitative analysis show that such non-native language learning with the peers of the same age is especially beneficial for the overall well-being of healthy seniors, especially as far as their social networks are concerned. Furthermore, participant's subjective feelings from their self-reports indicate that foreign language learning also contributes to acquiring new English words and phrases. However, as there are very few empirical studies on this research topic, further research is needed in order to confirm or refute the present research findings on the enhancement of cognitive performance through non-native language learning in healthy seniors.

Spousal Loss and Change in Cognitive Functioning: An Examination of Temporal Patterns and Gender Differences

OBJECTIVES

The study investigates whether the disadvantaged position of men in the adverse consequences of widowhood for health and mortality also exists for changes in cognitive health.

METHODS

We used data of up to 1,269 men and women aged 65 years and older who participated in the Longitudinal Aging Study Amsterdam in 3-yearly assessments between 1992 and 2012 (5,123 person-observations). All were married and without cognitive impairment (Mini-Mental State Examination ≥ 24) at baseline and up to 419 lost their spouse. In fixed effects regression models, the effect of spousal loss on change in four domains of cognitive functioning was estimated independently of age-related cognitive change.

RESULTS

For women, a robust temporary decrease was found in the second year after spousal loss in the reasoning domain, but not in global cognitive functioning, processing speed, or memory. No robust effects were found for men.

DISCUSSION

Considering that only one cognitive domain was affected and effects were temporary, cognitive functioning seems rather robust to the experience of spousal loss. Despite men having often been reported to be in a disadvantaged position in other health domains, our analyses indicate no such pattern for cognitive functioning.

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

OBJECTIVE

Using standardized tests which have been normed on monolinguals for the assessment of bilinguals presents challenges to the accurate characterization of cognitive profile as the literature provides compelling evidence for the influence of bilingualism on cognitive abilities. However, little is known about the generalizability of these findings to clinical neuropsychology. The aim of this review was to address this gap by summarizing current evidence on the performance of bilingual older adults on standardized tests routinely used in clinical practice.

METHOD

A systematic search of Web of Science, PsycINFO and PubMed was conducted. 27 cross-sectional and longitudinal studies which use at least one standardized neuropsychological test for cognitive impairment were included in the review. Potential demographic (cultural/linguistic background of the participants, immigrant status), clinical (diagnostic status), and methodological confounders (language of test administration, components of bilingualism) were also examined. The review protocol was registered at the PROSPERO International Prospective Register of Systematic Review with registration number CRD42018114658.

RESULTS

The results of this review revealed some bilingual advantage on measures of inhibitory control and bilingual disadvantage on measures of verbal fluency in cross-sectional studies. Bilingualism status was not associated with test performance in longitudinal studies. However, findings lack consistency due to demographic variables and methodological differences across studies.

CONCLUSION

Neuropsychological tests assessing language domains and, to some extent executive function act as clinically relevant features of bilingualism for neuropsychological evaluation. However, immigration status, acculturation level and language of test administration needs to be taken into account when assessing bilingual older adults.

Active bilingualism delays the onset of mild cognitive impairment

Lifelong bilingualism may contribute to cognitive reserve (CR) in neurodegenerative diseases as shown by a delay of the age at symptom onset in bilinguals with Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). However, some studies have failed to show this bilingual advantage, suggesting that it might depend on the type and degree of bilingualism. In the present study, we tested the hypothesis that active bilingualism, defined as the continuous use of the two languages as opposed to second language exposition only, may protect against cognitive decline. Moreover, we investigated whether bilingualism as a CR factor may be explained by an advantage within the executive control (EC) system. To do so, we collected clinical measures (age at onset of cognitive symptoms, age at the first medical visit for cognitive impairments, and age at diagnosis) in patients with MCI and patients with AD with different degrees of language experience and usage of Catalan and Spanish. Additionally, all participants were tested on four EC tasks and one long-term memory recognition task. First, results from multiple regression analyses showed that active bilingualism was a significant predictor of delay in the age at onset for all the clinical measures in MCI, but not AD patients. Second, the effect of active bilingualism was independent of occupation, educational level and job attainment across the individuals' lifespan. Finally, although we did not find an effect of active bilingualism across all EC tasks, we did find an effect for conflict resolution. These results are discussed in the context of CR hypotheses, suggesting that compensatory mechanisms may play a role in protecting against cognitive decline.

Brain Structure in Bilingual Compared to Monolingual Individuals with Alzheimer's Disease: Proof of Concept

BACKGROUND

Bilingualism is increasingly recognized as protective in persons at risk for Alzheimer's disease (AD).

OBJECTIVE

Compare MRI measured brain volumes in matched bilinguals versus monolinguals with AD.

METHODS

This IRB approved study analyzed T1 volumetric brain MRIs of patients with criteria-supported Probable AD. We identified 17 sequential bilinguals (any native language) with Probable AD, matched to 28 (62%) monolinguals on age and MMSE. Brain volumes were quantified with Neuroreader. Regional volumes as fraction of total intracranial volume (TIV) were compared between both groups, and Cohen's D effect sizes were calculated for statistically significant structures. Partial correlations between bilingualism and brain volumes adjusted for age, gender, and TIV.

RESULTS

Bilinguals had higher brain volumes in 37 structures. Statistical significance (p < 0.05) was observed in brainstem (t = 2.33, p = 0.02, Cohen's D = 0.71) and ventral diencephalon (t = 3.01, p = 0.004, Cohen's D = 0.91). Partial correlations showed statistical significance between bilingualism and larger volumes in brainstem (rp = 0 . 37, p = 0.01), thalamus (rp = 0.31, p = 0.04), ventral diencephalon (rp = 0.50, p = 0.001), and pallidum (rp = 0.38, p = 0.01). Bilingualism positively correlated with hippocampal volume, though not statistically significant (rp = 0.17, p = 0.26). No brain volumes were larger in monolinguals.

CONCLUSION

Bilinguals demonstrated larger thalamic, ventral diencephalon, and brainstem volumes compared to matched monolinguals with AD. This may represent a neural substrate for increased cognitive reserve in bilingualism. Future studies should extrapolate this finding into cognitively normal persons at risk for AD.

Current Research on the Impact of Foreign Language Learning Among Healthy Seniors on Their Cognitive Functions From a Positive Psychology Perspective-A Systematic Review

The purpose of this review study is to explore the existing research focusing on the impact of foreign language learning among healthy seniors on their cognitive functions from the positive psychology perspective. The methods are based on a literature review of available sources found on the research topic in two acknowledged databases: Web of Science and Scopus. The search period was not limited by any time period since there are not many studies on this topic. Altogether seven original studies were detected. The findings of this review study thus reveal that foreign language learning (FLL) has a positive impact on the maintenance and/or enhancement of cognitive abilities irrespective of age. In addition, the FLL courses seem to offer new opportunities for healthy seniors in the area of socializing and integration into society, which consequently may positively affect their overall well-being. Furthermore, the research shows that it is partly through the stimulation of social well-being that the cognitive effects of FLL might be observed. Cognitive aspects of older age are to be further investigated, including the importance of learning a foreign language, as basically all research conducted proves at least some maintenance or even improvement of cognitive functions of older people when starting intensive language training.

Bilingualism in Primary Progressive Aphasia: A Retrospective Study on Clinical and Language Characteristics

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive deterioration of language. Being rare, reports of PPA in multilingual individuals are scarce, despite more than half of the world population being multilingual.

METHODS

We describe clinical characteristics of 33 bilingual patients with PPA, including symptom presentation and language deficits pattern in their first (L1) and second language (L2), through a systematic literature review and new cases retrospectively identified in 5 countries.

RESULTS

In total, 14 patients presented with nonfluent/agrammatic variant, 6 with semantic variant, and 13 with logopenic variant, with a median symptom onset of 2 years. Word-finding difficulties was the first symptom in 65% of all cases, initially noticed in L2, and not always the dominant language. Our group had 22 different languages as L1, and 9 as L2. At the whole-group level there was a tendency for parallel impairment in both languages, in line with the shared bilingual neural substrate hypothesis, but each PPA variant showed some heterogeneity.

DISCUSSION

Each PPA variant showed heterogeneity, showing the need for comprehensive language and cognitive assessment across languages, as well as further clarification on the role of language mediators.

Bilingualism Is Associated with a Delayed Onset of Dementia but Not with a Lower Risk of Developing it: a Systematic Review with Meta-Analyses

Some studies have linked bilingualism with a later onset of dementia, Alzheimer's disease (AD), and mild cognitive impairment (MCI). Not all studies have observed such relationships, however. Differences in study outcomes may be due to methodological limitations and the presence of confounding factors within studies such as immigration status and level of education. We conducted the first systematic review with meta-analysis combining cross-sectional studies to explore if bilingualism might delay symptom onset and diagnosis of dementia, AD, and MCI. Primary outcomes included the age of symptom onset, the age at diagnosis of MCI or dementia, and the risk of developing MCI or dementia. A secondary outcome included the degree of disease severity at dementia diagnosis. There was no difference in the age of MCI diagnosis between monolinguals and bilinguals [mean difference: 3.2; 95% confidence intervals (CI): -3.4, 9.7]. Bilinguals vs. monolinguals reported experiencing AD symptoms 4.7 years (95% CI: 3.3, 6.1) later. Bilinguals vs. monolinguals were diagnosed with dementia 3.3 years (95% CI: 1.7, 4.9) later. Here, 95% prediction intervals showed a large dispersion of effect sizes (-1.9 to 8.5). We investigated this dispersion with a subgroup meta-analysis comparing studies that had recruited participants with dementia to studies that had recruited participants with AD on the age of dementia and AD diagnosis between mono- and bilinguals. Results showed that bilinguals vs. monolinguals were 1.9 years (95% CI: -0.9, 4.7) and 4.2 (95% CI: 2.0, 6.4) older than monolinguals at the time of dementia and AD diagnosis, respectively. The mean difference between the two subgroups was not significant. There was no significant risk reduction (odds ratio: 0.89; 95% CI: 0.68-1.16) in developing dementia among bilinguals vs. monolinguals. Also, there was no significant difference (Hedges' g = 0.05; 95% CI: -0.13, 0.24) in disease severity at dementia diagnosis between bilinguals and monolinguals, despite bilinguals being significantly older. The majority of studies had adjusted for level of education suggesting that education might not have played a role in the observed delay in dementia among bilinguals vs. monolinguals. Although findings indicated that bilingualism was on average related to a delayed onset of dementia, the magnitude of this relationship varied across different settings. This variation may be due to unexplained heterogeneity and different sources of bias in the included studies. Registration: PROSPERO CRD42015019100.

A Survey of Robot-Assisted Language Learning (RALL)

Robot-assisted language learning (RALL) is becoming a more commonly studied area of human-robot interaction (HRI). This research draws on theories and methods from many different fields, with researchers utilizing different instructional methods, robots, and populations to evaluate the effectiveness of RALL. This survey details the characteristics of robots used—form, voice, immediacy, non-verbal cues, and personalization—along with study implementations, discussing research findings. It also analyzes robot effectiveness. While research clearly shows that robots can support native and foreign language acquisition, it has been unclear what benefits robots provide over computer-assisted language learning. This survey examines the results of relevant studies from 2004 (RALL's inception) to 2017. Results suggest that robots may be uniquely suited to aid in language production, with apparent benefits in comparison to other technology. As well, research consistently indicates that robots provide unique advantages in increasing learning motivation and in-task engagement, and decreasing anxiety, though long-term benefits are uncertain. Throughout this survey, future areas of exploration are suggested, with the hope that answers to these questions will allow for more robust design and implementation guidelines in RALL.

Public Interest in Cognitive Impairment: An Analysis of the Top 50 Articles on Cognitive Impairment on Altmetric

Background

As the average life expectancy continues to increase, interest in cognitive impairment is increasing. Nowadays, as social media expands its reach, academic research is spreading through social media, changing the way and speed by which research is propagated and also who consumes this content. Therefore, using Altmetric, a new web-based set of metrics that analyzes the impact of content on social media platforms, we investigated the characteristics of influential research articles on the topic of cognitive impairment in social media.

Methods

An Altmetric Explorer search was performed on May 25, 2018, to extract the following information: (i) journal name, (ii) journal impact factor (IF), (iii) year of publication, (iv) article topic, (v) article type, and (vi) cognitive impairment subtype.

Results

The journal “Neurology” was the most cited journal for cognitive impairment articles shared on social media. Among the various types of cognitive impairment, most articles were related to dementia (all subtypes), Alzheimer's disease, and aging. The most common article type was original scientific paper, especially cohort study. The most popular topic was the identification of protective or risk factors for cognitive impairment.

Conclusion

The characteristics of articles with a high Altmetric Attention Score were somewhat different from those of articles with a high number of traditional citations. Social media had the disadvantage that it was difficult to verify the authenticity of the primary source in question, but the advantage was that it could immediately determine the trends regarding how information about that source was being shared and consumed. Therefore, it may be advisable to use Altmetric analysis in combination with traditional methods of evaluating the research articles to understand the dissemination of scientific research and to direct future research.

Capturing multiple interaction effects in L1 and L2 object-naming reaction times in healthy bilinguals: a mixed-effects multiple regression analysis

Background

It is difficult to set up a balanced higher-order full-factorial experiment that can capture multiple intricate interactions between cognitive and psycholinguistic factors underlying bilingual speech production. To capture interactions more fully in one study, we analyzed object-naming reaction times (RTs) by using mixed-effects multiple regression.

Methods

Ten healthy bilinguals (median age: 23 years, seven females) were asked to name 131 colored pictures of common objects in each of their languages. RTs were analyzed based on language status, proficiency, word choice, word frequency, word duration, initial phoneme, time series, and participant’s gender.

Results

Among five significant interactions, new findings include a facilitating effect of a cross-language shared initial phoneme (mean RT for shared phoneme: 974 ms vs. mean RT for different phoneme: 1020 ms), which profited males less (mean profit: 10 ms) than females (mean profit: 47 ms).

Conclusions

Our data support language-independent phonological activation and a gender difference in inhibitory cognitive language control. Single word production process in healthy adult bilinguals is affected by interactions among cognitive, phonological, and semantic factors.