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Li X, Ng KK, Wong JJY, Zhou JH, Yow WQ. Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults. Sci Rep 2024; 14:3193. [PMID: 38326334 PMCID: PMC10850089 DOI: 10.1038/s41598-023-48710-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/29/2023] [Indexed: 02/09/2024] Open
Abstract
Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines.
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Affiliation(s)
- Xiaoqian Li
- Humanities, Arts and Social Sciences, Singapore University of Technology and Design, Singapore, Singapore
| | - Kwun Kei Ng
- Centre for Sleep and Cognition & Centre for Translational Magnetic Resonance Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Joey Ju Yu Wong
- Centre for Sleep and Cognition & Centre for Translational Magnetic Resonance Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Juan Helen Zhou
- Centre for Sleep and Cognition & Centre for Translational Magnetic Resonance Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
| | - W Quin Yow
- Humanities, Arts and Social Sciences, Singapore University of Technology and Design, Singapore, Singapore.
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2
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Pacifico D, Sabatini S, Fiordelli M, Annoni AM, Frei A, Puhan M, Graf G, Albanese E. Associations of multilingualism and language proficiency with cognitive functioning: epidemiological evidence from the SwissDEM study in community dwelling older adults and long-term care residents. BMC Geriatr 2023; 23:629. [PMID: 37803260 PMCID: PMC10559505 DOI: 10.1186/s12877-023-04311-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 09/12/2023] [Indexed: 10/08/2023] Open
Abstract
BACKGROUND We explored whether number of languages spoken and language proficiency are associated with cognitive performance among older adults living in the community and in long-term care (LTC) in Switzerland. METHODS Among study participants, 664 lived in the community in the Canton of Zurich (Mean age = 72.97 years; SD = 6.08), 386 lived in the community in Ticino (Mean age = 76.24 years; SD = 6.66), and 176 resided in LTC in Ticino (Mean age = 87.61 years; SD = 6.45). We recorded sociodemographic variables, number of languages spoken, language proficiency, and assessed overall cognitive performance, immediate and delayed memory, and verbal fluency with standardized tests. We used adjusted regression models. RESULTS A higher number of spoken languages was positively associated with overall cognitive performance, verbal fluency and immediate and delayed memory performance in community-dwelling older adults in the Cantons of Ticino and Zurich, (all p values ≤ 0.012;), but not in in older adults living in LTC homes (all p values ≥ 0.35). Higher language proficiency was associated with better memory performance among individuals living in the community in Ticino (p value = 0.003), and to better performance in verbal fluency and memory tasks in Zurich (p values ≤ 0.002). Among LTC residents, proficiency levels were not associated with cognitive performance. CONCLUSIONS Multilingualism and greater language proficiency were associated with better cognitive functioning in community-dwelling but not in institutionalized older adults. Multilingualism may contribute to cognitive reserve, as well as protect and delay cognitive decline in late life.
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Affiliation(s)
- Deborah Pacifico
- Institute of Public Health, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland.
| | - Serena Sabatini
- School of Medicine, University of Nottingham, Nottingham, UK
| | - Maddalena Fiordelli
- Institute of Public Health, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
- Department of Health Sciences and Medicine, University of Lucerne, Lucerne, Switzerland
| | - Anna Maria Annoni
- Institute of Public Health, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Anja Frei
- Epidemiology Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Milo Puhan
- Epidemiology Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Gwendolyn Graf
- Epidemiology Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Emiliano Albanese
- Institute of Public Health, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
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3
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Rodriguez MJ, Burke S, Padron D, Duarte A, Rosselli M, Grieg-Custo M, Grudzien A, Loewenstein DA, Duara R. Associations Between Country where Education is Obtained and Cognitive Functioning Among South American and Caribbean Older Adults Living in the U.S. J Cross Cult Gerontol 2022; 37:257-274. [PMID: 36251109 PMCID: PMC10161283 DOI: 10.1007/s10823-022-09456-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2022] [Indexed: 10/24/2022]
Abstract
The increasing prevalence of AD among Hispanics calls for a need for examining factors that affect cognitive functioning and risk of AD among Hispanic older adults. The current study examined cognitive functioning among older Hispanic adults living in the U.S. from two Hispanic regions, South America and the Caribbean, in relation to the country where education was obtained. Participants (n = 139) were stratified into groups based on Hispanic education region and diagnostic categories: cognitively normal and amnestic MCI (aMCI). Results of Pearson correlations showed that among Hispanic Americans in general, there were significant positive correlations between the country of education to performance on measures of episodic, verbal, and word list tests. When examined separately by region and diagnosis, only cognitively normal (CN) South Americans showed significant relationships between country of education and cognitive functioning in these areas. Results of general linear models controlling for education identified differences in neuropsychological performance between groups with the CN groups demonstrating better performance than the aMCI groups within each region. Overall, it was evident that relationships between years of education obtained outside of the U.S. and cognitive functioning were not similar among individuals from these two disparate Spanish speaking regions. This is the first study to examine the country where education was obtained among individuals from countries located in different regions with different cultures that may influence their education and cognitive development throughout life. Findings contribute to the cross-cultural neuropsychological literature in understanding factors that are unique to Hispanic older adults at risk for developing AD.
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Affiliation(s)
- Miriam J Rodriguez
- Department of Health and Wellness Design, Indiana University-Bloomington, School of Public Health, Bloomington, IN, USA.
| | - Shanna Burke
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
| | | | - Andres Duarte
- Department of Psychology, Albizu University, Miami, FL, USA
| | - Monica Rosselli
- Department of Psychology, Charles E. Schmidt College of Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Maria Grieg-Custo
- Mt. Sinai Medical Center, Wien Center for Alzheimer's Disease and Memory Disorders, Miami Beach, FL, USA
| | - Adrienne Grudzien
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
| | - David A Loewenstein
- Department of Miller School of Medicine, University of Miami and Center on Aging, Miami, FL, USA
| | - Ranjan Duara
- Mt. Sinai Medical Center, Wien Center for Alzheimer's Disease and Memory Disorders, Miami Beach, FL, USA
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4
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Brantuo MA, An K, Biss RK, Ali S, Erdodi LA. Neurocognitive Profiles Associated With Limited English Proficiency in Cognitively Intact Adults. Arch Clin Neuropsychol 2022; 37:1579-1600. [PMID: 35694764 DOI: 10.1093/arclin/acac019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE The objective of the present study was to examine the neurocognitive profiles associated with limited English proficiency (LEP). METHOD A brief neuropsychological battery including measures with high (HVM) and low verbal mediation (LVM) was administered to 80 university students: 40 native speakers of English (NSEs) and 40 with LEP. RESULTS Consistent with previous research, individuals with LEP performed more poorly on HVM measures and equivalent to NSEs on LVM measures-with some notable exceptions. CONCLUSIONS Low scores on HVM tests should not be interpreted as evidence of acquired cognitive impairment in individuals with LEP, because these measures may systematically underestimate cognitive ability in this population. These findings have important clinical and educational implications.
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Affiliation(s)
- Maame A Brantuo
- Department of Psychology, Neuropsychology Track, University of Windsor, Windsor ON, Canada
| | - Kelly An
- Department of Psychology, Neuropsychology Track, University of Windsor, Windsor ON, Canada
| | - Renee K Biss
- Department of Psychology, Neuropsychology Track, University of Windsor, Windsor ON, Canada
| | - Sami Ali
- Department of Psychology, Neuropsychology Track, University of Windsor, Windsor ON, Canada
| | - Laszlo A Erdodi
- Department of Psychology, Neuropsychology Track, University of Windsor, Windsor ON, Canada
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Reaume M, Batista R, Rhodes E, Knight B, Imsirovic H, Seale E, Riad K, Prud'homme D, Tanuseputro P. The Impact of Language on Emergency Department Visits, Hospitalizations, and Length of Stay Among Home Care Recipients. Med Care 2021; 59:1006-1013. [PMID: 34432768 DOI: 10.1097/mlr.0000000000001638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Research considering the impact of language on health care utilization is limited. We conducted a population-based study to: (1) investigate the association between residents' preferred language and hospital-based health care utilization; and (2) determine whether this association is modified by dementia, a condition which can exacerbate communication barriers. METHODS We used administrative databases to establish a retrospective cohort study of home care recipients (2015-2017) in Ontario, Canada, where the predominant language is English. Residents' preferred language (obtained from in-person home care assessments) was coded as English (Anglophones), French (Francophones), or other (Allophones). Diagnoses of dementia were ascertained with a previously validated algorithm. We identified all emergency department (ED) visits and hospitalizations within 1 year. RESULTS Compared with Anglophones, Allophones had lower annual rates of ED visits (1.3 vs. 1.8; P<0.01) and hospitalizations (0.6 vs. 0.7; P<0.01), while Francophones had longer hospital stays (9.1 vs. 7.6 d per admission; P<0.01). After adjusting for potential confounders, Francophones and Allophones were less likely to visit the ED or be hospitalized than Anglophones. We found evidence of synergism between language and dementia; the average length of stay for Francophones with dementia was 25% (95% confidence interval: 1.10-1.39) longer when compared with Anglophones without dementia. CONCLUSIONS Residents whose preferred language was not English were less frequent users of hospital-based health care services, a finding that is likely attributable to cultural factors. Francophones with dementia experienced the longest stays in hospital. This may be related to the geographic distribution of Francophones (predominantly in rural areas) or to suboptimal patient-provider communication.
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Affiliation(s)
- Michael Reaume
- Faculty of Medicine, University of Ottawa
- Institut du Savoir Montfort
| | - Ricardo Batista
- Institut du Savoir Montfort
- Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa
- ICES
| | - Emily Rhodes
- Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa
| | - Braden Knight
- Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa
- ICES
| | - Haris Imsirovic
- Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa
- ICES
| | - Emily Seale
- Faculty of Medicine, University of Ottawa
- Institut du Savoir Montfort
| | - Karine Riad
- Faculty of Medicine, University of Ottawa
- Institut du Savoir Montfort
| | - Denis Prud'homme
- Institut du Savoir Montfort
- Faculty of Health Sciences, University of Ottawa
| | - Peter Tanuseputro
- Faculty of Medicine, University of Ottawa
- Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa
- ICES
- Bruyère Research Institute, Ottawa, Canada
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Heredia RR, Blackburn AM, Vega LA. Moderation-Mediation Effects in Bilingualism and Cognitive Reserve. Front Psychol 2020; 11:572555. [PMID: 33101142 PMCID: PMC7554512 DOI: 10.3389/fpsyg.2020.572555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023] Open
Abstract
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.
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Affiliation(s)
- Roberto R Heredia
- Department of Psychology and Communication, Texas A&M International University, Laredo, TX, United States
| | - Angélique M Blackburn
- Department of Psychology and Communication, Texas A&M International University, Laredo, TX, United States
| | - Luis A Vega
- Department of Psychology, California State University-Bakersfield, Bakersfield, CA, United States
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7
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Hack EE, Dubin JA, Fernandes MA, Costa SM, Tyas SL. Multilingualism and Dementia Risk: Longitudinal Analysis of the Nun Study. J Alzheimers Dis 2020; 71:201-212. [PMID: 31322560 DOI: 10.3233/jad-181302] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Multilingualism is associated with enhanced executive function and may thus prevent cognitive decline and reduce the risk of dementia. OBJECTIVE To determine whether multilingualism is associated with delayed onset or reduced risk of dementia. METHODS Dementia was diagnosed in the Nun Study, a longitudinal study of religious sisters aged 75+ years. Multilingualism was self-reported. Dementia likelihood was determined in 325 participants using discrete-time survival analysis; sensitivity analyses (n = 106) incorporated additional linguistic measures (idea density and grammatical complexity). RESULTS Multilingualism did not delay the onset of dementia. However, participants speaking four or more languages (but not two or three) were significantly less likely to develop dementia than monolinguals (OR = 0.13; 95% CI = 0.01, 0.65, adjusted for age, apolipoprotein E, and transition period). This significant protective effect of speaking four or more languages weakened (OR = 0.53; 95% CI = 0.06, 4.91) in the presence of idea density in models adjusted for education and apolipoprotein E. CONCLUSION Linguistic ability broadly was a significant predictor of dementia, although it was written linguistic ability (specifically idea density) rather than multilingualism that was the strongest predictor. The impact of language on dementia may extend beyond number of languages spoken to encompass other indicators of linguistic ability. Further research to identify the characteristics of multilingualism most salient for risk of dementia could clarify the value, target audience, and design of interventions to promote multilingualism and other linguistic training as a strategy to reduce the risk of dementia and its individual and societal impacts.
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Affiliation(s)
- Erica E Hack
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada
| | - Joel A Dubin
- Department of Statistics and Actuarial Science, and School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada
| | - Myra A Fernandes
- Department of Psychology, University of Waterloo, Waterloo, ON, Canada
| | - Sanduni M Costa
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada
| | - Suzanne L Tyas
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada
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8
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Teubner-Rhodes S. Cognitive Persistence and Executive Function in the Multilingual Brain During Aging. Front Psychol 2020; 11:568702. [PMID: 33013606 PMCID: PMC7494780 DOI: 10.3389/fpsyg.2020.568702] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/13/2020] [Indexed: 11/14/2022] Open
Abstract
Researchers have debated the extent to which the experience of speaking more than two languages induces long-term neuroplasticity that protects multilinguals from the adverse cognitive effects of aging. In this review, I propose a novel theory that multilingualism affects cognitive persistence, the application of effort to improve performance on challenging tasks. I review recent evidence demonstrating that the cingulo-opercular network, consisting of the bilateral inferior frontal gyrus (IFG) and dorsal anterior cingulate cortex (dACC), supports cognitive persistence. I then show that this same network is involved in multilingual language control and changes with multilingual language experience. While both early and late multilinguals exhibit differences in the cingulo-opercular network compared to monolinguals, I find that early multilinguals have a pattern of decreased dACC activity and increased left IFG activity that may enable more efficient cognitive control, whereas late multilinguals show larger dACC responses to conflict that may be associated with higher cognitive persistence. I further demonstrate that multilingual effects on the cingulo-opercular network are present in older adults and have been implicated in the mitigation of cognitive symptoms in age-related neurodegenerative disorders. Finally, I argue that mixed results in the literature are due, in part, to the confound between cognitive persistence and ability in most executive function tasks, and I provide guidance for separating these processes in future research.
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Affiliation(s)
- Susan Teubner-Rhodes
- Department of Psychological Sciences, Auburn University, Auburn, AL, United States
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9
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Costumero V, Marin-Marin L, Calabria M, Belloch V, Escudero J, Baquero M, Hernandez M, Ruiz de Miras J, Costa A, Parcet MA, Ávila C. A cross-sectional and longitudinal study on the protective effect of bilingualism against dementia using brain atrophy and cognitive measures. ALZHEIMERS RESEARCH & THERAPY 2020; 12:11. [PMID: 31924269 PMCID: PMC6954576 DOI: 10.1186/s13195-020-0581-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/05/2020] [Indexed: 01/27/2023]
Abstract
Background Evidence from previous studies suggests that bilingualism contributes to cognitive reserve because bilinguals manifest the first symptoms of Alzheimer’s disease (AD) up to 5 years later than monolinguals. Other cross-sectional studies demonstrate that bilinguals show greater amounts of brain atrophy and hypometabolism than monolinguals, despite sharing the same diagnosis and suffering from the same symptoms. However, these studies may be biased by possible pre-existing between-group differences. Methods In this study, we used global parenchymal measures of atrophy and cognitive tests to investigate the protective effect of bilingualism against dementia cross-sectionally and prospectively, using a sample of bilinguals and monolinguals in the same clinical stage and matched on sociodemographic variables. Results Our results suggest that the two groups did not differ in their cognitive status at baseline, but bilinguals had less parenchymal volume than monolinguals, especially in areas related to brain atrophy in dementia. In addition, a longitudinal prospective analysis revealed that monolinguals lost more parenchyma and had more cognitive decline than bilinguals in a mean follow-up period of 7 months. Conclusion These results provide the first prospective evidence that bilingualism may act as a neuroprotective factor against dementia and could be considered a factor in cognitive reserve.
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Affiliation(s)
- Víctor Costumero
- Center for Brain and Cognition, University Pompeu Fabra, Barcelona, Spain.,Neuropsychology and Functional Neuroimaging Group, University Jaume I, Castellón, Spain.,ERI Lectura, University of Valencia, Valencia, Spain
| | - Lidon Marin-Marin
- Neuropsychology and Functional Neuroimaging Group, University Jaume I, Castellón, Spain
| | - Marco Calabria
- Center for Brain and Cognition, University Pompeu Fabra, Barcelona, Spain
| | | | - Joaquín Escudero
- Department of Neurology, General Hospital of Valencia, Valencia, Spain
| | - Miguel Baquero
- Neurology Unit, University and Polytechnic Hospital La Fe, Valencia, Spain
| | - Mireia Hernandez
- Department of Cognition, Development, and Educational Psychology Section of Cognitive Processes, University of Barcelona, Barcelona, Spain.,Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Spain
| | | | - Albert Costa
- Center for Brain and Cognition, University Pompeu Fabra, Barcelona, Spain
| | - Maria-Antònia Parcet
- Neuropsychology and Functional Neuroimaging Group, University Jaume I, Castellón, Spain
| | - César Ávila
- Neuropsychology and Functional Neuroimaging Group, University Jaume I, Castellón, Spain.
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10
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Mendez MF. Bilingualism and Dementia: Cognitive Reserve to Linguistic Competency. J Alzheimers Dis 2019; 71:377-388. [DOI: 10.3233/jad-190397] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Mario F. Mendez
- V.A. Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Departments of Neurology and Psychiatry & Biobehavioral Sciences, Los Angeles, CA, USA
- David Geffen School of Medicine, University of California at Los Angeles, CA, USA
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11
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van den Noort M, Vermeire K, Bosch P, Staudte H, Krajenbrink T, Jaswetz L, Struys E, Yeo S, Barisch P, Perriard B, Lee SH, Lim S. A Systematic Review on the Possible Relationship Between Bilingualism, Cognitive Decline, and the Onset of Dementia. Behav Sci (Basel) 2019; 9:E81. [PMID: 31340609 PMCID: PMC6680432 DOI: 10.3390/bs9070081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 12/20/2022] Open
Abstract
A systematic review was conducted to investigate whether bilingualism has a protective effect against cognitive decline in aging and can protect against dementia. We searched the Medline, ScienceDirect, Scopus, and ERIC databases with a cut-off date of 31 March, 2019, thereby following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol. Our search resulted in 34 eligible studies. Mixed results were found with respect to the protective effect of bilingualism against cognitive decline. Several studies showed a protective effect whereas other studies failed to find it. Moreover, evidence for a delay of the onset of dementia of between 4 and 5.5 years in bilingual individuals compared to monolinguals was found in several studies, but not in all. Methodological differences in the set-up of the studies seem to explain these mixed results. Lifelong bilingualism is a complex individual process, and many factors seem to influence this and need to be further investigated. This can be best achieved through large longitudinal studies with objective behavioral and neuroimaging measurements. In conclusion, although some evidence was found for a cognitive reserve-enhancing effect of lifelong bilingualism and protection against dementia, to date, no firm conclusions can be drawn.
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Affiliation(s)
- Maurits van den Noort
- Research Group of Pain and Neuroscience, Kyung Hee University, Seoul 130-701, Korea.
- Brussels Institute for Applied Linguistics, Vrije Universiteit Brussel, Brussels 1050, Belgium.
| | - Katrien Vermeire
- Department of Communication Sciences and Disorders, Long Island University (LIU) Brooklyn, Brooklyn, NY 11201, USA
| | - Peggy Bosch
- Psychiatric Research Group, LVR-Klinik Bedburg-Hau, 47511 Bedburg-Hau, Germany
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University, 6525 Nijmegen, The Netherlands
| | - Heike Staudte
- Psychiatric Research Group, LVR-Klinik Bedburg-Hau, 47511 Bedburg-Hau, Germany
| | - Trudy Krajenbrink
- Department of Medicine, Neurology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Lars Jaswetz
- Behavioural Science Institute, Radboud University, 6525 Nijmegen, The Netherlands
| | - Esli Struys
- Brussels Institute for Applied Linguistics, Vrije Universiteit Brussel, Brussels 1050, Belgium
| | - Sujung Yeo
- College of Oriental Medicine, Sang Ji University, Wonju 26339, Korea
| | - Pia Barisch
- Department of Psychology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Benoît Perriard
- Department of Medicine, Neurology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Sook-Hyun Lee
- Research Group of Pain and Neuroscience, Kyung Hee University, Seoul 130-701, Korea
| | - Sabina Lim
- Research Group of Pain and Neuroscience, Kyung Hee University, Seoul 130-701, Korea.
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12
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MacPherson SE, Gillebert CR, Robinson GA, Vallesi A. Editorial: Intra- and Inter-individual Variability of Executive Functions: Determinant and Modulating Factors in Healthy and Pathological Conditions. Front Psychol 2019; 10:432. [PMID: 30906272 PMCID: PMC6418029 DOI: 10.3389/fpsyg.2019.00432] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 02/13/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Sarah E. MacPherson
- Human Cognitive Neuroscience, Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Celine R. Gillebert
- Department of Brain and Cognition, KU Leuven, Leuven, Belgium
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Gail A. Robinson
- Neuropsychology Research Unit, School of Psychology, The University of Queensland, Brisbane, QLD, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Antonino Vallesi
- Department of Neuroscience & Padova Neuroscience Center, University of Padua, Padua, Italy
- Brain Imaging and Neural Dynamics Research Group, IRCCS San Camillo Hospital, Venice, Italy
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13
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Braak H, Del Tredici K. Top-Down Projections Direct the Gradual Progression of Alzheimer-Related Tau Pathology Throughout the Neocortex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:291-303. [PMID: 32096045 DOI: 10.1007/978-981-32-9358-8_22] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In sporadic Alzheimer's disease (sAD), tau pathology gradually but relentlessly progresses from the transentorhinal region of the temporal lobe into both the allocortex and temporal high order association areas of the neocortex. From there, it ultimately reaches the primary sensory and motor fields of the neocortex. The brunt of the changes seen during neurofibrillary stages (NFT) I-VI is borne by top-down projection neurons that contribute to cortico-cortical connectivities between different neocortical fields. Very early changes develop in isolated pyramidal cells in layers III and V, and these cells are targets of top-down projections terminating in association areas of the first temporal gyrus or in peristriate regions of the occipital lobe. Neurofibrillary pathology in these regions is routinely associated with late NFT stages. Sequential changes occur in different cell compartments (dendritic, somatic, axonal) of these early-involved neurons. Tau pathology first develops in distal segments of basal dendrites, then in proximal dendrites, the soma, and, finally, in the axon of affected pyramidal neurons. This sequence of abnormal changes supports the concept that axons of cortico-cortical top-down neurons may carry and spread abnormal tau seeds in a focused manner (transsynaptically) into the distal dendritic segments of nerve cells directly following in the neuronal chain, thereby sustaining tau-seeded templating in sAD.
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Affiliation(s)
- Heiko Braak
- Clinical Neuroanatomy Section/Department of Neurology, Center for Biomedical Research, University of Ulm, Ulm, Germany
| | - Kelly Del Tredici
- Clinical Neuroanatomy Section/Department of Neurology, Center for Biomedical Research, University of Ulm, Ulm, Germany.
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Mendez MF, Chavez D, Akhlaghipour G. Bilingualism Delays Expression of Alzheimer's Clinical Syndrome. Dement Geriatr Cogn Disord 2019; 48:281-289. [PMID: 32045913 PMCID: PMC7195235 DOI: 10.1159/000505872] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/10/2020] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE To evaluate the effects of bilingualism on the emergence of Alzheimer's clinical syndrome. BACKGROUND Studies have proposed an increase in cognitive and neural reserve from the management and control of two languages, with a consequent delayed expression of dementia. METHODS In a clinic with a large immigrant population, we identified 253 patients with probable Alzheimer's disease (AD) with intermediate or high evidence of AD pathophysiological process. These patients were reviewed for demographic variables, native language (L1) other than English, ages of onset and presentation, Mini-Mental State Examination (MMSE), digit spans, word fluencies, naming, and memory. RESULTS Among these patients, 74 (29.2%) were bilinguals with various L1s (Farsi, Spanish, Chinese, Tagalog, Arabic, others). When compared to the 179 monolingual AD patients, those who were bilingual had significant delays in ages of onset and presentation of approximately 4 years (p = 0.003). These delays persisted despite bilinguals having worse MMSE scores on presentation. There were no significant group differences on other variables except for worse naming in English among bilinguals versus monolinguals. Caregiver/informants reported that 66 (89.2%) of the 74 bilingual AD patients had gradually regressed to the predominant use of their L1. CONCLUSIONS In line with published reports worldwide, we found that bilingualism delays the expression of Alzheimer's clinical syndrome. We also found frequent reversion to the first learned language. These findings suggest that, among bilinguals, the availability of an L1 "back-up" either facilitates compensation or masks emergence of the early symptoms of dementia.
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Affiliation(s)
- Mario F. Mendez
- V.A. Greater Los Angeles Healthcare System, Los Angeles, CA, USA,Departments of Neurology, David Geffen School of Medicine, University of California at Los Angeles, CA, USA,Psychiatry & Biobehavioral Sciences, and Medicine, David Geffen School of Medicine, University of California at Los Angeles, CA, USA
| | - Diana Chavez
- Departments of Neurology, David Geffen School of Medicine, University of California at Los Angeles, CA, USA
| | - Golnoush Akhlaghipour
- Departments of Neurology, David Geffen School of Medicine, University of California at Los Angeles, CA, USA
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Mungas D, Early DR, Glymour MM, Al Hazzouri AZ, Haan MN. Education, bilingualism, and cognitive trajectories: Sacramento Area Latino Aging Study (SALSA). Neuropsychology 2018; 32:77-88. [PMID: 28967765 PMCID: PMC5814330 DOI: 10.1037/neu0000356] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE This study examined the influence of education, country where education occurred, and monolingual-bilingual (English/Spanish) language usage on late life cognitive trajectories in the Sacramento Area Latino Study on Aging (SALSA), an epidemiological study of health and cognition in Hispanics, mostly of Mexican origin, age 60 and over (N = 1,499). METHOD SALSA followed a large cohort of older Latinos for up to 7 assessment waves from 1998 to 2007. Global cognition was assessed by using the Modified Mini Mental State Examination, and the Spanish English Verbal Learning Test was used to measure episodic memory. Education, country of origin, and language usage patterns were collected at the baseline assessment and used as predictors of longitudinal trajectories of cognition. Parallel process mixed effects models were used to examine effects of education and language variables on baseline cognition and rate of cognitive decline. RESULTS Mixed effects longitudinal models showed that education had strong effects on baseline global cognition and verbal memory but was not related to decline over up to 9 years of longitudinal follow-up. Differences in education effects between subgroups educated in Mexico and in the United States were minor. Monolingual-bilingual language usage was not related to cognitive decline, and bilinguals did not significantly differ from monolingual English speakers on baseline cognitive scores. CONCLUSIONS Hypotheses that higher education and bilingualism protect against late life cognitive decline were not supported and education effects on late-life cognitive trajectories did not substantially differ across U.S.- and Mexico-educated groups. (PsycINFO Database Record
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Affiliation(s)
- Dan Mungas
- Department of Neurology, University of California, Davis, Davis, CA
| | - Dawnté R. Early
- Department of Neurology, University of California, Davis, Davis, CA
| | - M. Maria Glymour
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA
| | | | - Mary N. Haan
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA
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Antoniou M, Wright SM. Uncovering the Mechanisms Responsible for Why Language Learning May Promote Healthy Cognitive Aging. Front Psychol 2017; 8:2217. [PMID: 29326636 PMCID: PMC5736569 DOI: 10.3389/fpsyg.2017.02217] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/07/2017] [Indexed: 01/08/2023] Open
Abstract
One of the great challenges facing humankind in the 21st century is preserving healthy brain function in our aging population. Individuals over 60 are the fastest growing age group in the world, and by 2050, it is estimated that the number of people over the age of 60 will triple. The typical aging process involves cognitive decline related to brain atrophy, especially in frontal brain areas and regions that subserve declarative memory, loss of synaptic connections, and the emergence of neuropathological symptoms associated with dementia. The disease-state of this age-related cognitive decline is Alzheimer's disease and other dementias, which may cause older adults to lose their independence and rely on others to live safely, burdening family members and health care systems in the process. However, there are two lines of research that offer hope to those seeking to promote healthy cognitive aging. First, it has been observed that lifestyle variables such as cognitive leisure activities can moderate the risk of Alzheimer's disease, which has led to the development of plasticity-based interventions for older adults designed to protect against the adverse effects of cognitive decline. Second, there is evidence that lifelong bilingualism acts as a safeguard in preserving healthy brain function, possibly delaying the incidence of dementia by several years. In previous work, we have suggested that foreign language learning programs aimed at older populations are an optimal solution for building cognitive reserve because language learning engages an extensive brain network that is known to overlap with the regions negatively affected by the aging process. Here, we will outline potential future lines of research that may uncover the mechanism responsible for the emergence of language learning related brain advantages, such as language typology, bi- vs. multi-lingualism, age of acquisition, and the elements that are likely to result in the largest gains.
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Affiliation(s)
- Mark Antoniou
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, NSW, Australia
| | - Sarah M Wright
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, NSW, Australia
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Alladi S, Bak TH, Shailaja M, Gollahalli D, Rajan A, Surampudi B, Hornberger M, Duggirala V, Chaudhuri JR, Kaul S. Bilingualism delays the onset of behavioral but not aphasic forms of frontotemporal dementia. Neuropsychologia 2017; 99:207-212. [PMID: 28322905 DOI: 10.1016/j.neuropsychologia.2017.03.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/04/2017] [Accepted: 03/16/2017] [Indexed: 12/14/2022]
Abstract
Bilingualism has been found to delay onset of dementia and this has been attributed to an advantage in executive control in bilinguals. However, the relationship between bilingualism and cognition is complex, with costs as well as benefits to language functions. To further explore the cognitive consequences of bilingualism, the study used Frontotemporal dementia (FTD) syndromes, to examine whether bilingualism modifies the age at onset of behavioral and language variants of Frontotemporal dementia (FTD) differently. Case records of 193 patients presenting with FTD (121 of them bilingual) were examined and the age at onset of the first symptoms were compared between monolinguals and bilinguals. A significant effect of bilingualism delaying the age at onset of dementia was found in behavioral variant FTD (5.7 years) but not in progressive nonfluent aphasia (0.7 years), semantic dementia (0.5 years), corticobasal syndrome (0.4 years), progressive supranuclear palsy (4.3 years) and FTD-motor neuron disease (3 years). On dividing all patients predominantly behavioral and predominantly aphasic groups, age at onset in the bilingual behavioral group (62.6) was over 6 years higher than in the monolingual patients (56.5, p=0.006), while there was no difference in the aphasic FTD group (60.9 vs. 60.6 years, p=0.851). The bilingual effect on age of bvFTD onset was shown independently of other potential confounding factors such as education, gender, occupation, and urban vs rural dwelling of subjects. To conclude, bilingualism delays the age at onset in the behavioral but not in the aphasic variants of FTD. The results are in line with similar findings based on research in stroke and with the current views of the interaction between bilingualism and cognition, pointing to advantages in executive functions and disadvantages in lexical tasks.
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Affiliation(s)
- Suvarna Alladi
- Department of Neurology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500082, India.
| | - Thomas H Bak
- Department of Psychology, Centre for Cognitive Aging and Cognitive Epidemiology (CCACE) and Centre for Clinical Brain Sciences (CCBS), University of Edinburgh, Edinburgh, UK.
| | - Mekala Shailaja
- Department of Neurology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500082, India.
| | - Divyaraj Gollahalli
- Department of Neurology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500082, India.
| | - Amulya Rajan
- Department of Neurology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500082, India.
| | - Bapiraju Surampudi
- Cognitive Science Lab, International Institute of Information Technology, Hyderabad & Centre for Neural and Cognitive Sciences, University of Hyderabad, Hyderabad, India.
| | | | | | | | - Subhash Kaul
- Department of Neurology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500082, India.
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Cox SR, Bak TH, Allerhand M, Redmond P, Starr JM, Deary IJ, MacPherson SE. Bilingualism, social cognition and executive functions: A tale of chickens and eggs. Neuropsychologia 2016; 91:299-306. [PMID: 27586077 PMCID: PMC5090873 DOI: 10.1016/j.neuropsychologia.2016.08.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 08/27/2016] [Accepted: 08/27/2016] [Indexed: 11/30/2022]
Abstract
The influence of bilingualism on cognitive functioning is currently a topic of intense scientific debate. The strongest evidence for a cognitive benefit of bilingualism has been demonstrated in executive functions. However, the causal direction of the relationship remains unclear: does learning other languages improve executive functions or are people with better executive abilities more likely to become bilingual? To address this, we examined 90 male participants of the Lothian Birth Cohort 1936; 26 were bilingual, 64 monolingual. All participants underwent an intelligence test at age 11 years and were assessed on a wide range of executive and social cognition tasks at age 74. The only notable differences between both groups were found for the Simon Effect (which indexes stimulus-response conflict resolution; β=-.518, p=0.025) and a trend effect for the Faux Pas task (a measure of complex theory of mind; ToM, β=0.432, p=0.060). Controlling for the influence of childhood intelligence, parental and own social class significantly attenuated the bilingual advantage on the Faux Pas test (β=0.058, p=0.816), whereas the Simon task advantage remained (β=-.589, p=0.049). We find some weak evidence that the relationship between bilingualism and cognitive functions may be selective and bi-directional. Pre-existing cognitive and social class differences from childhood may influence both ToM ability in older age and the likelihood of learning another language; yet, bilingualism does not appear to independently contribute to Faux Pas score. Conversely, learning a second language is related to better conflict processing, irrespective of initial childhood ability or social class.
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Affiliation(s)
- Simon R Cox
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK
| | - Thomas H Bak
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK.
| | - Michael Allerhand
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK
| | - Paul Redmond
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK
| | - John M Starr
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK; Geriatric Medicine, University of Edinburgh, UK; Alzheimer Scotland Dementia Research Centre, University of Edinburgh, UK
| | - Ian J Deary
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK
| | - Sarah E MacPherson
- Centre for Cognitive Aging and Cognitive Epidemiology, University of Edinburgh, UK; Department of Psychology, University of Edinburgh, 7 Geroge Square, Edinburgh EH8 9JZ, UK
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Klein RM, Christie J, Parkvall M. Does multilingualism affect the incidence of Alzheimer's disease?: A worldwide analysis by country. SSM Popul Health 2016; 2:463-467. [PMID: 29349161 PMCID: PMC5757845 DOI: 10.1016/j.ssmph.2016.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/25/2016] [Accepted: 06/09/2016] [Indexed: 11/25/2022] Open
Abstract
It has been suggested that the cognitive requirements associated with bi- and multilingual processing provide a form of mental exercise that, through increases in cognitive reserve and brain fitness, may delay the symptoms of cognitive failure associated with Alzheimer′s disease and other forms of dementia. We collected data on a country-by-country basis that might shed light on this suggestion. Using the best available evidence we could find, the somewhat mixed results we obtained provide tentative support for the protective benefits of multilingualism against cognitive decline. But more importantly, this study exposes a critical issue, which is the need for more comprehensive and more appropriate data on the subject.
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Affiliation(s)
- Raymond M Klein
- Dalhousie University, Department of Psychology & Neuroscience, Halifax, Nova Scotia, Canada B3H 4R2
| | - John Christie
- Dalhousie University, Department of Psychology & Neuroscience, Halifax, Nova Scotia, Canada B3H 4R2
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Ihle A, Oris M, Fagot D, Kliegel M. The relation of the number of languages spoken to performance in different cognitive abilities in old age. J Clin Exp Neuropsychol 2016; 38:1103-14. [PMID: 27350393 DOI: 10.1080/13803395.2016.1197184] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Findings on the association of speaking different languages with cognitive functioning in old age are inconsistent and inconclusive so far. Therefore, the present study set out to investigate the relation of the number of languages spoken to cognitive performance and its interplay with several other markers of cognitive reserve in a large sample of older adults. METHOD Two thousand eight hundred and twelve older adults served as sample for the present study. Psychometric tests on verbal abilities, basic processing speed, and cognitive flexibility were administered. In addition, individuals were interviewed on their different languages spoken on a regular basis, educational attainment, occupation, and engaging in different activities throughout adulthood. RESULTS Higher number of languages regularly spoken was significantly associated with better performance in verbal abilities and processing speed, but unrelated to cognitive flexibility. Regression analyses showed that the number of languages spoken predicted cognitive performance over and above leisure activities/physical demand of job/gainful activity as respective additional predictor, but not over and above educational attainment/cognitive level of job as respective additional predictor. There was no significant moderation of the association of the number of languages spoken with cognitive performance in any model. CONCLUSIONS Present data suggest that speaking different languages on a regular basis may additionally contribute to the build-up of cognitive reserve in old age. Yet, this may not be universal, but linked to verbal abilities and basic cognitive processing speed. Moreover, it may be dependent on other types of cognitive stimulation that individuals also engaged in during their life course.
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Affiliation(s)
- Andreas Ihle
- a Department of Psychology , University of Geneva , Geneva , Switzerland.,b Center for the Interdisciplinary Study of Gerontology and Vulnerability , University of Geneva , Geneva , Switzerland.,c Swiss National Center of Competences in Research LIVES-Overcoming Vulnerability: Life Course Perspectives
| | - Michel Oris
- b Center for the Interdisciplinary Study of Gerontology and Vulnerability , University of Geneva , Geneva , Switzerland.,c Swiss National Center of Competences in Research LIVES-Overcoming Vulnerability: Life Course Perspectives
| | - Delphine Fagot
- b Center for the Interdisciplinary Study of Gerontology and Vulnerability , University of Geneva , Geneva , Switzerland.,c Swiss National Center of Competences in Research LIVES-Overcoming Vulnerability: Life Course Perspectives
| | - Matthias Kliegel
- a Department of Psychology , University of Geneva , Geneva , Switzerland.,b Center for the Interdisciplinary Study of Gerontology and Vulnerability , University of Geneva , Geneva , Switzerland.,c Swiss National Center of Competences in Research LIVES-Overcoming Vulnerability: Life Course Perspectives
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Bialystok E, Abutalebi J, Bak TH, Burke DM, Kroll JF. Aging in two languages: Implications for public health. Ageing Res Rev 2016; 27:56-60. [PMID: 26993154 DOI: 10.1016/j.arr.2016.03.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/03/2016] [Accepted: 03/14/2016] [Indexed: 01/17/2023]
Abstract
With the population aging and a dramatic increase in the number of senior citizens, public health systems will be increasingly burdened with the need to deal with the care and treatment of individuals with dementia. We review evidence demonstrating how a particular experience, bilingualism, has been shown to protect cognitive function in older age and delay onset of symptoms of dementia. This paper describes behavioral and brain studies that have compared monolingual and bilingual older adults on measures of cognitive function or brain structure and reviews evidence demonstrating a protective effect of bilingualism against symptoms of dementia. We conclude by presenting some data showing the potential savings in both human costs in terms of demented patients and economic considerations in terms of public money if symptoms of dementia could be postponed.
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Prevalence of Dementia and Cognitive Complaints in the Context of High Cognitive Reserve: A Population-Based Study. PLoS One 2015; 10:e0138818. [PMID: 26390288 PMCID: PMC4577122 DOI: 10.1371/journal.pone.0138818] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/03/2015] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVES This study aimed to assess the prevalence of dementia and cognitive complaints in a cross-sectional sample of Luxembourg seniors, and to discuss the results in the societal context of high cognitive reserve resulting from multilingualism. METHODS A population sample of 1,377 people representative of Luxembourg residents aged over 64 years was initially identified via the national social insurance register. There were three different levels of contribution: full participation in the study, partial participation, and non-participation. We examined the profiles of these three different samples so that we could infer the prevalence estimates in the Luxembourgish senior population as a whole using the prevalence estimates obtained in this study. RESULTS After careful attention to the potential bias and of the possibility of underestimation, we considered the obtained prevalence estimates of 3.8% for dementia (with corresponding 95% confidence limits (CL) of 2.8% and 4.8%) and 26.1% for cognitive complaints (CL = [17.8-34.3]) as trustworthy. CONCLUSION Based on these findings, we postulate that high cognitive reserve may result in surprisingly low prevalence estimates of cognitive complaints and dementia in adults over the age of 64 years, which thereby corroborates the longer disability-free life expectancy observed in the Luxembourg population. To the best of our knowledge, this study is the first to report such Luxembourgish public health data.
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Braak H, Del Tredici K. The preclinical phase of the pathological process underlying sporadic Alzheimer’s disease. Brain 2015; 138:2814-33. [DOI: 10.1093/brain/awv236] [Citation(s) in RCA: 293] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/21/2015] [Indexed: 12/13/2022] Open
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Bak TH, Alladi S. Bilingualism, dementia and the tale of many variables: Why we need to move beyond the Western World. Commentary on Lawton et al. (2015) and Fuller-Thomson (2015). Cortex 2015; 74:315-7. [PMID: 26537794 DOI: 10.1016/j.cortex.2015.04.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 04/19/2015] [Accepted: 04/20/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas H Bak
- University of Edinburgh, Department of Psychology, Edinburgh, UK; University of Edinburgh, Centre for Clinical Brain Sciences, Edinburgh, UK.
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Iyer GK, Alladi S, Bak TH, Shailaja M, Mamidipudi A, Rajan A, Gollahalli D, Chaudhuri JR, Kaul S. Dementia in developing countries: Does education play the same role in India as in the West? Dement Neuropsychol 2014; 8:132-140. [PMID: 29213894 PMCID: PMC5619120 DOI: 10.1590/s1980-57642014dn82000008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 05/20/2014] [Indexed: 11/21/2022] Open
Abstract
Evidence suggests that education protects from dementia by enhancing cognitive reserve. However, this may be influenced by several socio-demographic factors. Rising numbers of dementia in India, high levels of illiteracy and heterogeneity in socio-demographic factors provide an opportunity to explore this relationship. OBJECTIVE To study the association between education and age at dementia onset, in relation to socio-demographic factors. METHODS Association between age at dementia onset and literacy was studied in relationship to potential confounding factors such as gender, bilingualism, place of dwelling, occupation, vascular risk factors, stroke, family history of dementia and dementia subtypes. RESULTS Case records of 648 dementia patients diagnosed in a specialist clinic in a University hospital in Hyderabad, India were examined. All patients were prospectively enrolled as part of an ongoing longitudinal project that aims to evaluate dementia subjects with detailed clinical, etiological, imaging, and follow-up studies. Of the 648 patients, 98 (15.1%) were illiterate. More than half of illiterate skilled workers were engaged in crafts and skilled agriculture unlike literates who were in trade or clerical jobs. Mean age at onset in illiterates was 60.1 years and in literates 64.5 years (p=0.0002). Factors independently associated with age at dementia onset were bilingualism, rural dwelling and stroke, but not education. CONCLUSION Our study demonstrates that in India, rural dwelling, bilingualism, stroke and occupation modify the relationship between education and dementia.
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Affiliation(s)
- Gowri K. Iyer
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
| | - Suvarna Alladi
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
| | - Thomas H. Bak
- Department of Psychology, Centre for Cognitive Aging and
Cognitive Epidemiology (CCACE) and Centre for Clinical Brain Sciences (CCBS),
University of Edinburgh
| | - Mekala Shailaja
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
| | - Annapurna Mamidipudi
- Department of Science, Technology and Society studies,
Maastricht University, Netherlands
| | - Amulya Rajan
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
| | - Divyaraj Gollahalli
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
| | | | - Subhash Kaul
- Department of Neurology, Nizam’s Institute of Medical
Sciences, Hyderabad, India
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