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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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Peitz K, Stumme J, Jockwitz C, Bittner N, Caspers S, Heim S. The influence of bilingualism on gray matter volume in the course of aging: a longitudinal study. Front Aging Neurosci 2023; 15:1193283. [PMID: 37547741 PMCID: PMC10400456 DOI: 10.3389/fnagi.2023.1193283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 06/29/2023] [Indexed: 08/08/2023] Open
Abstract
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.
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Affiliation(s)
- Katharina Peitz
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Institute for Anatomy I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Johanna Stumme
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Institute for Anatomy I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Christiane Jockwitz
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Institute for Anatomy I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Nora Bittner
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Institute for Anatomy I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Svenja Caspers
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Institute for Anatomy I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Stefan Heim
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Learning a Second Language in Adulthood Changes Subcortical Neural Encoding. Neural Plast 2020; 2020:8836161. [PMID: 33144853 PMCID: PMC7596456 DOI: 10.1155/2020/8836161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/27/2020] [Accepted: 09/30/2020] [Indexed: 01/22/2023] Open
Abstract
Second language learning has been shown to impact and reshape the central nervous system, anatomically and functionally. Most of the studies on second language learning and neuroplasticity have been focused on cortical areas, whereas the subcortical neural encoding mechanism and its relationship with L2 learning have not been examined extensively. The purpose of this study was to utilize frequency-following response (FFR) to examine if and how learning a tonal language in adulthood changes the subcortical neural encoding in hearing adults. Three groups of subjects were recruited: native speakers of Mandarin Chinese (native speakers (NS)), learners of the language (L2 learners), and those with no experience (native speakers of foreign languages (NSFL)). It is hypothesized that differences would exist in FFRs obtained from the three language experience groups. Results revealed that FFRs obtained from L2 learners were found to be more robust than the NSFL group, yet not on a par with the NS group. Such results may suggest that in human adulthood, subcortical neural encoding ability may be trainable with the acquisition of a new language and that neuroplasticity at the brainstem level can indeed be influenced by L2 learning.
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The effect of bilingualism on brain development from early childhood to young adulthood. Brain Struct Funct 2020; 225:2131-2152. [PMID: 32691216 PMCID: PMC7473972 DOI: 10.1007/s00429-020-02115-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/09/2020] [Indexed: 11/30/2022]
Abstract
Bilingualism affects the structure of the brain in adults, as evidenced by experience-dependent grey and white matter changes in brain structures implicated in language learning, processing, and control. However, limited evidence exists on how bilingualism may influence brain development. We examined the developmental patterns of both grey and white matter structures in a cross-sectional study of a large sample (n = 711 for grey matter, n = 637 for white matter) of bilingual and monolingual participants, aged 3–21 years. Metrics of grey matter (thickness, volume, and surface area) and white matter (fractional anisotropy and mean diffusivity) were examined across 41 cortical and subcortical brain structures and 20 tracts, respectively. We used generalized additive modelling to analyze whether, how, and where the developmental trajectories of bilinguals and monolinguals might differ. Bilingual and monolingual participants manifested distinct developmental trajectories in both grey and white matter structures. As compared to monolinguals, bilinguals showed: (a) more grey matter (less developmental loss) starting during late childhood and adolescence, mainly in frontal and parietal regions (particularly in the inferior frontal gyrus pars opercularis, superior frontal cortex, inferior and superior parietal cortex, and precuneus); and (b) higher white matter integrity (greater developmental increase) starting during mid-late adolescence, specifically in striatal–inferior frontal fibers. The data suggest that there may be a developmental basis to the well-documented structural differences in the brain between bilingual and monolingual adults.
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Danylkiv A, Krafnick AJ. A Meta-Analysis of Gray Matter Differences Between Bilinguals and Monolinguals. Front Hum Neurosci 2020; 14:146. [PMID: 32390815 PMCID: PMC7191056 DOI: 10.3389/fnhum.2020.00146] [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: 11/28/2019] [Accepted: 03/31/2020] [Indexed: 01/17/2023] Open
Abstract
Bilingualism is of great interest to the neuroscience of language, and understanding the anatomical changes associated with second language learning help inform theories of bilingual advantage across the lifespan. While the literature on structural differences between bilinguals and monolinguals is robust, relatively few studies of gray matter (GM) have directly compared bilinguals with monolinguals in a whole-brain analysis. Overall, this and heterogeneity of study samples and methodology have led to a lack of clear anatomical support for major theories. Here, we engage in an activation likelihood estimate (ALE) meta-analysis of voxel-based morphometry (VBM) studies of GM for cases that directly compare bilingual and monolingual subjects in a whole-brain analysis. The analysis (sixteen foci, from ten contrasts across eight studies) resulted in one cluster located primarily within the anterior lobe of the right cerebellum. However, when the one pediatric study was removed, the analysis revealed no consistent results across the studies included in this meta-analysis. This suggests that for VBM studies of bilingual and monolingual adults there is considerable heterogeneity of results that complicate the understanding of the bilingual brain. Future studies will need to include larger, more well-defined samples and interrogate more fine-grained anatomical features such as cortical thickness and surface area in order to more fully examine the anatomical changes associated with bilingualism across the lifespan.
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Affiliation(s)
- Anastasiya Danylkiv
- Psychology Department, Dominican University, River Forest, IL, United States
| | - Anthony J Krafnick
- Psychology Department, Dominican University, River Forest, IL, United States
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Claussenius-Kalman H, Vaughn KA, Archila-Suerte P, Hernandez AE. Age of acquisition impacts the brain differently depending on neuroanatomical metric. Hum Brain Mapp 2019; 41:484-502. [PMID: 31600019 PMCID: PMC7267963 DOI: 10.1002/hbm.24817] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 08/23/2019] [Accepted: 09/23/2019] [Indexed: 12/24/2022] Open
Abstract
Although researchers generally agree that a certain set of brain areas underlie bilingual language processing, there is discrepancy regarding what effect timing of language acquisition has on these regions. We aimed to investigate the neuroanatomical correlates of age of acquisition (AoA), which has been examined previously, but with inconsistent results, likely influenced by methodological differences across studies. We analyzed gray matter density, volume, and thickness using whole-brain linear models in 334 bilinguals and monolinguals. Neuroanatomical correlates of AoA differed depending on gray matter metric. Relative to early bilinguals, late bilinguals had thicker cortex in language processing and cognitive control regions, and greater density in multiple frontal areas and the right middle temporal and supramarginal gyri. Early bilinguals had greater volume than late bilinguals in the left middle temporal gyrus. Overall, volume was the least sensitive to AoA-related differences. Multiple regions not classically implicated in dual-language processing were also found, which highlights the important role of whole-brain analyses in neuroscience. This is the first study to investigate AoA and gray matter thickness, volume, and density all in the same sample. We conclude that cognitive models of bilingualism should consider the roles of development and neuroanatomical metric in driving our understanding of bilingual and monolingual language organization.
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Affiliation(s)
| | - Kelly A Vaughn
- Department of Psychology, University of Houston, Houston, Texas
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Kousaie S, Baum S, Phillips NA, Gracco V, Titone D, Chen JK, Chai XJ, Klein D. Language learning experience and mastering the challenges of perceiving speech in noise. BRAIN AND LANGUAGE 2019; 196:104645. [PMID: 31284145 DOI: 10.1016/j.bandl.2019.104645] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 06/20/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
Given the ubiquity of noisy environments and increasing globalization, the necessity to perceive speech in noise in a non-native language is common and necessary for successful communication. In the current investigation, bilingual individuals who learned their non-native language at different ages underwent magnetic resonance imaging while listening to sentences in both of their languages, in quiet and in noise. Sentence context was varied such that the final word could be of high or low predictability. Results show that early non-native language learning is associated with superior ability to benefit from contextual information behaviourally, and a pattern of neural recruitment in the left inferior frontal gyrus that suggests easier processing when perceiving non-native speech in noise. These findings have implications for our understanding of speech processing in non-optimal listening conditions and shed light on how individuals navigate every day complex communicative environments, in a native and non-native language.
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Affiliation(s)
- Shanna Kousaie
- Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada; Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada.
| | - Shari Baum
- Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada; School of Communication Sciences and Disorders, Faculty of Medicine, McGill University, Montreal, QC H3A 1G1, Canada
| | - Natalie A Phillips
- Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada; Department of Psychology/Centre for Research in Human Development, Concordia University, Montreal, QC H4B 1R6, Canada; Bloomfield Centre for Research in Aging, Lady Davis Institute for Medical Research and Jewish General Hospital/McGill University Memory Clinic, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - Vincent Gracco
- Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada; School of Communication Sciences and Disorders, Faculty of Medicine, McGill University, Montreal, QC H3A 1G1, Canada; Haskins Laboratories, New Haven, CT 06511, USA
| | - Debra Titone
- Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada; Department of Psychology, McGill University Montreal, QC H3A 1G1, Canada
| | - Jen-Kai Chen
- Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada; Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada
| | - Xiaoqian J Chai
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Denise Klein
- Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada; Centre for Research on Brain, Language and Music, McGill University, Montreal, QC H3G 2A8, Canada.
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Beyond volume: A surface-based approach to bilingualism-induced grey matter changes. Neuropsychologia 2018; 117:1-7. [DOI: 10.1016/j.neuropsychologia.2018.04.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 01/14/2023]
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Beyond bilingualism: multilingual experience correlates with caudate volume. Brain Struct Funct 2018; 223:3495-3502. [DOI: 10.1007/s00429-018-1695-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 06/06/2018] [Indexed: 12/13/2022]
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10
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Bilingualism modulates the white matter structure of language-related pathways. Neuroimage 2017; 152:249-257. [DOI: 10.1016/j.neuroimage.2017.02.081] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 02/06/2017] [Accepted: 02/27/2017] [Indexed: 11/24/2022] Open
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Pliatsikas C, Chondrogianni V. Editorial: Learning a non-native language in a naturalistic environment: insights from behavioral and neuroimaging research. Front Psychol 2015; 6:1009. [PMID: 26236272 PMCID: PMC4505070 DOI: 10.3389/fpsyg.2015.01009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 07/06/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Vicky Chondrogianni
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh Edinburgh, UK
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