The many shades of bilingualism: language experiences modulate adaptations in brain structure

Recent years have seen an expansion in the research related to structural brain adaptations related to the acquisition and processing of additional languages. However, the accumulating evidence remains to a great extent inconsistent, with a large variety of cortical, subcortical and cerebellar effects reported in various studies. Here we propose that the variability in the data can be explained by the differences in the language background and experiences of the tested samples. We also propose that the field should move away from monolithic bilingual vs. monolingual comparisons; instead, it should focus on the experiences of the bilingual groups as predictors of structural changes in the brain, and also employ longitudinal designs to test the dynamic effects of active bilingualism. The implications of the proposed approaches for the suggested benefits of bilingualism on ageing and patient populations are also discussed

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

Cognitive Neuroscience Perspectives on Language Acquisition and Processing

The earliest investigations of the neural implementation of language started with examining patients with various types of disorders and underlying brain damage. The advent of neuroimaging tools in the twentieth century drastically changed the landscape of the field of the (cognitive) neuroscience of language, expanding the variety and depth of research questions one could ask without being confined to specific populations. Today we have better insights regarding the potential (neuro)cognitive correlates of language and an improved understanding of the neurocognitive consequences of language(s) in the mind/brain. And yet the linking hypotheses between neuroscience on the one hand and language on the other do not offer the level of detail needed to move the field from correlational to explanatory [1]. Thus, any further work that takes a more fine-grained look at both language processing and its neurocognitive substrates is warranted and welcome

Beyond Alzheimer’s disease: can bilingualism be a more generalized protective factor in neurodegeneration?

Bilingualism has been argued to have an impact on cognition and brain structure. Effects have been reported across the lifespan: from healthy children to ageing adults, including clinical (ageing) populations. It has been argued that active bilingualism may significantly contribute to the delaying of the expression of Alzheimer’s disease symptoms. If bilingualism plays an ameliorative role against the expression of neurodegeneration in dementia, it is possible that it could have similar effects for other neurodegenerative disorders, including Multiple Sclerosis, Parkinson’s and Huntington’s Diseases. To date, however, direct relevant evidence remains limited, not least because the necessary scientific motivations for investigating this with greater depth have not yet been fully articulated. Herein, we provide a roadmap that reviews the relevant literatures, highlighting potential links across neurodegenerative disorders and bilingualism more generally

Degree of multilingual engagement modulates resting state oscillatory activity across the lifespan

Multilingualism has been demonstrated to lead to a more favorable trajectory of neurocognitive aging, yet our understanding of its effect on neurocognition across the lifespan remains limited. We collected resting state EEG recordings from a sample of multilingual individuals across a wide age range. Additionally, we obtained data on participant multilingual language use patterns alongside other known lifestyle enrichment factors. Language experience was operationalized via a modified multilingual diversity (MLD) score. Generalized additive modeling was employed to examine the effects and interactions of age and MLD on resting state oscillatory power and coherence. The data suggest an independent modulatory effect of individualized multilingual engagement on age-related differences in whole brain resting state power across alpha and theta bands, and an interaction between age and MLD on resting state coherence in alpha, theta, and low beta. These results provide evidence of multilingual engagement as an independent correlational factor related to differences in resting state EEG power, consistent with the claim that multilingualism can serve as a protective factor in neurocognitive aging

Monolingual comparative normativity in bilingualism research is out of “control”: Arguments and alternatives

Accepted manuscript, to appeared in Applied Psycholinguistics: https://www.cambridge.org/core/journals/applied-psycholinguistics.Herein, we contextualize, problematize and offer some insights for moving beyond the problem of monolingual comparative normativity in (psycho)linguistic research on bilingualism. We argue that, in the vast majority of cases, juxtaposing (functional) monolinguals to bilinguals fails to offer what the comparison is supposedly intended to do: meet the standards of empirical control in line with the scientific method. Instead, the default nature of monolingual comparative normativity has historically contributed to inequalities in many facets of bilingualism research and continues to impede progress on multiple levels. Beyond framing our views on the matter, we offer some epistemological considerations and methodological alternatives to this standard practice that improve empirical rigor while fostering increased diversity, inclusivity and equity in our field

Monolingual comparative normativity in bilingualism research is out of “control”: Arguments and alternatives

Herein, we contextualize, problematize, and offer some insights for moving beyond the problem of monolingual comparative normativity in (psycho) linguistic research on bilingualism. We argue that, in the vast majority of cases, juxtaposing (functional) monolinguals to bilinguals fails to offer what the comparison is supposedly intended to do: meet the standards of empirical control in line with the scientific method. Instead, the default nature of monolingual comparative normativity has historically contributed to inequalities in many facets of bilingualism research and continues to impede progress on multiple levels. Beyond framing our views on the matter, we offer some epistemological considerations and methodological alternatives to this standard practice that improve empirical rigor while fostering increased diversity, inclusivity, and equity in our field

Monolingual comparative normativity in bilingualism research is out of “control”: Arguments and alternatives

Herein, we contextualize, problematize, and offer some insights for moving beyond the problem of monolingual comparative normativity in (psycho) linguistic research on bilingualism. We argue that, in the vast majority of cases, juxtaposing (functional) monolinguals to bilinguals fails to offer what the comparison is supposedly intended to do: meet the standards of empirical control in line with the scientific method. Instead, the default nature of monolingual comparative normativity has historically contributed to inequalities in many facets of bilingualism research and continues to impede progress on multiple levels. Beyond framing our views on the matter, we offer some epistemological considerations and methodological alternatives to this standard practice that improve empirical rigor while fostering increased diversity, inclusivity, and equity in our field.publishedVersio

Role of bilingualism in neurodegenerative disease II. Beyond Alzheimer's.

Over the past decades, bilingualism has emerged as a potential factor having a significant impact on cognition and brain structure. Such research typically examines the effects of bilingualism in healthy children and adults. Conversely, the body of literature examining bilingualism effects in ageing populations remains comparatively small. This holds especially true with regards to effects of bilingualism in clinical ageing populations. Current evidence suggests that bilingualism might contribute to delaying the expression and/or progression of the symptoms of Alzheimer’s dementia for as much as 5 years. To the extent bilingualism plays an ameliorative role at all, it seems reasonable to expect that it would have similar effects for other neurodegenerative disorders. Nevertheless, relevant studies examining disorders other than Alzheimer’s Disease or Mild Cognitive Impairment are extremely limited. Despite compelling reasons to the contrary, the few relevant studies that do exist are not properly linked, nor appreciated as a meaningful cohort in their own right. Making links across neurodegenerative disorders and bilingualism, to the extent possible, serves both practical health-related and theoretical-oriented needs. This chapter considers whether the currently available evidence is sufficient to allow for claims of bilingualism conveying more general protective effects in clinical ageing while identifying gaps in our knowledge and recommending future work to better understand these proposed links