Christos Pliatsikas

University of Reading · School of Psychology and Clinical Language Sciences

Significance This article fills an important gap in the literature on structural changes in the brain that are induced by speaking two languages. It has been suggested that early lifelong bilingualism affects the structure of white matter (WM) of the brain and preserves its integrity in older age. Here we show that similar WM effects are also found...

Derivational morphological processes allow us to create new words (e.g. punish (V) to noun (N) punishment from base forms. The number of steps from the basic units to derived words often varies (e.g., nationality<national<nation: two-steps) and there is evidence that complex derivations cause more brain activity than simple ones (Meinzer, Lahiri, F...

The experience of learning and using a second language (L2) has been shown to affect the grey matter (GM) structure of the brain. Importantly, GM density in several cortical and subcortical areas has been shown to be related to performance in L2 tasks. Here, we show that bilingualism can lead to increased GM volume in the cerebellum, a structure th...

An ongoing debate on second language (L2) processing revolves around whether or not L2learners process syntactic information similarly to monolinguals (L1), and what factors lead to anative-like processing. According to the Shallow Structure Hypothesis (Clahsen & Felser,2006a), L2 learners’ processing does not include abstract syntactic features, s...

Bilingualism is associated with distinct patterns of resting-state functional brain connectivity – a consequence of ongoing language control demands that do not apply to monolinguals. However, it is not well understood how these patterns affect, and are affected by, brain activation for domain-general cognitively demanding tasks. Here, we employ a...

Experience-based neuroplasticity in the healthy brain is a well-documented finding, with functional and structural adaptations in cortical and subcortical structures reported as the brain’s response to cognitively challenging experiences. These experiences include bi-/multilingualism: speaking more than one language entails increased cognitive dema...

There is increasing evidence that using more than one languages has significant effects on brain function. These effects have been observed in the developing, adult and ageing brain, and have been suggested to have implications for cognitive and brain decline in bilinguals and multilinguals. Aside from extensive investigations with behavioral metho...

This study established psycholinguistic norms in Cantonese for a set of 1286 colored pictures sourced from several picture databases, including 750 colored line drawings from MultiPic (Duñabeitia et al., 2018) and 536 photographs selected for McRae et al. (2005) concepts. The pictures underwent rigorous normalization processes. We provided picture...

Think the human brain stops transforming in adulthood? You might want to think again! Contrary to popular belief, the human brain continues to change throughout our lifetime in response to the various experiences that we acquire. One such experience is the use of more than one language – an activity many of us already engage in in our daily lives....

Subcortical structures implicated in language control and processing adapt structurally with increasing language experience. However, the adaptation patterns across different subcortical structures remain unclear. Previous findings from bilinguals and multilinguals reveal renormalisation patterns, lending support to the Dynamic Restructuring Model...

It remains an open question how the brain adapts structurally to handle strenuous cognitive challenges. Interpreters and translators rely on high cognitive control to regulate two languages in their jobs, which makes them ideal models in investigating experience-based neuroplasticity induced by exceptional cognitive demands. Using structural MRI, w...

In our increasingly multilingual modern world, understanding how languages beyond the first are acquired and processed at a brain level is essential to design evidence-based teaching, clinical interventions and language policy. Written by a team of world-leading experts in a wide range of disciplines within cognitive science, this Handbook provides...

[This corrects the article DOI: 10.3389/fpsyg.2023.1149062.].

Bilingualism is a ubiquitous global phenomenon. Beyond being a language experience, bilingualism also entails a social experience, and it interacts with development and learning, with cognitive and neural consequences across the lifespan. The authors of this volume are world renowned experts across several subdisciplines including linguistics, deve...

Bilingualism has been shown to contribute to increased resilience against cognitive aging. One of the key brain structures linked to memory and dementia symptom onset, the hippocampus, has been observed to adapt in response to bilingual experience – at least in healthy individuals. However, in the context of neurodegenerative pathology, it is yet u...

Bilingualism has been associated with changes in our language-related and domain-general cog-nition. However, it remains controversial whether bilingualism-related cognitive effects are robust and stable. Also, it is still unclear which aspects of bilingual experiences affect the plasticity of cognitive processes. This article offers a selective ov...

Bilingualism has been linked to structural adaptations of subcortical brain regions that are important for controlling multiple languages. However, research on the location and extent of these adaptations has yielded variable patterns, especially as far as the subcortical regions are concerned. Existing literature on bilingualism-induced brain rest...

Studies investigating the role of dual language use in modulating executive functions have reported mixed results, with some studies reporting benefits in older adults. These studies typically focus on bilingual settings, while the role of dual language use in diglossic settings is rarely investigated. In diglossia, the two language varieties are s...

Recent studies investigating whether bilingualism has effects on cognitive abilities beyond language have produced mixed results, with evidence from young adults typically showing no effects. These inconclusive patterns have been attributed to many uncontrolled factors, including linguistic similarity and the conversational contexts the bilinguals...

The growing interdisciplinary research field of psycholinguistics is in constant need of new and up-to-date tools which will allow researchers to answer complex questions, but also expand on languages other than English, which dominates the field. One type of such tools are picture datasets which provide naming norms for everyday objects. However,...

Although the question of whether and how bilingualism affects executive functions has been extensively debated, less attention has been paid to the cognitive abilities of speakers of different varieties of the same language, in linguistic situations such as bidialectalism and diglossia. Similarly to the bilingual situation, in bidialectalism and di...

Second language acquisition (SLA) research has traditionally used paper‐and‐pencil tasks, such as grammaticality judgment and completion tasks. In such tasks, participants usually have time to read the whole sentence, think and reflect about its form and meaning, and then make a conscious judgment about its grammaticality or how to complete it. Thi...

Bilingualism has been associated with changes in our language-related and domain-general cognition. However, it remains controversial whether bilingualism-related cognitive effects are robust and stable. Also, it is still unclear what about being bilingual causes the plasticity of cognitive processes. This article offers a selective overview of the...

The growing interdisciplinary research field of psycholinguistics is in constant need of new and up-to-date tools which will allow researchers to answer complex questions, but also expand on languages other than English, which dominates the field. One type of such tools are picture datasets which provide naming norms for everyday objects. However,...

Bilingualism has been shown to induce neuroplasticity in the brain, but conflicting evidence regarding its specific effects in grey matter continues to emerge, probably due to methodological differences between studies, as well as approaches that may miss the variability and dynamicity of bilingual experience. In our study, we devised a continuous...

Long-term management of more than one language has been argued to contribute to changes in brain and cognition. This has been particularly well documented in older age, where bilingualism has been linked to protective effects against neurocognitive decline. Since memory difficulties are key aspects of this decline, herein we examine potential effec...

Bilingualism impacts brain structure, especially in regions involved in language control and processing. However, the relation between structural brain changes and key aspects of bilingual language use is still poorly understood. Here we used structural MRI and non-linear modelling to investigate the effects of habitual code-switching (CS) practice...

Background Research has shown that lifelong bilingualism may contribute to cognitive reserve in neurodegenerative diseases as shown by a delay of the age at symptom onset in bilinguals with different types of dementia. However, the study of the neural mechanisms behind this bilingual advantage is limited, especially for the preclinical stages of de...

Autism Spectrum Disorders (ASD) are a set of neurodevelopmental conditions characterised by difficulties in social interaction and communication as well as stereotyped and restricted patterns of interest. Autistic traits exist in a continuum across the general population, whilst the extreme end of this distribution is diagnosed as clinical ASD. Whi...

Bilingualism has been linked to structural adaptations of subcortical brain regions that are important nodes in controlling of multiple languages. However, research on the location and extent of these adaptations has yielded variable patterns. Existing literature on bilingualism-induced brain adaptations has so far largely overseen evidence from ot...

Recent studies investigating whether bilingualism has effects on cognitive abilities beyond language have produced mixed results, with evidence from young adults typically showing no effects. These inconclusive patterns have been attributed to many uncontrolled factors, including linguistic similarity and the conversational contexts the bilinguals...

Autism Spectrum Disorders (ASD) are a set of neurodevelopmental conditions characterised by difficulties in social interaction and communication as well as stereotyped and restricted patterns of interest. Autistic traits exist in a continuum across the general population, whilst the extreme end of this distribution is diagnosed as clinical ASD. Whi...

Cognitively demanding experiences, including complex skill acquisition and processing, have been shown to induce brain adaptations, at least at the macroscopic level, e.g. on brain volume and/or functional connectivity. However, the neurobiological bases of these adaptations, including at the cellular level, are unclear and understudied. Here we us...

Aprender una segunda lengua o lengua extranjera durante la adolescencia o edad adulta constituye un complejo desafío. Dicha complejidad a menudo resulta en un alto índice de variabilidad sobre los logros, ya que es frecuente encontrarse con que personas con experiencias de aprendizaje de una L2/LE similares desarrollan niveles de competencia lingüí...

The question of whether and how bilingualism affects domain general cognition has been extensively debated. Less attention has been paid to the cognitive abilities of speakers of different variants of the same language, in linguistic situations such as bidialectalism and diglossia. Similarly to the bilingual situation, in bidialectalism and digloss...

Cognitively demanding experiences, including complex skills acquisition and processing, have been shown to induce brain adaptations, at least at the macroscopic level, e.g. on brain volume and/or functional connectivity. However, the neurobiological bases of these adaptations, including at the microstructural cellular level, remain poorly understoo...

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 whit...

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....

Long-term management of more than one language has been suggested to lead to changes in cognition and the brain. This is particularly documented in older age, where bilingualism is associated with protective effects against decline, for example, affording compensation for symptoms of Alzheimer’s disease leading to delayed diagnosis relative to non-...

Brain plasticity associated with second language acquisition and learning has been a focus of research in the past two decades. Recent research on cognitive neuroscience has enriched current understanding on the neurological underpinning of second language learning. Beyond behavioral findings, examining brain functions and structures provides a bio...

Bilingualism affects the structure of the brain in adults. This is indicated by experience-dependent gray and white matter changes in brain structures implicated in language learning, processing, or control. However, limited evidence exists on how bilingualism may influence brain development. We examined the developmental trajectories of both grey...

It has been suggested that bilingualism is beneficial for executive control and could have positive long-term effects by delaying the onset of symptoms of degenerative diseases. This research investigates, for the first time, the impact of bilingualism on executive control (monitoring and inhibitory control) in individuals with Multiple Sclerosis (...

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 t...

Bilingualism has been argued to have an impact on cognition and brain structure. Such effects have been reported in healthy children and young adults, but also in ageing adults, including clinical ageing populations. For example, bilingualism may significantly contribute to the delaying of the expression of Alzheimer’s dementia symptoms. If bilingu...

The potential effects of bilingualism on executive control (EC) have been heavily debated. One possible source of discrepancy in the evidence may be that bilingualism tends to be treated as a monolithic category distinct from monolingualism. We address this possibility by examining the effects of different bilingual language experiences on brain ac...

There is considerable behavioral evidence that morphologically complex words such as ‘tax-able’ and ‘kiss-es’ are processed and represented combinatorially. In other words, they are decomposed into their constituents ‘tax’ and ‘-able’ during comprehension (reading or listening), and producing them might also involve onetheespot combination of these...

Recent advances in neuroimaging methods have led to a renewed interest in the brain correlates of language processing. Most intriguing is how experiences of language use relates to variation in brain structure and how brain structure predicts language acquisition. These two lines of inquiry have important implications on considering language use as...

Learning and using an additional language is shown to have an impact on the structure and function of the brain, including in regions involved in cognitive control and the connections between them. However, the available evidence remains variable in terms of the localization, extent, and trajectory of these effects. Variability likely stems from th...

This chapter focuses on how neurolinguistic evidence, such as electroencephalography/event‐related potential (EEG/ERP) and functional magnetic resonance imaging (fMRI) data, can help us adjudicate between various views regarding the critical period debate and how to best account for the ubiquitously noted differences that align with age of acquisit...

This chapter provides a contemporary snapshot of the literature on multilingualism‐induced changes in the brain, including theoretical suggestions about the origin and the nature of these changes. It presents a brief overview of the anatomy of the neuron and the brain, and turns to grey matter, specifically to the available effects on the cortical,...

Research on the effects of bi-/multilingualism on brain structure has so far yielded variable patterns. Although it cannot be disputed that learning and using additional languages restructures grey (cortical, subcortical and cerebellar) and white matter in the brain, both increases and reductions in regional volume and diffusivity have been reporte...

Four experiments investigate the effects of covert morphological complexity during visual word recognition. Zero-derivations occur in English in which a change of word class occurs without any change in surface form (e.g., a boat-to boat; to soak-a soak). Boat is object-derived and is a basic noun (N), whereas soak is action-derived and is a basic...

Working memory (WM), which underlies the temporary storage and manipulation of information, is critical for multiple aspects of cognition and everyday life. Nevertheless, research examining WM specifically in older adults remains limited, despite the global rapid increase in human life expectancy. We examined WM in a large sample (N = 754) of healt...

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Learning and using additional languages can result in structural changes in the brain. However, the time course of these changes, as well as the factors the predict them, are still not well understood. In this longitudinal study we test the effects of bilingual immersion on brain structure of adult sequential bilinguals not undergoing any language...

Numerous studies in psychology, cognitive neuroscience and psycholinguistics have used pictures of objects as stimulus materials. Currently, authors engaged in cross-linguistic work or wishing to run parallel studies at multiple sites where different languages are spoken must rely on rather small sets of black-and-white or colored line drawings. Th...

Recent behavioural evidence from second language (L2) learners has suggested native-like processing of syntactic structures, such as long-distance wh-dependencies in L2. The underlying processes are still largely debated, while the available neuroimaging evidence has been restricted to native (L1) processing. Here we test highly proficient L2 learn...

Stuttering is a disorder in which the smooth flow of speech is interrupted. People who stutter show structural and functional abnormalities in the speech and motor system. It is unclear whether functional differences reflect general traits of the disorder or are specifically related to the dysfluent speech state. We used a hierarchical approach to...

Bilingualism has been shown to affect the structure of the brain, including cortical regions related to language. Less is known about subcortical structures, such as the basal ganglia, which underlie speech monitoring and language selection, processes that are crucial for bilinguals, as well as other linguistic functions, such as grammatical and ph...

This special issue is a testament to the recent burgeoning interest by theoretical linguists, language acquisitionists and teaching practitioners in the neuroscience of language. It offers a highly valuable, state-of-the-art overview of the neurophysiological methods that are currently being applied to questions in the field of second language (L2)...

The investigation of bilingualism and cognition has been enriched by recent developments in functional magnetic resonance imaging (fMRI). Extending how bilingual experience shapes cognition, this review examines recent fMRI studies adopting executive control tasks with minimal or no linguistic demands. Across a range of studies with divergent ages...

Research on bilingualism has boomed in the past two decades. The processes by which a second language is acquired and processed has been investigated via linguistic, psycholinguistic, and neurolinguistic perspectives, focusing not only on second language (L2) acquisition and processing, but also the effects it might have on cognition and brain stru...

Background: Cluttering is a fluency disorder characterised by overly rapid or jerky speech patterns that compromise intelligibility. The neural correlates of cluttering are unknown but theoretical accounts implicate the basal ganglia and medial prefrontal cortex. Dysfunction in these brain areas would be consistent with difficulties in selection a...

Background The quality of the early environment is hypothesized to be an influence on morphological development in key neural areas related to affective responding, but direct evidence to support this possibility is limited. In a 22-year longitudinal study, we examined hippocampal and amygdala volumes in adulthood in relation to early infant attach...

Behavioural evidence suggests that English regular past tense forms are automatically decomposed into their stem and affix (played = play+ed) based on an implicit linguistic rule, which does not apply to the idiosyncratically formed irregular forms (kept). Additionally, regular, but not irregular inflections, are thought to be processed through the...

According to dual-system accounts of English past-tense processing, regular forms are decomposed into their stem and affix (played=play+ed) based on an implicit linguistic rule, whereas irregular forms (kept) are retrieved directly from the mental lexicon. In second language (L2) processing research, it has been suggested that L2 learners do not ha...

Dual-system models suggest that English past tense morphology involves two processing routes: rule application for regular verbs and memory retrieval for irregular verbs (Pinker, 1999). In second language (L2) processing research, Ullman (2001a) suggested that both verb types are retrieved from memory, but more recently Clahsen and Felser (2006) an...

Using functional magnetic resonance imaging, we found that when bilinguals named pictures or read words aloud, in their native or nonnative language, activation was higher relative to monolinguals in 5 left hemisphere regions: dorsal precentral gyrus, pars triangularis, pars opercularis, superior temporal gyrus, and planum temporale. We further dem...