Neuroplasticity as a function of second language learning: anatomical changes in the human brain

Auditory cortex anatomy reflects multilingual phonological experience

This study examines whether auditory cortex anatomy reflects multilingual experience, specifically individuals' phonological repertoire. Using data from over 200 participants exposed to 1-7 languages across 36 languages, we analyzed the role of language experience and typological distances between languages they spoke in shaping neural signatures of multilingualism. Our findings reveal a negative relationship between the thickness of the left and right second transverse temporal gyrus (TTG) and participants' degree of multilingualism. Models incorporating phoneme-level information in the language experience index explained the most variance in TTG thickness, suggesting that a more extensive and more phonologically diverse language experience is associated with thinner cortices in the second TTG. This pattern, consistent across two datasets, supports the idea of experience-driven pruning and neural efficiency. Our findings indicate that experience with typologically distant languages appear to impact the brain differently than those with similar languages. Moreover, they suggest that early auditory regions seem to represent phoneme-level cross-linguistic information, contrary to the most established models of language processing in the brain, which suggest that phonological processing happens in more lateral posterior superior temporal gyrus (STG) and superior temporal sulcus (STS).

Distinct neural representations of different linguistic components following sign language learning

Learning a new language is a process everyone undergoes at least once. However, studying the neural mechanisms behind first-time language learning is a challenging task. Here we aim to explore the functional alterations following learning Israeli Sign Language, a visuo-spatial rather than an auditory-based language. Specifically, we investigate how phonological, lexical, and sentence-level components of the language system differ in their neural representations. In this within-participant design, hearing individuals naïve to sign languages (n = 79) performed an fMRI task requiring the processing of different linguistic components, before and after attending an Israeli Sign Language course. A learning-induced increase in activation was detected in various brain regions in task contrasts related to all sign language linguistic components. Activation patterns while processing different linguistic components post-learning were spatially distinct, suggesting a unique neural representation for each component. Moreover, post-learning activation maps successfully predicted learning retention six months later, associating neural and performance measures.

Working Memory as the Focus of the Bilingual Effect in Executive Functions

The bilingual effect on executive functions (EFs) has garnered considerable attention, with most studies focusing on the visual domain and largely overlooking the auditory domain. Furthermore, research has predominantly concentrated on specific subcomponents of executive functions, with few studies systematically examining all three key subcomponents. This raises two important questions: (a) Is the bilingual effect specific to certain modalities (modality-specific), or a more general phenomenon (modality-general)? (b) Is the bilingual effect concentrated in a specific component of executive functions (process-specific), or does it extend to all three components (process-general)? To explore these questions, this study recruited monolingual Chinese and bilingual Chinese-English participants, using matched visual and auditory Stroop, N-back, and task-switching tasks to assess inhibitory control, working memory, and cognitive flexibility in both groups. The results showed that, after controlling for variables like intelligence, socioeconomic status, and age, bilingualism significantly predicted performance in both auditory and visual working memory tasks, explaining 34% and 19% of the variance, respectively. However, no evidence was found to support a bilingual effect in inhibitory control or cognitive flexibility. In conclusion, these results suggest that bilingual effects are not only process-specific (affecting only working memory) but also modality-general (providing advantages in both visual and auditory modalities).

The Neurodevelopmental Dynamics of Multilingual Experience During Childhood: A Longitudinal Behavioral, Structural, and Functional MRI Study

BACKGROUND/OBJECTIVES

A neurobiological framework of bi- or multilingual neurocognitive development must consider the following: (i) longitudinal behavioral and neural measures; (ii) brain developmental constraints across structure and function; and (iii) the development of global multilingual competence in a homogeneous social environment. In this study, we investigated whether multilingual competence yields early changes in executive attention control mechanisms and their underlying neural structures in the frontal-striatal system, such as the dorsal anterior cingulate cortex/pre-supplemental area and the left caudate.

METHODS

We employed longitudinal neuroimaging and functional connectivity methods in a small group of multilingual children over two years.

RESULTS

We found that the dACC/preSMA is functionally influenced by changes in multilingual competence but not yet structurally adapted, while the left caudate, in a developmental stage, is influenced, adapts, and specializes due to multilingual experience. Furthermore, increases in multilingual competence strengthen connections between the dACC/preSMA, left caudate, and other structures of the cognitive control network, such as the right inferior frontal gyrus and bilateral inferior parietal lobules.

CONCLUSIONS

These findings suggest that multilingual competence impacts brain "adaptation" and "specialization" during childhood. The results may provide insights and guide future research on experience-expectant and experience-dependent brain plasticity to explain the "interaction" between multilingualism and neurodevelopment.

NEBULA101: an open dataset for the study of language aptitude in behaviour, brain structure and function

This paper introduces the "NEBULA101 - Neuro-behavioural Understanding of Language Aptitude" dataset, which comprises behavioural and brain imaging data from 101 healthy adults to examine individual differences in language and cognition. Human language, a multifaceted behaviour, varies significantly among individuals, at different processing levels. Recent advances in cognitive science have embraced an integrated approach, combining behavioural and brain studies to explore these differences comprehensively. The NEBULA101 dataset offers brain structural, diffusion-weighted, task-based and resting-state MRI data, alongside extensive linguistic and non-linguistic behavioural measures to explore the complex interaction of language and cognition in a highly multilingual sample. By sharing this multimodal dataset, we hope to promote research on the neuroscience of language, cognition and multilingualism, enabling the field to deepen its understanding of the multivariate panorama of individual differences and ultimately contributing to open science.

Bilingualism, sleep, and cognition: An integrative view and open research questions

Sleep and language are fundamental to human existence and have both been shown to substantially affect cognitive functioning including memory, attentional performance, and cognitive control. Surprisingly, there is little-to-no research that examines the shared impact of bilingualism and sleep on cognitive functions. In this paper, we provide a general overview of existing research on the interplay between bilingualism and sleep with a specific focus on executive functioning. First, we highlight their interconnections and the resulting implications for cognitive performance. Second, we emphasize the need to explore how bilingualism and sleep intersect at cognitive and neural levels, offering insights into potential ways of studying the interplay between sleep, language learning, and bilingual language use. Finally, we suggest that understanding these relationships could enhance our knowledge of reserve and its role in mitigating age-related cognitive decline.

Plasticity in older infants' perception of phonetic contrasts: The role of selective attention in context

Developmental plasticity refers to conditions and circumstances that increase phenotypic variability. In infancy, plasticity expands and contracts depending on domains of functioning, developmental history, and timing. In terms of language processing, infants attend to and discriminate both native and non-native phonetic contrasts, but selectively attune to their native phonemes by the end of the first postnatal year. However, relevant studies have excluded factors regarded as promoters of attention such as infant-directed (ID) speech, synchronous multimodal presentations, and female speakers. Here we investigated whether English-learning 11-month-olds would discriminate a non-native phonetic contrast while manipulating these factors. Results showed significant discrimination of the non-native contrast, regardless of speech register, provided that they were presented by a dynamic female speaker. Interestingly, when a static object or a dynamic male ID speaker replaced the female, no significant discrimination was found. These results show infants to be capable of discriminating non-native phonetic contrasts in an enhanced context at an age when they have been characterized as not being able to do so. Synchronized, multimodal information from female speakers allowed infants to perceive difficult non-native phonemes, highlighting the importance of an ecologically valid context for studying speech perception and language learning in early development.

Neural correlates of basketball proficiency: An MRI study across skill levels

Background

Basketball is an attractive sport required both cooperative and antagonistic motor skills. However, the neural mechanism of basketball proficiency remains unclear. This study aimed to examine the brain functional and structural substrates underlying varying levels of basketball capacity.

Methods

Twenty advanced basketball athletes (AB), 20 intermediate basketball athletes (IB) and 20 age-matched non-athlete individuals without basketball experience (NI) participated in this study and underwent T1-weighted MRI and resting-state fMRI scanning. Voxel-mirrored homotopic connectivity (VMHC), amplitude of low frequency fluctuations (ALFF), and gray matter (GM) density were calculated and compared among the three groups.

Results

The VMHC in the bilateral postcentral gyrus, middle temporal gyrus, and superior temporal gyrus, as well as the GM density in the right precentral gyrus, exhibited a hierarchical structure of AB > IB > NI. Compared with NI group, AB and IB groups showed strengthened VMHC in supplementary motor area, paracentral lobule and superior frontal gyrus. Additionally, the ALFF of left middle occipital gyrus and right hippocampal and the GM density of left medial superior frontal gyrus exhibited differences in AB-IB and AB-NI comparisons.

Conclusions

By conducting the cross-sectional comparison, this study firstly identifies the varying levels of basketball proficiency related brain resting-state functional and structural plasticity. Especially, the regions associated with motor perception and control, including bilateral postcentral gyrus, middle and superior temporal gyrus and right precentral gyrus, are involved in the key neural mechanisms of basketball proficiency. Future longitudinal studies are necessary to further validate these findings.

Tractography analysis results of the trigeminus nerve, which contains fibers responsible for proprioception sensation and motor control in Adolescent Idiopathic Scoliosis

STUDY DESIGN

Cross-sectional Study.

BACKGROUND

It is not yet clear whether the loss of proprioceptive sensation and muscle weakness seen in adolescent idiopathic scoliosis (AIS) is the result of central nervous system dysfunction or secondary to spinal deformity. In our study, in order to find an answer to this question, we examined the microarchitecture of the nervus trigeminus, which is least affected by spinal deformity and contains both proprioceptive sensory and motor fibers.

METHODS

In this single-center, cross-sectional cohort study, 40 Lenke Type 3 (27 female, 13 male) AIS patients and 40 (25 female, 15 male) healthy individuals between the ages of 10-18 years. Tractography of the nervus trigenimus was performed using the "DSI Studio" program. The volumes of the targeted musculus pterygoideus lateralis and musculus pterygoideus medialis were measured using the Insight Segmentation and Registration Tool Kit (ITK -SNAP) program. The data were evaluated using the Statistical Package for the Social Sciences 22.0 program for Windows.

RESULTS

There was no significant difference between the two groups in terms of baseline characteristics (p˃0.05). Left nervus trigeminus fiber number and fiber ratio were significantly higher in the control group compared to the scoliosis group p < 0.05. Right and left lateral pterygoid muscle showed lower volume and volume percentage in the scoliosis group compared to the control group (p < 0.05).

CONCLUSION

According to the study data, proprioceptive sensory and motor control dysfunction in AIS is predicted to develop independently of spinal deformity.

Subcortical volume and language proficiency in bilinguals and monolinguals: A structural MRI study

The current study focused on an understudied but most prominent bilingual population in the U.S. - heritage bilinguals. The current study combined data from eight MRI studies to examine the relationship between language experience and subcortical gray matter volume in 215 heritage Spanish-English bilinguals and 145 English monolinguals, within and between groups. For bilinguals, higher Spanish (L1) proficiency was related to less volume in the bilateral globus pallidus, and higher English (L2) proficiency and earlier English AoA were related to greater volume in the right thalamus, left accumbens, and bilateral globus pallidus. For monolinguals, higher English proficiency was associated with greater volume only in the right pallidum. These results suggest that subcortical gray matter structures are related to the learning of a second language. Future research is encouraged to understand subcortical adaptation in relation to L1 and L2 acquisition from a developmental perspective.

Differential neural representations of syntactic and semantic information across languages in Chinese-English bilinguals

Bilingual individuals manage multiple languages that align in conceptual meaning but differ in forms and structures. While prior research has established foundational insights into the neural mechanisms in bilingual processing, the extent to which the first (L1) and second language (L2) systems overlap or diverge across different linguistic components remains unclear. This study probed the neural underpinnings of syntactic and semantic processing for L1 and L2 in Chinese-English bilinguals (N = 44) who performed sentence comprehension tasks and an N-back working memory task during functional MRI scanning. We observed that the increased activation for L2 processing was within the verbal working memory network, suggesting a greater cognitive demand for processing L2. Crucially, we looked for brain regions showing adaptation to the repetition of semantic information and syntactic structure, and found more robust adaptation effects in L1 in the middle and superior temporal cortical areas. The differential adaptation effects between L1 and L2 were more pronounced for the semantic condition. Multivariate pattern analysis further revealed distinct neural sensitivities to syntactic and semantic representations between L1 and L2 across frontotemporal language regions. Our findings suggest that while L1 and L2 engage similar neural systems, finer representation analyses uncover distinct neural patterns for both semantic and syntactic aspects in the two languages. This study advances our understanding of neural representations involved in different language components in bilingual individuals.

Early language experience and modality affect parietal cortex activation in different hemispheres: Insights from hearing bimodal bilinguals

The goal of this study was to investigate the impact of the age of acquisition (AoA) on functional brain representations of sign language in two exceptional groups of hearing bimodal bilinguals: native signers (simultaneous bilinguals since early childhood) and late signers (proficient sequential bilinguals, who learnt a sign language after puberty). We asked whether effects of AoA would be present across languages - signed and audiovisual spoken - and thus observed only in late signers as they acquired each language at different life stages, and whether effects of AoA would be present during sign language processing across groups. Moreover, we aimed to carefully control participants' level of sign language proficiency by implementing a battery of language tests developed for the purpose of the project, which confirmed that participants had high competences of sign language. Between-group analyses revealed a hypothesized modulatory effect of AoA in the right inferior parietal lobule (IPL) in native signers, compared to late signers. With respect to within-group differences across languages we observed greater involvement of the left IPL in response to sign language in comparison to spoken language in both native and late signers, indicating language modality effects. Overall, our results suggest that the neural underpinnings of language are molded by the linguistic characteristics of the language as well as by when in life the language is learnt.

Lenition in L2 Spanish: The Impact of Study Abroad on Phonological Acquisition

Objective: This study investigated the degrees of lenition, or consonantal weakening, in the production of Spanish stop consonants by native English speakers during a study abroad (SA) program. Lenition is a key phonological process in Spanish, where voiced stops (/b/, /d/, /ɡ/) typically weaken to fricatives or approximants in specific phonetic environments. For L2 learners, mastering this subtle process is essential for achieving native-like pronunciation. Methods: To assess the learners' progress in acquiring lenition, we employed Phonet, a deep learning model. Unlike traditional quantitative acoustic methods that focus on measuring the physical properties of speech sounds, Phonet utilizes recurrent neural networks to predict the posterior probabilities of phonological features, particularly sonorant and continuant characteristics, which are central to the lenition process. Results: The results indicated that while learners showed progress in producing the fricative-like variants of lenition during the SA program and understood how to produce lenition in appropriate contexts, the retention of these phonological gains was not sustained after their return. Additionally, unlike native speakers, the learners never fully achieved the approximant-like realization of lenition. Conclusions: These findings underscore the need for sustained exposure and practice beyond the SA experience to ensure the long-term retention of L2 phonological patterns. While SA programs offer valuable opportunities for enhancing L2 pronunciation, they should be supplemented with ongoing support to consolidate and extend the gains achieved during the immersive experience.

Transcranial photobiomodulation on the left inferior frontal gyrus enhances Mandarin Chinese L1 and L2 complex sentence processing performances

This study investigated the causal enhancing effect of transcranial photobiomodulation (tPBM) over the left inferior frontal gyrus (LIFG) on syntactically complex Mandarin Chinese first language (L1) and second language (L2) sentence processing performances. Two (L1 and L2) groups of participants (thirty per group) were recruited to receive the double-blind, sham-controlled tPBM intervention via LIFG, followed by the sentence processing, the verbal working memory (WM), and the visual WM tasks. Results revealed a consistent pattern for both groups: (a) tPBM enhanced sentence processing performance but not verbal WM for linear processing of unstructured sequences and visual WM performances; (b) Participants with lower sentence processing performances under sham tPBM benefited more from active tPBM. Taken together, the current study substantiated that tPBM enhanced L1 and L2 sentence processing, and would serve as a promising and cost-effective noninvasive brain stimulation (NIBS) tool for future applications on upregulating the human language faculty.

Second language learning in older adults modulates Stroop task performance and brain activation

Introduction

Numerous studies have highlighted cognitive benefits in lifelong bilinguals during aging, manifesting as superior performance on cognitive tasks compared to monolingual counterparts. Yet, the cognitive impacts of acquiring a new language in older adulthood remain unexplored. In this study, we assessed both behavioral and fMRI responses during a Stroop task in older adults, pre- and post language-learning intervention.

Methods

A group of 41 participants (age:60-80) from a predominantly monolingual environment underwent a four-month online language course, selecting a new language of their preference. This intervention mandated engagement for 90 minutes a day, five days a week. Daily tracking was employed to monitor progress and retention. All participants completed a color-word Stroop task inside the scanner before and after the language instruction period.

Results

We found that performance on the Stroop task, as evidenced by accuracy and reaction time, improved following the language learning intervention. With the neuroimaging data, we observed significant differences in activity between congruent and incongruent trials in key regions in the prefrontal and parietal cortex. These results are consistent with previous reports using the Stroop paradigm. We also found that the amount of time participants spent with the language learning program was related to differential activity in these brain areas. Specifically, we found that people who spent more time with the language learning program showed a greater increase in differential activity between congruent and incongruent trials after the intervention relative to before.

Discussion

Future research is needed to determine the optimal parameters for language learning as an effective cognitive intervention for aging populations. We propose that with sufficient engagement, language learning can enhance specific domains of cognition such as the executive functions. These results extend the understanding of cognitive reserve and its augmentation through targeted interventions, setting a foundation for future investigations.

The effect of spinal correction surgery on the tractography data of the pain pathway in scoliosis patients: a preliminary report

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

Pain in individuals with opered scoliosis is usually evaluated with a postural analysis or questionnaire. In this study, we evaluated pain in individuals with scoliosis who underwent spinal correction surgery by tractography and compared it with individuals with non-opered scoliosis and healthy individuals.

DESIGN

Fifteen healthy individuals, 15 non-operated scoliosis patients and 15 operated scoliosis patients were included in the study.

METHODS

All female participants in this prospectively planned study used their right hand as the dominant hand. Bilateral tractography analysis of the pain pathways was performed with DSI Studio software using brain magnetic resonance images (MRI) of the participants. Statistical analysis of the study was performed with IBM SPSS 23.0 and p<0.05 values were considered significant.

RESULTS

It was observed that the tractography values of the operated scoliosis group were similar to the control group (p˃0.05). In the non-operated scoliosis group, tractography findings related to nerve conduction velocity such as fiber count, fiber ratio and axial diffusivity (AD) were found to be higher than the other two groups (p<0.05). Fractional anisotropy (FA) values of the unoperated scoliosis group were significantly different between the pain pathways projected from the right/left side of the body (p<0.05).

CONCLUSION

The fact that the pain path tractography values of patients with scoliosis who underwent surgery were similar to those of healthy individuals may be evidence of decreased pain sensation reaching the brain. Surgery may be a good choice in the treatment of pain in patients with scoliosis.

Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently

Introduction

Exposure to maternal speech during the prenatal period shapes speech perception and linguistic preferences, allowing neonates to recognize stories heard frequently in utero and demonstrating an enhanced preference for their mother's voice and native language. Yet, with a high prevalence of bilingualism worldwide, it remains an open question whether monolingual or bilingual maternal speech during pregnancy influence differently the fetus' neural mechanisms underlying speech sound encoding.

Methods

In the present study, the frequency-following response (FFR), an auditory evoked potential that reflects the complex spectrotemporal dynamics of speech sounds, was recorded to a two-vowel /oa/ stimulus in a sample of 129 healthy term neonates within 1 to 3 days after birth. Newborns were divided into two groups according to maternal language usage during the last trimester of gestation (monolingual; bilingual). Spectral amplitudes and spectral signal-to-noise ratios (SNR) at the stimulus fundamental (F0) and first formant (F1) frequencies of each vowel were, respectively, taken as measures of pitch and formant structure neural encoding.

Results

Our results reveal that while spectral amplitudes at F0 did not differ between groups, neonates from bilingual mothers exhibited a lower spectral SNR. Additionally, monolingually exposed neonates exhibited a higher spectral amplitude and SNR at F1 frequencies.

Discussion

We interpret our results under the consideration that bilingual maternal speech, as compared to monolingual, is characterized by a greater complexity in the speech sound signal, rendering newborns from bilingual mothers more sensitive to a wider range of speech frequencies without generating a particularly strong response at any of them. Our results contribute to an expanding body of research indicating the influence of prenatal experiences on language acquisition and underscore the necessity of including prenatal language exposure in developmental studies on language acquisition, a variable often overlooked yet capable of influencing research outcomes.

Development and validation of a predictive model for poor prognosis of communication disorders in children with cerebral palsy after cervical perivascular sympathectomy

Cervical perivascular sympathectomy (CPVS) can improve communication disorders in children with cerebral palsy (CP); however, there are no research reports on the factors affecting surgical efficacy. This study aimed to establish a nomogram for poor prognosis after CPVS. We collected data from 313 CP patients who underwent CPVS at the Neurosurgery Cerebral Palsy Center of the Second Affiliated Hospital of Xinjiang Medical University from January 2019 to January 2023. Among them, 70% (n = 216) formed the training cohort and 30% (n = 97) the validation cohort. The general data and laboratory examination data of both groups were analyzed. In training cohort, 82 (37.96%) showed improved postoperative communication function. Logistic analysis identified motor function, serum alkaline phosphatase, serum albumin, and prothrombin activity as the prognostic factors. Using these four factors, a prediction model was constructed with an area under the curve (AUC) of 0.807 (95% confidence interval [CI], 0.743-0.870), indicating its ability to predict adverse outcomes after CPVS. The validation cohort results showed an AUC of 0.76 (95% CI, 0.650-0.869). The consistency curve and Hosmer-Lemeshow test (χ2 = 10.988 and p = 0.202, respectively) demonstrated good consistency between the model-predicted incidence and the actual incidence of poor prognosis. Motor function, serum alkaline phosphatase, serum albumin, and prothrombin activity are independent risk factors associated with the prognosis of communication disorders after CPVS. The combined prediction model has a good clinical prediction effect and has promising potential to be used for early prediction of prognosis of CPVS.

At the Basis of Brain Malformations: Brain Plasticity, Developmental Neurobiology, and Considerations for Rehabilitation

From early age in the human brain occurs plasticity process that influences its development. The functioning of the brain is governed by its neuronal connectivity and the synaptic dynamics of these connections. A neuron, over thousands of synapses, can receive a large number of inputs and produce different outputs leading to the consolidation and integration of memory. Synaptic plasticity is the set of experience-dependent changes in neuronal pathways that support acquired habits. It is the ability of the nervous system to reshape connectivity between neurons, changing the functional and structural organization of neuronal circuits that allows us to adapt to the multiple and continuous changes in the environment and leading to processes such as cognitive development and the ability to learn. Synaptic plasticity is mainly due to short- and long-term mechanisms. Short-term synaptic plasticity refers to changes in synaptic strength that occurs very quickly (from one-thousandth of a second to 5 minutes) and are temporary and decay over minutes (maximum 30 minutes). Long-term synaptic plasticity is defined by a long-lasting, activity-dependent change in synaptic efficacy, last from hours up to a lifetime (from 30 minutes to weeks, months, and years) and is thought to constitute the basis of learning and memory. A significant difference occurs in the nature of the change; short-term plasticity adds only a functional change, whereas long-term plasticity causes not only functional but also structural changes. Aside from genetic factors and metabolic processes, brain development is mediated also by environmental factors. Interaction with the environment plays a key role in the development and growth of neural networks and neuroplasticity. Environmental interactions that can modify and increase the development of neural networks and intelligence in children are several and are herein discussed.

Limited but specific engagement of the mature language network during linguistic statistical learning

Statistical learning (SL) is the ability to detect and learn regularities from input and is foundational to language acquisition. Despite the dominant role of SL as a theoretical construct for language development, there is a lack of direct evidence supporting the shared neural substrates underlying language processing and SL. It is also not clear whether the similarities, if any, are related to linguistic processing, or statistical regularities in general. The current study tests whether the brain regions involved in natural language processing are similarly recruited during auditory, linguistic SL. Twenty-two adults performed an auditory linguistic SL task, an auditory nonlinguistic SL task, and a passive story listening task as their neural activation was monitored. Within the language network, the left posterior temporal gyrus showed sensitivity to embedded speech regularities during auditory, linguistic SL, but not auditory, nonlinguistic SL. Using a multivoxel pattern similarity analysis, we uncovered similarities between the neural representation of auditory, linguistic SL, and language processing within the left posterior temporal gyrus. No other brain regions showed similarities between linguistic SL and language comprehension, suggesting that a shared neurocomputational process for auditory SL and natural language processing within the left posterior temporal gyrus is specific to linguistic stimuli.

Decoding bilingualism from resting-state oscillatory network organization

Can lifelong bilingualism be robustly decoded from intrinsic brain connectivity? Can we determine, using a spectrally resolved approach, the oscillatory networks that better predict dual-language experience? We recorded resting-state magnetoencephalographic activity in highly proficient Spanish-Basque bilinguals and Spanish monolinguals, calculated functional connectivity at canonical frequency bands, and derived topological network properties using graph analysis. These features were fed into a machine learning classifier to establish how robustly they discriminated between the groups. The model showed excellent classification (AUC: 0.91 ± 0.12) between individuals in each group. The key drivers of classification were network strength in beta (15-30 Hz) and delta (2-4 Hz) rhythms. Further characterization of these networks revealed the involvement of temporal, cingulate, and fronto-parietal hubs likely underpinning the language and default-mode networks (DMNs). Complementary evidence from a correlation analysis showed that the top-ranked features that better discriminated individuals during rest also explained interindividual variability in second language (L2) proficiency within bilinguals, further supporting the robustness of the machine learning model in capturing trait-like markers of bilingualism. Overall, our results show that long-term experience with an L2 can be "brain-read" at a fine-grained level from resting-state oscillatory network organization, highlighting its pervasive impact, particularly within language and DMN networks.

Neural specificity for semantic and syntactic processing in Spanish-English bilingual children

Brain development for language processing is associated with neural specialization of left perisylvian pathways, but this has not been investigated in young bilinguals. We examined specificity for syntax and semantics in early exposed Spanish-English speaking children (N = 65, ages 7-11) using an auditory sentence judgement task in English, their dominant language of use. During functional near infrared spectroscopy (fNIRS), the morphosyntax task elicited activation in left inferior frontal gyrus (IFG) and the semantic task elicited activation in left posterior middle temporal gyrus (MTG). Task comparisons revealed specialization in left superior temporal (STG) for morphosyntax and left MTG and angular gyrus for semantics. Although skills in neither language were uniquely related to specialization, skills in both languages were related to engagement of the left MTG for semantics and left IFG for syntax. These results are consistent with models suggesting a positive cross-linguistic interaction in those with higher language proficiency.

Large-scale investigation of white matter structural differences in bilingual and monolingual children: An adolescent brain cognitive development data study

Emerging research has provided valuable insights into the structural characteristics of the bilingual brain from studies of bilingual adults; however, there is a dearth of evidence examining brain structural alterations in childhood associated with the bilingual experience. This study examined the associations between bilingualism and white matter organization in bilingual children compared to monolingual peers leveraging the large-scale data from the Adolescent Brain Cognitive Development (ABCD) Study. Then, 446 bilingual children (ages 9-10) were identified from the participants in the ABCD data and rigorously matched to a group of 446 monolingual peers. Multiple regression models for selected language and cognitive control white matter pathways were used to compare white matter fractional anisotropy (FA) values between bilinguals and monolinguals, controlling for demographic and environmental factors as covariates in the models. Results revealed significantly lower FA values in bilinguals compared to monolinguals across established dorsal and ventral language network pathways bilaterally (i.e., the superior longitudinal fasciculus and inferior frontal-occipital fasciculus) and right-hemispheric pathways in areas related to cognitive control and short-term memory (i.e., cingulum and parahippocampal cingulum). In contrast to the enhanced FA values observed in adult bilinguals relative to monolinguals, our findings of lower FA in bilingual children relative to monolinguals may suggest a protracted development of white matter pathways associated with language and cognitive control resulting from dual language learning in childhood. Further, these findings underscore the need for large-scale longitudinal investigation of white matter development in bilingual children to understand neuroplasticity associated with the bilingual experience during this period of heightened language learning.

Subcortical and cerebellar volume differences in bilingual and monolingual children: An ABCD study

Research suggests that bilingual children experience an extension or delay in the closing of the sensitive/critical period of language development due to multiple language exposure. Moreover, bilingual experience may impact the development of subcortical regions, although these conclusions are drawn from research with adults, as there is a scarcity of research during late childhood and early adolescence. The current study included 1215 bilingual and 5894 monolingual children from the ABCD Study to examine the relationship between subcortical volume and English vocabulary in heritage Spanish bilingual and English monolingual children, as well as volumetric differences between the language groups. We also examined the unique effects of language usage in bilingual children's subcortical volumes. In general, bilingual children had less cerebellar volume and greater volume in the putamen, thalamus, and globus pallidus than monolingual children. English vocabulary was positively related to volume in the cerebellum, thalamus, caudate, putamen, nucleus accumbens, and right pallidum in all children. Moreover, the positive relationship between vocabulary and volume in the nucleus accumbens was stronger for monolingual adolescents than bilingual adolescents. The results are somewhat in line with existing literature on the dynamic volume adaptation of subcortical brain regions due to bilingual development and experience. Future research is needed to further explore these regions longitudinally across development to examine structural changes in bilingual brains.

Mapping individual aspects of bilingual experience to adaptations in brain structure

Individual differences in using multiple languages are thought to differentially affect brain structure and function. The present study assessed the neuroanatomical predictions of an emerging theory, the Unifying the Bilingual Experience Trajectories framework, which provides the most comprehensive set of predictions of how individual differences in bilingual experiences lead to specific neural and cognitive adaptations. A total of 140 young adults with variable language experiences were scanned using magnetic resonance imaging and completed demographic questionnaires. Brain structure measures implicated in predictions of the Unifying the Bilingual Experience Trajectories model were extracted and regressed against the model's experiential factors. Consistent with the model's predictions, greater intensity and diversity of bilingual language use resulted in changes in gray matter volume in cortical regions involved in executive control (including inferior frontal gyrus, middle temporal gyrus, angular gyrus, and medial frontal gyrus), indicating adaptations toward handling increased executive control demands. Conversely, duration of bilingual engagement resulted in changes within white matter microstructure (bilateral superior longitudinal fasciculus) and increases in subcortical gray matter (left caudate), indicative of adaptations toward increased efficiency of control. Overall, this research enhances our understanding of how bilingual experiences influence brain structure and provides the first direct empirical evidence for the predictions made by the Unifying the Bilingual Experience Trajectories framework.

White matter plasticity during second language learning within and across hemispheres

Adult second language (L2) learning is a challenging enterprise inducing neuroplastic changes in the human brain. However, it remains unclear how the structural language connectome and its subnetworks change during adult L2 learning. The current study investigated longitudinal changes in white matter (WM) language networks in each hemisphere, as well as their interconnection, in a large group of Arabic-speaking adults who learned German intensively for 6 mo. We found a significant increase in WM-connectivity within bilateral temporal-parietal semantic and phonological subnetworks and right temporal-frontal pathways mainly in the second half of the learning period. At the same time, WM-connectivity between the two hemispheres decreased significantly. Crucially, these changes in WM-connectivity are correlated with L2 performance. The observed changes in subnetworks of the two hemispheres suggest a network reconfiguration due to lexical learning. The reduced interhemispheric connectivity may indicate a key role of the corpus callosum in L2 learning by reducing the inhibition of the language-dominant left hemisphere. Our study highlights the dynamic changes within and across hemispheres in adult language-related networks driven by L2 learning.

Expanding the emergentist Account:Reply to open peer commentaries

Emergentism provides a framework for understanding how language learning processes vary across developmental age and linguistic levels, as shaped by core mechanisms and constraints from cognition, entrenchment, input, transfer, social support, motivation, and neurology. As our commentators all agree, this landscape is marked by intense variability arising from the complexity. These mechanisms interact in collaborative and competitive ways during actual moments of language use. To better understand these interactions and their effects, we need much richer longitudinal data regarding both input and output during actual contexts of usage. We believe that modern technology can eventually provide this data (Flege & Bohn, 2021) in ways that will allow us to more fully populate an emergent landscape.

Navigating the Intersection of Technology and Depression Precision Medicine

This chapter primarily focuses on the progress in depression precision medicine with specific emphasis on the integrative approaches that include artificial intelligence and other data, tools, and technologies. After the description of the concept of precision medicine and a comparative introduction to depression precision medicine with cancer and epilepsy, new avenues of depression precision medicine derived from integrated artificial intelligence and other sources will be presented. Additionally, less advanced areas, such as comorbidity between depression and cancer, will be examined.

Developmental outcomes with perinatal exposure (DOPE) to prescription opioids

Researchers have found considerable evidence in the past 20 years that perinatal opioid exposure leads to an increased risk of developmental disorders in offspring that persist into adulthood. The use of opioids to treat pain concerning pregnancy, delivery, and postpartum complications has been rising. As a result, communities have reported a 300-400 % increase in Neonatal Opioid Withdrawal Syndrome (NOWS). NOWS represents the initial stage of several behavioral, phenotypic, and synaptic deficits. This review article summarizes the Developmental Outcomes of Perinatal Exposure (DOPE) to prescription opioids. Moreover, we also seek to connect these findings to clinical research that describes DOPE at multiple stages of life. Since specific mechanisms that underlie DOPE remain unclear, this article aims to provide a framework for conceptualizing across all ages and highlight the implications they may have for longevity.

Reorganization of the structural connectome during vision recovery in pituitary adenoma patients post-transsphenoidal surgery

Pituitary adenomas (PAs) can exert pressure on the optic apparatus, leading to visual impairment. A subset of patients may observe a swift improvement in their vision following surgery. Nevertheless, the alterations in the structural connectome during the early postoperative period remain largely unexplored. The research employed probabilistic tractography, graph theoretical analysis, and statistical methods on preoperative and postoperative structural magnetic resonance imaging and diffusion tensor images from 13 PA patients. Postoperative analysis revealed an increase in global and local efficiency, signifying improved network capacity for parallel information transfer and fault tolerance, respectively. Enhanced clustering coefficient and reduced shortest path length were also observed, suggesting a more regular network organization and shortened communication steps within the brain network. Furthermore, alterations in node graphical properties were detected, implying a restructuring of the network's control points, possibly contributing to more efficient visual processing. These findings propose that rapid vision recovery post-surgery may be associated with significant reorganization of the brain's structural connectome, enhancing the efficiency and adaptability of the network, thereby facilitating improved visual processing.

AoA-L2 and Usage-L2 modulate the functional neuroplasticity of the subcortex

Previous studies revealed structural differences in subcortical regions between monolinguals and bilinguals; however, whether the functional neuroplasticity of the subcortex is modulated by different bilingual experiences remains unclear. Here, we examined the effect of age of second language acquisition (AoA-L2) and usage of L2 (Usage-L2) on subcorto-cortical and intra-subcortical functional connectivity (FC) in bilinguals by using resting-state fMRI data. The relations between brain measurements and bilingual experiences were revealed by using multiple regression analysis. We found that increased AoA-L2 was mainly related to decreased subcortical FC involving the anterior thalamus, basal ganglia, and hippocampus. Increased Usage-L2 at home was mainly associated with decreased subcortical FC of the amygdala, globus pallidus, hippocampus, and nucleus accumbens. The FC of these subcortical regions displayed a positive relation with Usage-L2 in social settings. These findings reveal that bilingual experiences modulate the functional neuroplasticity of the subcortex in different ways.

Rapid neural changes during novel speech-sound learning: An fMRI and DTI study

While the functional and microstructural changes that occur when we learn new language skills are well documented, relatively little is known about the time course of these changes. Here a combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) study that tracks neural change over three days of learning Arabic phonetic categorization as a new language (L-training) is presented. Twenty adult native English-speaking (L-native) participants are scanned before and after training to perceive and produce L-training phonetic contrasts for one hour on three consecutive days. A third (Chinese) language is used as a control language (L-control). Behavioral results show significant performance improvement for L-training in both learnt tasks; the perception and production task. Imaging analysis reveals that, training-related hemodynamic fMRI signal and fractional anisotropy (FA) value increasing can be observed, in the left inferior frontal gyrus (LIFG) and positively correlated with behavioral improvement. Moreover, post training functional connectivity findings show a significant increasing between LIFG and left inferior parietal lobule for L-training. These results indicate that three hours of phonetic categorization learning causes functional and microstructural changes that are typically associated with much more long-term learning.

Changes in functional brain activity patterns associated with computer programming learning in novices

BACKGROUND

Computer programming, the process of designing, writing, and testing executable computer code, is an essential skill in numerous fields. A description of the neural structures engaged and modified during programming skill acquisition could help improve training programs and provide clues to the neural substrates underlying the acquisition of related skills.

METHODS

Fourteen female university students without prior computer programing experience were examined by functional magnetic resonance imaging (fMRI) during the early and late stages of a 5-month 'Computer Processing' course. Brain regions involved in task performance and learning were identified by comparing responses to programming and control tasks during the early and late stages.

RESULTS

The accuracy of performing a programming task was significantly improved during the late stage. Various regions of the frontal, temporal, parietal, and occipital cortex as well as several subcortical structures (caudate nuclei and cerebellum) were activated during programming tasks. Brain activity in the right inferior frontal gyrus was greater during the late stage and significantly correlated with improved task performance. Although the left inferior frontal gyrus was also highly active during the programming task, there were no learning-induced changes in activity or a significant correlation between activity and improved task performances.

CONCLUSION

Computer programming learning among novices induces functional neuroplasticity within the right inferior frontal gyrus but not the left inferior gyrus (Broca's area).

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

Background

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

Methods

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

Results

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

Conclusion

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

Intraoperative functional remapping unveils evolving patterns of cortical plasticity

The efficiency with which the brain reorganizes following injury not only depends on the extent and the severity of the lesion, but also on its temporal features. It is established that diffuse low-grade gliomas (DLGG), brain tumours with a slow-growth rate, induce a compensatory modulation of the anatomo-functional architecture, making this kind of tumours an ideal lesion model to study the dynamics of neuroplasticity. Direct electrostimulation (DES) mapping is a well-tried procedure used during awake resection surgeries to identify and spare cortical epicentres which are critical for a range of functions. Because DLGG is a chronic disease, it inevitably relapses years after the initial surgery, and thus requires a second surgery to reduce tumour volume again. In this context, contrasting the cortical mappings obtained during two sequential neurosurgeries offers a unique opportunity to both identify and characterize the dynamic (i.e. re-evolving) patterns of cortical re-arrangements. Here, we capitalized on an unprecedented series of 101 DLGG patients who benefited from two DES-guided neurosurgeries usually spaced several years apart, resulting in a large DES dataset of 2082 cortical sites. All sites (either non-functional or associated with language, speech, motor, somatosensory and semantic processing) were recorded in Montreal Neurological Institute (MNI) space. Next, we used a multi-step approach to generate probabilistic neuroplasticity maps that reflected the dynamic rearrangements of cortical mappings from one surgery to another, both at the population and individual level. Voxel-wise neuroplasticity maps revealed regions with a relatively high potential of evolving reorganizations at the population level, including the supplementary motor area (SMA, Pmax = 0.63), the dorsolateral prefrontal cortex (dlPFC, Pmax = 0.61), the anterior ventral premotor cortex (vPMC, Pmax = 0.43) and the middle superior temporal gyrus (STG Pmax = 0.36). Parcel-wise neuroplasticity maps confirmed this potential for the dlPFC (Fisher's exact test, PFDR-corrected = 6.6 × 10-5), the anterior (PFDR-corrected = 0.0039) and the ventral precentral gyrus (PFDR-corrected = 0.0058). A series of clustering analyses revealed a topological migration of clusters, especially within the left dlPFC and STG (language sites); the left vPMC (speech arrest/dysarthria sites) and the right SMA (negative motor response sites). At the individual level, these dynamic changes were confirmed for the dlPFC (bilateral), the left vPMC and the anterior left STG (threshold free cluster enhancement, 5000 permutations, family-wise error-corrected). Taken as a whole, our results provide a critical insight into the dynamic potential of DLGG-induced continuing rearrangements of the cerebral cortex, with considerable implications for re-operations.

Bilingualism and Structural Network Organization in Temporal Lobe Epilepsy: Resilience in Neurologic Disease

BACKGROUND AND OBJECTIVES

There is growing evidence that bilingualism can induce neuroplasticity and modulate neural efficiency, resulting in greater resistance to neurologic disease. However, whether bilingualism is beneficial to neural health in the presence of epilepsy is unknown. We tested whether bilingual individuals with temporal lobe epilepsy (TLE) have improved whole-brain structural white matter network organization.

METHODS

Healthy controls and individuals with TLE recruited from 2 specialized epilepsy centers completed diffusion-weighted MRI and neuropsychological testing as part of an observational cohort study. Whole-brain connectomes were generated via diffusion tractography and analyzed using graph theory. Global analyses compared network integration (path length) and specialization (transitivity) in TLE vs controls and in a 2 (left vs right TLE) × 2 (bilingual vs monolingual) model. Local analyses compared mean local efficiency of predefined frontal-executive and language (i.e., perisylvian) subnetworks. Exploratory correlations examined associations between network organization and neuropsychological performance.

RESULTS

A total of 29 bilingual and 88 monolingual individuals with TLE matched on several demographic and clinical variables and 81 age-matched healthy controls were included. Globally, a significant interaction between language status and side of seizure onset revealed higher network organization in bilinguals compared with monolinguals but only in left TLE (LTLE). Locally, bilinguals with LTLE showed higher efficiency in frontal-executive but not in perisylvian networks compared with LTLE monolinguals. Improved whole-brain network organization was associated with better executive function performance in bilingual but not monolingual LTLE.

DISCUSSION

Higher white matter network organization in bilingual individuals with LTLE suggests a neuromodulatory effect of bilingualism on whole-brain connectivity in epilepsy, providing evidence for neural reserve. This may reflect attenuation of or compensation for epilepsy-related dysfunction of the left hemisphere, potentially driven by increased efficiency of frontal-executive networks that mediate dual-language control. This highlights a potential role of bilingualism as a protective factor in epilepsy, motivating further research across neurologic disorders to define mechanisms and develop interventions.

Folate deprivation induced neuroinflammation impairs cognition

Nutritional status is associated with many neurocognitive diseases. Folate is one of the micronutrients, and its deficiency is associated with clinical outcomes of neurological diseases. Nevertheless, molecular mechanism behind the folate deficiency induced neurological disorders are not well-known. We have hypothesized that folate-deficiency is a cardinal determinant responsible for manifestation of cognitive impairment through inflammation mediated neurodegenerative pathologies. Objective of the current study was to assess whether folate deficiency is associated with cognitive dysfunction or is merely an epiphenomenon and to identify the underlying mechanisms. We developed folate insufficient zebrafish model through intra-peritoneal treatment of methotrexate. T-maze test was carried to assess the spatial learning and memory of the fish. Higher latency of the folate-deprived zebrafishes in the T-maze test is a reflection of altered cognition. This result is supported by declined levels of dopamine and serotonin, neurotransmitters linked with learning and memory. Elevated IL-6 and CRP in peripheral blood, along with increased expression of NF-ĸB in brain indicates manifestation of neuroinflammation. Indeed, together with upregulation of maptb gene it can be implied that folate deficiency acts as a risk factor for neurodegeneration in the form of tauopathies. Furthermore, diminished localisation of synaptopodin, a protein linked to neural plasticity, suggests that neuroinflammation caused by folate deprivation hampers the plasticity of brain. Histological analysis of brain revealed the development of histopathological features including spongiform degeneration and neuronal loss in folate deprived condition. We thus conclude that folate deficiency results in NF-ĸB activation, which through multiple processes mediated by neuroinflammation could lead to cognitive decline.

Functional preference of the left inferior parietal lobule to second language reading

Additional neural substance for reading in a second language has been reported by prior studies. However, to date, there has been little investigation into whether and how the brain's adaptation to a second language is induced by specific linguistic tasks or is a general effect during reading in a new language. To address this issue, our study investigated Chinese children learning English as a second language by combining cross-sectional and longitudinal Functional Magnetic Resonance Imaging (fMRI) studies. We compared brain activation across four reading tasks, orthographic tasks and phonological tasks in Chinese (the first language, L1) and English (the second language, L2). By comparing the activation pattern across languages, we observed greater activation in the left inferior parietal lobule (LIPL) in English compared to Chinese, suggesting a functional preference of the LIPL to L2. In addition, greater correlation between LIPL-related FC and L2 was mainly observed in the phonological task, indicating that LIPL could be associated with phonological processing. Moreover, a proportion of the children were enrolled in an 8-week phonological-based reading-training program. We observed significant functional plasticity of the LIPL elicited by this training program only in the English phonological task and not in the orthographic task, further substantiating that the additional requirements of the LIPL in L2 are mainly associated with phonological processing. The findings provide new insights into understanding the functional contribution of the LIPL to reading in a second language.

Native language differences in the structural connectome of the human brain

Is the neuroanatomy of the language structural connectome modulated by the life-long experience of speaking a specific language? The current study compared the brain white matter connections of the language and speech production network in a large cohort of 94 native speakers of two very different languages: an Indo-European morphosyntactically complex language (German) and a Semitic root-based language (Arabic). Using high-resolution diffusion-weighted MRI and tractography-based network statistics of the language connectome, we demonstrated that German native speakers exhibited stronger connectivity in an intra-hemispheric frontal to parietal/temporal dorsal language network, known to be associated with complex syntax processing. In comparison, Arabic native speakers showed stronger connectivity in the connections between semantic language regions, including the left temporo-parietal network, and stronger inter-hemispheric connections via the posterior corpus callosum connecting bilateral superior temporal and inferior parietal regions. The current study suggests that the structural language connectome develops and is modulated by environmental factors such as the characteristic processing demands of the native language.

Short-term training helps second-language learners read like native readers: An ERP study

This randomized controlled trial study aimed to examine what experience other than immersion may help adult learners read with native-like neural responses. We compared a group of 13 native Chinese English learners completing English letter-sound association training with another group of 12 completing visual symbol-sound association training and included one group of native English readers as the reference. The results showed that after three hours of training, all learners no longer showed attenuated cross-modal mismatch negativity (MMN) to English letter-sound integration as in the pretest. After six hours of training, the learners receiving English letter-sound association training showed enhanced cross-modal MMN and theta oscillations, as native English readers did. The enhanced neural responses were significantly correlated with better phonological awareness. Thus, with training specific to critical second language reading skills of appropriate dosages, adult learners can overcome the constraints of their native language background and learn to read with native-like neural responses.

Linking early-life bilingualism and cognitive advantage in older adulthood

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

Subcortical lesions impact confrontation naming in bilinguals with later age of acquisition: An exploratory study

The bilingual experience is believed to impact brain development and, possibly, cognitive performance. Subcortical structures, including the striatum and white matter, are believed related to confrontation naming performance among bilingual individuals with later age of acquisition (AoA) and lower proficiency of a second language (L2). However, these findings are primarily derived from healthy adult samples, although there is clinical significance for the interpretation of naming performance. The present study examined whether striatal and white matter lesions were associated with naming tasks in clinic-referred bilingual veterans (n = 29) and whether L2 AoA moderated this relationship. Clinically rated lesions, without regard for AoA, were not consistently correlated with naming performance. Moderation models (lesion × AoA) were significant across naming tasks (i.e., naming scores were negatively correlated with striatal lesions with increasing AoA). Effect sizes were higher among striatal models as compared to white matter models. Results extend prior neuroimaging findings with healthy bilinguals that AoA moderates the relationship between subcortical lesions and naming performance in bilingual patients, and suggests that clinicians should consider specifics of bilingual experience when interpreting test scores.

How processing emotion affects language control in bilinguals

Research has shown that several variables affect language control among bilingual speakers but the effect of affective processing remains unexplored. Chinese-English bilinguals participated in a novel prime-target language switching experiment in which they first judged the affective valence (i.e., positive or negative) of auditorily presented words and then named pictures with neutral emotional valence in either the same (non-switch trial) or different language (switch trial). Brain activity was monitored using functional magnetic resonance imaging (fMRI). The behavioral performance showed that the typical switch cost (i.e., the calculated difference between switch and non-switch trials) emerged after processing positive words but not after negative words. Brain imaging demonstrated that processing negative words immediately before non-switch picturing naming trials (but not for switch trials) increased activation in brain areas associated with domain-general cognitive control. The opposite patterns were found after processing positive words. These findings suggest that an (emotional) negative priming effect is induced by spontaneous exposure to negative words and that these priming effects may be triggered by reactive emotional processing and that they may interact with higher level cognitive functions.

White matter brain structure predicts language performance and learning success

Individual differences in the ability to process language have long been discussed. Much of the neural basis of these, however, is yet unknown. Here we investigated the relationship between long-range white matter connectivity of the brain, as revealed by diffusion tractography, and the ability to process syntactically complex sentences in the participants' native language as well as the improvement thereof by multiday training. We identified specific network motifs by singular value decomposition that indeed related white matter structural connectivity to individual language processing performance. First, for two such motifs, one in the left and one in the right hemisphere, their individual prevalence significantly predicted the individual language performance, suggesting an anatomical predisposition for the individual ability to process syntactically complex sentences. Both motifs comprise a number of cortical regions, but seem to be dominated by areas known for the involvement in working memory rather than the classical language network itself. Second, we identified another left hemispheric network motif, whose change of prevalence over the training period significantly correlated with the individual change in performance, thus reflecting training induced white matter plasticity. This motif comprises diverse cortical areas including regions known for their involvement in language processing, working memory and motor functions. The present findings suggest that individual differences in language processing and learning can be explained, in part, by individual differences in the brain's white matter structure. Brain structure may be a crucial factor to be considered when discussing variations in human cognitive performance, more generally.

Investigation of the Relationships Between Beck Depression/Anxiety Scores and Neuropsychological Tests Scores with Lifestyle Behaviors in the Context of Neuroplasticity and Neurogenesis Approach

In this study, the relationships between lifestyle behaviors within the scope of neuroplasticity and neurogenesis approach and depression, anxiety and neuropsychological test scores were examined. As this study aimed to reveal the relationships between events or variables, it was designed using the "descriptive cross-sectional study" method, one of descriptive and relational research methods, was used. The data were collected from 117 students by the researchers using the Öktem Verbal Memory Test, WCST, Digit Span Test, Beck Depression Inventory, Beck Anxiety Scale and Lifestyle Behaviors Survey.According to the results, the quality of sport/exercise and the quality of life showed a significant difference in the depression model, while social support demonstrated a significant difference in the anxiety model. It was seen that those with high scores in life quality and in perceived social support had significantly lower depression and anxiety scores. Moreover, those with good levels of sleep quality, social interaction and nutrition had significantly lower depression scores.Both depression and anxiety scores of those who did sport/exercise, which was among the lifestyle behaviors, were found to be significantly lower. Lastly, the correlations between the neuropsychological test scores and the depression and anxiety scores were examined, and a significant positive correlation was found between both depression and anxiety scores and the "failure to maintain set" scores.

Analysis of changes in brain morphological structure of taekwondo athletes by diffusion tensor imaging

OBJECTIVE

Taekwondo, which is the most preferred sport among the martial arts, is known to improve individuals physically, spiritually and mentally. The aim of this study is to reveal the effect of teakwondo sport on the brain and brain structures. DESIGN;: 30 taekwondo athletes and 15 control groups were included in this study. Diffusion tensor MR images of each participant were taken. The information was obtained by the self-declaration of the athletes, whether they were sports years, amateur or elite.

METHOD

Total brain volume and volumes of white matter, gray matter, frontal lobe, precentral gyrus, corticospinal tract, basal nuclei, postcentral gyrus, hippocampus and amigdala and the ratio of these volumes to total brain volume were evaluated statistically between the groups using MriCloud software and ROIEditor program.

RESULTS

An increase in total brain volume, gray matter, frontal lobe and precentral gyrus volume in athletes was associated with taekwondo training. When the ratio of brain parts to total brain volume was examined, it was determined that there was a difference in the ratio of gray matter, white matter volumes in amateur athletes, right frontal lobe, left corticospinal tract, right postcentral gyrus volumes in elite athletes, and left postcentral gyrus volumes of both athletes compared to sedentary individuals.

CONCLUSIONS

The increase in the volume of gray matter, frontal lobe, postcentral gyrus and corticospinal tract together with the brain volume shows that taekwondo exercise contributes to physical, spiritual and mental development.

Two different brain networks underlying picture naming with familiar pre-existing native words and new vocabulary

The present research used fMRI to longitudinally investigate the impact of learning new vocabulary on the activation pattern of the language control network by measuring BOLD signal changes during picture naming tasks with familiar pre-existing native words (old words) and new vocabulary. Nineteen healthy participants successfully learned new synonyms for already known Spanish words, and they performed a picture naming task using the old words and the new words immediately after learning and two weeks after learning. The results showed that naming with old words, compared to naming with newly learned words, produced activations in a cortical network involving frontal and parietal regions, whereas the opposite contrast showed activation in a broader cortical/subcortical network, including the SMA/ACC, the hippocampus, and the midbrain. These two networks are maintained two weeks after learning. These results suggest that the language control network can be separated into two functional circuits for diverse cognitive purposes.

Cortical mapping in multilinguals undergoing awake brain surgery for brain tumors: Illustrative cases and systematic review

BACKGROUND

Awake brain mapping in multilingual patients with brain tumors presents unique challenges to the neurosurgeon. Knowledge of potential eloquent sites is vital to preserve language function.

METHODS

We present two cases of pars opercularis glioma and perform a systematic review in accordance with PRISMA guidelines.

RESULTS

Our review yielded 7 studies, with a total of 25 multilingual brain tumor patients who underwent awake brain mapping. The age ranged from 25 to 62 years. Majority were female (56.5%). Most (52%) were trilingual, while 20% were quadrilingual and 28% were pentalingual. All tumors were left-sided, mostly in the frontal lobe. These were predominantly gliomas. Extent of resection was gross total in 61%. The brain mapping findings were heterogeneous. Some authors reported a greater number of cortical sites for the first language compared to others. Others found that the first and second languages shared cortical sites whereas the third and subsequent languages were located in distant sites. The peri-Sylvian area was also found to be involved in language that was learned at an earlier age. Subsequent languages thus involved more distant sites. A larger number of cortical areas were also activated for languages that were learned later in life. In terms of language disturbance and recovery, there were mixed results.

CONCLUSION

Cortical mapping in multilingual brain tumor patients showed heterogeneity in terms of the location and number of language areas in the face of pathology. These findings may influence neurosurgical and oncological management of tumors in the speech area but emphasize the need to tailor surgical approaches and intraoperative testing to the patient.