The language network as a natural kind within the broader landscape of the human brain

Nature reviews. Neuroscience, Journal Year: 2024, Volume and Issue: 25(5), P. 289 - 312

Published: April 12, 2024

Language: Английский

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Against cortical reorganisation

eLife, Journal Year: 2023, Volume and Issue: 12

Published: Nov. 21, 2023

Neurological insults, such as congenital blindness, deafness, amputation, and stroke, often result in surprising impressive behavioural changes. Cortical reorganisation, which refers to preserved brain tissue taking on a new functional role, is invoked account for these Here, we revisit many of the classical animal patient cortical remapping studies that spawned this notion reorganisation. We highlight empirical, methodological, conceptual problems call into doubt. argue appeal idea reorganisation attributable part way maps are empirically derived. Specifically, defined based oversimplified assumptions 'winner-takes-all', turn leads an erroneous interpretation what it means when appear change. Conceptually, interpreted circuit receiving novel input processing unrelated its original function. This implies neurons either pluripotent enough change they tuned or can computes. Instead more likely occur due potentiation pre-existing architecture already has requisite representational computational capacity pre-injury. be facilitated via Hebbian homeostatic plasticity mechanisms. Crucially, our revised framework proposes opportunities constrained throughout lifespan by underlying structural 'blueprint'. At no period, including early development, does cortex offer pluripotency. conclude distinct form plasticity, ubiquitously evoked with words 'take-over'' 'rewiring', not exist.

Language: Английский

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Current Approaches to the Treatment of Post-Stroke Aphasia

Journal of Stroke, Journal Year: 2021, Volume and Issue: 23(2), P. 183 - 201

Published: May 31, 2021

Aphasia, impairment of language after stroke or other neurological insult, is a common and often devastating condition that affects nearly every social activity interaction. Behavioral speech therapy the mainstay treatment, although interventions have been introduced to augment effects behavioral therapy. In this narrative review, we discuss advances in aphasia last 5 years focus primarily on properly powered, randomized, controlled trials both therapies for post-stroke aphasia. These include evaluation computer-delivered therapies. We also outcome prediction as well interventional employed noninvasive brain stimulation, medications Supported by evidence from Phase III large meta-analyses, it now generally accepted can improve processing many patients. Not all patients respond similarly with most severe being least likely responders. Nevertheless, imperative patients, regardless severity, receive management focused direct deficits, counseling, both. Emerging II suggests transcranial stimulation promising method boost outcomes.

Language: Английский

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Neuroplasticity in Post-Stroke Aphasia: A Systematic Review and Meta-Analysis of Functional Imaging Studies of Reorganization of Language Processing

Neurobiology of Language, Journal Year: 2020, Volume and Issue: 2(1), P. 22 - 82

Published: Sept. 23, 2020

Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such they take new or expanded roles in language processing. We carried out a systematic review and meta-analysis all articles published between 1995 early 2020 have described imaging studies six more individuals with post-stroke aphasia, reported analyses bearing neuroplasticity Each study was characterized appraised detail, particular attention three critically important methodological issues: task performance confounds, contrast validity, correction for multiple comparisons. identified 86 describing total 561 relevant analyses. found limitations related comparisons been pervasive. Only few claims about processing are strongly supported by the extant literature: first, left hemisphere less activated than neurologically normal controls, second, cohorts activity regions, possibly temporal lobe region right hemisphere, positively correlated function. There modest, equivocal evidence claim differentially recruit homotopic but no compelling differential recruitment additional domain-general networks. modest return function over time, longitudinal dynamic network.

Language: Английский

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The role of mirror mechanism in the recovery, maintenance, and acquisition of motor abilities

Neuroscience & Biobehavioral Reviews, Journal Year: 2021, Volume and Issue: 127, P. 404 - 423

Published: April 25, 2021

Language: Английский

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Disentangling neuroplasticity mechanisms in post-stroke language recovery

Brain and Language, Journal Year: 2024, Volume and Issue: 251, P. 105381 - 105381

Published: Feb. 24, 2024

A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal enhancing treatment outcomes. Subsequent recent advances neuroimaging techniques, we now have ability examine more closely how neural activity patterns change after stroke. However, way these changes relate impairments and recovery still debated. The aim this review provide theoretical framework better investigate interpret neuroplasticity underlying aphasia. We detail two sets observed at synaptic level may explain functional findings network level: feedback-based homeostatic plasticity associative Hebbian plasticity. In conjunction mechanisms, higher-order cognitive control processes dynamically modulate other regions meet communication demands, despite reduced resources. This work provides network-level neurobiological for can be used define guidelines personalized development.

Language: Английский

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An empirical comparison of univariate versus multivariate methods for the analysis of brain–behavior mapping

Human Brain Mapping, Journal Year: 2020, Volume and Issue: 42(4), P. 1070 - 1101

Published: Nov. 20, 2020

Abstract Lesion symptom mapping (LSM) tools are used on brain injury data to identify the neural structures critical for a given behavior or symptom. Univariate lesion (ULSM) methods provide statistical comparisons of behavioral test scores in patients with and without voxel by basis. More recently, multivariate (MLSM) have been developed that consider effects all lesioned voxels one model simultaneously. In current study, we much‐needed systematic comparison several ULSM MLSM methods, using both synthetic real potential strengths weaknesses approaches. We tested spatial precision each LSM method single dual (network type) anatomical target simulations across location, sample size, noise level, smoothing. Additionally, performed false positive characteristics associated method's spurious findings. Simulations showed no clear superiority either overall, but rather highlighted specific advantages different methods. No produced thresholded map exclusively delineated regions behavior. Thus, indicated, depending particular study design, hypotheses, size. Overall, recommend use tandem enhance confidence results: Brain foci identified as significant types unlikely be can confidently reported robust results.

Language: Английский

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Functional Mapping before and after Low-Grade Glioma Surgery: A New Way to Decipher Various Spatiotemporal Patterns of Individual Neuroplastic Potential in Brain Tumor Patients

Cancers, Journal Year: 2020, Volume and Issue: 12(9), P. 2611 - 2611

Published: Sept. 13, 2020

Intraoperative direct electrostimulation mapping (DEM) is currently the gold-standard for glioma surgery, since functional-based resection allows an optimization of onco-functional balance (increased with preserved quality life). Besides intrasurgical awake conation, cognition, and behavior, preoperative by means functional neuroimaging (FNI) transcranial magnetic stimulation (TMS) has increasingly been utilized surgical selection planning. However, because these techniques suffer from several limitations, particularly subcortical white matter pathways, DEM remains crucial to map neural connectivity. On other hand, non-invasive FNI TMS can be repeated before after resection(s), enabling longitudinal investigation brain reorganization, especially in slow-growing tumors like low-grade gliomas. Indeed, neoplasms generate neuroplastic phenomena patients usually no or only slight neurological deficits at diagnosis, despite gliomas involving so-called “eloquent” structures. Here, data gained perioperative FNI/TMS methods are reviewed, order decipher mechanisms underpinning cerebral reshaping induced tumor its possible relapse, (re)operation(s), postoperative rehabilitation. Heterogeneous spatiotemporal patterns rearrangement across a single patient over time have evidenced, structural changes as well modifications intra-hemispheric (in ipsi-lesional and/or contra-lesional hemisphere) inter-hemispheric Such various fingerprints reconfiguration were correlated different levels cognitive compensation. Serial multimodal studies exploring neuroplasticity might lead new management strategies based upon multistage therapeutic approaches adapted individual profile reallocation.

Language: Английский

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Language networks in aphasia and health: A 1000 participant activation likelihood estimation meta-analysis

NeuroImage, Journal Year: 2021, Volume and Issue: 233, P. 117960 - 117960

Published: March 18, 2021

Aphasia recovery post-stroke is classically and most commonly hypothesised to rely on regions that were not involved in language premorbidly, through 'neurocomputational invasion' or engagement of 'quiescent homologues'. Contemporary accounts have suggested, instead, might be supported by under-utilised areas the premorbid network, which are downregulated health save neural resources ('variable neurodisplacement'). Despite importance understanding bases clinically theoretically, there no consensus as specific more likely activated aphasia (PSA) than healthy individuals. Accordingly, we performed an Activation Likelihood Estimation (ALE) meta-analysis functional neuroimaging studies PSA. We obtained coordinate-based data for 481 individuals with following left-hemisphere stroke 530 linked controls from 33 met predefined inclusion criteria. ALE identified consistent, above-chance spatial convergence activation, well significantly different activation likelihood, between participant groups tasks. Overall, these findings dispute prevailing theory involves recruitment novel right hemisphere territory into network post-stroke. Instead, multiple throughout both hemispheres consistently during tasks PSA controls. Regions anterior insula, frontal operculum inferior gyrus (IFG) pars opercularis across all Similar higher lower demand comprehension production tasks, consistent them representing enhanced utilisation spare capacity within executive-control related regions. This provides evidence 'variable neurodisplacement' underlies changes occur Conversely, undamaged less controls, including domain-general medial superior paracingulate cortex, IFG triangularis temporal pole. These represent diaschisis, demonstrate global, undifferentiated upregulation Such knowledge essential if design neurobiologically-informed therapeutic interventions facilitate recovery.

Language: Английский

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The multidimensional nature of aphasia recovery post-stroke

Brain, Journal Year: 2021, Volume and Issue: 145(4), P. 1354 - 1367

Published: Oct. 8, 2021

Abstract Language is not a single function, but instead results from interactions between neural representations and computations that can be damaged independently of each other. Although there now clear evidence the language profile in post-stroke aphasia reflects graded variations along multiple underlying dimensions (‘components’), it still entirely unknown if these distinct components have different recovery trajectories rely on same, or different, regions during recovery. Accordingly, this study examined whether subacute stage: (i) mirror those observed chronic stage; (ii) recover together homogeneous manner; (iii) relate to changing activation overlapping brain regions. We analysed longitudinal data 26 individuals with mild–moderate following left hemispheric infarct who underwent functional MRI behavioural testing at ∼2 weeks ∼4 months post-stroke. The profiles early reflected three orthogonal principal consisting fluency, semantic/executive function phonology. These did singular, rather, their were uncorrelated, suggesting heterogeneous multidimensional. Mean regional overt speech production unlesioned areas was compared patient scores both late time points. In addition, change over component scores, before after controlling for baseline scores. found associated multiple, non-overlapping bilateral Specifically, fluency increasing middle frontal gyri right temporo-occipital temporal gyrus; reducing anterior lobes; while phonology precentral gyri, dorso-medial poles precuneus. Overlapping clusters ventromedial prefrontal cortex positively negatively This combination detailed provides novel insights into basis Because aspects seem recovery, treatment strategies target same region all stroke survivors might ineffective even impair depending specific individual patient.

Language: Английский

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