Functional Contributions of the Arcuate Fasciculus to Language Processing

Frontiers in Human Neuroscience, Journal Year: 2021, Volume and Issue: 15

Published: June 25, 2021

Current evidence strongly suggests that the arcuate fasciculus (AF) is critical for language, from spontaneous speech and word retrieval to repetition comprehension abilities. However, further pinpoint its unique differential role in anatomy needs be explored greater detail contribution language processing beyond of known cortical areas must established. We address this a comprehensive evaluation specific functional AF well-characterized cohort individuals with chronic aphasia (n = 33) following left hemisphere stroke. To evaluate macro- microstructural integrity AF, tractography based on constrained spherical deconvolution model was performed. The right hemispheres were then manually reconstructed using modified 3-segment (Catani et al., 2005), 2-segment (Glasser Rilling, 2008). normalized volume measure long posterior segments significantly correlated indices while controlling gender lesion volume. Specific contributions accounting - inferior frontal, parietal, temporal tested multiple regression analyses. Involvement tract demonstrated: segment contributed naming abilities; anterior fluency naming; comprehension. results highlight important fiber pathways impairments areas. At same time, no clear tracts could ascertained. In sum, our findings lend support broader processing, particular emphasis naming, point as being most crucial supporting residual

Language: Английский

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Anatomy of phonemic and semantic fluency: A lesion and disconnectome study in 1231 stroke patients

Cortex, Journal Year: 2021, Volume and Issue: 143, P. 148 - 163

Published: Aug. 5, 2021

Disturbances of semantic and phonemic fluency are common after brain damage, as a manifestation language, executive, or memory dysfunction. Lesion-symptom mapping (LSM) studies can provide fundamental insights in shared distinct anatomical correlates these cognitive functions help to understand which patients suffer from deficits. We performed multivariate support vector regression-based lesion-symptom structural disconnection study on 1231 with acute ischemic stroke. With the largest-ever LSM verbal we achieved almost complete lesion coverage. Lower performance both types was related left hemispheric frontotemporal parietal cortical regions, subcortical regions centering thalamus. Distinct for were anterior divisions middle inferior frontal gyri. posterior temporal gyri, parahippocampal fusiform gyri triangular part gyrus. The disconnectome-based analyses additionally revealed associated more extensive frontoparietal white matter network, whereas fornix, mesiotemporal matter, splenium corpus callosum. These results most detailed outline date, stress crucial role reveal novel dissociation lobe.

Language: Английский

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Statistical and Artificial Neural Networks Models for Electricity Consumption Forecasting in the Brazilian Industrial Sector

Energies, Journal Year: 2022, Volume and Issue: 15(2), P. 588 - 588

Published: Jan. 14, 2022

Forecasting the industry’s electricity consumption is essential for energy planning in a given country or region. Thus, this study aims to apply time-series forecasting models (statistical approach and artificial neural network approach) industrial Brazilian system. For statistical approach, Holt–Winters, SARIMA, Dynamic Linear Model, TBATS (Trigonometric Box–Cox transform, ARMA errors, Trend, Seasonal components) were considered. of networks, NNAR (neural autoregression) MLP (multilayer perceptron) The results indicate that model was one obtained best performance industry under analysis.

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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Indirect structural disconnection-symptom mapping

Brain Structure and Function, Journal Year: 2022, Volume and Issue: 227(9), P. 3129 - 3144

Published: Sept. 1, 2022

Language: Английский

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Multivariate mapping of low-resilient neurocognitive systems within and around low-grade gliomas

Brain, Journal Year: 2024, Volume and Issue: 147(8), P. 2718 - 2731

Published: April 22, 2024

Accumulating evidence suggests that the brain exhibits a remarkable capacity for functional compensation in response to neurological damage, resilience potential is deeply rooted malleable features of its underlying anatomofunctional architecture. This propensity particularly exemplified by diffuse low-grade glioma, subtype primary tumour. However, plasticity not boundless, and surgical resections directed at structures with limited neuroplasticity can lead incapacitating impairments. Yet, maximizing glioma offers substantial oncological benefits, especially when resection extends beyond tumour margins (i.e. supra-tumour or supratotal resection). In this context, objective study was identify which cerebral were associated less favourable cognitive outcomes after surgery, while accounting intra-tumour resections. To achieve objective, we leveraged unique cohort 400 patients who underwent surgery awake mapping. Patients benefitted from neuropsychological assessment consisting 18 subtests administered before 3 months surgery. We analysed changes performance applied topography-focused disconnection-focused multivariate lesion-symptom mapping using support vector regressions, an attempt capture resected cortico-subcortical amenable full compensation. The observed magnitude, suggesting overall recovery (13 tasks recovered fully despite mean extent 92.4%). Nevertheless, analyses revealed lack picture naming linked damage left inferior temporal gyrus longitudinal fasciculus. Likewise, semantic fluency abilities, association established precuneus/posterior cingulate. For phonological dorsomedial frontal cortex aslant tract implicated. Moreover, difficulties spatial exploration injury right prefrontal connectivity. An exploratory analysis suggested pronounced following specific patterns, such as uncinate fasciculus (picture naming), corticostriatal anterior corpus callosum (phonological fluency), hippocampus parahippocampus (episodic memory) frontal-mesial areas (visuospatial exploration). Collectively, these patterns results shed new light on both low-resilient neural systems prediction Furthermore, they indicate only occasionally well tolerated viewpoint. doing so, have deep implications planning rehabilitation strategies.

Language: Английский

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Predicting functional impairments with lesion‐derived disconnectome mapping: Validation in stroke patients with motor deficits

European Journal of Neuroscience, Journal Year: 2024, Volume and Issue: 59(11), P. 3074 - 3092

Published: April 5, 2024

Focal structural damage to white matter tracts can result in functional deficits stroke patients. Traditional voxel-based lesion-symptom mapping is commonly used localize brain structures linked neurological deficits. Emerging evidence suggests that the impact of focal may extend beyond immediate lesion sites. In this study, we present a disconnectome approach based on support vector regression (SVR) identify and pathways associated with For clinical validation, utilized imaging data from 340 patients exhibiting motor A map was initially derived lesions for each patient. Bootstrap sampling then employed balance sample size between minority group right or left those without Subsequently, SVR analysis voxels (p < .005). Our disconnectome-based significantly outperformed alternative approaches identifying major within corticospinal upper-lower limb Bootstrapping increased sensitivity (80%-87%) deficits, minimum 32 235 mm

Language: Английский

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Common and distinct neural substrates of sentence production and comprehension

NeuroImage, Journal Year: 2020, Volume and Issue: 224, P. 117374 - 117374

Published: Sept. 17, 2020

Functional neuroimaging and lesion-symptom mapping investigations implicate a left frontal-temporal-parietal network for sentence processing. The majority of studies have focused on comprehension, with fewer in the domain production, which not fully elucidated overlapping and/or unique brain structures associated two domains, particularly sentences noncanonical word order. Using voxel-based lesion symptom (VLSM) we examined relationship between lesions within hemisphere language both comprehension production simple complex syntactic 76 participants chronic stroke-induced aphasia. Results revealed shared regions across domains anterior posterior superior temporal gyri (aSTG, pSTG), pole (adjusted verb production/comprehension). Additionally, was middle (aMTG, pMTG), MTG temporooccipital regions, SMG/AG, central parietal operculum, insula. Subsequent VLSM analyses (production versus comprehension) critical each domain: were production; temporo-parietal implicating important roles ventral dorsal stream processing routes, respectively. Processing syntactically complex, canonical), damage to pSTG additional pMTG IPL impaired suggesting that is crucial computing pMTG, are necessary re-analysis thematic as required resolution long-distance dependencies. These findings converge previous extend our knowledge neural mechanisms highlighting further address mechanism engaged computation, controlled contribution

Language: Английский

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Functional differentiation in the language network revealed by lesion-symptom mapping

NeuroImage, Journal Year: 2021, Volume and Issue: 247, P. 118778 - 118778

Published: Dec. 9, 2021

Theories of language organization in the brain commonly posit that different regions underlie distinct linguistic mechanisms. However, such theories have been criticized on grounds many neuroimaging studies processing find similar effects across regions. Moreover, condition by region interaction effects, which provide strongest evidence functional differentiation between regions, rarely offered support these theories. Here we address this using lesion-symptom mapping three large, partially-overlapping groups aphasia patients with left hemisphere damage due to stroke (N = 121, N 92, 218). We identified multiple measure associating posterior middle temporal gyrus syntactic comprehension deficits, inferior frontal expressive agrammatism, and angular semantic category word fluency deficits. Our results are inconsistent recent hypotheses network undifferentiated respect high-level processing.

Language: Английский

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The Wernicke conundrum revisited: evidence from connectome-based lesion-symptom mapping

Brain, Journal Year: 2022, Volume and Issue: 145(11), P. 3916 - 3930

Published: June 21, 2022

Abstract Wernicke’s area has been assumed since the 1800s to be primary region supporting word and sentence comprehension. However, in 2015 2019, Mesulam colleagues raised what they termed ‘Wernicke conundrum’, noting widespread variability anatomical definition of this presenting data from progressive aphasia that challenged classical assumption. To resolve conundrum, posited a ‘double disconnection’ hypothesis: comprehension deficits stroke-based result disconnection anterior temporal inferior frontal regions other parts brain due white matter damage, rather than dysfunction itself. test hypothesis, we performed lesion-deficit correlations, including connectome-based lesion-symptom mapping, four large, partially overlapping groups English-speaking chronic left hemisphere stroke survivors. After removing variance object recognition associative semantic processing, same middle posterior lobe were implicated both complex non-canonical deficits. Connectome mapping revealed similar temporal-occipital disconnections for impaired comprehension, pole. We found an additional significant temporal-parietal deficits, which may indicate role phonological working memory processing syntax, but no disconnections. Moreover, damage these middle-posterior was associated with even when accounting strongest disconnections, respectively. Our results largely agree notion area, defined here as superior gyrus sulcus, supports suggest pole speak against hypothesis double disconnection.

Language: Английский

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