The Structural Language Network

2017 ◽  
Author(s):  
Angela D. Friederici ◽  
Noam Chomsky
Keyword(s):  
White Matter ◽  
Language Processing ◽  
Sentence Processing ◽  
Information Transfer ◽  
Right Hemisphere ◽  
Brain Regions ◽  
Neural Basis ◽  
Fiber Tracts ◽  
White Matter Fiber Tracts ◽  
The Right

An adequate description of the neural basis of language processing must consider the entire network both with respect to its structural white matter connections and the functional connectivities between the different brain regions as the information has to be sent between different language-related regions distributed across the temporal and frontal cortex. This chapter discusses the white matter fiber bundles that connect the language-relevant regions. The chapter is broken into three sections. In the first, we look at the white matter fiber tracts connecting the language-relevant regions in the frontal and temporal cortices; in the second, the ventral and dorsal pathways in the right hemisphere that connect temporal and frontal regions; and finally in the third, the two syntax-relevant and (at least) one semantic-relevant neuroanatomically-defined networks that sentence processing is based on. From this discussion, it becomes clear that online language processing requires information transfer via the long-range white matter fiber pathways that connect the language-relevant brain regions within each hemisphere and between hemispheres.

The Brain Basis of Language Processing: From Structure to Function

2011 ◽  
Vol 91 (4) ◽  
pp. 1357-1392 ◽  
Author(s):  
Angela D. Friederici
Keyword(s):  
Language Processing ◽  
Right Hemisphere ◽  
Structural Connectivity ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Posterior Portion ◽  
Language Functions ◽  
Marker Studies ◽  
The Right ◽  
The Brain

Language processing is a trait of human species. The knowledge about its neurobiological basis has been increased considerably over the past decades. Different brain regions in the left and right hemisphere have been identified to support particular language functions. Networks involving the temporal cortex and the inferior frontal cortex with a clear left lateralization were shown to support syntactic processes, whereas less lateralized temporo-frontal networks subserve semantic processes. These networks have been substantiated both by functional as well as by structural connectivity data. Electrophysiological measures indicate that within these networks syntactic processes of local structure building precede the assignment of grammatical and semantic relations in a sentence. Suprasegmental prosodic information overtly available in the acoustic language input is processed predominantly in a temporo-frontal network in the right hemisphere associated with a clear electrophysiological marker. Studies with patients suffering from lesions in the corpus callosum reveal that the posterior portion of this structure plays a crucial role in the interaction of syntactic and prosodic information during language processing.

scholarly journals Individual alpha power predicts language comprehension

2021 ◽  
Author(s):  
Peng Wang ◽  
Yifei He ◽  
Burkhard Maess ◽  
Jinxing Yue ◽  
Luyao Chen ◽  
...  
Keyword(s):  
Language Processing ◽  
Language Comprehension ◽  
Right Hemisphere ◽  
Cognitive Task ◽  
Individual Performance ◽  
Brain Regions ◽  
Oscillatory Activity ◽  
Alpha Power ◽  
The Individual ◽  
The Right

Alpha power attenuation during cognitive task performing has been suggested to reflect a process of release of inhibition, increase of excitability, and thereby benefit the improvement of performance. Here, we hypothesized that changes in individual alpha power during the execution of a complex language comprehension task may correlate with the individual performance in that task. We tested this using magnetoencephalography (MEG) recorded during comprehension of German sentences of different syntactic complexity. Results showed that neither the frequency nor the power of the spontaneous oscillatory activity at rest were associated with the individual performance. However, during the execution of a sentences processing task, the individual alpha power attenuation did correlate with individual language comprehension performance. Source reconstruction localized effects in temporal-parietal regions of both hemispheres. While the effect of increased task difficulty is localized in the right hemisphere, the difference in power attenuation between tasks of different complexity exhibiting a correlation with performance was localized in left temporal-parietal brain regions known to be associated with language processing. From our results, we conclude that in-task attenuation of individual alpha power is related to the essential mechanisms of the underlying cognitive processes, rather than merely to general phenomena like attention or vigilance.

scholarly journals Diffusion tensor imaging correlates of hippocampal sclerosis and anterior temporal lobe T2 signal changes in pharmacoresistant epilepsy

2014 ◽  
Vol 01 (01) ◽  
pp. 001-007 ◽  
Author(s):  
Kevin Spitler ◽  
Francis Tirol ◽  
Itzhak Fried ◽  
Jerome Engel ◽  
Noriko Salamon
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Temporal Lobe ◽  
Diffusion Tensor ◽  
Hippocampal Sclerosis ◽  
Anterior Temporal Lobe ◽  
Pharmacoresistant Epilepsy ◽  
Fiber Tracts ◽  
White Matter Fiber Tracts ◽  
The Right

AbstractBackground and purpose Our goal was to determine fiber tract integrity in hippocampal sclerosis (HS) using diffusion tensor imaging (DTI) and to correlate white matter damage with other pathology in this disease.Methods Twenty-six patients and eight controls were studied with DTI tractography for 8 pairs of white matter fiber tracts and 2 commissural tracts. Fractional anisotropy (FA) of the fiber tracts was compared with controls. The FA of select fiber tracts was also compared with change in T2 signal in the anterior temporal lobe (ATC), and the performance on neuropsychological tests.Results In comparison with controls, subjects with left sided hippocampal sclerosis (L-HS) had 3 ipsilateral fiber tracts with decreased FA. The FA of fiber tracts was similar in right sided HS (R-HS) to controls. The ipsilateral inferior longitudinal fasciculus had a decrease in FA that correlated with the ATC (T2 signal change). The right superior longitudinal fasciculus had a decrease in FA proportional to lower performance on tests of memory and language.Conclusion The subjects with L-HS had more extensive structural abnormalities involving white matter tracts, both ipsilateral and contralateral. In contrast, subjects with R-HS had limited changes in white matter integrity. Pathology of white matter appears to be involved in deficits associated with HS, including ATC and cognitive performance.

scholarly journals A Review on Treatment-Related Brain Changes in Aphasia

2020 ◽  
Vol 1 (4) ◽  
pp. 402-433
Author(s):  
Klara Schevenels ◽  
Cathy J. Price ◽  
Inge Zink ◽  
Bert De Smedt ◽  
Maaike Vandermosten
Keyword(s):  
Language Processing ◽  
Large Scale ◽  
Right Hemisphere ◽  
Brain Plasticity ◽  
Integrated Approach ◽  
Brain Regions ◽  
Specific Information ◽  
Language Recovery ◽  
Brain Changes ◽  
The Right

Numerous studies have investigated brain changes associated with interventions targeting a range of language problems in patients with aphasia. We strive to integrate the results of these studies to examine (1) whether the focus of the intervention (i.e., phonology, semantics, orthography, syntax, or rhythmic-melodic) determines in which brain regions changes occur; and (2a) whether the most consistent changes occur within the language network or outside, and (2b) whether these are related to individual differences in language outcomes. The results of 32 studies with 204 unique patients were considered. Concerning (1), the location of treatment-related changes does not clearly depend on the type of language processing targeted. However, there is some support that rhythmic-melodic training has more impact on the right hemisphere than linguistic training. Concerning (2), we observed that language recovery is not only associated with changes in traditional language-related structures in the left hemisphere and homolog regions in the right hemisphere, but also with more medial and subcortical changes (e.g., precuneus and basal ganglia). Although it is difficult to draw strong conclusions, because there is a lack of systematic large-scale studies on this topic, this review highlights the need for an integrated approach to investigate how language interventions impact on the brain. Future studies need to focus on larger samples preserving subject-specific information (e.g., lesion effects) to cope with the inherent heterogeneity of stroke-induced aphasia. In addition, recovery-related changes in whole-brain connectivity patterns need more investigation to provide a comprehensive neural account of treatment-related brain plasticity and language recovery.

Neuropragmatics

2013 ◽  
Author(s):  
Brigitte Stemmer
Keyword(s):  
Language Processing ◽  
Sentence Processing ◽  
Figurative Language ◽  
Right Hemisphere ◽  
Large Field ◽  
General Level ◽  
Right Hemisphere Hypothesis ◽  
Brain Correlates ◽  
Figurative Language Processing ◽  
The Right

This essay summarizes the findings of studies investigating aspects of linguistic pragmatic behaviour and the brain correlates underlying such behaviour. Although pragmatics is a large field, most brain-oriented studies have focused on specific aspects of linguistic pragmatics such as structural discourse and figurative language. Research indicates that linguistic pragmatic behaviour relies on brain correlates that are routinely activated during word and sentence processing (the default language network). Although no agreement has yet been reached concerning questions such as whether these correlates are qualitatively and/or quantitatively different, whether additional brain areas/networks are implicated, and, if so, what these are, some concrete suggestions have emerged. At a more general level, there is consensus that the classical standard pragmatic model is not supported by most neuroimaging studies and that the right-hemisphere hypothesis on figurative language processing needs revision. The essay ends with some speculations on interpreting pragmatic behaviour within a microgenetic framework.

scholarly journals An edge-centric perspective on the human connectome: link communities in the brain

2014 ◽  
Vol 369 (1653) ◽  
pp. 20130527 ◽  
Author(s):  
Marcel A. de Reus ◽  
Victor M. Saenger ◽  
René S. Kahn ◽  
Martijn P. van den Heuvel
Keyword(s):  
Community Structure ◽  
White Matter ◽  
Right Hemisphere ◽  
Brain Regions ◽  
Network Nodes ◽  
Network Characteristics ◽  
Anatomical Basis ◽  
Neural Information ◽  
Neural Interactions ◽  
The Right

Brain function depends on efficient processing and integration of information within a complex network of neural interactions, known as the connectome. An important aspect of connectome architecture is the existence of community structure, providing an anatomical basis for the occurrence of functional specialization. Typically, communities are defined as groups of densely connected network nodes, representing clusters of brain regions. Looking at the connectome from a different perspective, instead focusing on the interconnecting links or edges, we find that the white matter pathways between brain regions also exhibit community structure. Eleven link communities were identified: five spanning through the midline fissure, three through the left hemisphere and three through the right hemisphere. We show that these link communities are consistently identifiable and investigate the network characteristics of their underlying white matter pathways. Furthermore, examination of the relationship between link communities and brain regions revealed that the majority of brain regions participate in multiple link communities. In particular, the highly connected and central hub regions showed a rich level of community participation, supporting the notion that these hubs play a pivotal role as confluence zones in which neural information from different domains merges.

scholarly journals Disruptions of the Human Connectome Associated With Hemispatial Neglect

Neurology ◽  
2022 ◽  
Vol 98 (2) ◽  
pp. e107-e114
Author(s):  
Sadhvi Saxena ◽  
Zafer Keser ◽  
Chris Rorden ◽  
Leonardo Bonilha ◽  
Julius Fridriksson ◽  
...  
Keyword(s):  
White Matter ◽  
Parietal Cortex ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Horizontal Line ◽  
Hemispatial Neglect ◽  
White Matter Tracts ◽  
The Right ◽  
Contralesional Side

Background and ObjectivesHemispatial neglect is a heterogeneous and complex disorder that can be classified by frame of reference for “left” vs “right,” including viewer-centered neglect (VCN, affecting the contralesional side of the view), stimulus-centered neglect (SCN, affecting the contralesional side of the stimulus, irrespective of its location with respect to the viewer), or both. We investigated the effect of acute stroke lesions on the connectivity of neural networks that underlie VCN or SCN.MethodsA total of 174 patients within 48 hours of acute right hemispheric infarct underwent a detailed hemispatial neglect assessment that included oral reading, scene copy, line cancellation, gap detection, horizontal line bisection tests, and MRI. Each patient's connectivity map was generated. We performed a linear association analysis between network connectivity strength and continuous measures of neglect to identify lesion-induced disconnections associated with the presence or severity of VCN and SCN. Results were corrected for multiple comparisons.ResultsAbout 42% of the participants with right hemisphere stroke had at least one type of neglect. The presence of any type of neglect was associated with lesions to tracts connecting the right inferior parietal cortex, orbitofrontal cortex, and right thalamus to other right-hemispheric structures. VCN only was strongly associated with tracts connecting the right putamen to other brain regions and tracts connecting right frontal regions with other brain regions. The presence of both types of neglect was most strongly associated with tracts connecting the right inferior and superior parietal cortex to other brain regions and those connecting left or right mesial temporal cortex to other brain regions.DiscussionOur study provides new evidence for the specific white matter tracts where disruption can cause hemispatial neglect in a relatively large number of participants and homogeneous time after onset. We obtained MRI and behavioral testing acutely, before the opportunity for rehabilitation or substantial recovery.Classification of EvidenceThis study provides Class II evidence that damage to specific white matter tracts identified on MRI are associated with the presence of neglect following right hemispheric stroke.

scholarly journals Plasticity in language cortex and white matter tracts after resection of dominant inferior parietal lobule arteriovenous malformations: a combined fMRI and DTI study

2020 ◽  
pp. 1-8 ◽  
Author(s):  
Yuming Jiao ◽  
Fuxin Lin ◽  
Jun Wu ◽  
Hao Li ◽  
Weilun Fu ◽  
...  
Keyword(s):  
White Matter ◽  
Arteriovenous Malformations ◽  
Right Hemisphere ◽  
Nerve Fibers ◽  
Hemispheric Dominance ◽  
Short Term ◽  
Fiber Tracts ◽  
Wernicke’S Area ◽  
The Right ◽  
Language Cortex

OBJECTIVEThe dominant inferior parietal lobe (IPL) contains cortical and subcortical structures that serve language processing. A high incidence of postoperative short-term aphasia and good potential for language reorganization have been observed. The authors’ goal was to study the plasticity of the language cortex and language-related fibers in patients with brain arteriovenous malformations (BAVMs) located in the IPL.METHODSA total of 6 patients who underwent microsurgical treatment of an IPL BAVM were prospectively recruited between September 2016 and May 2018. Blood oxygen level–dependent functional MRI (BOLD-fMRI) and diffusion tensor imaging (DTI) were performed within 1 week before and 6 months after microsurgery. Language-related white matter (WM) eloquent fiber tracts and their contralateral homologous fiber tracts were tracked. The Western Aphasia Battery was administered to assess language function. The authors determined the total number of fibers and mean fractional anisotropy (FA) indices for each individual tract. In addition, they calculated the laterality index (LI) between the activated language cortex voxels in the lesional and contralesional hemispheres and compared these indices between the preoperative and postoperative fMR and DT images.RESULTSOf the 6 patients with IPL BAVMs, all experienced postoperative short-term language deficits, and 5 (83.3%) recovered completely at 6 months after surgery. Five patients (83.3%) had right homologous reorganization of BOLD signal activations in both Broca’s and Wernicke’s areas. More fibers were observed in the arcuate fasciculus (AF) in the lesional hemisphere than in the contralesional hemisphere (1905 vs 254 fibers, p = 0.035). Six months after surgery, a significantly increased number of fibers was seen in the right hemispheric AF (249 fibers preoperatively vs 485 postoperatively, p = 0.026). There were significantly more nerve fibers in the postoperative left inferior frontooccipital fasciculus (IFOF) (874 fibers preoperatively vs 1186 postoperatively, p = 0.010). A statistically significant increase in right hemispheric dominance of Wernicke’s area was observed. The overall functional LI showed functional lateralization of Wernicke’s area in the right hemisphere (LI ≤ −0.20) in all patients.CONCLUSIONSThe authors’ findings provide evidence for the functional reorganization by recruiting the right hemispheric homologous region of Broca’s and Wernicke’s areas, right hemispheric AFs, and left hemispheric IFOFs following resection of IPL BAVMs.Clinical trial registration no.: NCT02868008 (clinicaltrials.gov)

scholarly journals The correlation between white matter integrity and pragmatic language processing in first episode schizophrenia

2020 ◽  
Author(s):  
Agnieszka Pawełczyk ◽  
Emila Łojek ◽  
Natalia Żurner ◽  
Marta Gawłowska-Sawosz ◽  
Piotr Gębski ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Language Processing ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Pragmatic Language ◽  
First Episode ◽  
Arcuate Fasciculus ◽  
The Right ◽  
First Episode Schizophrenia

Abstract Objective: Higher-order language disturbances could be the result of white matter tract abnormalities. The study explores the relationship between white matter and pragmatic skills in first-episode schizophrenia. Methods: Thirty-four first-episode patients with schizophrenia and 32 healthy subjects participated in a pragmatic language and Diffusion Tensor Imaging study, where fractional anisotropy of the arcuate fasciculus, corpus callosum and cingulum was correlated with the Polish version of the Right Hemisphere Language Battery. Results: The patients showed reduced fractional anisotropy in the right arcuate fasciculus, left anterior cingulum bundle and left forceps minor. Among the first episode patients, reduced understanding of written metaphors correlated with reduced fractional anisotropy of left forceps minor, and greater explanation of written and picture metaphors correlated with reduced fractional anisotropy of the left anterior cingulum. Conclusions: The white matter dysfunctions may underlie the pragmatic language impairment in schizophrenia. Our results shed further light on the functional neuroanatomical basis of pragmatic language use by patients with schizophrenia.

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