scholarly journals A transcallosal fiber system between homotopic inferior frontal regions supports complex linguistic processing

2016 ◽  
Author(s):  
Philipp Kellmeyer ◽  
Magnus-Sebastian Vry ◽  
Tonio Ball
Keyword(s):  
Right Hemisphere ◽  
Diffusion Tensor ◽  
The Body ◽  
Canonical Model ◽  
Stroke Recovery ◽  
Linguistic Processing ◽  
Fiber System ◽  
Affective Prosody ◽  
Left And Right ◽  
The Right

AbstractInferior frontal regions in the left and right hemisphere support different aspects of language processing. In the canonical model, left inferior frontal regions are mostly involved in processing based on phonological, syntactic and semantic features of language, whereas the right inferior frontal regions process paralinguistic aspects like affective prosody.Using diffusion tensor imaging (DTI) based probabilistic fiber tracking in 20 healthy volunteers, we identify a callosal fiber system connecting left and right inferior frontal regions that are involved in linguistic processing of varying complexity. Anatomically, we show that the interhemispheric fibers are highly aligned and distributed along a rostral to caudal gradient in the body and genu of the corpus callosum to connect homotopic inferior frontal regions.In light of converging data, taking previous DTI-based tracking studies and clinical case studies into account, our findings suggest that the right inferior frontal cortex not only processes paralinguistic aspects of language (such as affective prosody), as purported by the canonical model, but also supports the computation of linguistic aspects of varying complexity in the human brain. Our model may explain patterns of right hemispheric contribution to stroke recovery as well as disorders of prosodic processing. Beyond language-related brain function, we discuss how interspecies differences in interhemispheric connectivity and fiber density, including the system we described here, may also explain differences in transcallosal information transfer and cognitive abilities across different mammalian species.

Bihemispheric Language: How the Two Hemispheres Collaborate in the Processing of Language

2004 ◽  
Author(s):  
Norman D. Cook
Keyword(s):  
Language Processing ◽  
Right Hemisphere ◽  
Central Question ◽  
Linguistic Processing ◽  
Figures Of Speech ◽  
Language Functions ◽  
Left And Right ◽  
Level Of Understanding ◽  
The Right

Speech production in most people is strongly lateralized to the left hemisphere (LH), but language understanding is generally a bilateral activity. At every level of linguistic processing that has been investigated experimentally, the right hemisphere (RH) has been found to make characteristic contributions, from the processing of the affective aspects of intonation, through the appreciation of word connotations, the decoding of the meaning of metaphors and figures of speech, to the understanding of the overall coherency of verbal humour, paragraphs and short stories. If both hemispheres are indeed engaged in linguistic decoding and both processes are required to achieve a normal level of understanding, a central question concerns how the separate language functions on the left and right are integrated. This chapter reviews relevant studies on the hemispheric contributions to language processing and the role of interhemispheric communications in cognition.

Linguistic Processing and Reaction Time Differences in Stutterers and Nonstutterers

1983 ◽  
Vol 26 (2) ◽  
pp. 181-185 ◽  
Author(s):  
C. Rebekah Hand ◽  
William O. Haynes
Keyword(s):  
Right Hemisphere ◽  
Reaction Times ◽  
Decision Task ◽  
Linguistic Processing ◽  
Hemispheric Processing ◽  
Left And Right ◽  
Response Modes ◽  
Field Efficiency ◽  
The Right ◽  
Visual Hemifields

Linguistic processing by the left and right cerebral hemispheres was investigated in 10 adult male stutterers and l0 matched nonstutterers. Subjects performed a lexical decision task in which nonword and real-word stimuli were presented tachistoscopically to the right and left visual hemifields. Vocal and manual reaction times to real words were measured to assess hemispheric participation in processing linguistic information and to determine differences between response modes. The stuttering group exhibited a left visual field efficiency or right hemisphere preference for this task and were slower in both vocal and manual reaction times. Ramifications for hemispheric processing theories and laryngeal dysfunction hypothesis are discussed.

scholarly journals White Matter Integrity Correlates of the Reading Span

2021 ◽  
Author(s):  
Ekaterina V. Pechenkova ◽  
Yana R. Panikratova ◽  
Maria A. Fomina ◽  
Elena A. Mershina ◽  
Daria A. Bazhenova ◽  
...  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Verbal Working Memory ◽  
The Body ◽  
White Matter Integrity ◽  
Reading Span ◽  
The Right

Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 67) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. After taking into account effects of age, sex, education and handedness, reading span positively correlated with the white matter integrity in multiple sites: the body, the genu and the splenium of corpus callosum; bilateral corona radiata (anterior, posterior, and superior); bilateral superior longitudinal fasciculus; several tracts in the right hemisphere only, including the internal and external capsule; bilateral superior parietal and frontal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

scholarly journals Can Tactile Neglect Occur at an Intra-Limb Level? Vibrotactile Reaction Times in Patients with Right Hemisphere Damage

1994 ◽  
Vol 7 (2) ◽  
pp. 67-77 ◽  
Author(s):  
J. B. Mattingley ◽  
J. L. Bradshaw
Keyword(s):  
Right Hemisphere ◽  
Reaction Times ◽  
The Body ◽  
Right Hemisphere Damage ◽  
Tactile Stimuli ◽  
Supine Posture ◽  
Visual Reaction ◽  
Left And Right ◽  
Tactile Modality ◽  
The Right

Visual reaction time (RT) studies on patients with right hemisphere (RH) damage have demonstrated that the attentional imbalance to stimuli occupying left and right positions exists even within the “intact” ipsilesional hemifield. The purpose of the present study was to test whether such patients might also exhibit relative left-sided impairments in the tactile modality, where stimuli and responses involve the index and middle fingers of the non-hemiplegic ipsilesional hand. Eight patients with RH damage, and eight matched normal controls, were tested using a vibrotactile choice RT paradigm, with the responding hand held in prone or supine posture, and located either at the body midline, or in left or right hemispace. Patients showed significantly slower RTs with the left than the right finger in both hand postures, a difference which remained constant as a function of the hemispatial location of the responding hand. In the prone posture, patients' left finger RTs were slower than those of controls, who showed no difference between left and right finger RTs, while their right finger RTs were faster than those of controls. In the supine posture, both patients and controls exhibited slower left than right finger RTs, though in controls the left finger disadvantage was attributed to biomechanical rather than attentional factors. Patients also made more errors with left than right finger stimuli, both as failures of detection and as incorrect responses, while controls made fewer errors overall and showed no differences between fingers. These data demonstrate a bias in the distribution of attention to tactile stimuli at an intra-limb level, and suggest that the attentional imbalance created by RH damage may be supramodal.

scholarly journals White Matter Integrity in the Right Hemisphere Correlates with the Reading Span

2021 ◽  
Author(s):  
Ekaterina Pechenkova ◽  
Yana Panikratova ◽  
Maria Fomina ◽  
Elena Mershina ◽  
Daria Bazhenova ◽  
...  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Verbal Working Memory ◽  
The Body ◽  
White Matter Integrity ◽  
Reading Span ◽  
The Right

Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 47) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. Reading span positively correlated with the white matter integrity in several sites of the right hemisphere: the body and the splenium of corpus callosum; the posterior limb of internal capsule; posterior corona radiata; and superior parietal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

Brain Network Dysfunction in Poststroke Delirium and Spatial Neglect: An fMRI Study

Stroke ◽  
2021 ◽  
Author(s):  
Olga Boukrina ◽  
Mateusz Kowalczyk ◽  
Yury Koush ◽  
Yekyung Kong ◽  
A.M. Barrett
Keyword(s):  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Brain Network ◽  
Spatial Neglect ◽  
Stroke Recovery ◽  
Network Activity ◽  
Brain Disorder ◽  
Fmri Study ◽  
The Right ◽  
Right Hemisphere Stroke

Background and Purpose: Delirium, an acute reduction in cognitive functioning, hinders stroke recovery and contributes to cognitive decline. Right-hemisphere stroke is linked with higher delirium incidence, likely, due to the prevalence of spatial neglect (SN), a right-brain disorder of spatial processing. This study tested if symptoms of delirium and SN after right-hemisphere stroke are associated with abnormal function of the right-dominant neural networks specialized for maintaining attention, orientation, and arousal. Methods: Twenty-nine participants with right-hemisphere ischemic stroke undergoing acute rehabilitation completed delirium and SN assessments and functional neuroimaging scans. Whole-brain functional connectivity of 4 right-hemisphere seed regions in the cortical-subcortical arousal and attention networks was assessed for its relationship to validated SN and delirium severity measures. Results: Of 29 patients, 6 (21%) met the diagnostic criteria for delirium and 16 (55%) for SN. Decreased connectivity of the right basal forebrain to brain stem and basal ganglia predicted more severe SN. Increased connectivity of the arousal and attention network regions with the parietal, frontal, and temporal structures in the unaffected hemisphere was also found in more severe delirium and SN. Conclusions: Delirium and SN are associated with decreased arousal network activity and an imbalance of cortico-subcortical hemispheric connectivity. Better understanding of neural correlates of poststroke delirium and SN will lead to improved neuroscience-based treatment development for these disorders.

Right-Hemisphere Linguistic Functioning

1983 ◽  
Vol 57 (2) ◽  
pp. 407-414 ◽  
Author(s):  
Caven S. McLoughlin ◽  
Patricia J. McLoughlin
Keyword(s):  
Experimental Evidence ◽  
Right Hemisphere ◽  
Relevant Literature ◽  
Cerebral Hemispheres ◽  
Linguistic Processing ◽  
Language Functioning ◽  
Qualitative And Quantitative ◽  
Processing Abilities ◽  
Left And Right

This review examined the linguistic processing abilities and potential of adults' nondominant hemisphere. Relevant literature was reviewed for experimental evidence of qualitative and quantitative differences in language functioning between the left and right cerebral hemispheres. Selected studies representing typical methodologies and subjects were included.

Right hemisphere speech perception revealed by amobarbital injection and electrical interference

Neurology ◽  
1998 ◽  
Vol 51 (2) ◽  
pp. 458-464 ◽  
Author(s):  
D. Boatman ◽  
J. Hart ◽  
R. P. Lesser ◽  
N. Honeycutt ◽  
N. B. Anderson ◽  
...  
Keyword(s):  
Speech Perception ◽  
Left Hemisphere ◽  
Temporal Lobe ◽  
Right Hemisphere ◽  
Adult Brain ◽  
Left Posterior ◽  
Left And Right ◽  
Sodium Amobarbital ◽  
The Right ◽  
Electrical Interference

Objective: To investigate the right hemispheric speech perception capabilities of an adult right-handed patient with seizures.Methods: Consecutive, unilateral, intracarotid sodium amobarbital injections and left hemispheric electrical interference mapping were used to determine lateralization and localization of speech perception, measured as syllable discrimination.Results: Syllable discrimination remained intact after left and right intracarotid sodium amobarbital injections. Language otherwise strongly lateralized to the left hemisphere. Despite evidence of bilateral speech perception capabilities, electrical interference testing in the left posterior temporal lobe impaired syllable discrimination.Conclusions: The results suggest a functionally symmetric, parallel system in the adult brain with preferential use of left hemispheric pathways for speech perception.

Migraine affects white-matter tract integrity: A diffusion-tensor imaging study

Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1162-1171 ◽  
Author(s):  
Catherine D Chong ◽  
Todd J Schwedt
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
White Matter Tract ◽  
Inferior Longitudinal Fasciculus ◽  
Left And Right ◽  
The Right

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.

Hemispheric Asymmetries in a Signal Detection Task

1983 ◽  
Vol 57 (3) ◽  
pp. 923-929 ◽  
Author(s):  
John L. Andreassi ◽  
Charles S. Rebert ◽  
Ferol F. Larsen
Keyword(s):  
Signal Detection ◽  
Right Hemisphere ◽  
Reaction Times ◽  
Vigilance Task ◽  
Verbal Stimulus ◽  
Right Visual Field ◽  
Left And Right ◽  
The Right ◽  
Male Subjects ◽  
Central Fixation

Reaction time and signal detection performance were measured during a 78-min. vigilance task. 12 right-handed male subjects served in two experimental sessions. Subjects focused on a central fixation point and responded to signals presented at unpredictable times in one of three locations: 2.5° to right of central fixation, central, and 2.5° to the left of center. Subjects decided whether to press a response key with either the left or right hand with each presentation. Over-all vigilance performance (signal detections and response time) was similar for left and right visual-field presentations. Evidence from reaction times indicated that responses controlled by the left hemisphere were faster to a verbal stimulus (T) while reactions controlled by the right hemisphere were faster to an apparent non-verbal stimulus, an inverted T.

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