scholarly journals Engagement of Language and Domain General Networks during Word Monitoring in a Native and Unknown Language

2021 ◽  
Vol 11 (8) ◽  
pp. 1063
Author(s):  
Kelly Cotosck ◽  
Jed Meltzer ◽  
Mariana Nucci ◽  
Katerina Lukasova ◽  
Letícia Mansur ◽  
...  
Keyword(s):  
Phonological Processing ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Native Language ◽  
Dorsal Stream ◽  
Ventral Stream ◽  
Language Performance ◽  
Monitoring Task ◽  
Auditory Word ◽  
The Right

Functional neuroimaging studies have highlighted the roles of three networks in processing language, all of which are typically left-lateralized: a ventral stream involved in semantics, a dorsal stream involved in phonology and speech production, and a more dorsal “multiple demand” network involved in many effortful tasks. As lateralization in all networks may be affected by life factors such as age, literacy, education, and brain pathology, we sought to develop a task paradigm with which to investigate the engagement of these networks, including manipulations to selectively emphasize semantic and phonological processing within a single task performable by almost anyone regardless of literacy status. In young healthy participants, we administered an auditory word monitoring task, in which participants had to note the occurrence of a target word within a continuous story presented in either their native language, Portuguese, or the unknown language, Japanese. Native language task performance activated ventral stream language networks, left lateralized but bilateral in the anterior temporal lobe. Unfamiliar language performance, being more difficult, activated left hemisphere dorsal stream structures and the multiple demand network bilaterally, but predominantly in the right hemisphere. These findings suggest that increased demands on phonological processing to accomplish word monitoring in the absence of semantic support may result in the bilateral recruitment of networks involved in speech perception under more challenging conditions.

scholarly journals The Protective Influence of Bilingualism on the Recovery of Phonological Input Processing in Aphasia After Stroke

2021 ◽  
Vol 11 ◽  
Author(s):  
Miet De Letter ◽  
Elissa-Marie Cocquyt ◽  
Oona Cromheecke ◽  
Yana Criel ◽  
Elien De Cock ◽  
...  
Keyword(s):  
Phonological Processing ◽  
Right Hemisphere ◽  
Source Distribution ◽  
Normative Values ◽  
Language Performance ◽  
Discrimination Ability ◽  
Input Processing ◽  
Related Potentials ◽  
The Right ◽  
Aphasia Recovery

Language-related potentials are increasingly used to objectify (mal)adaptive neuroplasticity in stroke-related aphasia recovery. Using preattentive [mismatch negativity (MMN)] and attentive (P300) phonologically related paradigms, neuroplasticity in sensory memory and cognitive functioning underlying phonological processing can be investigated. In aphasic patients, MMN amplitudes are generally reduced for speech sounds with a topographic source distribution in the right hemisphere. For P300 amplitudes and latencies, both normal and abnormal results have been reported. The current study investigates the preattentive and attentive phonological discrimination ability in 17 aphasic patients (6 monolinguals and 11 bilinguals, aged 41–71 years) at two timepoints during aphasia recovery. Between the two timepoints, a significant improvement of behavioral language performance in both languages is observed in all patients with the MMN latency at timepoint 1 as a predictive factor for aphasia recovery. In contrast to monolinguals, bilingual aphasic patients have a higher probability to improve their processing speed during rehabilitation, resulting in a shortening of the MMN latency over time, which sometimes progresses toward the normative values.

scholarly journals Glass Half Full: Preserved Anatomical Bypasses Predict Variance in Language Functions After Stroke

2021 ◽  
Author(s):  
Brian A Erickson ◽  
Brian Kim ◽  
Benjamin Deck ◽  
Dorian Pustina ◽  
Andrew Tesla DeMarco ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Shortest Paths ◽  
Dorsal Stream ◽  
Support Vector ◽  
Auditory Comprehension ◽  
Language Performance ◽  
Language Functions ◽  
Stroke Imaging ◽  
Shortest Network ◽  
The Right

The severity of post-stroke aphasia is related to damage to white matter connections. However, neural signaling can route not only through direct connections, but also along multi-step network paths. When brain networks are damaged by stroke, paths can bypass around the damage to restore communication. The shortest network paths between regions could be the most efficient routes for mediating bypasses. We examined how shortest-path bypasses after left hemisphere strokes were related to language performance. Regions within and outside of the canonical language network could be important in aphasia recovery. Therefore, we innovated methods to measure the influence of bypasses in the whole brain. Distinguishing bypasses from all residual shortest paths is difficult without pre-stroke imaging. We identified bypasses by finding shortest paths in subjects with stroke that were longer than those observed in the average network of the most reliably observed connections in age-matched controls. We tested whether features of those bypasses predicted scores in four orthogonal dimensions of language performance derived from a factor analysis of a battery of language tasks. The features were the length of each bypass in steps, and how many bypasses overlapped on each individual direct connection. We related these bypass features to language factors using grid-search cross-validated Support Vector Regression, a technique that extracts robust relationships in high-dimensional data analysis. We discovered that the length of bypasses reliably predicted variance in lexical production (R2 = .576) and auditory comprehension scores (R2 = .164). Bypass overlaps reliably predicted variance in Lexical Production scores (R2 = .247). The predictive elongation features revealed that bypass efficiency along the dorsal stream and ventral stream were most related to Lexical Production and Auditory Comprehension, respectively. Among the predictive bypass overlaps, increased bypass routing through the right hemisphere putamen was negatively related to lexical production ability.

What Does the Brain Do When You Fake It? An fMRI Study of Pantomimed and Real Grasping

2007 ◽  
Vol 97 (3) ◽  
pp. 2410-2422 ◽  
Author(s):  
G. Króliczak ◽  
C. Cavina-Pratesi ◽  
D. A. Goodman ◽  
J. C. Culham
Keyword(s):  
Visual Processing ◽  
Right Hemisphere ◽  
Statistical Significance ◽  
Three Dimensional ◽  
Dorsal Stream ◽  
Occipital Cortex ◽  
Ventral Stream ◽  
Underlying Assumption ◽  
Neuropsychological Evidence ◽  
The Right

Given that studying neural bases of actions is very challenging with fMRI, numerous experiments have used pantomimed actions as a proxy to studying neural circuits of real actions. However, the underlying assumption that the same neural mechanisms mediate real and pantomimed actions has never been directly tested. Moreover, the assumption is called into question by neuropsychological evidence suggesting that real actions depend on the dorsal stream of visual processing whereas pretend actions also recruit the ventral stream. Here, we directly tested these ideas in neurologically intact subjects. Ten right-handed participants performed four tasks: 1) grasping real three-dimensional objects, 2) reaching toward the objects and touching them with the knuckle without hand preshaping, 3) pantomimed grasping in an adjacent location where no object was present, and 4) pantomimed reaching toward an adjacent location. As expected, in the anterior intraparietal area, there was significantly higher activation during real grasping than that during real reaching. However, the activation difference between pantomimed grasping and pantomimed reaching did not reach statistical significance. There was also no effect of pantomimed grasping within the ventral stream, including an object-selective area in the lateral occipital cortex. Instead, we found that pantomimed grasping was mediated by right-hemisphere activation, particularly the right parietal cortex. These results suggest that areas typically invoked by real actions may not necessarily be driven by “fake” actions. Moreover, pantomimed grasping may not tap object-related areas within the ventral stream, but rather may rely on mechanisms within the right hemisphere that are recruited by artificial and less practiced actions.

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.

Age-Related Changes in the Allocation of Vertical Attention

2018 ◽  
Vol 24 (10) ◽  
pp. 1121-1124 ◽  
Author(s):  
Aleksandra Mańkowska ◽  
Kenneth M. Heilman ◽  
John B. Williamson ◽  
Michał Harciarek
Keyword(s):  
Spatial Attention ◽  
Right Hemisphere ◽  
Ventral Stream ◽  
Midsagittal Plane ◽  
Visual Stream ◽  
Leftward Bias ◽  
Healthy Elderly ◽  
Age Related ◽  
The Right ◽  
Dorsal Visual Stream

AbstractObjectives: Healthy individuals often have a leftward and upward attentional spatial bias; however, there is a reduction of this leftward bias with aging. The right hemisphere mediates leftward spatial attention and age-related reduction of right hemispheric activity may account for this reduced leftward bias. The right hemisphere also appears to be responsible for upward bias, and this upward bias might reduce with aging. Alternatively, whereas the dorsal visual stream allocates attention downward, the ventral stream allocates attention upward. Since with aging there is a greater atrophy of the dorsal than ventral stream, older participants may reveal a greater upward bias. The main purpose of this study was to learn if aging influences the vertical allocation of spatial attention. Methods: Twenty-six young (17 males; mean age 44.62±2.57 years) and 25 healthy elderly (13 males; mean age 72.04±.98 years), right-handed adults performed line bisections using 24 vertical lines (24 cm long and 2 mm thick) aligned with their midsagittal plane. Results: Older adults had a significantly greater upward bias than did younger adults. Conclusions: Normal upward attentional bias increases with aging, possibly due to an age-related reduction of the dorsal attentional stream that is responsible for the allocation of downward attention. (JINS, 2018, 24, 1121–1124)

scholarly journals Right Hemisphere Grey Matter Volume and Language Functions in Stroke Aphasia

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Sladjana Lukic ◽  
Elena Barbieri ◽  
Xue Wang ◽  
David Caplan ◽  
Swathi Kiran ◽  
...  
Keyword(s):  
Grey Matter ◽  
Right Hemisphere ◽  
Language Ability ◽  
Grey Matter Volume ◽  
Lesion Site ◽  
Language Performance ◽  
Support Functions ◽  
Language Functions ◽  
Lesion Symptom Mapping ◽  
The Right

The role of the right hemisphere (RH) in recovery from aphasia is incompletely understood. The present study quantified RH grey matter (GM) volume in individuals with chronic stroke-induced aphasia and cognitively healthy people using voxel-based morphometry. We compared group differences in GM volume in the entire RH and in RH regions-of-interest. Given that lesion site is a critical source of heterogeneity associated with poststroke language ability, we used voxel-based lesion symptom mapping (VLSM) to examine the relation between lesion site and language performance in the aphasic participants. Finally, using results derived from the VLSM as a covariate, we evaluated the relation between GM volume in the RH and language ability across domains, including comprehension and production processes both at the word and sentence levels and across spoken and written modalities. Between-subject comparisons showed that GM volume in the RH SMA was reduced in the aphasic group compared to the healthy controls. We also found that, for the aphasic group, increased RH volume in the MTG and the SMA was associated with better language comprehension and production scores, respectively. These data suggest that the RH may support functions previously performed by LH regions and have important implications for understanding poststroke reorganization.

scholarly journals Virtual reality-based sensorimotor adaptation shapes subsequent spontaneous and naturalistic stimulus-driven brain activity

2021 ◽  
Author(s):  
Meytal Wilf ◽  
Celine Dupuis ◽  
Davide Nardo ◽  
Diana Huber ◽  
Sibilla Sander ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Large Scale ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Visual Response ◽  
Spatial Shift ◽  
Before And After ◽  
Behavioural Tests ◽  
The Right

Our everyday life summons numerous novel sensorimotor experiences, to which our brain needs to adapt in order to function properly. However, tracking plasticity of naturalistic behaviour and associated brain modulations is challenging. Here we tackled this question implementing a prism adaptation training in virtual reality (VRPA) in combination with functional neuroimaging. Three groups of healthy participants (N=45) underwent VRPA (with a spatial shift either to the left/right side, or with no shift), and performed fMRI sessions before and after training. To capture modulations in free-flowing, task-free brain activity, the fMRI sessions included resting state and free viewing of naturalistic videos. We found significant decreases in spontaneous functional connectivity between large-scale cortical networks, namely attentional and default mode/fronto-parietal networks, only for adaptation groups. Additionally, VRPA was found to bias visual representations of naturalistic videos, as following rightward adaptation, we found upregulation of visual response in an area in the parieto-occipital sulcus (POS) in the right hemisphere. Notably, the extent of POS upregulation correlated with the size of the VRPA induced after-effect measured in behavioural tests. This study demonstrates that a brief VRPA exposure is able to change large-scale cortical connectivity and correspondingly bias the representation of naturalistic sensory inputs.

PRAXIS AND LANGUAGE ORGANIZATION IN LEFT-HANDERS

2020 ◽  
Vol 18 (1) ◽  
pp. 15-28
Author(s):  
Grzegorz Króliczak ◽  
Brian J. Piper ◽  
Weronika Potok ◽  
Mikołaj Buchwald ◽  
Paweł Kleka ◽  
...  
Keyword(s):  
Bimanual Coordination ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Spatial Processing ◽  
Language Functions ◽  
Attentional Resources ◽  
Neural Processes ◽  
The Mean ◽  
The Right

The performance of learned manual gestures (praxis) and the production of speech are thought to depend on related neural processes. If this relationship is not invoked by an unknown, third variable then shifts in their laterality, including dissociations of these two functions, would be unlikely unless the sharing of some neural resources with other functions is advantageous. This could be the case in lefthanders, in whom actions requiring manual precision are controlled by their right hemispheres, and whose representations could attract the control of skilled gesture. Functional neuroimaging (fMRI) was used to study praxis and language functions. Their lateralization indices were measured in 56 consecutively tested lefthanders (28 females), with the mean age of 23.3±4.9 years (range 18.4 – 47 years), and an Edinburgh Handedness Inventory quotient between –100 and –55.6 (with the mean of –83.8±14.2). We show that atypical, bilateral organization or right-lateralization of praxis is more common than atypical organization/lateralization of language, observed, respectively, in 23 (41%) vs. 15 (26.8%) of cases. Specifically, we found: (a) seven cases (12.5%) of clear, and an additional three cases (5.4%) of less pronounced dissociations of atypically represented praxis from typically represented language; (b) 13 cases (23.2%) with atypically organized praxis also associated with atypically organized language, and (c) only two cases (3.6%) of rather strongly atypical lateralization of language, yet with quite typical lateralization of praxis. These outcomes are consistent with an idea that, in some lefthanders, the guidance of skilled manual actions can profit from tighter links with the right hemisphere, whose motor specialization is linked in this particular population to manual precision, but in general to attentional resources, visuo-spatial processing and even bimanual coordination. Because of the presumed links of praxis with productive language, such transfers are often, and unsurprisingly accompanied by the reorganization of the latter. Yet, the very rare cases of reversed language functions, without any pronounced shifts in representations of praxis, indicate that such a pattern of segregation – or inverse dissociation – of these two functions could be maladaptive.

scholarly journals Magnetoencephalography resting-state correlates of executive and language components of verbal fluency

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Victor Oswald ◽  
Younes Zerouali ◽  
Aubrée Boulet-Craig ◽  
Maja Krajinovic ◽  
Caroline Laverdière ◽  
...  
Keyword(s):  
Phonological Processing ◽  
Resting State ◽  
Verbal Fluency ◽  
Right Hemisphere ◽  
Spectral Power ◽  
Inferior Frontal Gyrus ◽  
Factor Loading ◽  
Verbal Test ◽  
Eyes Open ◽  
The Right

AbstractVerbal fluency (VF) is a heterogeneous cognitive function that requires executive as well as language abilities. The purpose of this study was to elucidate the specificity of the resting state MEG correlates of the executive and language components. To this end, we administered a VF test, another verbal test (Vocabulary), and another executive test (Trail Making Test), and we recorded 5-min eyes-open resting-state MEG data in 28 healthy participants. We used source-reconstructed spectral power estimates to compute correlation/anticorrelation MEG clusters with the performance at each test, as well as with the advantage in performance between tests, across individuals using cluster-level statistics in the standard frequency bands. By obtaining conjunction clusters between verbal fluency scores and factor loading obtained for verbal fluency and each of the two other tests, we showed a core of slow clusters (delta to beta) localized in the right hemisphere, in adjacent parts of the premotor, pre-central and post-central cortex in the mid-lateral regions related to executive monitoring. We also found slow parietal clusters bilaterally and a cluster in the gamma 2 and 3 bands in the left inferior frontal gyrus likely associated with phonological processing involved in verbal fluency.

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