scholarly journals Transient perturbation of the left temporal cortex evokes plasticity-related reconfiguration of the lexical network

2019 ◽  
Author(s):  
Jana Klaus ◽  
Dennis J.L.G. Schutter ◽  
Vitória Piai
Keyword(s):  
Language Impairment ◽  
Language Production ◽  
Semantic Network ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Naming Task ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Lexical Retrieval ◽  
Control Mechanisms

Language impairment is common after left-hemisphere damage. However, the involvement of perilesional and homologous contralateral regions in compensating for left-sided lesions remains poorly understood. The aim of this study was to examine acute organizational changes in brain activity related to conceptual and lexical retrieval in unimpaired language production following transient disruption of the left middle temporal gyrus (MTG). In a randomized singleblind within-subject experiment, we recorded the electroencephalogram from sixteen healthy participants during a context-driven picture-naming task. Prior to the task, the left MTG was perturbed with real neuronavigated continuous theta-burst stimulation (cTBS) or sham stimulation. During the task, participants read lead-in sentences that created a constraining (e.g. “The farmer milks the”) or non-constraining context (e.g. “The farmer buys the”). The last word was shown as a picture that participants had to name (e.g. “cow”). Replicating behavioral studies, participants were overall faster in naming pictures following a constraining relative to a non-constraining context, but this effect did not differ between real and sham cTBS. Real cTBS, however, increased overall error rates compared to sham cTBS. In line with previous studies, we observed a decrease in alpha-beta (8-24 Hz) oscillatory power for constraining relative to non-constraining contexts over left temporal-parietal cortex after participants received sham cTBS. However, following real cTBS, this decrease extended towards left prefrontal regions associated with both domain-general and domain-specific control mechanisms. Our findings provide evidence that immediately after the disruption of the left MTG, the lexical-semantic network is able to quickly reconfigure, also recruiting domain-general regions.

scholarly journals ERP Correlates of Word Production before and after Stroke in an Aphasic Patient

2011 ◽  
Vol 23 (2) ◽  
pp. 374-381 ◽  
Author(s):  
Marina Laganaro ◽  
Stéphanie Morand ◽  
Christoph M. Michel ◽  
Laurent Spinelli ◽  
Armin Schnider
Keyword(s):  
Picture Naming ◽  
Healthy Subjects ◽  
Language Production ◽  
Time Window ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Word Production ◽  
Control Group ◽  
Healthy Controls ◽  
Aphasic Patient

Changes in brain activity characterizing impaired speech production after brain damage have usually been investigated by comparing aphasic speakers with healthy subjects because prestroke data are normally not available. However, when interpreting the results of studies of stroke patients versus healthy controls, there is an inherent difficulty in disentangling the contribution of neuropathology from other sources of between-subject variability. In the present work, we had an unusual opportunity to study an aphasic patient with severe anomia who had incidentally performed a picture naming task in an ERP study as a control subject one year before suffering a left hemisphere stroke. The fortuitous recording of this patient's brain activity before his stroke allows direct comparison of his pre- and poststroke brain activity in the same language production task. The subject did not differ from other healthy subjects before his stroke, but presented major electrophysiological differences after stroke, both in comparison to himself before stroke and to the control group. ERP changes consistently appeared after stroke in a specific time window starting about 250 msec after picture onset, characterized by a single divergent but stable topographic configuration of the scalp electric field associated with a cortical generator abnormally limited to left temporal posterior perilesional areas. The patient's pattern of anomia revealed a severe lexical–phonological impairment and his ERP responses diverged from those of healthy controls in the time window that has previously been associated with lexical–phonological processes during picture naming. Given that his prestroke ERPs were indistinguishable from those of healthy controls, it seems highly likely that the change in his poststroke ERPs is due to changes in language production processes as a consequence of stroke. The patient's neurolinguistic deficits, combined with the ERPs results, provide unique evidence for the role of left temporal cortex in lexical–phonological processing from about 250 to 450 msec during word production.

scholarly journals Cognitive Brain Signatures of Youth With Early Onset and Relatives With Schizophrenia: Evidence From fMRI Meta-analyses

2020 ◽  
Vol 46 (4) ◽  
pp. 857-868
Author(s):  
Marie Arsalidou ◽  
Zachary Yaple ◽  
Tomas Jurcik ◽  
Vadim Ushakov
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Function ◽  
Early Onset ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Middle Temporal Gyrus ◽  
Early Onset Schizophrenia ◽  
Dorsolateral Prefrontal ◽  
Brain Correlates ◽  
Meta Analyses

Abstract Deficits in cognitive function are a major characteristic of schizophrenia. Many functional magnetic resonance imaging (fMRI) studies examine brain correlates of cognitive function in adults with schizophrenia, showing altered implication of associative areas such as the prefrontal cortex and temporal cortex. fMRI studies also examine brain representation of cognitive function in adolescents with early onset schizophrenia and those at risk of the disorder, yet results are often inconsistent. We compile and analyze data from eligible fMRI studies using quantitative meta-analyses to reveal concordant brain activity associated with adolescent relatives of patients with schizophrenia and those with early onset schizophrenia. Results show similar functional hubs of brain activity (eg, precuneus) yet in opposite hemispheres and clusters in ventrolateral rather than dorsolateral prefrontal cortices. Other areas of altered implication include the middle temporal gyrus, insula, and cerebellum. We discuss the findings in reference to the protracted maturation of the prefrontal cortex and possible effects due to the medication status of the two groups.

scholarly journals A Common Neural Substrate for Language Production and Verbal Working Memory

2011 ◽  
Vol 23 (6) ◽  
pp. 1358-1367 ◽  
Author(s):  
Daniel J. Acheson ◽  
Massihullah Hamidi ◽  
Jeffrey R. Binder ◽  
Bradley R. Postle
Keyword(s):  
Working Memory ◽  
Language Production ◽  
Alternative Hypothesis ◽  
Verbal Working Memory ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Phonological Encoding ◽  
Semantic Retrieval ◽  
Retrieval Task ◽  
Lexical Semantic

Verbal working memory (VWM), the ability to maintain and manipulate representations of speech sounds over short periods, is held by some influential models to be independent from the systems responsible for language production and comprehension [e.g., Baddeley, A. D. Working memory, thought, and action. New York, NY: Oxford University Press, 2007]. We explore the alternative hypothesis that maintenance in VWM is subserved by temporary activation of the language production system [Acheson, D. J., & MacDonald, M. C. Verbal working memory and language production: Common approaches to the serial ordering of verbal information. Psychological Bulletin, 135, 50–68, 2009b]. Specifically, we hypothesized that for stimuli lacking a semantic representation (e.g., nonwords such as mun), maintenance in VWM can be achieved by cycling information back and forth between the stages of phonological encoding and articulatory planning. First, fMRI was used to identify regions associated with two different stages of language production planning: the posterior superior temporal gyrus (pSTG) for phonological encoding (critical for VWM of nonwords) and the middle temporal gyrus (MTG) for lexical–semantic retrieval (not critical for VWM of nonwords). Next, in the same subjects, these regions were targeted with repetitive transcranial magnetic stimulation (rTMS) during language production and VWM task performance. Results showed that rTMS to the pSTG, but not the MTG, increased error rates on paced reading (a language production task) and on delayed serial recall of nonwords (a test of VWM). Performance on a lexical–semantic retrieval task (picture naming), in contrast, was significantly sensitive to rTMS of the MTG. Because rTMS was guided by language production-related activity, these results provide the first causal evidence that maintenance in VWM directly depends on the long-term representations and processes used in speech production.

scholarly journals The Neural Correlates of Semantic Control Revisited

2020 ◽  
Author(s):  
Rebecca L. Jackson
Keyword(s):  
Semantic Network ◽  
Meta Analysis ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Neural Correlates ◽  
Middle Temporal Gyrus ◽  
Control Network ◽  
Temporal Region ◽  
List Type ◽  
Semantic Cognition

AbstractSemantic control, the ability to selectively access and manipulate meaningful information on the basis of context demands, is a critical component of semantic cognition. The precise neural correlates of semantic control are disputed, with particular debate surrounding parietal involvement, the spatial extent of the posterior temporal contribution and network lateralisation. Here semantic control is revisited, utilising improved analysis techniques and a decade of additional data to refine our understanding of the network. A meta-analysis of 876 peaks over 121 contrasts illuminated a left-focused network consisting of inferior frontal gyrus, posterior middle temporal gyrus, posterior inferior temporal gyrus and dorsomedial prefrontal cortex. This extended the temporal region implicated, and found no parietal involvement. Although left-lateralised overall, relative lateralisation varied across the implicated regions. Supporting analyses confirmed the multimodal nature of the semantic control network and situated it within the wider set of regions implicated in semantic cognition.Highlights➢A multimodal semantic control network was delineated with formal meta-analyses➢Semantic control recruits inferior and medial frontal and posterior temporal cortex➢A large extent of posterior temporal cortex was implicated and no parietal regions➢Semantic control is left-lateralised but regions show differential lateralisation➢The semantic control regions were situated in the context of the wider semantic network

scholarly journals Lexical selection with competing distractors: Evidence from left temporal lobe lesions

2016 ◽  
Author(s):  
Vitória Piai ◽  
Robert T. Knight
Keyword(s):  
Interference Effect ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Lexical Selection ◽  
Semantic Interference ◽  
Middle Temporal ◽  
Relative Contribution ◽  
Unrelated Condition

AbstractAccording to the competition account of lexical selection in word production, conceptually driven word retrieval involves the activation of a set of candidate words in left temporal cortex, and competitive selection of the intended word from this set, regulated by frontal cortical mechanisms. However, the relative contribution of these brain regions to competitive lexical selection is uncertain. In the present study, five patients with left prefrontal cortex lesions (overlapping in ventral and dorsal lateral cortex), eight patients with left lateral temporal cortex lesions (overlapping in middle temporal gyrus), and 13 matched controls performed a picture-word interference task. Distractor words were semantically related or unrelated to the picture, or the name of the picture (congruent condition). Semantic interference (related vs unrelated), tapping into competitive lexical selection, was examined. An overall semantic interference effect was observed for the control and left-temporal groups separately. The left-frontal patients did not show a reliable semantic interference effect as a group. The left-temporal patients had increased semantic interference in the error rates relative to controls. Error distribution analyses indicated that these patients had more hesitant responses for the related than for the unrelated condition. We propose that left middle temporal lesions affect the lexical activation component, making lexical selection more susceptible to errors.

Language switching in bilingual speech production

2008 ◽  
Vol 3 (2) ◽  
pp. 214-238 ◽  
Author(s):  
John W. Schwieter ◽  
Gretchen Sunderman
Keyword(s):  
Speech Production ◽  
Language Production ◽  
Naming Task ◽  
Control Mechanisms ◽  
Verbal Fluency Task ◽  
Lexical Representations ◽  
English Dominant ◽  
Fluency Task ◽  
Selective Mechanism ◽  
Inhibitory Control Mechanisms

Recent research on language production suggests that bilinguals shift from using inhibitory control mechanisms to a language-specific selective mechanism during development (Costa, Santesteban, & Ivanova, 2006). Costa et al. argue that the robustness of the L2 lexical representations may be critical to the functionality of a language-specific selective mechanism. Accordingly, in the present study we measured the lexical robustness of a group of 54 English dominant learners of Spanish using a verbal fluency task and investigated its effect on their performance in a picture-naming task with language switches. The results suggest that L2 lexical robustness predicts the shift to a language-specific selective mechanism during speech production. Moreover, we demonstrate a specific threshold of lexical robustness necessary to engage the mechanism.

The impact of brief exposure to the second language on native language production: Global or item specific?

2019 ◽  
Vol 41 (1) ◽  
pp. 153-183
Author(s):  
Tamar Degani ◽  
Hamutal Kreiner ◽  
Haya Ataria ◽  
Farha Khateeb
Keyword(s):  
Language Production ◽  
Low Frequency ◽  
Error Rates ◽  
Control Mechanisms ◽  
Post Exposure ◽  
Before And After ◽  
Exposure Error ◽  
Language Context ◽  
Cross Language ◽  
The Impact

AbstractBilinguals routinely shift between their languages, changing languages between communicative settings. To test the consequences of such changes in language use, 48 Arabic–Hebrew bilinguals named pictures in Arabic (L1) before and after a brief exposure manipulation, including either reading a list of Hebrew (L2) words aloud or performing a nonlinguistic task. Half of the items post-exposure were new and half were translation equivalents of the words presented during the L2 exposure task. Further, half of the items were very low-frequency L1 words, typically replaced by borrowed L2 words. Results show that across word types bilinguals were less accurate and produced more L2 cross-language errors in their dominant L1 following brief L2 exposure. Error rates were comparable for translation equivalents and new items, but more cross-language errors were observed post-exposure on translation equivalents. These findings demonstrate the engagement of both global whole-language control mechanisms and item-based competitive processes, and highlight the importance of language context and the dynamic nature of bilingual performance.

Distinguishing hypochondriasis and schizophrenia using regional homogeneity: a resting-state fMRI study and support vector machine analysis

2021 ◽  
pp. 1-29
Author(s):  
Kangyu Jin ◽  
Zhe Shen ◽  
Guoxun Feng ◽  
Zhiyong Zhao ◽  
Jing Lu ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Resting State ◽  
Parietal Lobe ◽  
Brain Activity ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Regional Homogeneity ◽  
Middle Temporal Gyrus ◽  
Support Vector ◽  
Fmri Study

Abstract Objective: A few former studies suggested there are partial overlaps in abnormal brain structure and cognitive function between Hypochondriasis (HS) and schizophrenia (SZ). But their differences in brain activity and cognitive function were unclear. Methods: 21 HS patients, 23 SZ patients, and 24 healthy controls (HC) underwent Resting-state functional magnetic resonance imaging (rs-fMRI) with the regional homogeneity analysis (ReHo), subsequently exploring the relationship between ReHo value and cognitive functions. The support vector machines (SVM) were used on effectiveness evaluation of ReHo for differentiating HS from SZ. Results: Compared with HC, HS showed significantly increased ReHo values in right middle temporal gyrus (MTG), left inferior parietal lobe (IPL) and right fusiform gyrus (FG), while SZ showed increased ReHo in left insula, decreased ReHo values in right paracentral lobule. Additionally, HS showed significantly higher ReHo values in FG, MTG and left paracentral lobule but lower in insula than SZ. The higher ReHo values in insula were associated with worse performance in MCCB in HS group. SVM analysis showed a combination of the ReHo values in insula and FG was able to satisfactorily distinguish the HS and SZ patients. Conclusion: our results suggested the altered default mode network (DMN), of which abnormal spontaneous neural activity occurs in multiple brain regions, might play a key role in the pathogenesis of HS, and the resting-state alterations of insula closely related to cognitive dysfunction in HS. Furthermore, the combination of the ReHo in FG and insula was a relatively ideal indicator to distinguish HS from SZ.

The effects of language impairment on the use of direct object pronouns and verb inflections in heritage Spanish speakers: A look at attrition, incomplete acquisition and maintenance

2011 ◽  
Vol 15 (1) ◽  
pp. 22-38 ◽  
Author(s):  
PEGGY F. JACOBSON
Keyword(s):  
Language Impairment ◽  
Error Rates ◽  
School Age Children ◽  
Gender Assignment ◽  
Verb Inflection ◽  
Heritage Spanish Speakers ◽  
Third Person ◽  
And Gender ◽  
Verb Inflections ◽  
Incomplete Acquisition

This study examined object clitic pronouns (OCPs) and verb inflections in twenty-five school-age children with typical development (TD) and twenty children with bilingual language impairment (BLI). MANOVA and ANOVA were used to explore differences according to grade level and language status (TD vs. BLI). Although children with BLI produced higher rates of grammatical errors overall, accuracy on number and gender assignment for OCPs was better for both groups in the higher grades. Although the rate of verb inflection errors did not differ for children with TD and BLI in the lower grades, a significant interaction yielded higher error rates on subject–verb agreement for third person singular and plural inflections in the later grades for children with BLI. Greater accuracy on OCP use in later grades weakens claims that bilingualism exacerbates language impairment. For BLI, whether incomplete acquisition or delayed development is the determining factor for verb inflection errors remains undetermined.

scholarly journals Intra-Cranial Recordings of Brain Activity During Language Production

2011 ◽  
Vol 2 ◽  
Author(s):  
Anaïs Llorens ◽  
Agnès Trébuchon ◽  
Catherine Liégeois-Chauvel ◽  
F.-Xavier Alario
Keyword(s):  
Language Production ◽  
Brain Activity
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