Simin Meykadeh , Ali Khadem , Simone Sulpizio , Werner Sommer
{"title":"Functional connectivity during morphosyntactic processing: An fMRI study in balanced Turkish-Persian bilinguals","authors":"Simin Meykadeh , Ali Khadem , Simone Sulpizio , Werner Sommer","doi":"10.1016/j.jneuroling.2023.101162","DOIUrl":null,"url":null,"abstract":"<div><p><span>Previous research has documented the impact of bilingualism on the functional connectivity (FC) of brain networks responsible for processing of two languages during a resting-state brain activity. However, the BOLD signal modulation during task-evoked neural activity remains unclear. To address this question we focused on language-related differences of fMRI-based FC of bilingual brains during </span>morphosyntactic processing<span> in L1 and L2 among balanced L1-Turkish-L2-Persian bilinguals who had learnt L2 at age 7. The task required grammaticality judgements to alternating L1-L2 sentences. In our previous study on the present dataset, we had demonstrated changes in BOLD activation in the Pars opercularis<span> (PO), posterior Superior Temporal Gyrus<span> (pSTG), Planum Temporale<span> (PT), and Supplementary Motor Area (SMA), associated with auditory morphosyntactic processing. In the present reanalysis of these data we focused on FC within and between the language network and the control network. Regions of interest were based on the syntax- and control-specific regions activated by the task. Our findings confirm the FC between the syntax-specific regions PO and pSTG within the language network. The FC between these areas in the processing of morphosyntax turned to be quite similar for L1 and L2, reflecting the high competences of our balanced bilinguals in both languages. In the control network, direct FCs were found in two key areas of the PT and SMA (i.e. left PT to right PT and left PT to left SMA), supporting the view that these areas subserve control operations when bilinguals perceive and process spoken language. Remarkably, inter- and intra-hemispheric connectivities in the control network were indistinguishable for L1 and L2. Regarding intra-network results, although increased FCs were observed in L1 for the left PO-PT neurocircuit and in L2 for the pSTG-PT neurocircuit, none of them significantly interacted with grammaticality. Overall, these results suggest that being balanced bilingual with age of acquisition at 7 years appears to be associated with similarities of FC between syntax processing-related and input- and output-related brain networks. Considering that previous resting state studies had not found evidence for the above-mentioned connections in bilinguals, the present results indicate the importance of task-driven reconfigurations on functional connections between brain networks.</span></span></span></span></p></div>","PeriodicalId":50118,"journal":{"name":"Journal of Neurolinguistics","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Neurolinguistics","FirstCategoryId":"102","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0911604423000398","RegionNum":3,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"LINGUISTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Previous research has documented the impact of bilingualism on the functional connectivity (FC) of brain networks responsible for processing of two languages during a resting-state brain activity. However, the BOLD signal modulation during task-evoked neural activity remains unclear. To address this question we focused on language-related differences of fMRI-based FC of bilingual brains during morphosyntactic processing in L1 and L2 among balanced L1-Turkish-L2-Persian bilinguals who had learnt L2 at age 7. The task required grammaticality judgements to alternating L1-L2 sentences. In our previous study on the present dataset, we had demonstrated changes in BOLD activation in the Pars opercularis (PO), posterior Superior Temporal Gyrus (pSTG), Planum Temporale (PT), and Supplementary Motor Area (SMA), associated with auditory morphosyntactic processing. In the present reanalysis of these data we focused on FC within and between the language network and the control network. Regions of interest were based on the syntax- and control-specific regions activated by the task. Our findings confirm the FC between the syntax-specific regions PO and pSTG within the language network. The FC between these areas in the processing of morphosyntax turned to be quite similar for L1 and L2, reflecting the high competences of our balanced bilinguals in both languages. In the control network, direct FCs were found in two key areas of the PT and SMA (i.e. left PT to right PT and left PT to left SMA), supporting the view that these areas subserve control operations when bilinguals perceive and process spoken language. Remarkably, inter- and intra-hemispheric connectivities in the control network were indistinguishable for L1 and L2. Regarding intra-network results, although increased FCs were observed in L1 for the left PO-PT neurocircuit and in L2 for the pSTG-PT neurocircuit, none of them significantly interacted with grammaticality. Overall, these results suggest that being balanced bilingual with age of acquisition at 7 years appears to be associated with similarities of FC between syntax processing-related and input- and output-related brain networks. Considering that previous resting state studies had not found evidence for the above-mentioned connections in bilinguals, the present results indicate the importance of task-driven reconfigurations on functional connections between brain networks.
期刊介绍:
The Journal of Neurolinguistics is an international forum for the integration of the neurosciences and language sciences. JNL provides for rapid publication of novel, peer-reviewed research into the interaction between language, communication and brain processes. The focus is on rigorous studies of an empirical or theoretical nature and which make an original contribution to our knowledge about the involvement of the nervous system in communication and its breakdowns. Contributions from neurology, communication disorders, linguistics, neuropsychology and cognitive science in general are welcome. Published articles will typically address issues relating some aspect of language or speech function to its neurological substrates with clear theoretical import. Interdisciplinary work on any aspect of the biological foundations of language and its disorders resulting from brain damage is encouraged. Studies of normal subjects, with clear reference to brain functions, are appropriate. Group-studies on well defined samples and case studies with well documented lesion or nervous system dysfunction are acceptable. The journal is open to empirical reports and review articles. Special issues on aspects of the relation between language and the structure and function of the nervous system are also welcome.