Unraveling the functional attributes of the language connectome: crucial subnetworks, flexibility and variability.

Language processing is a highly integrative function, intertwining linguistic operations (processing the language code intentionally used for communication) and extra-linguistic processes (e.g., attention monitoring, predictive inference, long-term memory). This synergetic cognitive architecture requires a distributed and specialized neural substrate. Brain systems have mainly been examined at rest. However, task-related functional connectivity provides additional and valuable information about how information is processed when various cognitive states are involved. We gathered thirteen language fMRI tasks in a unique database of one hundred and fifty neurotypical adults (InLang [Interactive networks of Language] database), providing the opportunity to assess language features across a wide range of linguistic processes. Using this database, we applied network theory as a computational tool to model the task-related functional connectome of language (LANG atlas). The organization of this data-driven neurocognitive atlas of language was examined at multiple levels, uncovering its major components (or crucial subnetworks), and its anatomical and functional correlates. In addition, we estimated its reconfiguration as a function of linguistic demand (flexibility) or several factors such as age or gender (variability). We observed that several discrete networks could be specifically shaped to promote key functional features of language: coding-decoding (Net1), control-executive (Net2), abstract-knowledge (Net3), and sensorimotor (Net4) functions. The architecture of these systems and the functional connectivity of the pivotal brain regions varied according to the nature of the linguistic process, gender, or age. By accounting for the multifaceted nature of language and modulating factors, this study can contribute to enriching and refining existing neurocognitive models of language. The LANG atlas can also be considered a reference for comparative or clinical studies involving various patients and conditions.

Application of childhood apraxia of speech clinical markers to French-speaking children: A preliminary study.

PURPOSE: Childhood apraxia of speech (CAS) is difficult to diagnose because there is little agreement on objective clinical markers. Since studies of phonological development in French-speaking children are scarce, there are even fewer recognised markers in French as compared to English. This study aims to determine if a set of operationalised, quantitative measures derived from clinical markers of CAS in English corroborate with clinical CAS diagnosis in French-speaking children. This research contributes to improving differential diagnosis of CAS and phonological disorder cross-linguistically. METHOD: We collected data from five children diagnosed with CAS, nine children diagnosed with phonological disorder, and 75 typically-developing children aged 5.10-9.2 years old. All children were assessed on three speech production tasks: picture-naming, non-word repetition, and diadochokinesis. We extracted 20 quantitative measures corresponding to commonly accepted clinical features of CAS. RESULT: Similar to English-speaking children, French-speaking children with CAS exhibited a high number of vowel errors, consonant and cluster errors, consonant epentheses, devoicing errors, slow diadochokinesis rate, more inconsistency and increased errors with longer words. Contrary to studies on English, these children with CAS did not produce intrusive schwas or vowels. CONCLUSION: This multiple-case study highlights the need for cross-linguistic diagnostic criteria for CAS.