The role of the corpus callosum in language network connectivity in children

Abstract

The specific role of the corpus callosum (CC) in language network organization remains unclear, two contrasting models have been proposed: inhibition of homotopic areas allowing for independent functioning of the hemispheres versus integration of information from both hemispheres. This study aimed to add to this discussion with the first investigation of language network connectivity in combination with CC volume measures. In 38 healthy children aged 6–12, we performed task‐based functional magnetic resonance imaging to measure language network connectivity, used structural magnetic resonance imaging to quantify CC subsection volumes, and administered various language tests to examine language abilities. We found an increase in left intrahemispheric and bilateral language network connectivity and a decrease in right intrahemispheric connectivity associated with larger volumes of the posterior, mid‐posterior, and central subsections of the CC. Consistent with that, larger volumes of the posterior parts of the CC were significantly associated with better verbal fluency and vocabulary, the anterior CC volume was positively correlated with verbal span. Thus, children with larger volumes of CC subsections showed increased interhemispheric language network connectivity and were better in different language domains. This study presents the first evidence that the CC is directly linked to language network connectivity and underlines the excitatory role of the CC in the integration of information from both hemispheres.

Effect of corpus callosum agenesis on the language network in children and adolescents

“…The findings in ACC patients are in line with previous research in healthy children and adolescents, showing that bilateral language representation is favourable for language abilities ( Bartha-Doering et al 2018a ). The present study furthermore resumes a recent study from our lab that demonstrated the integrative function of the posterior CC in functional language network connectivity, fostering improved interhemispheric functional connectivity and enhanced language abilities in healthy children ( Bartha-Doering et al 2020 ). Interestingly, some previous studies point to different effects of the CC on language lateralization in temporal and frontal brain areas dependent on the nature of task.…”

“…Although language is predominantly processed in the left hemisphere in most healthy children ( Szaflarski et al 2002 , 2012 ), stronger functional connectivity with the right hemisphere enables better verbal abilities ( Bartha-Doering et al 2020 ). Thus, the CC seems to play an excitatory role in the integration of information of both hemispheres and language abilities profit from additional right hemisphere language processing that support and interact with left hemisphere processing.…”

“…The corpus callosum (CC) is involved in the neural organization of language. In a recent functional magnetic resonance imaging (fMRI) study in healthy children, we described the integrative function of the central and posterior parts of the CC in the language network allowing stronger interhemispheric functional connectivity and enhanced language abilities ( Bartha-Doering et al 2020 ). These findings are in line with the previous studies on the association of language lateralization and callosal measures, where weaker language lateralization was associated with increased posterior CC size and volume in healthy adults ( Hines et al 1992 ; Josse et al 2008 ).…”

White matter network disruption and cognitive correlates underlying impaired memory awareness in mild cognitive impairment

“…Two contrasting models have been suggested. According to the excitatory model, the callosal fibers integrate information from both cerebral hemispheres to facilitate interhemispheric connectivity ( Bartha‐Doering et al, 2021 , Gazzaniga, 2000 ). By contrast, the inhibitory model postulates that callosal fibers inhibit homologous areas, which allows for independent functioning of the hemispheres ( Cook, 1984 ).…”

Early Detection of Radiation-Induced Injury and Prediction of Cognitive Deficit by MRS Metabolites in Radiotherapy of Low-Grade Glioma

“…It is has been shown that the variation in the microstructure of the CC can strongly affect visuospatial perception and verbal fluency tasks, as well as other cognitive functions such as memory which may result in serious cognitive disorders [53][54][55]. The positive correlation of the posterior callosum with verbal fluency and language lateralization and also the anterior callosum with visuospatial ability has been demonstrated [56][57][58].…”