Stronger right-hemispheric involvement in language processing is associated with greater functional connectivity...

Language comprehension and production are predominantly supported by the left-lateralized language-related network (LRN). However, right-hemispheric homologs of the language regions can also contribute to language processing, resulting in reduced left-hemispheric language lateralization. To date, it remains unclear whether less left-hemispheric language lateralization is associated with the recruitment of other non-language networks and their interaction with the LRN during language processing. In this study, we investigated how the degree of left-hemispheric language lateralization in healthy adults relates to the activation of non-language networks and the LRN connectivity to those networks. We applied independent component analysis to task-based functional magnetic resonance imaging data with sentence completion collected from 50 healthy adults. Instead of a single network, we identified the left-lateralized LRN and a mirror right-lateralized LRN. During language processing, the salience network was co-activated alongside the left-lateralized LRN and the right-lateralized LRN, regardless of individual language lateralization. We found that a weaker degree of lateralization was not associated with either domain-general network activation or left-lateralized LRN connectivity to domain-general networks. However, we present novel evidence that stronger right-hemispheric involvement in language processing is associated with greater left-lateralized LRN connectivity to the cingulo-opercular network (CON). Given the role of the CON in the action mode, this result might indicate greater cognitive control to support language processing in people with stronger right-hemispheric involvement in language processing.