Slide Slam R17
Language experience modulates functional connectivity at rest in deaf individuals
Valeria Vinogradova1, Barbara Manini2, Bencie Woll2, Velia Cardin2; 1University of East Anglia, 2University College London
Early sensory and language experience can modulate brain reorganisation (Manini et al., 2021). Studies on deaf individuals have demonstrated that reorganisation can extend beyond the sensory cortices (Cardin et al., 2018). Functional connectivity has also been shown to be reshaped by early sensory experience (Bonna et al., 2020). Previous work on functional connectivity and language in deaf individuals has not distinguished the language experience of deaf people from their sensory experience (Malaia et al., 2014). The aim of the current study is to directly investigate the effect of language experience on functional connectivity at rest in deaf individuals. 25 congenitally or early deaf participants took part in the study. Participants had different language backgrounds, which is reflective of the heterogeneity in language experiences observed in the deaf communities. Their language skills were measured using British Sign Language Grammaticality Judgement (Cormier et al., 2012) and English Grammaticality Judgement tasks and were combined into a single, modality-independent measure of language proficiency (Manini et al., 2021). Data were collected during resting-state scans of approximately 10 minutes in length. The neuroimaging data were preprocessed using a standard pipeline in SPM12. The Schaefer-Yeo 2018 atlas (Schaefer et al., 2018) was used to conduct the connectivity analysis in Conn, with a number of seeds reassigned to a different network in order to create separate language and auditory networks. The general language proficiency measure was used as a second-level covariate. The analysis revealed significant effects of language proficiency (pFDR < .05) on the functional connectivity between various networks. Deaf individuals who had higher general, modality-independent language proficiency scores showed increased connectivity between the visual network and a number of other networks, including the salience / ventral attention, dorsal attention, somatomotor, control, temporoparietal, and language networks. The pSTS/pSTG seed from the language network revealed predominantly increasing connectivity to the salience / ventral attention network in individuals with higher language scores, while the connectivity with the control and the DMN decreased. The study demonstrated extensive influence of language proficiency on various large-scale resting-state networks, highlighting the role of language experience in organisation of networks beyond the temporoparietal and language networks in deaf individuals. We have demonstrated that in participants with higher language scores, independently of language modality, connectivity of the visual network is stronger than in participants with lower language scores. The enhanced connectivity of the visual network with the language network in participants with better language proficiency scores can indicate increased involvement of the visual system in communication processes. The enhanced connectivity of the salience network with seeds from the visual and language networks may reflect the increased role of the salience network in detecting visual stimuli and in situational awareness during communication in these participants. Taken together, the findings demonstrate how early language experience modulates connectivity between different areas in the brain, including those beyond the typical language and the sensory areas.