Functional and structural brain connectivity in congenital deafness

Abstract

Several studies have been carried out to verify neural plasticity and the language process in deaf individuals. However, further investigations regarding the intrinsic brain organization on functional and structural neural networks derived from congenital deafness is still an open question. The objective of this study was to investigate the main differences in brain organization manifested in deaf individuals, concerning the resting-state functional patterns, and white matter structuring. Functional and diffusiontensor magnetic resonance imaging modalities were acquired from 18 congenitally deaf individuals and 18 age-sex-matched hearing controls. Compared to the hearing group, the deaf individuals presented higher functional connectivity (FC) among the posterior cingulate cortex node of the default mode network (DMN) with visual and motor networks, lower FC between salience networks, language networks, and prominence of functional connectivity changes in the right hemisphere, mostly in the frontoparietal and temporal lobes. In terms of structural connectivity (SC), we found changes mainly in the occipital and parietal lobes, involving both classical sign language support regions as well as concentrated networks for focus activity, attention, and cognitive ltering. Our ndings elucidate the general brain network modi cations, contributing to a better understanding of brain plasticity driven by deafness.

A systematic review of altered resting‐state networks in early deafness and implications for cochlear implantation outcomes

“…Findings of nine studies on adults (Ding et al, 2016; Cardin et al, 2018; Sinke et al, 2019; Bonna et al, 2021; Dell Ducas et al, 2021; Kumar et al, 2021; Andin & Holmer, 2022; Cardin et al, 2023; Ma et al, 2023) and one study on adolescents (Li et al, 2016) with C/PD were in support of the idea that cortical reorganisation following long‐term auditory deprivation is not limited to the auditory cortex and involves brain areas beyond the auditory cortex, which contribute to cognitive processing. In the Kumar et al (2021) study, stronger functional connectivity was observed between the auditory network and the Fusiform gyrus in prelingual deaf adults compared to control peers.…”

“…Thus, the right‐side lateralisation of RSFC might be a result of the functional reorganisation of the STG for visuospatial processing. Additionally, Dell Ducas et al (2021) reported greater changes in functional connectivity in the right hemisphere, particularly in frontoparietal and temporal lobes, in adults with congenital or prelingual deafness relative to their control peers. This observation is potentially modulated by the right‐side dominance of visuospatial processing in early auditory deprivation.…”

Crossmodal reorganization in deaf auditory cortices compensates for the impaired body-centered visuomotor transformation after early deafness

“…Efficient task performance was associated with stronger modularity in the task-negative DMN in terms of higher within-module connectivity in the DMN and lower between-module connectivity between the DMN and the task-relevant neural networks (Gonzalez-Castillo and Bandettini, 2017). It has been suggested that the DAN and the FPN, two task-critical networks supporting the egocentric task, show stronger functional and structural connectivity with the DMN in early deaf people (Dell Ducas et al, 2021; Li et al, 2022). Moreover, the increased inter-network connectivity between the task-irrelevant DMN and the task-relevant DAN and FPN was associated with impaired egocentric performance in congenitally deaf people (Li et al, 2022).…”

Stronger neural response to canonical finger‐number configurations in deaf compared to hearing adults revealed by FPVS‐EEG

“…This approach was opted as we compared groups, and differences in brain responses, not specific to our manipulation, can therefore not be excluded. Many studies have indeed already indicated that deaf individuals develop functional and structural brain reorganisation, especially following cross‐modal plasticity (e.g., Alencar et al, 2019 ; Bottari et al, 2011 ; Cardin et al, 2020 ; Dell Ducas et al, 2021 ; Scott et al, 2014 ; Vachon et al, 2013 ). Given that such differences can be due to physiological (e.g., skull thickness, gyri folding, etc.)…”