Right inferior frontal gyrus: An integrative hub in tonal bilinguals

Abstract

Right hemispheric dominance in tonal bilingualism is still controversial. In this study, we investigated hemispheric dominance in 30 simultaneous Bai-Mandarin tonal bilinguals and 28 Mandarin monolinguals using multimodal neuroimaging. Resting-state functional connectivity (RSFC) analysis was first performed to reveal the changes of functional connections within the language-related network. Voxel-based morphology (VBM) and tract-based spatial statistics (TBSS) analyses were then used to identify bilinguals' alterations in gray matter volume (GMV) and fractional anisotropy (FA) of white matter, respectively. RSFC analyses revealed significantly increased functional connections of the right pars-orbital part of the inferior frontal gyrus (IFG) with right caudate, right pars-opercular part of IFG, and left inferior temporal gyrus in Bai-Mandarin bilinguals compared to monolinguals. VBM and TBSS analyses further identified significantly greater GMV in right pars-triangular IFG and increased FA in right superior longitudinal fasciculus (SLF) in bilinguals than in monolinguals. Taken together, these results demonstrate the integrative role of the right IFG in tonal language processing of bilinguals. Our findings suggest that the intrinsic language network in simultaneous tonal bilinguals differs from that of monolinguals in terms of both function and structure.

Altered Dynamic Amplitude of Low-Frequency Fluctuations in Patients With Migraine Without Aura

“…The low-frequency oscillation of the brain is mainly characterized using resting-state fMRI with blood oxygen level-dependent (BOLD) signals (Biswal et al, 1995 ; Fox and Raichle, 2007 ). Resting-state fMRI has been widely applied to study the brain functional organization (Greicius et al, 2003 ; Fox et al, 2006 ; Wang et al, 2015 , 2017c ; Xu et al, 2019 ; Gao et al, 2020 ), to identify the functional abnormalities in patients with brain disorders (Greicius et al, 2007 ; Brier et al, 2012 ; Muller et al, 2013 ; Wu et al, 2016 ; Sun et al, 2018 ), and to reveal the neural basis of treatment response (Guo et al, 2012 ; Mulders et al, 2016 ; Wang et al, 2017b , 2018 ; Xu et al, 2020 ). To quantitatively measure low-frequency oscillation, the amplitude of low-frequency fluctuations (ALFF) is proposed (Zang et al, 2007 ).…”

Static and Dynamic Changes of Amplitude of Low-Frequency Fluctuations in Cervical Discogenic Pain

“…Resting-state fMRI is commonly used to measure the spontaneous low-frequency fluctuations of brain activities with blood oxygen level-dependent (BOLD) signals ( Biswal et al, 1995 ; Fox and Raichle, 2007 ). A large number of previous studies applied resting-state fMRI to reveal the intrinsic functional organization of brain in healthy subjects and to identify the changes of the intrinsic functional connectivities under diseases ( Greicius et al, 2003 ; Fox et al, 2006 ; Wang et al, 2015 , 2017d ; Sun et al, 2018 ; Xu et al, 2019a ; Gao et al, 2020 ). Moreover, many recent studies have applied resting-state fMRI to reveal the brain mechanism of neuromodulation treatment for clinical disorders ( Peng et al, 2012 ; Liu et al, 2015 ; Wang et al, 2017b , c , d , 2020 ; Wang J. et al, 2018 ; Bai et al, 2018 , 2019 ).…”

Individual differences in representational similarity of first and second languages in the bilingual brain

“…Consistent with our hypotheses, several regions of the language network showed patterns of representation that differentiated languages depending on individual differences. For example, one of these regions was the left IFG (including both the pars opercularis and the pars triangularis), an area engaged in representing and planning articulatory codes for speech and tone [44][45][46][47] . Indeed, these features differ between English and Mandarin in that each language has phonological features that are not present in the other (e.g., tone in Mandarin, consonant clusters in English).…”