Aberrant Cerebellar Resting‐State Functional Connectivity Related to Reading Performance in Struggling Readers

Abstract

Reading is a critical neurodevelopmental skill for school‐aged children, which requires a distributed network of brain regions including the cerebellum. However, we do not know how functional connectivity between the cerebellum and other brain regions contributes to reading. Here we used resting‐state functional connectivity to understand the cerebellum's role in decoding, reading speed, and comprehension in a group of struggling readers (RD) and a group of adolescents and children with typical reading abilities (TD). We observed an increase in functional connectivity between the sensorimotor network and the left angular gyrus, left lateral occipital cortex, and right inferior frontal gyrus in the RD group relative to the TD group. Additionally, functional connectivity between the cerebellum network and the precentral gyrus was decreased and was related to reading fluency in the RD group. Seed‐based analysis revealed increased functional connectivity between crus 1, lobule 6, and lobule 8 of the cerebellum and brain regions related to the default mode network and the motor system for the RD group. We also found associations between reading performance and the functional connectivity between lobule 8 of the cerebellum and the left angular gyrus for both groups, with stronger relationships in the TD group. Specifically, the RD group displayed a positive relationship between functional connectivity, whereas the TD group displayed the opposite relationship. These results suggest that the cerebellum is involved in multiple components of reading performance and that functional connectivity differences observed in the RD group may contribute to poor reading performance.

An fMRI study of finger movements in children with and without dyslexia

“…It did, however, find more intrinsic functional connectivity between a seed region in right crus I and three left-hemisphere perisylvian target seed regions, angular gyrus, posterior superior temporal gyrus, and inferior frontal gyrus ( Ashburn et al, 2020 ). A more recent resting-state iFC study by Greeley et al (2021) found both weaker and stronger functional connectivity in a group of children with dyslexia (compared to a control group) between cerebellar right crus I, right lobule VI, and right lobule VIII seeds and widespread motor and non-motor regions of the cerebral cortex. Further, functional connections between right cerebellar lobule VIII and right frontal pole, and between cerebellar lobule VIII and left angular gyrus were positively related to reading measures in the group with dyslexia.…”

Neural bases of reading fluency: A systematic review and meta-analysis

“…A comparison of high- and low-fluency readers in English also showed reduced FC in low-fluency readers within two cognitive control networks: the cingulo-opercular (CO) and ventral attention (VA) networks (Freedman et al, 2020), the latter of which overlaps extensively with the traditional reading network’s frontal and temporal regions. Last, evidence of reduced FC between the cerebellum and cortical reading regions has been reported in individuals diagnosed with DD (Greeley et al, 2020). Reading fluency scores in the DD group positively correlated with FC between right cerebellar lobule VIII and the left AG.…”

“…Right crus I of the cerebellum interconnects with left hemisphere regions supporting reading and is activated in concert with these regions during reading tasks, as evident from a neuroimaging meta-analysis of typical adult readers (Martin et al, 2015). Functional and structural differences between readers with typical development and those diagnosed with DD have also been found in the posterolateral cerebellum (e.g., crus I, crus II, lobule VI; Greeley et al, 2020; Stoodley, 2014; Stoodley & Stein, 2011).…”

“…Reading fluency scores in the DD group positively correlated with FC between right cerebellar lobule VIII and the left AG. Further, reading fluency scores predicted the strength of FC between a cerebellar network identified through ICA and the right precentral gyrus (Greeley et al, 2020).…”

Activation and functional connectivity of cerebellum during reading and during arithmetic in children with combined reading and math disabilities

“…There are few resting-state studies in typically developing children using alphabetic languages and some of these have used seed-to-voxel analysis focusing on regions known to be involved in reading and relating them to performance ( Koyama et al, 2011 , 2013 ; Cross et al, 2021 ). Of the few seed-to-voxel studies explicitly considering the cerebellum, Greeley and colleagues found a positive connection between right cerebellar lobule VIII and left angular gyrus to be related to reading scores in typical readers ( Greeley et al, 2021 ).…”