Decoupling of the Occipitotemporal Cortex and the Brain’s Default-Mode Network in Dyslexia and a Role for the Cingulate Cortex in Good Readers: A Brain Imaging Study of Brazilian Children

Abstract

The goal of the present study was to investigate intrinsic and reading-related brain function associated with dyslexia and typical readers in monolingual Brazilian children. Two fMRI studies were carried out: a resting-state and a word-reading study. The results show (a) underconnectivity between the occipitotemporal region (visual word form area) and the brain's default-mode network in dyslexic readers and (b) more activation of the anterior cingulate cortex for typical readers relative to dyslexic readers. The findings provide evidence for brain connectivity and function differences in an underrepresented population in fMRI studies of dyslexia; the results suggest atypical intrinsic function, and differences in directed attention processes in dyslexia.

Development of Print-Speech Integration in the Brain of Beginning Readers With Varying Reading Skills

“…Next to the reduced activation in brain areas critical for AV integration, dyslexia has also been associated with atypical patterns of functional connectivity (FC) between brain regions for visual and auditory language information processing ( van der Mark et al, 2011 ; Stevens et al, 2017 ). Of note, many insights into orthographic-phonological network connectivity are derived from studies that used complex phonological tasks ( Sandak et al, 2004 ; Cao et al, 2008 ; Buchweitz et al, 2017 ; Paz-Alonso et al, 2018 ). For example, Paz-Alonso et al (2018) recently compared task-related FC during AV integration between adults with dyslexia and controls by using a single-word naming task with four conditions: consistent words, inconsistent words, pseudowords, and pseudohomophones.…”

“…For inconsistent words, they found stronger functional coupling between the left vOT and inferior parietal cortex for adults with dyslexia vs. controls ( Paz-Alonso et al, 2018 ). In addition, a recent study showed reduced resting state-based coupling between the occipito-temporal (OT) cortex and the posterior cingulate cortex (PCC) of the default-mode network (DMN) in children with dyslexia compared to typical readers ( Buchweitz et al, 2017 ). This finding was discussed as indicating a state of reduced readiness for reading in children with dyslexia as compared with typical readers ( Buchweitz et al, 2017 ).…”

“…In addition, a recent study showed reduced resting state-based coupling between the occipito-temporal (OT) cortex and the posterior cingulate cortex (PCC) of the default-mode network (DMN) in children with dyslexia compared to typical readers ( Buchweitz et al, 2017 ). This finding was discussed as indicating a state of reduced readiness for reading in children with dyslexia as compared with typical readers ( Buchweitz et al, 2017 ). In contrary, studies examining task-based functional coupling reported stronger ( Schurz et al, 2015 ) functional coupling of the OT cortex (and other regions of the language network) and areas linked to the DMN, such as the precuneus, in children with dyslexia, suggesting a failure in decoupling during language tasks (but see van der Mark et al, 2011 ).…”

Leitura de palavras em língua minoritária: a construção do léxico ortográfico em hunsriqueano

“…Atualmente, tem sido possível investigar os diversos processos subjacentes à leitura de palavras na aprendizagem da leitura por crianças (Buchweitz et al, 2019;Dehaene, 2012;Salles & Parente, 2007;Teixeira et al, 2016;Ziegler & Goswami, 2005, entre outros). Para tanto, os pesquisadores utilizam diferentes métodos, ferramentas e perspectivas.…”

Developmental dyslexia: a condensed review of literature

“…During the last decade brain imaging techniques, such Magnetoencephalography (MEG), and functional Magnetic Resonance Imaging (fMRI), havebeen extensively used to investigate dyslexia (Baillieux et al, 2009;Beneventi, TøNnessen, Ersland, & Hugdahl, 2010;Buchweitz et al, 2019;Hoet et al, 2011;Norton, Beach, & Gabrieli, 2014;Richards & Berninger, 2008;Rimrodt et al, 2009;S. Shaywitz et al, 1998;Shaywitz et al, 2002).…”