Cerebral Cortex Advance Access first published online on May 30, 2008
This version published online on June 4, 2008
Cerebral Cortex, doi:10.1093/cercor/bhn092
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Functional MRI of Sentence Comprehension in Children with Dyslexia: Beyond Word Recognition
1 Kennedy Krieger Institute, Baltimore, MD 21205, USA, 2 Department of Pediatrics, 3 Department of Psychological & Brain Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA, 4 Haskins Laboratories, New Haven, CT 06511, USA, 5 Department of Pediatrics, Yale University, New Haven, CT 06511, USA, 6 Department of Neuroscience, 7 Department of Radiology, 8 Department of Neurology, 9 Department of Education, Johns Hopkins University, Baltimore, MD 21218, USA
Address correspondence to Laurie E. Cutting, PhD, Kennedy Krieger Institute, Department of Developmental Cognitive Neurology, 707 North Broadway, Suite 232, Baltimore, MD 21205, USA. Email: cutting{at}kennedykrieger.org.
Sentence comprehension (SC) studies in typical and impaired readers suggest that reading for meaning involves more extensive brain activation than reading isolated words. Thus far, no reading disability/dyslexia (RD) studies have directly controlled for the word recognition (WR) components of SC tasks, which is central for understanding comprehension processes beyond WR. This experiment compared SC to WR in 29, 9–14 year olds (15 typical and 14 impaired readers). The SC-WR contrast for each group showed activation in left inferior frontal and extrastriate regions, but the RD group showed significantly more activation than Controls in areas associated with linguistic processing (left middle/superior temporal gyri), and attention and response selection (bilateral insula, right cingulate gyrus, right superior frontal gyrus, and right parietal lobe). Further analyses revealed this overactivation was driven by the RD group's response to incongruous sentences. Correlations with out-of-scanner measures showed that better word- and text-level reading fluency was associated with greater left occipitotemporal activation, whereas worse performance on WR, fluency, and comprehension (reading and oral) were associated with greater right hemisphere activation in a variety of areas, including supramarginal and superior temporal gyri. Results provide initial foundations for understanding the neurobiological correlates of higher-level processes associated with reading comprehension.
Key Words: dyslexia • neuroimaging • reading disabilities • sentence comprehension
Fig. 1, Fig. 2 are in Colour has been updated.