Affiliations: [a] Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA | [b] Stanford Institute for Reading and Learning, Stanford University, Stanford, CA, USA | [c] Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, USA | [d] Department of Psychological and Brain Sciences and Department of Education, Dartmouth College, Hanover, NH, USA | [e] Children’s Hospital Boston, Developmental Medicine Center, Harvard Medical School, Boston, MA, USA
Correspondence:
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Corresponding author: Nadine Gaab, PhD, Children’s Hospital Boston, Developmental Medecine Center, Harvard Medical School, Office 611, 1 Autumn Street, Mailbox #713, Boston, MA 02115, USA. Tel.: +1 857 218 3021; E-mail: [email protected].
Abstract: Purpose: Developmental dyslexia, characterized by unexpected difficulty in reading, may involve a fundamental deficit in processing rapid acoustic stimuli. Using functional magnetic resonance imaging (fMRI) we previously reported that adults with developmental dyslexia have a disruption in neural response to rapid acoustic stimuli in left prefrontal cortex. Here we examined the neural correlates of rapid auditory processing in children. Methods: Whole-brain fMRI was performed on twenty-two children with developmental dyslexia and twenty-three typical-reading children while they listened to nonlinguistic acoustic stimuli, with either rapid or slow transitions, designed to mimic the spectro-temporal structure of consonant-vowel-consonant speech syllables. Results: Typical-reading children showed activation for rapid compared to slow transitions in left prefrontal cortex. Children with developmental dyslexia did not show any differential response in these regions to rapid versus slow transitions. After eight weeks of remediation focused primarily on rapid auditory processing, phonological and linguistic training the children with developmental dyslexia showed significant improvements in language and reading skills, and exhibited activation for rapid relative to slow transitions in left prefrontal cortex. Conclusion: The presence of a disruption in the neural response to rapid stimuli in children with developmental dyslexia prior to remediation, coupled with significant improvement in language and reading scores and increased brain activation after remediation, gives further support to the importance of rapid auditory processing in reading development and disorders.
Keywords: Developmental dyslexia, fMRI, rapid auditory processing, remediation, training, children
