title: Developmental evaluation of atypical auditory sampling in dyslexia: Functional and structural evidence.
abstract: Whether phonological deficits in developmental dyslexia are associated with impaired neural sampling of auditory information at either syllabic- or phonemic-rates is still under debate. In addition, whereas neuroanatomical alterations in auditory regions have been documented in dyslexic readers, whether and how these structural anomalies are linked to auditory sampling and reading deficits remains poorly understood. In this study, we measured auditory neural synchronization at different frequencies corresponding to relevant phonological spectral components of speech in children and adults with and without dyslexia, using magnetoencephalography. Furthermore, structural MRI was used to estimate cortical thickness of the auditory cortex of participants. Dyslexics showed atypical brain synchronization at both syllabic (slow) and phonemic (fast) rates. Interestingly, while a left hemispheric asymmetry in cortical thickness was functionally related to a stronger left hemispheric lateralization of neural synchronization to stimuli presented at the phonemic rate in skilled readers, the same anatomical index in dyslexics was related to a stronger right hemispheric dominance for neural synchronization to syllabic-rate auditory stimuli. These data suggest that the acoustic sampling deficit in development dyslexia might be linked to an atypical specialization of the auditory cortex to both low and high frequency amplitude modulations.
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.
authors.forename: Mikel
authors.initials: M
authors.lastname: Lizarazu
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.
authors.forename: Marie
authors.initials: M
authors.lastname: Lallier
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.|Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
authors.forename: Nicola
authors.initials: N
authors.lastname: Molinaro
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.|Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bourguignon
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Paz-Alonso
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.
authors.forename: Garikoitz
authors.initials: G
authors.lastname: Lerma-Usabiaga
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL), Donostia/San Sebastian, Spain.|Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Carreiras
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000254:growth & development* / Q000473:pathology*; D002648:Child; D004410:Dyslexia / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007360:Intelligence; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D010700:Phonetics; D011571:Psychoacoustics; D011932:Reading; D013223:Statistics as Topic; D055815:Young Adult
keywords: auditory cortex; cortical thickness; magnetoencephalography; phonology; reading disorder