Newborn brain event-related potentials revealing atypical processing of sound frequency and the subsequent association with later literacy skills in children with familial dyslexia

The role played by an auditory processing deficit in dyslexia has been debated for several decades In a longitudinal study using brain event related potentials (ERPs) we investigated 1) whether dyslexic children with familial risk background would show atypical pitch processing from birth and 2) how these newborn ERPs later relate to these same children s pre reading cognitive skills and literacy outcomes Auditory ERPs were measured at birth for tones varying in pitch and presented in an oddball paradigm (1100 Hz 12% and 1000 Hz 88%) The brain responses of the typically reading control group children (TRC group N = 25) showed clear differentiation between the frequencies while those of the group of reading disability with familial risk (RDFR 8 children) and the group of typical readers with familial risk (TRFR 14 children) did not differentiate between the tones The ERPs of the latter two groups differed from those of the TRC group However the two risk groups also showed a differential hemispheric ERP pattern Furthermore newborn ERPs reflecting passive change detection were associated with phonological skills and letter knowledge prior to school age and with phoneme duration perception reading speed (RS) and spelling accuracy in the 2nd grade of school The early obligatory response was associated with more general pre school language skills as well as with RS and reading accuracy (RA) Results suggest that a proportion of dyslexic readers with familial risk background are affected by atypical auditory processing This is already present at birth and also relates to pre reading phonological processing and speech perception These early differences in auditory processing could later affect phonological representations and reading development However atypical auditory processing is unlikely to suffice as a sole explanation for dyslexia but rather as one risk factor dependent on the genetic profile of the child (C) 2010 Elsevier Sri All rights reserved