On the importance of considering individual profiles when investigating the role of auditory sequential deficits in developmental dyslexia

The goal of this study was to gain a better understanding of the relationship between nonverbal auditory disorders and developmental dyslexia. This question has led to conflicting results in the literature, which we argued might be due to a failure to consider the heterogeneity of dyslexic profiles. This study included three groups of adult participants: unimpaired readers and dyslexic readers with or without a phonological deficit. Auditory temporal processing deficits, as measured by stream segregation thresholds, were present in most dyslexic participants with phonological disorders. In contrast, most dyslexic participants with preserved phonological skills had normal auditory stream segregation thresholds. Overall, the present study leads to a better understanding of the relationship between phonological and sequential auditory processing disorders in developmental dyslexia. In addition, it demonstrates for the first time the importance of considering the heterogeneity of individual cognitive profiles when investigating the role of auditory deficits in developmental dyslexia. (C) 2012 Elsevier B.V. All rights reserved.