Casini, L. 1, 2 , Pech-Georgel, C. 4 , Burle, B. 1, 2 & Ziegler, J. 2, 3
1 Laboratoire de Neurobiologie de la Cognition.Université de Provence. Marseille, France
2 CNRS. France
3 Laboratoire de Psychologie Cognitive.Université de Provence. Marseille, France
4 Service de neurologie pédiatrique. CHU La Timone. Marseille, France
Developmental dyslexia is typically associated with a phonological deficit but the origin of this deficit is still a matter of debate. The purpose of the present study was to reexamine Tallal's rapid processing deficit theory according to which phonological deficits are caused by auditory temporal processing impairments. This was done by investigating whether such a temporal deficit could be found in speech as well as non-speech stimuli, and whether it would generalize to other sensory modalities. In particular, we studied how children with dyslexia dealt with temporal judgments in three different tasks: 1/ judgment of segmental duration in a speech perception task, 2/ duration judgment of non speech auditory stimuli, and 3/ duration judgment of visual stimuli. The results showed that children with dyslexia, compared to normally developing age-matched controls, presented deficits when processing segmental durations as well as the duration of non speech auditory or visual stimuli. These results are in agreement with Tallal's theory but are also consistent with a general and amodal temporal processing deficit. In the framework of cognitive theories of temporal processing, these data suggest a dysfunction of the “internal clock” in children with dyslexia.