Dehaene (in Reading in the Brain) reviews and finds support for the phonological deficit hypothesis of developmental dyslexia, which proposes that dyslexics have a basic deficit in processing the constituents of spoken words. This hypothesis can be seen as reflecting three associated claims: a) there is only one basic kind of dyslexia; b) all (or most) dyslexic children have phonological impairments, and c) these phonological impairments cause their dyslexia. We consider each of these claims, and the evidence presented by Dehaene, (...) and conclude that questions remain about all three. Phonological deficits alone seem unlikely to be able to account for the complexity and heterogeneity of developmental dyslexia. (shrink)

The properties of a specific orthography dictate the way people read it. We bring considerations from dyslexia to suggest that the claim can be extended further. First, the effect of orthographic neighborhood density can be extended beyond letter-position encoding and beyond the orthographic lexicon. Second, Hebrew and Arabic differ with respect to letter forms, and hence, in letter-position encoding.

Evidence from various subtypes of Specific Language Impairment and developmental peripheral dyslexias is presented to support the idea that even developmental disorders can be modular. However, in developmental letter position dyslexia and neglect dyslexia we show that additional errors can occur because of insufficient orthographic-lexical knowledge.

Children with hearing impairment (HI) show disorders in morphology and syntax. The question is whether and how these disorders are connected to problems in the auditory domain. The aim of this paper is to examine whether moderate to severe hearing loss at a young age affects the ability of German-speaking orally trained children to understand and produce sentences. We focused on sentence structures that are derived by syntactic movement, which have been identified as a sensitive marker for syntactic impairment in (...) other languages and in other populations with syntactic impairment. Therefore, our study tested the repetition and/or comprehension of subject and object relatives, subject and object Wh-questions, passive sentences, and topicalized sentences, as well as sentences with verb movement to second sentential position. We tested 19 HI children aged 9;5-13;6 and compared their performance with hearing children using sentence-picture matching and sentence repetition tasks. For the comprehension tasks, we included HI children who passed an auditory discrimination task; for the sentence repetition tasks, we selected children who passed a screening task of simple sentence repetition without lip-reading; this made sure that they could perceive the words in the tests, so that we could test their grammatical abilities. The results clearly showed that most HI children had considerable difficulties in the comprehension and repetition of sentences with syntactic movement: they had significant difficulties understanding object relatives, Wh-questions, and topicalized sentences, and in the repetition of object who and which questions and subject relatives, as well as in sentences with verb movement to second sentential position. Repetition of passives was only problematic for some children. Object relatives were still difficult at this age for both HI and hearing children. An additional important outcome of the study is that not all sentence structures are impaired—passive structures did not pose a problem for the HI children in comprehension, and caused fewer problems in repetition than other structures. (shrink)