The linguistic profile of Greek individuals with Down Syndrome : evidence from syntactic and morphological phenomena

• Main Author: Stathopoulou, Nikolitsa
• Published: University of Essex 2009
• Subjects: 155
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502590

This thesis aims to contribute to cross-linguistic research in the area of neurodevelopmental disorders by investigating the morphosyntactic abilities of Greek-speaking adolescents with Down Syndrome (henceforth DS). DS is the most common neurodevelopmental disorder and is considered the main genetic cause of mental retardation (Hagerman, 1999). Language development is a special challenge for people with DS since it is regarded to be relatively more impaired that other cognitive functions (Lenneberg, 1967). In addition, some aspects of language are more affected than others, with grammar more severely impaired than lexicon, semantics and pragmatics. The following questions were examined: (1) is the language of Greek-speaking people with DS severely delayed or deviant? (2) Is the language deficit in DS a consequence of a general (non-linguistic) cognitive impairment? (3) Does the language of people with DS exhibit the same clinical markers as other congenital syndromes with different genetic origin (e.g. SLI, WS), or are the impairments of the DS population syndrome-specific? Two groups took part: eight adolescents with DS (mean mental age: 5.9) and sixteen typically developing children whose chronological age was matched with the mental ages of the DS participants. The phenomena under investigation were syntactic binding, relative clauses and wh-questions, and perfective past tense morphology. Findings revealed that the grammatical development in DS was not simply delayed, but that their language performance also deviated from that of typically developing children. Moreover, whilst difficulties were found for the DS participants in all the domains we investigated, the results do not decide as to whether these difficulties are grammar-specific or due to general cognitive impairments. Finally, comparisons with SLI children (Stavrakaki, 2001) revealed syndrome-specific problems between atypical populations with different genetic origin.