The fragileX syndrome : What about the deficit in the pragmatic component of language ?

Language profile of fragile-X syndrome individuals looks like the one of Down syndrome individuals, except for phonological and pragmatic abilities. If the pragmatic aspect of language is relatively preserve in Down syndrome, it is one of the most impaired language component in fragile-X syndrome. Discourse of fragile X persons generally contains of repetitions, perseverations and stereotypies. These behaviors are well documented in the literature but, we do not know, for now, the reasons of these repetitions and perseverations. Are they the consequence of a real pragmatic disorder or the consequence of motor difficulties ? Another aspect of the pragmatic component of language remains almost unexplored in this pathology : the common ground management and the organization of the old and the new information in conversation. It is this last point that we want to explore. We decided to conduct a preliminary study with four fragile-X boys aged from 6 to 12 years-old. Groups of two boys work together on referential communication tasks. We proposed traditional experimental situations in a non-eye contact condition between participants. We compare the results of our subjects with those of typically developing children matched on the lexical age. Fragile-X boys are less efficient than typically developing children when the message to give or receive contains spatial terms or "ordinal" attributes. They also manage less efficiently with an incomplete message especially when it is given by an adult.