Syntactic problems in German children with Down syndrome: evidence from wh-questions
A controversial issue in the research field of language development in Down syndrome (DS) is to what extent children with DS are able to produce and comprehend complex syntactic structures (cf. Thordardottir et al., 2002).Another issue of debate is ifsyntactic problemsare restricted to specific syntactic movement operations.For example, Ring & Clahsen (2005)propose a deficit in the formation of binding chains (A-chains) to account fordifficultieswith passivization and reflexive bindingobserved in English speaking children with DS. Studies by Tsakiridou (2006) and Joffe & Varlokosta (2007) on English and Greek suggest that thesyntactic deficit extends to other syntactic dependencies like wh-movement (A’-construction). To investigate these issues, we are going to present new data on the comprehension as well as production of wh-questions from a group of German subjects with DS.
We conducted two question tasks with 23 children and adolescents with DS and a control group of 20 typically developing (TD) matched on mental age (MA, determined by a nonverbal intelligence screening, Tellegen et al., 2007) which was on average 4 years (group DS: mean MA: 4;6 years; mean chronological age (CA): 11;4 years; group TD: mean MA 4;4, mean CA: 4;0 years). In the production task, 14 wh-questions (8 who-subject/object questions, 6 when/where questions) were elicited by use of a game in which the investigator asked the child to pose different questions to a figurine ('Ask what the snail is doing' – target: What are you doing?). In the receptive task, subjects had to point to one of two persons in a picture to answer 20 who-subject and who-object questions (e.g. Who is brushing the boy?).
In the production task, children with DS performed significantly worse than the control group (t-test, p < 0.05) (cf. Fig. 1). They had severe difficulties to produce wh-questions correctly, defined in terms of a correct CP-structure. Syntactic errors consisted in word order errors, e.g. questions lacking the subject or other essential elements of the target structure.With respect to comprehension, children with DS displayed comparably better results than in production and did not differ from unimpaired children as a group (t-test, p = 0.166, ns). However, four children with DS showed deficits, with chance performance on one question type (subject-object-asymmetry) or both types. Comparing both experiments, two groups can be observed: While 9 subjects with DS have mastered both comprehension and production of wh-questions, the other 14 children lag behind TD children in one or both of these tasks in spite of comparable or even higher mental ages. These two subgroups did not differ with respect to mental age nor chronological age (t-test, each p > 0.05, ns). However, the subgroup of the good performers had significantly better phonological working memory skills than the other group, as measured by nonword repetition (subtest PGN, Grimm, 2003) (t-test, p < 0.05).
The results suggest that DS is not necessarily associated with deficits in acquiring syntactic structures representing A’-constructions.However, a deficit in syntactic development affecting comprehension and/orproductionoccurs in a substantial proportion of children with DS and cannot simply be attributed to their general cognitive delay. We will discuss to what extent factors like phonological working memory skills contribute tosyntactic problems in children with DS.
Figures
Figure 1. Correctness scores of DS and TD subjects in both wh-question tasks
References
Grimm, H. (2003). SSV. Sprachscreening für das Vorschulalter [language screening for preschool children].Kurzform des SETK 3-5. Göttingen: Hogrefe.
Joffe, V., & Varlokosta, S. (2007). Patterns of syntactic development in children with Williams syndrome and Down's syndrome: Evidence from passives and wh‐questions. Clinical Linguistics & Phonetics, 21(9), 705–727.
Ring, M., & Clahsen, H. (2005). Distinct patterns of language impairment in Down's syndrome and Williams syndrome: The case of syntactic chains. Journal of Neurolinguistics, 18(6), 479-501.
Tellegen, P.J., Laros, J.A., & Petermann, F. (2007). SON-R 2,5-7. Non-verbaler Intelligenztest. [Nonverbal intelligence screening]. Göttingen: Hogrefe.
Thordardottir, E. T., Chapman, R. S., & Wagner, L. (2002). Complex sentence production by adolescents with Down syndrome. Applied Psycholinguistics, 23(02).
Tsakiridou, M. (2006). The linguistic profile of Down's syndrome subjects: evidence from wh-movement construction. In: SOAS Working Papers in Linguistics,14, 227–248.