Vocabulary and Morphological Patterns in Hungarian Children with Williams Syndrome: a Preliminary Report*

Williams syndrome (WMS), a rare neurogenetic disorder, has been in the forefront of research in cognitive psychology for the last ten years. WMS is characterized by a distinctive cognitive pro le: mild to moderate mental retardation with relatively and surprisingly good linguistic abilities, while performance on spatial tasks is extremely poor. Concentrating on the linguistic abilities of children and adolescents with WMS, studies of vocabulary development and grammatical development in 15 Hungarian WMS children are presented: children were tested on tasks testing vocabulary, regular and irregular morphological; measures of nonword repetition and digit span were also obtained. In contrast to previous observations, results on the vocabulary task do not show that uncommon words activated as easily for a WMS child as common ones. Results in a picture-naming task support that conforming to the normal pattern, uncommon words are harder to retrieve. Results on the production of accusative and plural forms con rmed for Hungarian as well that regardless of the frequency of the item, in ected forms of irregulars are harder to produce, and often overregularized in WMS, revealing a dissociation between the rules of grammar vs. the mental lexicon. Performance on rare words in the vocabulary task, and overall performance on the morphology task is associated to the capacity of phonological short-term memory: subjects with higher span perform better on both tasks. The speci cation of the close relation between the capacity of phonological short-term memory and their linguistic measures awaits further study.