SYNTAX AND MORPHOLOGY IN WILLIAMS-SYNDROME

Williams syndrome (WS) is a neuro-developmental disorder which is char acterized by an unusual fractionation of language abilities and other cognitive functions. We have investigated four cases of English-speaki ng subjects with WS, and we show that despite their low IQs the WS chi ldren's performance on syntactic tasks and on regular inflection is no t impaired. Irregular inflection, however, is affected causing many er rors. We also report results from studies investigating the same lingu istic phenomena in children with specific language impairment. These c hildren exhibit a different pattern of impairment, with relatively poo r performance on syntactic tasks and regular inflection. We suggest a linguistic characterization of the morphosyntax in WS according to whi ch WS subjects are impaired in accessing (particular kinds of) informa tion from lexical entries, with their computational system for languag e appearing to be intact. We interpret the selective impairments found in WS and SLI as supporting the theoretical distinction between a com putational system and an associative memory system for language. (C) 1 998 Elsevier Science B.V. All rights reserved.