Past tense morphology in Cri du chat syndrome: experimental evidence

It has been observed that persons with Cri du chat syndrome (CDCS) have poor language production. However, very few studies have addressed the question whether all aspects of language production are equally afflicted, or whether there are differences between for instance phonological and morphological abilities. The present study was aimed at investigating to what extent persons with CDCS inflect verbs, and, if so, which inflectional patterns in the target language they make use of, and further what kinds of inflectional errors they make. We compared the performance of three subjects (aged 11, 15 and 22) with CDCS on a past tense elicitation task. We found that all three subjects inflected verbs. The number of correct responses, however, varied from 28% to 53%. The majority of errors were over-generalizations, imitation of input, no response and substitution by semantically related verbs.