The use of primary sentence stress by normal, aphasic, and autistic children.

Primary sentence stress is an important aspect of the English prosodic system. Its adequate use is a prerequisite in the development of normal intonation patterns. This study examined the use of primary sentence stress in autistic children with mean length of utterance (MLU) scores between 1.9 and 4.1 morphemes. Normal and aphasic subjects at similar MLU levels served as contrast groups. The primary sentence task required that the subjects verbally respond to a request for information and provide a description of a play situation. Toy manipulation was used to elicit the desired responses. Listener judgment served as the basis for analyzing results. Although all subjects were able to perform the task, differences were seen in the number of correct responses and in the pattern of stress misassignment. These results are at variance with a prediction of stress placement on grammatical grounds. An explanation is offered, based on pragmatic considerations and cognitive developmental trends in young children.