Speech-Motor Program/Programming in Children with Childhood Apraxia of Speech, Children with Articulatory and Phonological Disorders and Typically Developing Children

Objectives: This study aims to examine the underlying difficulties that children with childhood apraxia of speech (CAS) have in their speech process by comparing their speech-motor Program/Programming abilities to those of children with articulatory and phonological disorders (APD) and typically-developing (TD) children. Methods: Nine children with CAS, 15 children with APD, and 15 TD children participated in this study. We compared the reaction time (RT) and the percentage of correct responses in immediate/delayed word/nonword repetition tasks among the three groups. Results: The CAS group showed significantly slower RT in all tasks than the other groups. While the APD and TD groups showed faster immediate reaction time (IRT) than delayed reaction time (DRT) in both the word and non-word tasks, the CAS group showed faster DRT than IRT in the non-word task. The CAS group showed a significantly lower percentage of correct responses than the APD and TD groups in the word task, and a significantly lower percentage of correct responses than the TD group in the non-word task. Conclusion: The speech-motor Program/Programming ability of the CAS group was lower than the other groups. This study suggests that groups of CAS, APD, and TD can be distinguished from each other through word and non-word IRT as well as the percentage of correct responses from a word task.