Articulatory Control in Childhood Apraxia of Speech in a Novel Word-Learning Task.

Purpose: Articulatory control and speech production accuracy were examined in children with childhood apraxia of speech (CAS) and typically developing (TD) controls within a novel word-learning task to better understand the influence of planning and programming deficits in the production of unfamiliar words. Method: Participants included 16 children between the ages of 5 and 6 years (8 CAS, 8 TD). Short- and long-term changes in lip and jaw movement, consonant and vowel accuracy, and token-to-token consistency were measured for 2 novel words that differed in articulatory complexity.
Results: Children with CAS displayed short- and long-term changes in consonant accuracy and consistency. Lip and jaw movements did not change over time. Jaw movement duration was longer in children with CAS than in TD controls. Movement stability differed between low- and high-complexity words in both groups. Conclusions: Children with CAS displayed a learning effect for consonant accuracy and consistency. Lack of change in movement stability may indicate that children with CAS require additional practice to demonstrate changes in speech motor control, even within production of novel word targets with greater consonant and vowel accuracy and consistency. The longer movement duration observed in children with CAS is believed to give children additional time to plan and program movements within a novel skill.