Exploring the Relationship Between Speech Motor Control and Phonological Processing in Children Who Stutter and Typically Developed Children

Language processing (especially phonology) and speech motor control are disordered in stuttering. However, it is unclear how they are related based on the models of speech processing. The present study aimed to study non-word repetition, rhyme and alliteration judgment, and speech motor control and investigate their relationship in children who stutter (CWS) compared to typically developed children (TDC).

Twenty-eight CWS (mean age=5.46 years) and 28 peers TDC (mean age=5.52 years) participated in this study. Phonological processing, according to the speech processing model, is divided into phonological input and output. Phonological input, phonological output, and speech motor control were assessed by rhyme and alliteration tasks, accurate phonological production during non-word repetition task, and Robbins-Klee oral speech motor protocol, respectively. The Pearson correlation coefficient, independent t-test, and Cohen’s d were used for data analysis.

Both non-word repetition and speech motor skills were significantly different in CWS than TDC (P<0.001). But rhyme and alliteration judgment were similar across groups (P>0.001). Phonological processing and speech motor control were not significantly correlated (P>0.001).

Phonological processing (output), a level before articulation, and speech motor control are not correlated, but both are disordered in preschool CWS. Additionally, phonological processing (input) is similar in CWS and TDC. That is, phonological input is not affected by stuttering in CWS.