Phonological and speech motor abilities in children with childhood apraxia of speech

Childhood apraxia of speech (CAS) is a motor speech disorder in which the precision and consistency of speech sounds are impaired due to deficits in motor planning and programming. The literature on CAS suggests that the clinical features of CAS cannot be limited to one level of speech processing and that a more comprehensive understanding of how all levels involved in speech production are part of a complex system is needed. The aim of this study was to investigate the relationship between phonological and speech motor abilities in children with CAS and to determine the extent to which speech motor performance accounts for phonological processing in children with CAS. Croatian children with CAS (n = 30) and typically developing children (n = 28) aged 5-7 years participated in this study. Behavioural measures representing different aspects of the speech production chain were created taking into account the inevitable overlap of linguistic and motor processes underlying each task. The results showed that children with CAS performed significantly worse on all measured tasks. Spearman correlation analysis revealed positive relationships between the speech motor tasks and the expressive and receptive phonological processing tasks. A hierarchical regression analysis showed that both receptive phonological processing and speech motor performance contribute significantly to expressive phonological processing in children with CAS, with monosyllabic MRR emerging as a significant predictor. These results emphasise the interconnectedness of phonological and speech motor skills in CAS and provide valuable insights for assessment and intervention.